RITE 2007 - Yale School of Medicine

Anatomy 

Question 1: Anatomy - Peripheral/Autonomic Nervous Systems 

Discussion: 

Entrapment of the suprascapular nerve may cause shoulder pain, weakness of shoulder abduction, and sparing of 

sensation about the shoulder. 

References: 

Devinsky O, Feldmann E. Examination of the cranial and peripheral nerves. New York: Churchill Livingston, 

1998. 


Discussion: 

The tibialis posterior muscle is derived from the L5 and S1 myotomes, but it is supplied by the tibial nerve. An 

abnormality in this muscle would rule out a peroneal mononeuropathy at the fibular head. The peroneus longus 

and extensor hallicus longus could both be involved in an L5 radiculopathy or peroneal mononeuropathy and 

would therefore not distinguish the two. The gastrocnemius is an S1 muscle supplied by the tibial nerve, and the 

vastus lateralis is an L3 and L4 muscle supplied by the femoral nerve. 

References: 

Perotto A. Anatomical guide for the electromyographer. Springfield: Charles C. Thomas, 1994. 

Question 9: Anatomy - Cortex and Connections 

Discussion: 

Asomatognosia is a category of neglect in which the patient denies ownership of a limb contralateral to a lesion 

of the supramarginal gyrus of the parietal lobe (usually nondominant). 

References: 

Brazis PW, Masdeu JC, Biller J. Localization in clinical neurology. 4th ed. Philadelphia: Lippincott, Williams & 

Wilkins, 2001. 

Question 10: Anatomy - Neuromuscular Junction and Muscle 

Discussion: 

The radial nerve supplies the extensor pollicis longus and brevis, abductor pollicis longus, and extensor 

digitorum longus. The abductor pollicis brevis is innervated by the median nerve. 

References: 

No author. Aids to the examination of the peripheral nervous system. 2nd ed. London: Bailliere Tindall, 1986. 



Question 11: Anatomy - Spinal Cord 

Discussion: 

2007 RITE Discussion & Reference Manual 

The patient has a dissociated sensory loss, with hypesthesias involving pain and temperature but sparing 

proprioception and vibration. The findings are most consistent with syringomyelia. A syrinx can involve the 

spinothalamic tracts bilaterally as they cross in the anterior white commissure that lies just anterior to the central 

canal. Lesions of the dorsal nerve roots would affect all sensory modalities. The fasciculus cuneatus and gracilis 

convey proprioceptive and vibration sensation, which are not involved in this patient. The lesion is at the level of 

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convey proprioceptive and vibration sensation, which are not involved in this patient. The lesion is at the level of 

the cervical spinal cord so would not directly involve the thalamus. 

References: 

Campbell WW. DeJong’s the neurologic examination. Philadelphia: Lippincott, Williams & Wilkins, 2005. 

Question 27: Anatomy - Brainstem/Cerebellum 

Discussion: 

The findings are most consistent with a left dorsolateral medullary syndrome (Wallenberg syndrome) due to 

ischemia in the distribution of the posterior inferior cerebellar artery. Ipsilateral limb ataxia in this case is due to 

involvement of the left inferior cerebellar peduncle. 

References: 

Carpenter MB. Core text of neuroanatomy. Baltimore: William & Wilkins, 1991 


Discussion: 

Anesthesia over the perineal area ("saddle anesthesia") in conjuction with loss of sphincter tone and erectile 

dysfunction can be caused by a lesion of the lower cauda equina or the conus medularis. The region of sensory 

abnormality is in the S2 to S5 dermatomes. There is no weakness noted indicating that the lumbar and 

lumbosacral plexi are likely spared. Since this happend 3 weeks ago and his sphincter function remains flacid, 

this is most likely to be a peripheral (lower motor neuron) problem. These factors implicate the bilateral S2-S5 

roots as the most likely culprit. An intramedullary lesion occuring 3 weeks ago would be expected to have some 

component of spasticity at this point. A medial frontal lesion would explain the bladder incontinence but would 

not explain the sensory findings and there is no lower extremity weakness. Onuf's nucleus is a sphincteromotor 

nucleus located at S2 and S4 and would only explain part the patient's urinary symptoms. Given the sesory and 

bowel and bladder symptoms, this process is involving the distal rather than the proximal cauda equina. Since 

the more distal roots of the cauda equina are located more medially, a central disc herniation would be entirely 

consistent with this clinical vignette. 

References: 

Blumenfeld H. Neuroanatomy through clinical cases. 1st ed. Sunderland: Sinauer Associates, Inc., 2002. 

Question 39: Anatomy - Basal Ganglia and Thalamus 

Discussion: 

The anterior nucleus of the thalamus receives information from the mammilothalamic tract and hippocampus 

and sends its outputs to the cingulate gyrus. The dorsomedial (or mediodorsal) nucleus connects prefrontal, 

olfactory, and limbic cortex with prefrontal cortical regions. These last two nuclei are the only two of those 

listed that would be reasonably expected to affect multimodal attention and motivational drive. The ventral 

anterior and ventral lateral nuclei receive input from the basal ganglia and cerebellum, respectively, and send 

their outputs to the motor cortex. The ventral posterior medial and lateral nuclei receive primary somatosensory 

information from the face and body on its way to primary sensory cortex. The pulvinar and lateral posterior 

nuclei are both involved in visual processing and subcortical modulation of visual attention. The medial and 

lateral geniculate receive primary auditory and visual information, respectively. 

References: 

Murray S, Guillery R. Exploring the thalamus. San Diego: Academic Press, 2001. 

Question 41: Anatomy - Embryology 

Discussion: 


The preganglionic sympathetic neurons are located in the intermediolateral cell column in all thoracic and the 

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upper two lumbar spinal segments. Thus, they are formed from the neural tube. 

References: 

Haines DE. Fundamental neuroscience. 2nd ed. New York: WB Saunders, 2002. 

Benarroch EE, Westmoreland BF, Daube JR, et al. Medical neurosciences--an approach to anatomy, pathology 

and physiology by systems and levels. 4th ed. New York: Lippincott, Williams & Wilkins, 1999. 


Discussion: 

The patient with multiple sclerosis and "rhythmic clicking" in her ears has palatal myoclonus. A lesion of the 

pathway connecting the red nucleus, central tegmental tract, inferior olivary nucleus, and dentate nucleus 

(Guillain-Mollaret triangle) results in palatal myoclonus. Of the choices given in the question the only correct 

answer is dentate nucleus. 

References: 



Question 47: Anatomy - Blood Supply of Brain/Spinal Cord 

Discussion: 

This patient presents with a classic subcortical infarction located in or around the internal capsule and involving 

fibers in the posterior limb and the genu. The anterior choroidal artery, a branch of the internal carotid artery, 

supplies the posterior limb of the internal capsule and at least a portion of the genu. Hemorrhage from the 

internal carotid, anterior cerebral, or middle cerebral arteries would be expected to produce cortical findings, 

which are not seen in this patient. The posterior communicating artery connects the posterior cerebral artery to 

the internal carotid artery. 

References: 



Discussion: 

The patient has components of Parinaud's syndrome (conjugate upgaze paresis, nystagmus retractorious, and 

unreactive pupils). A lesion producing these findings occurs in the midbrain tectal region. It often occurs by 

extraaxial compression on the quadrigeminal plate (particularly the superior colliculi). Pineal region masses as 

well as obstructive hydrocephalus may also cause the syndrome. 

References: 

Gilman S, Newman S. Manter & Gatz's essentials of clinical neuroanatomy and neurophysiology. 7th ed. 

Philadelphia: FA Davis, 1987. 

Question 64: Anatomy - Cranial Nerves, Roots, and Plexus 

Discussion: 

A lesion distal to the geniculate ganglion and proximal to the stapedius muscle would cause weakness in the 

muscles of facial expression, alter sublingual and submandibular gland function, cause loss of taste to the 

anterior two thirds of the tongue, and cause hyperacusis but would spare lacrimation. 

References: 


Brazis PW, Masdeu JC, Biller J. Localization in clinical neurology. 3rd ed. Boston: Little, Brown and Co., 1996. 

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Discussion: 

A unilateral lesion of the ventrocaudal pons results in ipsilateral lateral rectus and facial paresis and a 

contralateral facial sparing hemiparesis. This is known as the Millard-Gubler syndrome. 

References: 

Haines DE. Fundamental Neuroscience. 2nd ed. New York: WB Saunders, 2002. 


Discussion: 

The suprachiasmatic nucleus of the hypothalamus is the dominant circadian pacemaker of the mammalian brain. 

The intergeniculate leaflet and raphe nuclei mediate photic entrainment of the suprachiasmatic nucleus--light is 

the major entraining stimulus of the circadian system. The pineal gland is more important in seasonal rhythm 

control. The neurohypophysis does not have a major role in circadian pacemaking. 

References: 

Kandel ER, Schwartz JH, Jessel TM. Principles of neural science. 4th ed. New York: McGraw-Hill, 2000. 


Discussion: 

The nucleus accumbens, a component of the basal ganglia, recieves extensive input from the limbic system and 

the orbitofrontal cortex. It is involved in anticipating rewards and is therefore implicated in substance abuse and 

addiction. Alzheimer's disease is a cortical dementia that does not primarily affect the basal gangila. 

Creutzfeldt-Jakob disease, a spongiform encephalopathy caused by prions, does not have a predilection for deep 

gray nuclei such as the nuclues accumbens. Epilepsy is a also a cortical process without basal ganglia 

involvement. Although Huntington's disease involves the basal ganglia, it is primarily striatal neurons of the 

caudate and putamen that degenerate. 

References: 

Schoenbaum G, Roesch M, Stalnaker T. Orbitofrontal cortex, decision-making and drug addiction. Trends 

Neurosci 2006 Feb;29(2):116-24. 



Discussion: 

The symptoms experienced by the patient in question would localize to the frontal lobe (behavioral and 

personality changes) as well as the temporal lobe (semantic memory). This would be a common presentation of 

frontotemporal dementia. The posterior aspect of the superior temporal gyrus receives information from the 

primary auditory cortices and is integral to the network of areas which decode the meaning of words. This area, 

in the left lateral temporal cortex, is most likely responsible for the patient's semantic problems. The 

hippocampus is involved in memory and is part of the mesial temporal lobe. The orbitofrontal cortex is more 

likely involved in the patient's impulsive behavior and personality changes. The supplementary motor area is 

involved in complex motor programming. 

References: 

Kirshner H. Neurology in clinical practice, volume 1. In: Bradley W, Daroff R, Fenichel G, Marsden C, editors. 

Language disorders: aphasia. 3rd ed. Boston: Butterworth Heinemann, 2000; 141-159. 


Discussion: 


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Prosody, the ability to produce and understand the emotional quality of speech, is processsed by the 

non-dominant hemisphere. Production of prosody depends upon nondominant dorsolateral frontal lobe while 

comprehension of prosody is a function of the nondominant temporal lobe. 

References: 

Mitchell R, Elliott R, Barry M, Cruttenden A, Woodruff P. The neural response to emotional prosody, as 

revealed by functional magnetic resonance imaging. Neuropsychologia 2003;41(10):1410-1421. 


Discussion: 

The amygdala lies in the anterior pole of the temporal lobe just deep to the uncus and is an important structure in 

processing the emotional significance of stimuli, including pain. The caudate is the principal basal ganglia 

nucleus involved in processing oculomotor and prefrontal information. The nucleus acumbens is involved in 

anticipating reward and habit formation rather than the emotional component of pain. The hippocampus is part 

of the limbic system and is an essential component of memory formation. The pulvinar is an association nucleus 

in the thalamus involved in visual processing. 

References: 


Nolte J. The Human Brain. 4th ed. St Louis: Mosby, 1999. 


Discussion: 

The patient has neurological evidence to support a left abducens palsy and a left Horner’s syndrome. The sixth 

nerve and oculosympathetic fibers are close together in the cavernous sinus, near the internal carotid artery. 

Therefore, among the choices listed, the diagnosis that best explains his findings is a cavernous sinus aneurysm. 

A pontine glioma could produce similar symptoms, but one would also expect long tract signs. Vestibular 

shwannomas are usually in the cerebellopontine angle and can injure the seventh and eighth cranial nerves. An 

ecstatic basilar artery may compress the brainstem and injury multiple cranial nerves, but a Horner’s syndrome 

would be atypical. Similarly, tuberculous meningitis can cause a basilar meningitis and injure multiple cranial 

nerves, but the intraaxial location of the oculosympathetic fibers at that level would tend to be spared. 

References: 



Discussion: 

Both the superior orbital fissure and the cavernous sinus contain cranial nerves III, IV, VI, V1, and sympathetic 

nerve fibers. V2 does not travel through the superior orbital fissure. A lesion in neither location would produce 

facial anhidrosis. 

References: 




Discussion: 


The anterior interosseous nerve is a pure motor branch of the median nerve after it passes between the two 

heads of pronator teres. The anterior interosseous nerve innervates flexor pollicis longus, flexor digitorum 

profundis to the index and middle finger, and pronator quadratus. A lesion of this nerve impairs the ability of the 

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patient to make an OK sign with the thumb and index finger producing instead a pinch attitude. There is mild 

weakness of forearm pronation and pain located in the proximal forearm. 

References: 

Brazis PW, Masdeu JC, Biller J. Localization in Clinical Neurology. Boston: Little, Brown, 1996; 12-14. 


Discussion: 

The patient is presenting with a Bell’s palsy resulting in weakness of muscles supplied by the seventh cranial 

nerve. The platysmus is one of these muscles. The masseter is supplied by the trigeminal nerve, the levator 

palpebrae by the oculomotor nerve, the genioglossus by the hypoglossal nerve, and the stylopharyngeus by the 

glossopharyngeal nerve. 

References: 



Discussion: 

The tibialis anterior, which dorsiflexes and inverts the foot, is innervated by the deep peroneal nerve. The 

gastrocnemius plantar flexes the foot and is innervated by the tibial nerve (a branch of the sciatic nerve). The 

semitendinosus, one of the hamstring muscles, is innervated by the sciatic nerve. The tensor fasciae latae, 

innervated by the superior gluteal nerve, abducts and medially rotates the thigh. The sartorius muscle inwardly 

rotates the hip, and flexes the hip and knee and is innervated by the femoral nerve. 

References: 

No author. Aids to the examination of the peripheral nervous system. 2nd ed. London: Bailliere Tindall, 1986. 



Discussion: 

A lesion of the accessory cuneate nucleus would spare pain and temperature. Cells of origin of the lateral 

spinothalamic tract are present in laminae I, IV, and V of the dorsal horn. They project to ventral posterolateral 

and intralaminar and posterior nuclei of the thalamus. Further projection to the cortex is to areas three, one, and 

two and to the secondary somatic sensory area. 

References: 

Parent A. Carpenter's human neuroanatomy. 9th ed. Baltimore: Williams & Wilkins, 1996. 


Discussion: 

On the side of a spinal cord hemisection there is an upper motor neuron syndrome, greatly impaired 

discriminatory tactile sense, loss of kinesthetic sense, and reduced muscle tone. Contralateral to the lesion there 

is loss of pain and temperature due to interruption of the ascending spinothalamic tracts. 

References: 





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Discussion: 

The masseter, temporalis, medial and lateral pterygoids, tensor veli palati, tensor tympani, anterior belly of the 

digastric, and mylohyoid are innervated by the trigeminal nerve. The stapedius, buccinator, posterior belly of the 

digastric, frontalis, as well as other muscles of facial expression are all innervated by the facial nerve. The 

stylopharyngeus is innervated by the glossopharyngeal nerve. 

References: 




Discussion: 

The globus pallidus externa (GPe) is a part of the indirect pathway through the basal ganglia that projects 

inhibitory fibers to the subthalamic nucleus. The GPe is not part of the direct pathway where fibers project 

directly from the striatum to the globus pallidus interna (GPi). 

References: 



Discussion: 

The lateral inferior or caudal pontine syndrome due to occlusion of the anterior inferior cerebellar artery (AICA 

syndrome) involves lesions in the fascicles of cranial nerve VII, the spinal tract, and nucleus of cranial nerve V, 

the lateral spinal thalamic tract, descending sympathetic fibers (lateral reticular nucleus), the middle cerebellar 

peduncle, the inferior surface of the cerebellum, and, in addition, the inner ear and cochlear nerve due to 

occlusion of the labyrinthine artery, a common branch of the AICA. Clinical findings include ipsilateral ataxia, 

loss of pain and temperature sensation of the face, Horner’s syndrome, deafness, and contralateral pain and 

temperature loss of the limbs. 

References: 



Discussion: 

The recurrent artery of Heubner, a branch of the anterior cerebral artery, supplies the anteromedial part of the 

head of the caudate nucleus, adjacent parts of the internal capsule and putamen, and parts of the septal nuclei. 

References: 



Discussion: 

The caudate and the putamen serve as the primary input nuclei for the basal ganglia while the globus palidus, 

which projects to the ventral anterior nucleus of the thalamus, is the primary output nucleus. The substantia 

nigra pars compacta, located in the midbrain, sends dopamanergic fibers to the putamen. The subthalamic 

nucleus receives inhibitory input from the external part of the globus palidus and sends excitatory input to the 

globus palidus pars interna. 

References: 


Carpenter M, Sutin J. Human neuroanatomy. 8th ed. Baltimore: Williams and Wilkins, 1983. 

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Discussion: 

The medial antebrachial cutaneous nerve is a branch of the medial cord of the brachial plexus and would be 

expected to be injured in the neurogenic thoracic outlet syndrome (TOS) and would be spared in an ulnar nerve 

mononeuropathy at the elbow (UNE). The dorsal ulnar cutaneous nerve may be abnormal in both neurogenic 

TOS or UNE. The sensory portions of the median nerve, the superficial radial nerve, and lateral antebrachial 

cutaneous nerve would be spared in UNE and neurogenic TOS. 

References: 



Discussion: 

Contralateral hemianesthesia and hemiparesis followed by spontaneous pain in the affected limbs is due to 

involvement of the thalamoperforate branches of the posterior cerebral artery. Some of these branches supply 

portions of the posterior limb of the internal capsule and may produce contralateral hemiparesis in addition to 

the sensory changes and a central (thalamic) pain syndrome. 

References: 

Gilman S, Newman S. Manter & Gatz's essentials of clinical neuroanatomy and neurophysiology. 7th ed. 

Philadelphia: FA Davis, 1987. 


Discussion: 

The patient has a light-near dissociation, which is not seen in disorders of the oculomotor or optic nerve. The 

absence of other neurological findings in this case would make a midbrain tectal or superior colliculus lesion 

unlikely. The slow, nonuniform constriction of the pupil is consistent with an Adie’s pupil that is due to an 

abnormality of the ciliary ganglion or short ciliary nerves. 

References: 



Discussion: 

The paraventricular nucleus of the hypothalamus provides the bulk of the direct innervation of the preganglionic 

sympathetic neurons. 

References: 




Discussion: 


The dorsomedial nucleus of the thalamus receives input from limbic structures and projects diffusely to the 

frontal cortex. As the main relay for information passing to the frontal association areas, it is felt to be the cause 

of the amnestic confabulation in Korsakoff's syndrome. The anterior nucleus, although it receives input from 

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limbic structures, projects to the cingulate gyrus. The lateral posterior nucleus is involved in visual processing 

similar to the pulvinar. The ventral posteriolateral nucleus receives primary somatosensory information from the 

body. The reticular nucleus does not project to the cortex but instead regulates the activity of other thalamic 

nuclei. 

References: 




Discussion: 

Fibers from the dentatorubrothalamic tract primarily synapse on the ventral lateral nucleus of the thalamus, but 

also on the ventral posterolateral. Fibers from these thalamic nuclei then project to the primary motor cortex 

(Brodmann area 4). 

References: 



Discussion: 

The anterior commissure interconnects olfactory areas as well as homologous regions of the temporal lobe. The 

ansa lenticularis is an ipsilateral efferent pathway from the globus pallidus. The lateral olfactory stria arises in 

the olfactory bulb and projects to the ipsilateral prepyriform cortex and the amygdala. The median forebrain 

bundle projects to the hypothalamus and contains fibers from basal olfactory and periamygdaloid regions and 

the septal nuclei. The crus cerebri, on the ventral surface of the midbrain, contains the corticospinal and 

corticobulbar tracts. It does not connecct cortical regions. 

References: 



Discussion: 

Fifty patients with elevations of serum cardiac troponin levels had strokes involving the right posterior, superior 

medial insula, and the right inferior parietal lobule. Among patients with right middle cerebral artery strokes, the 

insular cortex was involved in 88% of patients with elevated serum cardiac troponin but in only 33% of patients 

without the elevation. 

References: 

Ay H, Koroshetz WJ, Benner T, et al. Neuroanatomic correlates of stroke-related myocardial injury. Neurology 

2006; 66: 13256. 


Discussion: 

The patient has a crossed paresis with right arm and leg weakness as well as left facial paresis. This localizes to 

the left pons. The sensory deficits of fine touch on the right arm, trunk, and leg are due to involvement of the 

left medial lemniscus. The patient's diplopia with left lateral gaze is due to involvement of the left abducens 

nucleus. 

References: 



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Discussion: 

Damage to the fornix can occur with transcallosal surgery to remove a colloid cyst of the third ventricle, which 

interrupts Papez's circuit and results in loss of the ability to form new memories. 

References: 



Discussion: 

The dorsal and ventral spinocerebellar tracts are the most lateral tracts in the spinal cord and therefore would be 

expected to be affected first by an extrinsic lateral process. The lateral corticospinal tract lies just medial to the 

dorsal spinocerebellar tract while the anterior corticospinal tract is in the anterior midline. The fasciculus 

gracilis is the medial aspect of the dorsal columns. The tectospinal pathway lies just anterior to the anterior 

commisure and the reticulospinal tract lies just anterior to the lateral corticospinal tract. The spinothalamic tracts 

run just interal to the ventral spinocerebellar tract. 

References: 




Discussion: 

The latissimus dorsi muscle is intervated by the thoracodorsal nerve, which is a branch of the posterior cord of 

the brachial plexus. 

References: 

Aids to the Examination of the Peripheral Nervous System. 4th ed. Edinburgh: WB Saunders; 2000. 


Discussion: 

The thalamoperforating branches of the posterior cerebral arteries perfuse the medial and anterior regions of the 

thalamus. The thalamogeniculate branches of the posterior cerebral arteries perfuse the pulvinar and lateral 

nuclei. The inferior thalamic arteries arise from the posterior communicating arteries and perfuse the inferior 

portions of the thalamus. The medial posterior choroidal artery supplies the superior and medial portions of the 

thalamus. 

References: 



Discussion: 


The dorsomedial nucleus connects prefrontal, limbic, and olfactory structures with prefrontal cortex. The 

intralaminar nuclei project to the cerebral cortex and the basal ganglia. The lateral dorsal nucleus receives input 

from the hippocampus and projects to the cingulate gyrus. The pulvinar is an associaton nucleus that receives 

inputs from parietal, temporal, and occipital cortex and then projects to these same areas. The reticular nucleus 

projects to other thalamic nuclei but not to the cortex. 

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References: 


Behavioral/Psychiatry 

Question 7: Behavioral/Psychiatry - Developmental Disorders 

Discussion: 

The most common cause of inherited mental retardation is fragile X syndrome. Nearly all affected boys manifest 

attention deficit disorder and have learning disabilities. The most frequent neurocognitive symptoms are abstract 

reasoning, complex problem solving, and expressive language. Many will also show manifestations of autism, 

with 33% meeting criteria for autism. Female carriers can have a milder form of the disease with learning 

disabilities, and about 50% will manifest attention deficit disorder. Characteristic physical features include a 

long thin face, prominent forehead and jaw, protuberant ears, hip dislocation, and club feet. 

References: 

Rittey CD. Learning difficulties: what the neurologist needs to know. J Neurol Neurosurg Psychiatr 

2003;74:30-36. 

Question 12: Behavioral/Psychiatry - General Psychiatry 

Discussion: 

This woman has obsessive-compulsive disorder, and flurodeoxyglucose PET consistently shows hypermetabolic 

activity in the caudate, anterior cingulate, and orbitofrontal cortex. 

References: 

Baxter LR, Phelps ME, Mazziotta JC, et al. Local cerebral glucose metabolic rates in obsessive-compulsive 

disorder: a comparison with rates in unipolar depression and normal controls. Arch Gen Psychiatry 

1987;44:211-218. 

Question 14: Behavioral/Psychiatry - Behavioral Complications of Systemic Disease 

Discussion: 

Forced normalization refers to a psychosis occurring after achievement of good clinical seizure control or 

resolution of interictal epileptiform discharges. 

References: 

Paraiso J, Devinsky D. Neurobehavioral Aspects of Epilepsy. In: Feinberg TE, Farah MJ, editors. Behavioral 

neurology and neuropsychology. 2nd ed. New York: McGraw-Hill, 2003. 

Question 15: Behavioral/Psychiatry - Psychopharmacology 

Discussion: 

Acetylcholine, vital to the formation and encoding of new memories is one of many neurotransmitters deficient 

in Alzheimer's disease. Medications including tricyclic antidepressants, antihistamines, and antiemetics with 

strong anticholinergic properties can worsen memory loss as well as cause confusion. 

References: 


Cummings JL, Mega MS. Neuropsychiatry and behavioral neuroscience. New York: Oxford University Press, 

2003. 

Question 16: Behavioral/Psychiatry - Occipital Syndromes 

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Discussion: 

There are numerous types of reading disorders seen after focal lesions and in neurodegenerative disorders. 

Surface dyslexia is characterized by impairment linking the visual word form system with the phonological 

output lexicon. Therefore, patients are unable to access the visual word image to link to proper pronounciation. 

Patients have to rely on "print to sound conversion" and cannot read words that do not sound the way they are 

spelled. 

References: 


2003. 

Question 19: Behavioral/Psychiatry - Dementia 

Discussion: 

Patients with frontotemporal dementia have been shown to manifest a variety of behavioral changes, including 

hoarding of items and nascent musical and/or artistic expression. This combination of behaviors is usually not 

seen in other degenerative dementias. 

References: 

Miller BL, Cummings JL, Boone K, et al. Emergence of artistic talent in frontotemporal dementia. Neurology 

1998;51:978-981. 


Discussion: 

Wilson’s disease is an autosomal recessive disorder caused by a mutation in the ATP7B gene on chromosome 

13. Clinical symptoms are neurological, psychiatric, hepatic, or ocular. Other disorders affecting basal ganglia 

circuitry can mimic Wilson’s disease; however, only Wilson’s disease will manifest with copper abnormalities 

on laboratory screens. These syndromes include pantothenate kinase disease (caused by a mutation in the 

PANK2 gene) and Huntington’s disease (trinucleotide repeat disorder on chromosome 4). 

References: 

Online Mendelian Inheritance in Man (OMIM) TM [homepage on the Internet]. Baltimore: McKusick-Nathans 

Institute for Genetic Medicine, Johns Hopkins University; Bethesda: National Center for Biotechnology 

Information, National Library of Medicine; c2006 [cited 2006 Aug 4;]. Available from: 

www.ncbi.nlm.nih.gov/omim/. 

Kitzberger R, Madl C, Ferenci P. Wilson disease. Metab Brain Dis 2005;20:295-302. 


Discussion: 

Paroxysmal autonomic instability with dystonia (PAID) is a common symptom cluster similar to malignant 

hyperthermia and neuroleptic malignant syndrome. It commonly appears following severe traumatic or hypoxic 

brain injury. Treatment generally consists of beta-adrenergic blockers, opioid analgesia, dopamine agonists, and 

benzodiazepines. Dopamine antagonists can precipitate symptoms similar to PAID. Drugs acting on cholinergic 

and serotonin systems have not been found to be effective. 

References: 

Blackman JA, Patrick PD, Buck ML, Rust RS. Paroxysmal autonomic instability with dystonia after brain 

injury. Arch Neurol 2004;61:321-328. 


Discussion: 


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Bilateral hilar adenopathy, bilateral cranial nerve palsies, and an encephalopathy due to a basilar 

meningoencephalitis is typical of neurosarcoid. Progressive multifocal leukoencephalopathy due to the JC virus, 

herpes simplex virus encephalitis, and HIV dementia all are characterized by white matter or cortical lesions on 

MRI. The case is inconsistent with strokes due to cardiac thrombi. 

References: 

Stern BJ. Neurological complications of sarcoidosis. Curr Opin Neurol 2004;17:311-316. 


Discussion: 

This patient with traumatic brain injury would most likely have frontal lobe impairment given the nature of his 

accident. Psychosis, visual hallucinations, delusions, and mania would all be atypical. Road rage, episodic 

dyscontrol, impulsivity, intrusiveness, apathy and aggression would be more common findings. 

References: 

Fann JR, Katon WJ, Uomoto JM, Esselman PC. Psychiatric disorders and functional disability in outpatients 

with traumatic brain injuries. Am J Psychiatry 1995;152:1493-1499. 

Question 70: Behavioral/Psychiatry - Temporal-Limbic Syndromes 

Discussion: 

Klüver-Bucy syndrome results from bilateral temporal lesions involving the amydala nuclei. Clinical features 

include hypermetamorphosis, hyperorality, hypersexuality, visual agnosia, and blunted emotional affect. 

Aggression is not a component of the syndrome. Hypermetamorphosis occurs when an individual is overly 

sensitive or acutely aware of minute stimuli in the environment, such as a speck of lint on someone's shirt or a 

scrap of paper on the floor. Patient's with Klüver-Bucy syndrome may become preoccupied with these stimuli 

by touching, picking or examining them, symptoms that are described as hypermetamorphosis. 

References: 

Mendez MF. Pick's disease. In: Feinberg TE, Farah MJ, editors. Behavioral neurology and neuropsychology. 

2nd ed. New York: McGraw-Hill, 2003. 

Question 75: Behavioral/Psychiatry - Language/Speech Abnormalities 

Discussion: 

Speech remains intact as language deteriorates with advancing Alzheimer's dementia, eventually producing an 

aphasia in which the patient is fluent and paraphasic, their speech is empty, and they have limited 

comprehension but repeat well, which is typical of transcortical sensory aphasia. 

References: 

Cummings JL, Darkins A, Mendez M, et al. Alzheimer's disease and Parkinson's disease: comparison of speech 

and language alterations. Arch Neurol 1988;38:680-684. 

Question 84: Behavioral/Psychiatry - Parietal Syndromes 

Discussion: 

Anosognosia (unawareness of deficit or illness) is usually seen associated with nondominant parietal lobe 

lesions. Achromatopsia is found after lesions of the inferior lip of the occipital lobe. Limb kinetic apraxia is seen 

after lesions of the anterior corpus callosum. Expressive aprosodia is seen after right frontal lesions. Semantic 

aphasia is seen after dominant hemisphere lesions. 

References: 


Feinberg TE, Farah MJ. Behavioral neurology and neuropsychology. 2nd ed. New York: McGraw-Hill, 2003. 

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Question 86: Behavioral/Psychiatry - Occipital Syndromes 

Discussion: 

Disturbance with the recognition of color in one visual field, hemiachromatopsia, occurs only with inferior, 

posterior occipital lesions. 

References: 

Damasio A, Tranel D, Rizzo M. Disorders of complex visual processing. In: Mesulam MM, editor. Principles of 

behavioral and cognitive neurology. New York: Oxford University Press, 2000. 

Question 96: Behavioral/Psychiatry - Neurobiology of Behavior 

Discussion: 

Depression is often associated with left anterior frontal vascular lesions. 

References: 


2003. 

Question 105: Behavioral/Psychiatry - Neurobehavioral/Neuropsychological Exam 

Discussion: 

Multiple system atrophy is a relatively uncommon disorder with a constellation of symptoms that include 

parkinsonism and autonomic and/or cerebellar dysfunction. Cognitive impairment can be a frequent 

manifestation of the syndrome and usually manifests with frontal executive dysfunction. 

References: 

Mendez MF, Cummings JL. Dementia: a clinical approach. 3rd ed. Philadelphia: Butterworth-Heinemann, 

2003;260-263. 


Discussion: 

Amyloid starts as an amyloid precursor protein. It is normally cleaved by a series of enzymes into a short 

version that can easily be excreted by the body. In pathological conditions such as Alzheimer’s disease, amyloid 

is incorrectly cleaved by beta-secretase and gamma-secretase. Presenilin-1 assists gamma-secretase in cleaving 

the amyloid precursor protein. This abnormal cleaving results in amyloid aggregation that ultimately leads to 

plaque formation. 

References: 

Hardy J, Selkoe DJ. The amyloid hypothesis of Alzheimer’s disease: progress and problems on the road to 

therapeutics. Science 2002;297:353-356. 


Discussion: 

The loss of remote memory, including autobiographical memory, in the face of intact new learning ability is 

consistent with psychogenic amnesia. 

References: 

Mendez MF, Cummings JL. Dementia: a clinical approach. 3rd ed. Philadelphia: Butterworth-Heinemann, 2003. 



14

Discussion: 

Any patient with Alzheimer's disease who acutely develops symptoms of a confusional state and behavioral 

changes first warrants a workup to look for the underlying cause. Even mild changes in metabolic status, 

medications, or an infection such as of the urinary tract may precipitate confusion and behavioral changes. 

References: 

Mendez MF, Cummings JL. Dementia: a clinical approach. 3rd ed. Philadelphia: Butterworth-Heinemann, 

2003;260-263. 


Discussion: 

Conduction aphasia, also called associative aphasia, is a relatively rare form of aphasia caused by damage to the 

nerve fibers in the arcuate fasciculus, which connects Wernicke's and Broca's areas. Patients with conduction 

aphasia show the following characteristics: speech is fluent, comprehension remains good, oral reading is poor, 

repetition is poor, transpositions of sounds within a word (television/velitision) are common. To understand the 

symptoms, recall that Broca's area controls expression whereas Wernicke's area is responsible for 

comprehension. When both areas are intact but the neural connections between them is broken, there is the 

curious condition in which the patient can understand what is being said but cannot repeat it (or repeats it 

incorrectly). Such a patient will also end up saying something inappropriate or wrong, realize his/her mistake, 

but continue making further mistakes while trying to correct it. 

References: 


2003. 


Discussion: 

Korsakoff amnestic syndrome causes impairment in declarative memory (anterograde amnesia) and forgetting 

of recent events (retrograde amnesia) with sparing of motor memory and semantic memory (memory for 

meaning of words). Digit span remains normal in this syndrome. 

References: 


2003. 


Discussion: 


The Clinical Dementia Rating (CDR) Scale is a dementia staging instrument used to rate cognitive function 

along five levels of impairment from none to maximal (rated as 0, 0.5, 1, 2, or 3) in each of six domains: (1) 

memory, (2) orientation, (3) judgment and problem solving, (4) function in community affairs, (5) home and 

hobbies, and (6) personal care. (Personal care has no 0.5 impairment level.) Only impairment caused by 

cognitive dysfunction is rated. Community affairs and home and hobbies assess instrumental activities of daily 

living relevant to the individual and hence vary according to that person’s accustomed activities; examples 

include job performance for those who still are employed and skills in driving, home repairs, household 

finances, shopping, cooking, and card games. Personal care represents basic activities of daily living common to 

almost all individuals (dressing, bathing and grooming, eating, and continence). Based on the collateral source 

and participant interviews, a global CDR score is derived from individual ratings in each domain such that CDR 

0 indicates no dementia and CDR 0.5, 1, 2, and 3 represent very mild--also referred to as mild cognitive 

impairment (MCI), mild, moderate, and severe dementia, respectively. Interrater reliability for the CDR has 

been established at about 88%. Not all domains need be rated at the same level of impairment as the global CDR 

score; for example, a participant may merit a box score of 1 for memory but scores of 0.5 or 0 for other domains 

and still have a global CDR of 0.5. The individual ratings can be totaled to yield the sum boxes, a more 

15

quantitative rating that ranges from 0 (or no impairment in any of the 6 domains) to 18 (or maximal impairment 

in each of the 6 domains). 

References: 

Morris JC, Ernesto C, Schaefer K, et al. Clinical dementia rating (CDR) training and reliability protocol: the 

Alzheimer Disease Cooperative Study Unit experience. Neurology 1997;48:1508-1510. 


Discussion: 

The Dementia with Lewy bodies (DLB) Consortium has revised criteria for the clinical and pathologic diagnosis 

of DLB incorporating new information about the core clinical features and suggesting improved methods to 

assess them. REM sleep behavior disorder, severe neuroleptic sensitivity, and reduced striatal dopamine 

transporter activity on functional neuroimaging are given greater diagnostic weighting as features suggestive of 

a DLB diagnosis. When any of these are present with one of the primary findings of visual hallucinations, 

parkinsonism, or fluctuating attention, then the diagnosis of probable DLB is supported. 

References: 

McKeith IG, Dickson DW, Lowe J, et al. Diagnosis and management of dementia with Lewy bodies: third 

report of the DLB consortium. Neurology 2005;65:1863–1872. 


Discussion: 

Pick's disease is usually manifested by disinhibition, socially inappropriate behavior, and sometimes the 

Kluver-Bucy syndrome. Although some patients may develop depression, it is far less likely than the incidence 

of depression in Parkinson's, Wilson's, Huntington's disease, and multiple sclerosis. 

References: 



Discussion: 

Bupropion has had a low incidence of erectile dysfunction associated with its use. All of the selective serotonin 

reuptake inhibitors (SSRIs) have been reported to have erectile dysfunction as a side effect. Amitriptyline and 

venlafaxine also cause erectile dysfunction. 

References: 

Arana GW, Rosenbaum JF. Handbook of psychiatric drug therapy. 5th ed. Philadelphia: Lippincott, Williams & 



Discussion: 

An aphasia is considered fluent if: word output per minute is high; there are five or more words per phrase; 

content per phrase is low; paraphasias are present; and speech is nondysarthric with normal prosody. 

References: 

Benson DF, Ardila A. Aphasia: a clinical perspective. Oxford: Oxford University Press, 1996. 

Question 167: Behavioral/Psychiatry - Parietal Syndromes 

Discussion: 


16

Asomatognosia is a form of neglect in which patients deny ownership of their limbs; it frequently accompanies 

anosognosia. The lesion is generally located in the nondominant supramarginal gyrus. 

References: 

Meador KJ, Loring DW, Feinberg TE, et al. Anosognosia and asomatognosia during intracarotid amobarbital 

inactivation. Neurology 2000;55:816-820. 

Feinberg TE, Laber LD, Needs NE. Verbal asomatognosia. Neurology 1990;40:1391-1394. 


Discussion: 

Several neurotransmitters and hormones have been implicated in the modulation of violent behavior. Most recent 

evidence has found low levels of CSF 5-HIAA in patients who have attempted suicide via violent means as well 

as in alcoholics with impulsive violent behavior. Norepinephrine and COMT have also been implicated in 

aggressive behavior. 

References: 

Volavka J. The neurobiology of violence: an update. J Neuropsychiatry and Clin Neurosci 1999;11:307-314 


Discussion: 

Numerous neuropsychiatric symptoms have been associated with epilepsy, particularly with temporal lobe 

epilepsy. The symptoms include psychosis, fear, anxiety, hypergraphia, hypermorality, and altered sexual 

function. The most commonly reported and readily treatable symptom is depression. 

References: 

Bortz JJ. Neuropsychiatric and memory issues in epilepsy. Mayo Clin Proc 2003;78:781-787. 

Jones JE, Hermann BP, Barry JJ, et al. Clinical assessment of Axis I psychiatric morbidity in chronic epilepsy: a 

multicenter investigation. J Neuropsychiatry Clin Neurosci 2005;17:172-179. 

Question 194: Behavioral/Psychiatry - Frontal Systems Syndromes 

Discussion: 

The thalamus is a major relay station for most inherent functions of the brain to include cognition. This nuclear 

structure can be subdivided into regions based on functional relationships. Lesions in specific subnuclei can lead 

to different clinical manifestations. For example, lesions in the anterior group are more likely to manifest 

amnesia, confabulation, anomia and preserved visuospatial function. Paramedian thalamic lesions can manifest 

wtih acute decreased consciousness followed by vertical gaze paresis, disinhibition and at times amnesia. 

References: 

Carrera E, Bogousslavsky J. The thalamus and behavior: effects of anatomically distinct strokes. Neurology 

2006;66(12):1817-1823. 

Question 197: Behavioral/Psychiatry - Frontal Systems Syndromes 

Discussion: 

Personality changes associated with dorsolateral frontal dysfunction include apathy, self-absorption, 

perseveration, neurovegetative symptoms (eg, eating and sleeping disturbances), irritability, and agitation. 

Psychosis is usually seen with temporal lobe dysfunction. Obsessive-compulsive traits, disinhibition, 

hypersexuality, and intrusiveness are typical of lesions affecting the orbitofrontal cortex. 

References: 


Miller BL, Cummings JL, editors. The human frontal lobes: Functions and disorders. New York: The Guilford 

17

Miller BL, Cummings JL, editors. The human frontal lobes: Functions and disorders. New York: The Guilford 

Press, 1999. 


Discussion: 

Factitious disorder is defined as a syndrome of intentional production of psychological or physical symptoms in 

the absence of external incentives but in the presence of a psychological need to assume the sick role. When 

there are external incentives for the behavior, then malingering is the likely diagnosis. Amnestic disorder is 

when the individual has difficulties learning new things. Conversion symptoms are subconscious and not 

intentionally produced. Somatoform disorder refers to individuals who have recurrent and multiple somatic 

complaints not due to any physical disorder. 

References: 

American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 4th ed., text revision. 

Washington DC: American Psychiatric Association, 2000. 


Discussion: 

Numerous studies have found a serotonergic deficit in patients with frontotemporal dementia (FTD). Experts in 

the field will often treat these patients with selective serotonin reuptake inhibitors (SSRIs) even in the absence of 

depression. There is no evidence of a cholinergic deficit in FTD, and studies evaluating the efficacy of 

cholinesterase inhibitors have been largely neutral or negative. Purported neuroprotective and antioxidant 

compounds have also not been found to be beneficial. 

References: 

Graff-Radford N, Woodruff B. Frontotemporal dementia. Continuum 2004;10:58-80. 

Litvan I. Therapy and management of frontal lobe dementia patients. Neurol 2001;56(Suppl 4):S41-S45. 


Discussion: 

Attention deficit hyperactivity disorder (ADHD) is a highly heritable, disruptive, childhood-onset condition, the 

etiology and pathogenesis of which is poorly understood. There have been relatively few genome-wide linkage 

studies, and no chromosomal region has yet been unequivocally implicated. In contrast, evidence from 

pharmacological, neuroimaging, and animal studies has suggested the involvement of specific neurotransmitter 

systems, notably dopaminergic pathways. Meta-analyses or pooled data analyses have supported association 

between ADHD and polymorphisms in DRD4, DRD5, and SLC6A3, which encode dopamine D4 and D5 

receptors and the dopamine transporter, respectively. 

References: 

Waldman ID, Gizer IR. The genetics of attention deficit hyperactivity disorder. Clin Psychol Rev 

2006;26:396-432. 


Discussion: 

Olanzapine is an atypical antipsychotic that frequently causes significant weight gain. Quetiapine, risperidone, 

haloperidol, and molindone are less likely to do so. 

References: 


Puzantian T, Stimmel G. Review of psychotropic drugs. New York: McMahon, 2001. 

18


Discussion: 

Prion proteins cause spongiform encephalopathy characterized by rapidly progressive dementia with myoclonus 

and seizures. Progressive multifocal leukoencephalopathy caused by the JC virus traditionally presents with 

encephalopathy, vision loss, paralysis, and ataxia. This syndrome, like human immunodeficiency virus (HIV), 

usually presents in patients who are immunocompromised. The neurological manifestations of HIV are many 

and include myelopathy, sensory neuropathy, and dementia. Tropheryma whippelii is the organism identified as 

the cause of Whipple’s disease. Patients typically present with gastrointestinal complaints including diarrhea, 

malabsorption, and weight loss. Other symptoms may include lymphadenopathy, hyperpigmented skin, 

movement disorders, oculomasticatory myodysrhythmia, and dementia. Herpes simplex virus typically presents 

with changes in personality and seizures; gastrointestinal symptoms are uncommon. 

References: 

Manzel K, Tranel D, Cooper G. Cognitive and behavioral abnormalities in a case of central nervous system 

Whipple disease. Arch Neurol 2000;57:399-403. 


Discussion: 

Most patients with Alzheimer’s disease (AD) have a sporadic late-onset form of the disease. A small percentage 

of patients, however, have familial disease produced by one of three autosomal dominant genes. Among familial 

AD patients, 50% to 70% have the presenilin-1 mutation or an associated mutation on chromosome 14. Five 

percent to 10% have the presenilin-2 mutation. A small percentage will have a mutation in the gene that codes 

for amyloid precursor protein. 

References: 

Bird TD. Genetic factors in Alzheimer’s disease. N Eng J Med 2005;352:862-864. 

Question 339: Behavioral/Psychiatry - Temporal-Limbic Syndromes 

Discussion: 

Often, pseudoseizures are considered when bilateral rhythmic motor output occurs without loss of 

consciousness, especially when an EEG captures the “spell” and no electrophysiological correlate is found with 

scalp or sphenoidal leads. However, the midportion of the anterior cingulate (adjacent to the supplementary 

motor cortex) has a bilateral motor homunculus that, when affected by an ictal focus, will produce bilateral 

rhythmic motor output (without loss of consciousness) detectable only with subdural brain surface electrodes. 

This limbic focus often manifests as a primary psychiatric disorder escaping routine neurological surveillance. 

References: 

Devinsky O, Morrell MJ, Vogt BA. Contributions of anterior cingulate cortex to behavior. Brain 

1995;118:279-306. 


Discussion: 

Numerous deficits of recognition following right hemisphere damage have been described. These syndromes 

generally do not involve deficits in discrimination and result from lesions outside of unimodal cortex. 

Prosopagnosia, a deficit in facial recognition, is probably the most well known. Lesser known syndromes 

include auditory agnosia, a deficit in recognition of verbal and nonverbal sounds; autotopagnosia, which 

represents the inability to localize stimuli on the affected side of the body; and phonagnosia, which is the 

inability to recognize familiar voices. Pure word deafness, unlike the others, results from lesions of the dominant 

hemisphere and leaves patients with the inability to recognize spoken language with spared nonverbal 

communication and fluency. 

References: 


19

Shah NJ, Marshall JC, Zafiris O, et al. The neural correlates of person familiarity. A functional magnetic 

resonance imaging study with clinical implications. Brain 2001;124:804-815. 

Van Lancker DR, Krieman J, Cummings J. Voice perception deficits: neuroanatomical correlates of 

phonagnosia. J Clin Exp Neuropsychol 1989;11:665-674. 


Discussion: 

Although chromosome 3 and 9 have been linked to kindreds with frontotemporal dementia (FTD), the 

overwhelming majority of patients with FTD have been found to have mutations on chromosome 17. They may 

also demonstrate features of parkinsonism. Chromosome 17 harbors the gene for tau and at least 30 mutations 

have been discovered in this gene among 100+ families. Chromosomes 12 and 19 have been implicated in 

Alzheimer’s disease. 

References: 


Sobrido MJ, Wiedau-Pazos M, Geschwind DH. The genetics of frontotemporal dementia and related disorders. 

Current Genomics 2000;1:339-352. 


Discussion: 

Numerous neurological symptoms can be seen associated with systemic lupus erythematosis (SLE). These 

manifestations include peripheral neuropathy and cerebritis as well as neuropsychiatric symptoms such as 

depression, mania, and psychosis. SLE is more frequently associated with psychosis than are Bechet's syndrome, 

Ehlers-Danlos syndrome, rheumatoid arthritis, or Sjogren's syndrome. 

References: 


2003. 


Discussion: 

Numerous neuropsychological tests have been devised that target predominantly one cognitive domains. These 

include tests of visuospatial abilities for parietal lobe functions, memory for mesial temporal structures and tests 

of sustained and complex attention for frontal lobe/executive function. 

References: 


2003. 


Discussion: 

HIV infection can result in minor cognitive and motor disorder, HIV-associated mild neurocognitive disorder, 

and HIV-associated dementia. The earliest symptoms revolve around mental slowing and processing speed. 

Tests that assess processing speed, including trails A and B, grooved pegboard, Symbol Digit Modalities Test, 

and the HIV Dementia Scale are likely to be abnormal early in the disease course. 

References: 



20


Discussion: 

Several disorders of language can result following damage to the dominant hemisphere. Detailed examination of 

the six components of the language examination (fluency, comprehension, repetition, reading, writing, and 

naming) is essential to help distinguish them. Wernicke’s aphasia is characterized by fluent speech with 

impaired comprehension of written and spoken words. Patient’s with aphemia are relatively nonfluent in spoken 

language; however, comprehension and written communication are much better preserved. The hallmark of 

conduction aphasia is impaired repetition with relative sparing of other components of language. Patients who 

suffer from pure word deafness are unable to repeat or comprehend spoken language; however, they can still 

communicate effectively via writing. 

References: 

Benson DF, Ardila A. Aphasia: a clinical perspective. New York: Oxford University Press, 1996. 


Discussion: 

Catatonia is a syndrome manifested by a number of motor and neurobehavioral features. It may have a 

"retarded-stuporous" form or an "excited-delirious" form. It may be seen in over 10% of inpatient psychiatric 

patients. Catatonia is more prevalent in mood disorders than in schizophrenia. The most common mood disorder 

in which it is seen is bipolar. Catalepsy, waxy flexibility, echophenomena, and negativism including mutism are 

common. Many neurological and systemic illnesses may also present as catatonia. Treatments include 

benzodiazepines, barbiturates, and electroconvulsive therapy. Dopamine antagonists as well as baclofen may 

worsen the condition. 

References: 

Taylor MA, Fink M. Catatonia in psychiatric classification: a home of its own. Am J Psychiatry 

2003;160:1233-1241. 


Discussion: 

Akinetic mutism may result from anterior cingulate lesions or a disconnection of the limbic connections 

projecting from the anterior cingulate through subcortical circuits. Based on nonhuman primate primate tracer 

studies, ventral pallidal lesions should disrupt the anterior cingulate frontal-subcortical circuit. A patient will 

develop a rigid akinetic mute state caused by bilateral lesions of the globus pallidus interna with ventral 

extension. 

References: 


2003. 


Discussion: 

A posterior parietal-occipital functional defect is often seen in dementia with Lewy bodies, unlike Alzheimer's 

disease, which typically has a temporal parietal functional defect. 

References: 


McKeith IG, Dickson DW, Lowe J, et al. Diagnosis and management of dementia with Lewy bodies: third 

report of the DLB consortium. Neurology 2005;65:1863–1872. 


21

Discussion: 

Tuberous sclerosis is a genetic disorder associated with numeorus skin and systemic manifestations as well as 

intracranial tubers, mental retardation, and seizures. Although numerous neuropsychiatric symptoms have been 

reported to be associated with tuberous sclerosis, autism spectrum disorder is the most common. 

References: 

Wiznitzer M. Autism and tuberous sclerosis. Child Neurol 2004;19:675-679. 


Discussion: 

The serotonin syndrome results from concomitant administration of medications that enhance serotonin 

transmission via decreased breakdown or increased production. Medication combinations to use cautiously 

include monoamine oxidase inhibitor agents with selective serotonin reuptake inhibitors, tricyclic 

antidepressants, or dextromethorphan. The serotonin syndrome can be differentiated from neuroleptic malignant 

syndrome by the presence of shivering and myoclonus in the former. 

References: 

Boyer EW, Shannon M. Current Concepts: the serotonin syndrome. New Eng J Med 2005;352:1112-1120. 

Christensen RC. Identifying serotonin syndrome in the emergency department. Am J Emerg Med 

2005;23:406-408. 


Discussion: 

Subcortical dementia is characterized clinically by psychomotor slowing, forgetfulness, cognitive decline, 

visuospatial impairment, and personality changes, especially in mood. Bradyphrenia (slowness of mental 

processing) is very common. 

References: 


Clinical Adult 

Question 3: Clinical Adult - Neuromuscular Disorders 

Discussion: 

Charcot-Marie-Tooth disease (CMT) 1A typically shows distal weakness, nerve hypertrophy, and pes cavus 

associated with a duplication of the PMP22 gene. In hereditary neuropathy with liability to pressure palsies 

(HNPP), there is a deletion of the PMP22 gene. CMT 2 is the axonal phenotype. 

References: 

Nicholson GA. The dominantly inherited motor and sensory neuropathies: clinical and molecular advances. 

Muscle Nerve 2006;33:589-597. 

Question 4: Clinical Adult - Dementia 

Discussion: 


According to the guidelines by the NINCDS-ADRDA, the routine evaluation of the patient with dementia 

should include the following laboratory tests: (1) complete blood count, (2) serum electrolytes, (3) glucose, (4) 

blood urea nitrogen/creatinine, (5) serum B12 levels, (6) depression screening, (7) liver function test, and (8) 

thyroid function test. Venereal Disease Research Laboratory (VDRL), HIV, lumbar puncture, and heavy metal 

screen are not recommended in routine dementia screening without clinical indication. 

22

References: 

Dubinsky RM, Stein AC, Lyons K. Practice parameter: risk of driving and Alzheimer's disease (an 

evidence-based review): report of the Quality Standards Subcommittee of the American Academy of Neurology. 

Neurology 2000;54(12):2205-2211. 

Question 23: Clinical Adult - Movement Disorders 

Discussion: 

The onset of orofacial dyskinesias with lingual and oral dystonia in a 30-year-old patient is characteristic of 

neuroacanthocytosis, which may also be associated with chorea and peripheral polyneuropathy. 

References: 

Bradley WG, Daroff RB, Fenichel GM, et al, editors. Neurology in clinical practice. 3rd ed. Boston: 

Butterworth-Heinemann, 2000. 

Question 33: Clinical Adult - Neurology of Systemic Disease 

Discussion: 

Anticoagulation may produce spontaneous hemorrhage into the psoas or iliacus muscle and produce and acute 

iliofemoral neuropathy. CT of the abdomen an pelvis is most useful for imaging acute blood in the 

retroperitoneum. 

References: 

Seijo-Martinez M. Acute femoral neuropathy secondary to an iliacus muscle hematoma. J Neurol Sci 2003; 

209(1-2): 119-122. 

Question 40: Clinical Adult - Headache 

Discussion: 

Valproic acid, amytriptilline, and propranolol have the best proven benefit as prophylactic agents. Drug choice 

should be balanced with the patient's comorbidities. AAN practice guidelines have evaluated evidence-based 

data for acute and prophylactic therapy based upon stastical and clinical benefit in published clinical trials. 

References: 

Silberstein S. Practice parameter: Evidence-based guidelines for migraine headache (an evidence-based review). 

Report of the Quality Standards Subcommittee of the American Academy of Neurology. Neurology 2000; 55: 

754-763. 

Question 49: Clinical Adult - Cerebrovascular Disease 

Discussion: 

In the syndrome of alexia without agraphia, a complete right homonymous hemianopsia is present in many 

cases, but there are exceptions. Impaired naming and understanding of color names in the presence of intact or 

nearly intact color vision is common, although some patients suffer from an actual impairment of color vision. 

Mild anomia is common but not always present. In most cases, there are no other aphasic disturbances or 

abnormalities of the primary motor or sensory systems. The most frequently reported pathology is occlusion of 

the dominant (left) posterior cerebral artery. 

References: 



Question 53: Clinical Adult - Motor Neuron/Nerve 


23

Discussion: 

This patient has peroneal compression neuropathy due to significant weight loss and leg crossing. The 

appropriate management would be to caution him against leg crossing. 

References: 

Rubin DI, Kimmel DW, Cascino TL. Outcome of peroneal neuropathies in patients with systemic malignant 

disease. Cancer 1998;83:1602-1606. 

Question 58: Clinical Adult - Critical Care/Trauma 

Discussion: 

This patient has raised intracranial pressure most probably due to a developing epidural hematoma. Pending 

definitive treatment with a neurosurgical procedure, intracranial pressure should be managed by putting the 

patient’s head up 40 degrees, intubation and hyperventilation, and administering IV mannitol. 

References: 

Wijdicks, EF. Neurologic Catastophies in the Emergency Department. Woburn, Mass: Butterworth-Heinemann, 

2000. 

Question 65: Clinical Adult - Spinal and Root Disorders 

Discussion: 

This patient has a C5 to C6 disc herniation producing a relatively mild acute C6 radiculopathy. The diagnosis is 

clear from the information provided, and no additional diagnostic testing (EMG, myelography) should be 

required. In most cases the symptoms will resolve spontaneously without need for cervical discectomy. Surgery 

would be required if the patient had significant radicular weakness, cervical myelopathy, or intractable radicular 

pain. Epidural steroid injection does not have a defined role in the treatment of radiculopathy but may improve 

pain control in patients with radicular pain that is severe or does not respond to oral analgesics. 

References: 

Noseworthy J. Neurological therapeutics Principles and Practice. 2nd ed. London: Informa Healthcare, 2006. 


Discussion: 

Cerebral amyloid angiopathy usually affects the elderly and accounts for up to 10% of intracranial hemorrhages. 

The typical location of the hemorrhages is in the lobar areas. The deposition of beta amyloid protein in the 

media and adventitia of small meningeal and cortical vessels result in lobar hemorrhages that frequently recur. 

References: 

Victor M, Ropper A. Adams and Victor's principles of neurology. 7th ed. New York: McGraw-Hill, 2001. 


Discussion: 

Polymyositis often presents as an acquired progressive proximal weakness with elevated creatine kinase levels 

and EMG demonstrating fibrillations and small polyphasic potentials. 

References: 

Engel AG, Franzini-Armstrong C. Myology. 3rd ed. New York: McGraw-Hill, 2004. 

Question 72: Clinical Adult - Neuro-ophthalmology/Neuro-otology 

Discussion: 


24

A lesion of the right upper bank of the calcarine fissure results in a homonymous left inferior quadrantanopsia. 

References: 

Haines DE. Fundamental Neuroscience. 3rd ed. Philadelphia: Churchill Livingstone/Elsevier 2006; 251. 


Discussion: 

When the examiner is testing the biceps strength, the subject's forearm should be held in supination to eliminate 

elbow flexion force produced by the brachioradialis muscle. 

References: 

Haerer AF. Dejong's The neurologic examination. 5th ed. Philadelphia: Lippincott, Williams & Wilkins, 1992. 


Discussion: 

This patient has drug-induced parkinsonism due to use of metoclopramide, a dopamine receptor antagonist. The 

other medications would not produce parkinsonism. 

References: 



Discussion: 

This patient has a cerebral infarct in the distribution of the right anterior cerebral artery. If contrast is 

administered, subacute infarcts commonly enhance, usually with a gyriform pattern. 

References: 

Ropper AH, Brown RH. Adams and Victor's Principles of Neurology. 8th ed. New York: McGraw-Hill, 2005; 

261-264. 

Question 108: Clinical Adult - Demyelinating Disease 

Discussion: 

Based on the history and examination, this patient most likely has optic neuritis. By history, she has had 

multiple episodes of neurological dysfunction separated temporally and anatomically. This patient most likely 

has demyelinating disease. The CSF immunoglobulin G index and oligoclonal bands are typically elevated in 

the CSF of a patient with acute optic neuritis. Sarcoidosis and Lyme disease can also produce optic neuritis but 

are less common in a patient of this age and gender. 

References: 



Discussion: 

The pronator quadratus is responsible for pronation of the forearm when the elbow is flexed. It is supplied by the 

anterior interosseous nerve, a branch of the median nerve. 

References: 


Daube JR, editor. Clinical neurophysiology. Philadelphia: FA Davis, 1996;81-84. 

25


Discussion: 

The daughter of a parent with multiple sclerosis has about a 5% chance of developing the disease. This 

percentage is higher than siblings, with the exception of monozygotic twins. 

References: 

Miller A, Bourdette D, Cohen J, et al. Multiple Sclerosis – Part B. In Miller A, editor. Continuum 1999; 5 (Oct): 

8. 

Question 118: Clinical Adult - Epilepsy 

Discussion: 

Levetiracetam, gabapentin, tiagabine, vigabatrin, zonisamide, and topiramate (

Neurology 2000;54(12):2205-2211. 


Discussion: 

Divalproex sodium is considered an effective prophylactic medication for migraines. Carbamazepine has not 

proven to be as effective and is reserved more for the treatment of painful peripheral neuropathies. The other 

medication choices (naratriptan, naproxen, and cyproheptadine) are used in the acute therapy of migraines. 

References: 

Silberstein S. Practice Parameter: Evidence-based guidelines for migraine headache (an evidence-based review): 

Report of the Quality Standards Subcommittee of the American Academy of Neurology. Neurology 

2000;55:754-762. 

Question 144: Clinical Adult - Neurotoxicology 

Discussion: 

This patient most likely has been exposed to an anticholinesterase toxin in liquid or gas form. The fact that the 

intoxication occurred in a crowded, enclosed, public space suggests terrorism. The clinical findings would be 

different with carbon monoxide, nitrous oxide, methane, or cyanide poisoning. 

References: 

Newmark J. Nerve agents. Neurol Clin 2005; 23(2): 623-641. 


Discussion: 

Paroxysmal hemicrania is a disorder, more common in women, characterized by frequent (7 to 22 per day) 

episodes of unilateral, severe, but short-lasting (5 to 45 minutes) headaches associated with ipsilateral 

autonomic manifestations. Indomethacin is the treatment of choice. 

References: 

Goadsby PJ, Lipton RB. A review of paroxysmal hemicranias, SUNCT syndrome and other short-lasting 

headaches with autonomic features, including new cases. Brain 1997;120:193-209. 

Question 161: Clinical Adult - Neuro-oncology 

Discussion: 

A seizure with postictal hemiparesis in a patient with known cancer should be presumed to be related to brain 

metastases until proven otherwise. Paraneoplastic limbic encephalitis would be much less likely, and 

hypertensive encephalopathy, hypoglycemia, and hyponatremia would be unlikely to produce focal deficits. 

Moreover, the patient does not have severe enough hypertension, hypoglycemia, or hyponatremia to produce a 

seizure. 

References: 


Question 163: Clinical Adult - Epilepsy 

Discussion: 

This is a single unprovoked generalized seizure in a patient with a normal neurological examination and a 

normal evaluation. The etiology is likely idiopathic, and his risk for recurrent seizure is low (about 30% over the 

next 5 years); therefore, observation is warranted. 

References: 


27

Sirven J. Antiepileptic Drug Therapy for Adults: When to Initiate and How to Choose. Mayo Clinic Proceedings 

2002; 77(12):1367-1375. 

Marson A, Jacoby A, Johnson A, et al. Medical Research Council MESS Study Group. Immediate versus 

deferred antiepileptic drug treatment for early epilepsy and single seizures: a randomized controlled trial. Lancet 

2005; 365 (9476):2007- 2013. 

Question 169: Clinical Adult - Neuro-oncology 

Discussion: 

This patient has Foster-Kennedy syndrome. Unilateral anosmia and optic neuropathy in conjunction with signs 

of raised ICP (papilledema in the opposite eye) are the clinical features of this disorder, which is most 

commonly due to a planum sphenoidale meningioma that could involve both the olfactory groove and optic 

canal. The other disorders listed would not typically have this constellation of signs and symptoms. 

References: 

Demetriades AK. Victor Horsley's contribution to the Foster Kennedy syndrome. Brit J Neurosurg 

2004;18(4):371-374. 


Discussion: 

Saddle anesthesia, sphincter loss, and loss of ankle reflexes after a fall signify midline disk herniation with 

compression of the caudal equina. 

References: 



Discussion: 

This patient has a history of migraine, a straightforward current history, and a normal neurological examination. 

No features suggest elevated ICP or meningeal irritation. No testing is necessary in this setting. 

References: 

Edmeads J. Migraine. In: Noseworthy JH, editor. Neurologic therapeutics: principles and practice. New York: 

Martin Dunitz, 2003;73-88. 


Discussion: 

This patient most likely has a vertebral dissection. This disorder is more common is women. It often follows 

neck trauma. When occurring spontaneously, it is often associated with a disorder of connective tissue, such as 

fibromuscular dysplasia. The other disorders listed (disseminated intravascular coagulation, factor V Leiden 

mutation, patent foramen ovale, and vasculitis) are less likely, particularly in view of the associated neck pain. 

References: 


Question 176: Clinical Adult - Other Pain Syndromes 

Discussion: 


Allodynia is the perception of a non-noxious stimulus as being painful. This is an associated feature common in 

neuropathic pain. Incident pain refers to pain that occurs with movement rather than with touch. Paresthesia 

28

efers to an abnormal spontaneous sensation that has no objective cause. 

References: 

Kanner R. Pain management secrets. Philadelphia: Hanley and Belfus, 1997;2. 

Question 182: Clinical Adult - Critical Care/Trauma 

Discussion: 

Practice guidelines have been established for concussion in sports through the AAN. This athlete has 

experienced one Grade II concussion (no loss of consciousness but concussion symptoms greater than 15 

minutes) and a more recent Grade III concussion(any loss of consciousness). Guidelines state he should be out 

of play for 1 week in this setting of recurrent concussion. 

References: 

Practice Parameter: Managing Concussion in Sports. Report of the Quality Standards Subcommittee. Neurology 

1997;48:581-585. 


Discussion: 

Patients with transverse myelitis are at risk, but may not necessarily develop, multiple sclerosis. Presence of a 

partial rather than complete myelitis gives a higher risk for progression to multiple sclerosis. The presence of 

subclinical evidence of demyelination on brain imaging at the time of initial event is the strongest predictor of 

subsequent demyelinating disease. Multiple sclerosis remains a clinical diagnosis, and exclusion of other genetic 

or autoimmune mimics is important. 

References: 

Lublin F, Tullman M, editors. Multiple Sclerosis. Continuum: Lifelong Learning in Neurol 2004; 10(6). 


Discussion: 

Diazepam is the mainstay of treatment for the stiff person syndrome, which occurs about as often in women as 

in men. Onset in adult life, proximal distribution of stiffness, development of lordosis, and precipitation by 

motion or emotion are typical. Diabetes and organ-specific autoimmune disorders are common. Seizures 

sometimes occur. 

References: 



Discussion: 

This patient has Anton's syndrome (denial of blindness). It is a result of severe acute bilateral injury to the 

medial occipital lobes and adjacent association cortex, usually due to ischemia in the distribution of the 

posterior cerebral arteries. The syndrome has also occured after traumatic injury to the optic nerve with 

associated bifrontal lobe contusions. 

References: 


McDaniel KD, McDaniel LD. Anton's syndrome in a patient with posttraumatic optic neuropathy and bifrontal 

contusions. Arch Neurol 1991;48 (1):101-105. 



29


Discussion: 

After an episode of optic neuritis, the best predictor for subsequent MS is an abnormal MRI of the brain. CSF 

findings do not add to the prognostic information available from brain MRI data. 

References: 

Jacobson D. Optic neuritis. In: Samuels MA, Feske SK, editors. Office Practice of Neurology. Philadelphia: 

Churchill-Livingstone, 2003; 416-420. 


Discussion: 

Mitoxantrone is USFDA-approved for the treatment of secondary progressive multiple sclerosis and for 

relapsing-progressive multiple sclerosis. The other treatments have no proven benefit for these stages of multiple 

sclerosis. 

References: 

AAN Clinical Practice Guidelines. The use of mitoxantrone (Novantrone) in the treatment of multiple sclerosis. 

Neurol 2003; 61: 1332-1338. 

Questions 204 - 208: Clinical Adult - Epilepsy 

Discussion: 

Choice of anticonvulsant therapy is based upon effectiveness of each drug in the reduction of specific seizure 

types (ie, generalized vs complex partial vs absence) and also least risk of side effects. Lamotrigine has recently 

been given a pregnancy category C rating, making it the safest selection for patients with refractory epilepsy in 

pregnancy, providing the seizure frequency is a greater risk to the pregnancy and medication risk. Valproic acid 

has a particular efficacy in absence seizures and juvenile myoclonic epilepsy. It also has the least risk of skin 

hypersensitivity. Levetriacetam is considered the safest in the setting of liver disease. Phenobarbital is used in 

the acute treatment of neonatal seizures. Carbamazepine is the initial monotherapy for a child with cryptogenic 

complex partial seizures. 

References: 

Asconape J. Some common issues in the use of antiepileptic drugs. Semin Neurol 2002;22:27-40. 

Wheless JW, Clarke DF, Carpenter D. Treatment of pediatric epilepsy: expert opinion. J Child Neurol 2005; 20 

(Suppl 1): S1-S56. 

Questions 219 - 223: Clinical Adult - Dementia 

Discussion: 

A subacute encephalopathy with multiple-enhancing MRI lesions and a high antinuclear antibody titer are 

consistent with lupus cerebritis. Creutzfeldt-Jakob disease is a prion disorder that can present subacutely with a 

syndrome of rapidly progressive dementia, ataxia, and stimulus-sensitive myoclonus. Joint laxity, ectopic lens, 

and aortic dissection can be seen as a complication of Marfan syndrome, which also carries a typical phenotype 

of tall stature and long arms. CADASIL is a genetic syndrome producing an arteriopathy that can present with 

migraine, dementia, and characteristic white matter infarcts on MRI imaging. Vascular dementia is 

distinguished from Alzheimer-type dementia primarily by stepwise decline in cognitive function. 

References: 

Gallagher C. Neurogenetics Review. Hospital Physician 2005;9(1):1-16. 


Discussion: 


30

This patient most likely has orthostatic headache secondary to spontaneous intracranial hypotension. The usual 

etiology is a CSF leak located in the spinal meninges. The leak is most readily identified with a myelogram. The 

other tests listed (meningeal biopsy, serum angiotensin converting enzyme, slit lamp examination, and CSF 

cytology) would not assist in the diagnosis of this syndrome. 

References: 

Schievink WI. Spontaneous spinal cerebrospinal fluid leaks and intracranial hypotension. JAMA 2006; 

295(19):2286-2296. 


Discussion: 

The clinical history and examination are most consistent with Lambert-Eaton myasthenic syndrome, which is 

associated with malignancy (usually small cell lung cancer) in two thirds of patients. 

References: 


Question 335: Clinical Adult - Infectious Disease 

Discussion: 

This patient most likely has cerebral malaria, which is due to sludging of infected erythrocytes in the cerebral 

capillaries. The CSF examination is not consistent with viral encephalitis nor has she been in a geographic area 

in which Japanese encephalitis is endemic. A Giemsa-stained peripheral blood smear will demonstrate the 

malaria parasite. 

References: 



Discussion: 

This patient has arteritic acute ischemic optic neuropathy, in which the findings are typically a swollen disc and 

retinal pallor. The mechanism is likely to be giant cell arteritis based on his clinical history. 

References: 



Discussion: 

This patient has pseudotumor cerebri, which has been linked to use of isotretinoin and other vitamin 

A–containing compounds. The other medications listed should not cause pseudotumor cerebri. 

References: 

Wall M. Papilledema and idiopathic intracranial hypertension (pseudotumor cerebri). In: Noseworthy JH, editor. 

Neurologic therapeutics: principles and practice. New York: Martin Dunitz, 2003;1730-1742. 


Discussion: 


This patients has symptoms and signs consistent with Guillain-Barre syndrome (GBS). IV immunoglobulin is 

recommended for GBS in nonambulant patients within 2 to 4 weeks of onset of neuropathic symptoms. 

31

References: 



Neurology 2000;54(12):2205-2211. 


Discussion: 

This patient has medication overuse headache related to daily use of an acetaminophen/caffeine/butalbital 

medication. Although the other interventions might help her headache problem, they would be less likely to do 

so than tapering the medication. 

References: 

Boes CJ, Black DF, Dodick DW. Pathophysiology and management of transformed migraine and medication 

overuse headache. Seminars in Neurology 2006;26(2):232-241. 


Discussion: 

In patients with Lewy body dementia, severe akinesia, dystonias, and neuroleptic malignant syndrome are 

common reactions to even very low doses of the older, typical antipsychotics. 

References: 

Ballard C, Grace J, McKeith I, et al. Neuroleptic sensitivity in dementia with Lewy bodies and Alzheimer's 

disease. Lancet 1998;351:1032-1033. 


Discussion: 

Disturbance of the S1 nerve root results in pain radiating down the posterior aspect of the lower extremity, 

sensory disturbance of the little toe, lateral foot, and most of the sole of the foot, weakness in several muscles 

including the gastrocnemius and soleus muscles, and reduction or absence of the ankle jerk. 

References: 



Question 387: Clinical Adult - Neurogenetics 

Discussion: 

This patient most likely has Duchenne's muscular dystrophy, which is characterized by X-linked recessive 

inheritance and a mutation of the dystrophin gene located on Xp21.2 

References: 


Question 398: Clinical Adult - Sleep 

Discussion: 


This patient most likely has restless legs syndrome. Medications that are most helpful for this disorder are 

dopamine agonists, opioids, and gabapentin. Dopaminergic agents (including pramipexole, ropinarole, and 

carbidopa-levadopa) usually work best with fewest side effects. Opioids are not the preferred agents, as they 

may produce drug dependency and tolerance, requiring dose escalation to maintain drug effect. 

32

References: 


Question 403: Clinical Adult - Neurology of Systemic Disease 

Discussion: 

The most common neurological complication of scleroderma is carpal tunnel syndrome. 

References: 

Rolak LA. Neurological complications of progressive systemic sclerosis. In: Noseworthy J, editor. Neurological 

therapeutics. London: Martin Dunitz, 2003. 

Question 406: Clinical Adult - Infectious Disease 

Discussion: 

This is a case of progressive multifocal leukoencephalopathy (PML), caused by the JC virus. Highly active 

antiretroviral therapy (HAART) is the only proven treatment of HIV-associated PML. Pyrimethamine is used to 

treat toxoplasmosis. Amphotericin B is an antifungal agent. The other drugs (AraC and interferon alpha) are not 

effective for HIV-associated PML. 

References: 

AAN Clinical Practice Guidelines. Evaluation and Management of Intracranial Mass Lesions in AIDS. Neurol 

1998; 50: 21-26. 

Question 410: Clinical Adult - Dementia 

Discussion: 

The patient has many clinical features consistent with a frontal dementia. The trails B test is a measure of 

executive function. It assesses sustained attention, visual scanning, and the ability to change sets (inhibit certain 

stimuli while facilitating others). It is a timed task, so speed of performance is also important. Finger tapping 

assesses motor speed. The Wechsler Memory Scale and California Verbal Learning Test assess memory. The 

Boston Naming Test evaluates language. 

References: 

Bartleson JD, Schierman B, Edlund W, editors. Summaries of AAN Clinical Practice Guidelines for Adult 

Neurology: Neuropsychological Testing. 2006-2006 ed. American Academy of Neurology 

Feinberg TE, Farah MJ. Behavioral neurology and neuropsychology. 2nd ed. New York: McGraw-Hill, 2003. 


Discussion: 

Adrenoleukodystrophy is an X-linked disorder characterized by defective beta oxidation and accumulations of 

very-long chain fatty acids. This metabolic defect is detectable in heterozygotes and prenatally. The adult-onset 

phenotype (progressive spastic paraparesis) is called adrenomyeloneuropathy. 

References: 

Moser HW, Raymond GV, Dubey P. Adrenoleukodystrophy: new approaches to a neurodegenerative disease. 

JAMA 2005;294(24):3131-3134. 

Question 424: Clinical Adult - Neurorehabilitation 

Discussion: 


Although the pattern of recovery following a stroke may be variable, the earliest evidence of a return of 

33

neurological function is usually an increase in tone. This generally occurs before improvement in strength or a 

return of reflexes. 

References: 

DeLisa JA, Gans BM. Rehabilitation medicine: Principles in Practice. 2nd ed. Philadelphia: Lippincott, 

1993;458. 


Discussion: 

This represents a Brown-Sequard syndrome with ipsilateral vibration/position sense involvement and 

contralateral pain/temperature abnormality below the level of the lesion. 

References: 

Haines DE, editor. Fundamental Neuroscience. 3rd ed. Philadelphia: Churchill Livingstone,2006;156. 

Question 428: Clinical Adult - Neurogenetics 

Discussion: 

Examples of X-linked inheritance include Duchenne/Becker muscular dystrophy, Kennedy’s disease, fragile X 

syndrome, adrenoleukodystrophy, and Fabry lipid storage disease. Characteristics of X-linked inheritance 

include that males are almost exclusively affected but symptomatic female carriers can have a mild phenotype as 

seen in Duchenne dystrophy. Transmission occurs through carrier females to their sons, each of whom have a 

50% chance of being affected. Daughters of affected males are obligate carriers, and male-to-male transmission 

does not occur. 

References: 

Gallagher C. Neurology Board Review Manual: Neurogenetic Review. Hospital Physician 2005; Vol 9: Part 1. 

Souayah N, Khella S. Neurology Examination and Board Review. New York:McGraw-Hill, 2005;221-230. 

Question 432: Clinical Adult - Neuro-ophthalmology/Neuro-otology 

Discussion: 

The history and examination is most consistent with benign positional vertigo. The other disorders listed would 

be associated with additional neurological deficits and/or the vertigo would be less likely to be associated with 

positional changes. 

References: 


Ropper AH, Brown RH. Adams and Victor's Principles of Neurology. 8th ed. New York: McGraw-Hill, 2005; 

261-264. 

Question 438: Clinical Adult - Motor Neuron/Nerve 

Discussion: 

This patient most likely has motor neuron disease, characterized by a mixture of upper and lower motor neuron 

signs in all four limbs. Cervical spinal stenosis could also produce painless four-limb weakness with upper motor 

neuron signs in the legs. Fasciculations and wasting in the lower extremities are not symptoms of cervical 

stenosis as they imply a disorder of the lower motor neuron at the lumbosacral level. Although patients with 

cervical stenosis may have spine and radicular pain, this is not always the case, and the absence of pain does not 

exclude cervical stenosis as a diagnosis. 

References: 



34



Discussion: 

A levodopa or apomorphine challenge should be considered when the diagnosis of Parkinson’s disease is in 

doubt. The other tests listed (olfaction, repeat MRI, PET, and autonomic testing) are not clinically useful in 

distinguishing Parkinson’s disease from other parkinsonian syndromes based upon insufficient evidence from 

clinical studies. 

References: 

AAN Clinical Practice Guidelines. Diagnosis and Prognosis of New Onset Parkinson Disease. Neurol 

2006;66:968-975. 


Discussion: 

This patient has suffered a transient ischemic event most likely related to either intracranial or extracranial 

atheromatous disease. There is no evidence to suggest a cardiac embolic source. The most appropriate therapy at 

this time is an antiplatelet agent. There is no advantage of clopidogrel over aspirin. Aspirin is less expensive. 

There is no role in this case for either anticoagulation or tissue plasminogen activase (tPA). 

References: 


Clinical Pediatrics 

Question 8: Clinical Pediatrics - Headache 

Discussion: 

The most important determinant of the differential between pseudotumor cerebri and chronic daily headache is 

the presence of papilledema, which mandates additional testing, including measurement of CSF pressure. 

References: 

Silberstein SD. Wolff's headache. In: Silberstein SD, Lipton RB, Dalessio DJ, editors. Wolff's headache and 

other head pain. 7th ed. New York: Oxford University Press, 2001. 

Question 13: Clinical Pediatrics - Heritable Metabolic or Degenerative 

Discussion: 

Maple syrup urine disease (MSUD) is due to a congenital inability to decarboxylate leucine, isoleucine, and 

valine. There is an associated severe metabolic acidosis and hypoglycemia. Infants with MSUD develop poor 

feeding and lethargy progressing to coma during the first week or two of life; examination reveals fluctuating 

hypertonicity and opisthotonus. Blood pH and CO2 are typically normal in the aminoacidopathies (such as 

phenylketonuria and homocystinuria), galactosemia, and urea cycle defects. Plasma ammonia is elevated in the 

urea cycle disorders. 

References: 

Swaiman KF, Ashwal S, Ferriero DM. Pediatric neurology: principles and practice. 4th ed. Philadephia: Mosby, 

2006. 

Question 22: Clinical Pediatrics - Learning/Language Disorders 

Discussion: 


35

This child has tuberous sclerosis complex, an autosomal dominant disorder associated with mutations in the 

tuberin and merlin genes. Intellectual outcome is best correlated with seizure control. 

References: 

Gomez MR, Sampson J, Whittemore V, editors. Tuberous sclerosis complex. 3rd ed. New York: Oxford 

University Press, 1999. 

Curatolo P, Verdecchia M, Bombardieri R. Vigabatrin for tuberous sclerosis complex. Brain Dev 

2001;23(7):649-653. 


Discussion: 

Migraines are more likely to be frontal than unilateral in children. Photophobia and other criteria can be inferred 

by the parents' observations, such as pulling curtains. Ibuprofen has been demonstrated efficacious in children; 

to date oral triptans have not. 

References: 

AAN Practice parameter: Pharmacological treatment of migraine headaches in children and adolescents. 

Neurology 2004;63;2215-2224. 

Question 44: Clinical Pediatrics - Learning/Language Disorders 

Discussion: 

Asperger syndrome is classified with the autistic spectrum disorders (pervasive developmental disorders). It 

shares the features of autistic disorder except that language is spared. Children with Asperger syndrome are often 

referred to as "little professors" owing to their extensive knowledge of very restricted fields of interest. 

References: 

American Psychiatric Association. Diagnostic and statistical manual of mental disorders (DSM IV-TR). 4th ed. 


Question 59: Clinical Pediatrics - Disturbances of Consciousness 

Discussion: 

The Presidents Commission recommeded 100% oxygen ventilation for 10 minutes, followed by passive 100% 

oxygen for a period long enough to achive a PCO2 of 60. The other tests have high incidence of false-negative 

results. 

References: 


2006. 

Question 66: Clinical Pediatrics - Motor Neuron/Neuromuscular 

Discussion: 

Examination of the affected infant is extremely nonspecific. Infants with congenital myotonic dystrophy present 

with a variety of findings in the newborn period, including hypotonia, contractures, poor suck, respiratory 

distress, cardiac arrhythmias, but not characteristic facies or myotonia seen later. Examination of the mother is 

much more likely to reveal the typical facial features and mild weakness of eye closure and neck flexors of 

myotonic dystrophy. DNA testing is definitive, but clinical diagnosis is usually possible with examination of 

mother, not infant. 

References: 



36


2006. 

Question 81: Clinical Pediatrics - Neurosurgery 

Discussion: 

At birth the median head circumference of a normal term infant is 35 cm. A head circumference of 45 cm is 

greater than the 98th percentile. In the absence of other cerebral malformations, congenital aqueductal stenosis is 

the most common cause of noncommunicating hydrocephalus. A familial X-linked form accounts for 2% of 

these. Increased intracranial pressure in the context of hypoxic-ischemic encephalopathy does not cause 

increased head circumference at birth. Klippel-Feil syndrome (fusion of the cervical vertebra) may be associated 

with Chiari malformation but is a much less common cause of hydrocephalus. Choroid plexus papillomas are 

typically located in one lateral ventricle and become symptomatic after the perinatal period, usually by 

obstructing ventricular outflow. Lissencephaly is typically associated with microcephaly. 

References: 



Question 90: Clinical Pediatrics - Behavioral/Psychiatric 

Discussion: 

Tourette syndrome is a disorder including motor tics over a year and vocal tics and is often associated with 

attention deficit hyperactivity disorder and/or obsessive-compulsive disorder. Coprolalia is rare and typically 

occurs in adolescence or later. 

References: 


2006. 

American Psychiatric Association. Diagnostic and statistical manual of mental disorders (DSM IV-TR). 4th ed. 


Question 120: Clinical Pediatrics - Tumors 

Discussion: 

Optic gliomas are the most common CNS tumor for children with neurofibromatosis type 1, but other cranial 

nerves can be affected by neurofibromas or schwannomas. Astrocytomas, meningiomas, medulloblastomas, 

ependymomas, and hamartomas also occur with increased frequency in patients with neurofibromatosis type 1. 

References: 

Berg BO, editor. Principles of child neurology. New York: McGraw-Hill, 1996. 


Discussion: 

The patient has the typical history and findings of subacute or acute onset of descending paralysis involving 

cranial nerves, neck, and shoulder girdle characteristic of infant botulism. Sluggish or fatiguable pupils are a 

characteristic finding of botulism. Nonketotic hyperglycinemia would not usually have a descending paralysis, 

nor would pupils be sluggish. Spinal muscular atrophy would likely have proximal weakness but rarely has 

ptosis and never has pupillary involvement. Myotonic discharges are not usually seen in infants, even with 

myotonic dystrophy. The clinical picture is not one of myotonic dystrophy. The child described has findings 

suggesting peripheral weakness, not central. 

References: 


37

Thompson JA, Filloux FM, Van Orman CB, et al. Infant botulism in the age of botulism immune globulin. 

Neurology 2005; 64:2029-2032. 


Discussion: 

The patient has the typical history and findings of subacute or acute onset of descending paralysis involving 

cranial nerves, neck, and shoulder girdle characteristic of infant botulism. Sluggish or fatiguable pupils are a 

characteristic finding of botulism. Human botulism immunoglobulin has been shown to significantly shorten the 

course of the condition. Broad-spectrum antibiotics may acutely worsen weakness. 

References: 

Thompson JA, Filloux FM, Van Orman CB, et al. Infant botulism in the age of botulism immune globulin. 

Neurology 2005; 64:2029-2032. 

Question 138: Clinical Pediatrics - Developmental Disorders 

Discussion: 

Lack of appropriate representative play in a young child presenting with developmental delay strongly suggests a 

diagnosis of autism. 

References: 


2006. 

Question 142: Clinical Pediatrics - Behavioral/Psychiatric 

Discussion: 

Masturbation is common in infancy and early childhood and often not recognized. It does not require 

intervention or futher testing. Videotapes of episodes by parents are often most helpful in establishing the 

diagnosis. 

References: 

Yang ML, Fullwood E, Goldstein J, Mink J. Masturbation in infancy and early childhood presenting as a 

movement disorder: 12 cases and a review of the literature. Pediatrics 2005;116:1427-1432. 

Question 175: Clinical Pediatrics - Epilepsy 

Discussion: 

Benign focal epilepsy of childhood with centrotemporal sharp waves presents from 2 to 13 years of age. About 

20% of patients only have one seizure and in two thirds of the cases seizures are infrequent. Children with this 

disorder are neurologically normal and the majority of patients outgrow the disorder. Carbemazepine is the 

treatment of choice if treatment is necessary. 

References: 

Wyllie, E. The treatment of epilepsy, principles and practice. 3rd ed. Philadelphia: Lippincott, Williams & 


Question 177: Clinical Pediatrics - Heritable Metabolic or Degenerative 

Discussion: 

Metachromatic leukodystrophy has striking peripheral neuropathy. Rett's syndrome has microcephaly. 

Alexander, Canavan, and Tay-Sachs diseases have megaloencephaly and hyperreflexia. 

References: 


38


2006. 

Question 183: Clinical Pediatrics - Critical Care/Trauma 

Discussion: 

Appropriate therapies for refractory status epilepticus include phenobarbital, pentobarbital, or benzodiazepine 

drips. The correct dose for phenobarbital loading is 20mg/kg. If a second dose of fosphenytoin is given after a 

20mg/kg load, it is generally limited to an additional 5 mg/kg. Midazolam and pentobarbital doses are incorrect 

in the options. They should be: midazolam 0.2 mg/kg slow IV bolus followed by 0.75 micrograms/kg/min to 10 

micrograms/kg/min IV drip; pentobarbital 5 mg/kg to 15 mg/kg IV bolus over 1 hour followed by 0.5 mg/kg/h 

to 3.0 mg/kg/h IV drip. Ventilatory assistance is usually necessary, as are vasopressors. Continuous EEG 

monitoring is ideal. 

References: 



Question 184: Clinical Pediatrics - Movement Disorders 

Discussion: 

The basal globus pallidus lesions produce an "eye of the tiger" on MRI, seen with pantothenate kinase 

deficiency (PKAN). The globus pallidus lesions are from iron deposition. Huntington's disease produces caudate 

atrophy, Niemann-Pick disease may have dystonia and rigidity but does not produce isolated globus pallidus 

lesions. Idiopathic torsion dystonia and Sandifer's syndrome have normal MRI. PKAN is no longer called 

Hallervorden-Spatz disease because of Hallervorden's role in Nazi genocide. 

References: 


2006. 


Discussion: 

The majority of children with recurrent headaches with complete clearing between episodes do not need 

neuroimaging. The following would mandate neuroimaging in a child presenting with headaches: auras lasting 

more than an hour, persistent neurological findings, abnormal neurological examination between headaches, 

predominantly occipital headaches, loss of vision at headache peak, or recent significant change in headache 

pattern. 

References: 



Question 201: Clinical Pediatrics - Vascular Disorders 

Discussion: 

Moyamoya syndrome can be primary genetic or secondary to various conditions, including radiation therapy 

involving the circle of Willis, sickle cell disease, neurofibromatosis, and Down syndrome. Primary moyamoya 

syndrome is more frequent in persons of Asian descent. 

References: 



2006. 

39

Questions 214 - 218: Clinical Pediatrics - Infectious Disease 

Discussion: 

The most common cause of early neonatal sepsis and meningitis is group B beta-hemolytic streptococcus. 

Tuberculous meningitis presents insidiously, then in later stages causes severe basilar meningitis, strokes due to 

involvement of basilar vessels, and hydrocephalus. It is poorly reversible at this stage. Young adults living in 

dormitories or barracks are at risk for meningococcal disease. A newborn with microcephaly, organ 

involvement, and subependymal calcifications most likely has congenital Cytomegalovirus, although other 

congenital infections may occasionally mimic this. A child from a hilly region in the Upper Midwest presenting 

during the late summer with fever, headache, stiff neck, and focal seizures has La Crosse encephalitis. 

References: 


2006. 


Discussion: 

Aicardi syndrome is an X-linked dominant syndrome, presumed lethal in males, with agenesis of corpus 

callosum, retinal lacunae, development disabilities, and frequently associated with infantile spasms. 

References: 


2006. 


Discussion: 

The lesion is typical of the acute inflammatory phase of neurocysticercosis. In the United States, most children 

with cysticercosis live in households with recent immigrants, but many are lifelong US residents. Most 

neurocysticercosis lesions will regress without treatment. Anticonvulsants are needed for several months, but 

only about 25% ultimately have chronic epilepsy requiring ongoing treatment. CT is generally adequate for 

diagnosis. Nearly all single lesion neurocysticercosis resolves spontaneously in 3 to 6 months. 

References: 

Ong S, Talan DA, Moran GJ, et al. Neurocysticercosis in radiologically imaged seizure patients in U.S. 

emergency departments. Emerg Infect Dis 2002;8:608-613. 


Discussion: 

The seizure pattern described is one of benign rolandic epilepsy, for which the EEG signature is 

central-temporal spikes, particularly in sleep, often bilateral independent. 

References: 


2006. 

Question 345: Clinical Pediatrics - Neonatal 

Discussion: 


MRI and, when available, diffusion-weighted imaging and magnetic resonance spectroscopy gives the most 

information on outcome of a newborn with persistent low Apgar scores and neurological complications. 

40

References: 

Ment LR, Bada HS, Barnes P, et al. Practice parameter: Neuroimaging of the neonate. Neurology 

2002;58:1726-1738. 


Discussion: 

The drop in hematocrit may indicate an intracranial bleed. Compared to MRI, a CT scan without contrast is 

safest and will detect most bleeds. EEG is not indicated, and contrast will add little and may pose a risk because 

of age and systemic illness. 

References: 

Ment LR, Bada HS, Barnes P, et al. Practice parameter: Neuroimaging of the neonate. Neurology 

2002;58:1726-1738. 

Question 350: Clinical Pediatrics - Movement Disorders 

Discussion: 

Clusters of head drops with flexor spasms of the trunk occuring around meal time in an otherwise healthy 

7-month-old with a normal EEG suggest benign myoclonus of infancy. The normal EEG effectively rules out 

infantile spasms. Benign occipital epilepsy of childhood, Lafora body disease, and Tourette syndrome occur in 

older children. 

References: 



Question 366: Clinical Pediatrics - Inflammatory Disease 

Discussion: 

Fever is present in 90% of children with systemic lupus erythematosus, and about the same number have joint 

involvement. It is more common in African Americans than whites or Hispanics. Seizures and cranial 

neuropathies are common presenting features. Acute encephalopathy is less common and is life-threatening. 

Sickle cell disease usually presents at a younger age. Lyme disease rarely causes seizures or confusion and has a 

different rash. MELAS and moyamoya syndrome ususally present with isolated infartions or transient ischemic 

attacks and do not have systemic symptoms. 

References: 



Question 382: Clinical Pediatrics - Spine 

Discussion: 

Hallmarks of Friedreich's ataxia are a combination of weakness, ataxia, absent tendon jerks, Babinski sign, and 

abnormal position sense. Romberg sign is the best indication of loss of position sense, not cerebellar 

functioning. Hammer toes, pes cavus deformities, and scoliosis are frequent findings. 

References: 


2006. 



41

Discussion: 

Neonatal seizures usually have a serious underlying reason. Treatable causes need to be recognized since delay 

in treatment can aggrevate serious neurological comprimise. Group B Streptococcus is the most common cause 

of bacterial meningitis/septicemia in the neonate and has about a 25% mortality rate; of the survivors, about 

20% will have severe deficits. If seizures in the neonate are secondary to subarachnoid hemorrhage, there 

usually is a good outcome. Benign epileptic syndromes and electrolyte disturbances (hypocalcemia or 

hypomagnesemia) in the newborn can generally present by the end of the first week, but infants are not febrile. 

References: 

Volpe JJ. Neurology of the newborn. 4th ed. Philadelphia: WB Saunders, 2001. 

Question 386: Clinical Pediatrics - Vascular Disorders 

Discussion: 

Cerebrovascular disease occurs in 25% of sickle cell disease. Eighty percent of events occur at or before age 15, 

and most are caused by a progressive cerebral vasculopathy that can be partially arrested by chronic transfusion 

therapy to keep hemoglobin S below 30%. Most events are thrombotic. 

References: 


2006. 


Discussion: 

Lead poisoning typically presents in young children living in substandard housing with peeling paint. However, 

children living in environments where paint is being removed or scraped may be at risk, even in upper-income 

environments. The other toxins, which are sometimes ingested by toddlers, do not present with increased 

intracranial pressure. 

References: 

Nordin J, Rolnick S, Ehlinger E, et al. Lead Levels in High-risk and Low-risk Young Children in the 

Minneapolis-St Paul Metropolitan Area. Pediatrics 1998;101:72-76. 


Discussion: 

Cerebral palsy is nonprogressive disease, and the study with the highest yield is MRI. The proper diagnosis of 

cerebral palsy excludes progressive or degenerative disorders. If the MRI is normal or nondiagnostic, further 

tests could be ordered. An EEG should be obtained only with a positive history of seizurelike events. 

References: 

Ashwal S, Russman B, Blasco P, et al. Practice Parameter: Diagnostic assessment of the child with cerebral 

palsy: Report of the Quality Standards Subcommittee of the American Academy of Neurology. Neurology 

2004;62;851-863. 


Discussion: 

Caffeine withdrawal is a common cause of acute severe headache in migraineurs. Vitamins D or A can cause 

pseudotumor cerebri, but onset is not abrupt. B vitamins are not associated with exacerbation of migraine. 

References: 



42



Discussion: 

This is a classic presentation of benign paroxysmal vertigo, a syndrome that occurs in children in the first 5 

years of life and is a frequent precursor of migraine. Investigations (MRI, EEG) are normal. The episodes 

usually resolve by the end of the first decade. 

References: 




Discussion: 

The 12-year-old boy has a characteristic history for juvenile myoclonic epilepsy with early-morning myoclonic 

and generalized tonic-clonic seizures, beginning in the second decade of life. Absence seizures may also occur. 

The EEG reveals generalized, fast (4 Hz to 6 Hz) spike-and-wave complexes. Valproic acid is the treatment of 

choice and recurrence of seizures is likely to occur if treatment is stopped. 

References: 

Menkes JH, Sarnat HB. Textbook of child neurology. 6th ed. Philadelphia: Lippincott, Williams & Wilkins, 

2000. 


Discussion: 

This 12-year-old boy has a characteristic history for juvenile myoclonic epilepsy with early-morning myoclonic 

and generalized tonic clonic seizures, beginning in the second decade of life. Absence seizures may also occur. 

The EEG reveals generalized, fast (4 Hz to 6 Hz) spike-and-wave complexes. Valproic acid is the treatment of 

choice and recurrence of seizures is likely to occur if treatment is stopped. 

References: 

Menkes JH, Sarnat HB. Textbook of child neurology. 6th ed. Philadelphia: Lippincott, Williams & Wilkins, 

2000. 


Discussion: 

Breath-holding spells occur in infants, usually triggered by sudden pain or frustration. Consciousness is lost 

prior to variable brief clonic jerking. These are common and occur in up to 5% of infants. 

References: 

Stephenson JPB. Fits and Faints. Philadelphia: JB Lippincott Co., 1990. 


Discussion: 

This is a typical presentation for infantile spasms. Adrenocorticotropic hormone (ACTH) is an accepted 

treatment. Colic or reflux are often mistaken for infantile spasms, although flexor spasms are not at all typical 

for reflux. Phenobarbital has not been shown effective in treatment and may worsen the disorder. 

References: 


43



Practice parameter: Medical treatment of infantile spasms: Report of the American Academy of Neurology and 

the Child Neurology Society. Neurology 2004;62:1668-1681. 


Discussion: 

The congenital myasthenic syndromes are not related to an immune process but are caused by genetic defects 

affecting the neuromuscular junction. These include defects in acetylcholine synthesis and packaging (familial 

infantile myasthenia gravis), end-plate deficiency of acetylcholinesterase, acetylcholine receptor deficiency, and 

the slow channel syndrome. 

References: 

Dubowitz V. Muscle disorders in childhood. Philadelphia: WB Saunders, 1995. 


Discussion: 

The child's presentation (opsoclonus, myoclonus, ataxia syndrome, alternatively called "OMS", "dancing eyes 

syndrome" or Kinsbourne's Syndrome) is most often a paraneoplastic manifestation of occult neuroblastoma in 

this age group. The most common initial misdiagnosis is acute cerebellar ataxia of childhood, a benign 

condition. The most helpful test in determining etiology of suspected OMS is CT of the chest, abdomen, and 

pelvis using oral contrast and fine cut images. 

References: 

Mitchell WG, Davalos-Gonzales Y, Brumm V, et al. Opsoclonus-ataxia caused by childhood neuroblastoma: 

Developmental and neurological sequelae. Pediatrics, 2002;109:86-98. 

Contemporary Issues 

Question 6: Contemporary Issues - Ethics 

Discussion: 

Physicians and other health care professionals must report suspected cases of child abuse. It is not the 

physician's obligation to prove the abuse, and testing to rule out other etiologies should not postpone reporting. 

Glutaric aciduria, Menkes disease, and hemophilia may present with intracranial or subdural bleeding but are 

less likely in this circumstance. Retinal hemorrhages are unusual in these conditions, however. Physicians are 

protected from liability for reporting in good faith, even if the allegation is ultimately not supported. 

References: 


2006. 


Discussion: 


Requests to lie to patients about their diagnoses arise from time to time. Some are based on the patient and 

family's cultural traditions, and some are based on fear of consequences. In this case, the son's request is based 

on fear of depression and is not a sufficient justification to lie to the patient. Telling the patient her son asked that 

her diagnosis should be withheld inappropriately undermines trust between the physician and the son, and 

between the son and his mother. To honor the son's request while later telling the patient her diagnosis by 

telephone consitutes lying to the son and is inappropriate. The AAN Code of Professional Conduct recommends 

telling the truth to patients who have decision-making capacity. AAN guidelines on humanistic dimension of 

44

professionalism in the practice of neurology state that neurologists have a role in helping patients and families 

overcome their fears of neurological disorders. Truth-telling allows patients with probable Alzheimer's disease 

to seek appropriate treatment and to make arrangements for their treatment preferences (eg, end-of-life care 

planning) and to select their surrogate decision maker. Not all patients want to know everything about their 

diagnosis and treatment, and some may wish to have their family handle this information and decisions for 

them. Asking the patient in advance how much information she wishes to receive respects her autonomy by 

allowing her to make a choice. 

References: 

Donatelli LA, Geocadin RG, Williams MA. Ethical issues in critical care and cardiac arrest: clinical research, 

brain death, and organ donation. Semin Neurol 2006;26:452–460. 

Ethics, Law and Humantities Committee, American Academy of Neurology. Humanistic dimension of 

professionalism in the practice of neurology. Neurology 2001; 56:1261-1263 

Question 48: Contemporary Issues - HIPAA 

Discussion: 

HIPAA regulations regarding patients' protected health information (PHI) are important to safeguard patients' 

privacy and confidentiality. HIPAA regulations are not intended to interfere with the legitimate exchange of PHI 

between health professionals caring for patients, as delay of information sharing could result in patient harm. 

The United States Department of Health and Human Services Office of Civil Rights states that "(physicians) 

may disclose protected health information for the treatment activities of any health care provider...." For 

example, a primary care provider may send a copy of an individual’s medical record to a specialist who needs 

the information to treat the individual, or vice versa. In addition, the circumstance need not be a medical 

emergency, nor is there a requirement that the request be made in writing as long as copies of the records are 

being sent for the purpose of patient care. 

References: 

United States Department of Health and Human Services Office for Civil Rights--HIPAA. Standards for Privacy 

of Individually Identifiable Health Information [45 CFR Parts 160 and 164]. 

http://www.hhs.gov/ocr/hipaa/guidelines/guidanceallsections.pdf. 

Question 79: Contemporary Issues - Driving 

Discussion: 

Driving is mildly impaired in drivers with probable Alzheimer's disease (AD) at a severity of Clinical Dementia 

Rating (CDR) 0.5. Patients and their families should be told that patients with possible AD with a severity of 

CDR 0.5 pose a significant traffic safety problem when compared to other elderly drivers. Referral of the patient 

for a driving performance evaluation by a qualified examiner should be considered. Drivers with AD at a 

severity of CDR 1 pose a significant traffic safety problem both from crashes and from driving performance 

measurements. Patients and their families should be told that patients with AD with a severity of CDR 1 or 

greater have a substantially increased accident rate and driving performance errors, and, therefore, 

discontinuation of driving should be strongly considered. 

References: 



Neurology 2000;54(12):2205-2211. 


Discussion: 


In the United States, the laws that govern withdrawal of artificial hydration and nutrition (AHN) are established 

by the individual states, territories, and District of Columbia. There is significant variation in the laws regarding 

the withdrawal of AHN in the absence of an advance directive, with state laws categorized as permissive and 

45

estrictive. In more than two thirds of the states, it is settled that surrogate decision makers are allowed to decide 

to withdraw AHN without review and approval by a judge if the patient is in PVS and there is no AD. On the 

other hand, in the presence of an advance directive (AD), state laws are consistent in permitting withdrawal of 

AHN if it is directed in the AD. There are no laws that specify the nature of diagnostic testing that must be 

performed to confirm the diagnosis of PVS. 

References: 

North Dakota Century Code. 23-06.5 Health Care Directives. http://www.legis.nd.gov/cencode/t23c065.pdf. 

Larriviere D, Bonnie RJ. Terminating artificial nutrition and hydration in persistent vegetative state patients: 

current and proposed state laws. Neurology 2006;66;1624-1628. 


Discussion: 

Huntington's disease is an autosomal dominant trait with complete penetrance, and offspring from affected 

patients have a 50% chance of developing the disease. Most patients become symptomatic in the third or fourth 

decade. Presymptomatic testing for Huntington's disease should be performed only voluntarily at the request of 

an at-risk patient. Genetic testing should be accompanied by pretest and posttest counseling. Guidelines are 

available and emphasize voluntariness, confidentiality, safety, absence of coercion, and availability of 

counseling. 

References: 

Case adapted from American Academy of Neurology Ethics, Law and Humanities Committee. Ethical 

Dimensions of Neurologic Practice: A case-based curriculum for neurology residents. March 2000. 

Went L. Ethical issues policy statement on Huntington's disease molecular genetics predictive test. International 

Huntington Association. World Federation of Neurology. J Med Genet 1990:27;34-38. 

Question 171: Contemporary Issues - End-of-Life/Palliative Care 

Discussion: 

Organ donation most commonly occurs in the context of severe brain injury and brain death. Public awareness 

and support of organ donation and transplantation has increased in the last decade. As a result, families often 

recognize that the patient's circumstances may be such that organ donation is a possibility. The family's request is 

not illegal, nor does it indicate they are inappropriate decision makers for the patient because the patient has 

previously indicated the desire to be an organ donor. While it is usually considered improper for physicians to 

raise the topic of organ donation with a family before brain death has been determined, it is proper to respond to 

family requests about organ donation whenever they are made. Organ donation can occur even for "coroner's 

cases" as the coroner can be in the operating room at the time the organs are removed for transplantation. 

Because patients must be evaluated for medical suitability for organ donation, and because conversations with 

families about organ donation require considerable skill, physicians should work closely with representatives of 

organ procurement organizations when organ donation is considered a possibility. 

References: 

Williams MA, Lipsett PA, Rushton CH, et al. The physician's role in discussing organ donation with families. 

Crit Care Med 2003;31(5):1568-1573. 

Question 188: Contemporary Issues - Core Competencies 

Discussion: 


Medical errors occur frequently and are currently thought to result from systems errors. The AAN Patient Safety 

Committee web page (http://www.aan.com/professionals/patient/patient_saf.cfm) offers patient safety tips as 

well as a link to the 2006 Patient Safety Colloquium syllabus, which addresses many of the issues in this test 

question (http://www.aan.com/professionals/patient/pdfs/colloquium_syllabi_06.pdf). The AAN, the American 

Medical Association, and other societies urge that errors should be disclosed to patients under most 

circumstances and should include an apology and a promise to investigate the causes of the error. Although in 

46

circumstances and should include an apology and a promise to investigate the causes of the error. Although in 

this case the patient was not harmed, the additional laboratory tests and extra hospital day are serious 

consequences of the error that justify the disclosure. The purpose of disclosure is not to place blame on 

individuals, but rather to inform the patient of the events. Errors should be disclosed by persons with the 

greatest experience, and those with responsiility for the patient's care--in this case, the attending physician. It is 

inappropriate to ask a resident to make an error disclosure alone, although it would be appropriate for the 

resident to be present with the attending physician when the error is disclosed. It is inappropriate to expect any 

health care professional will never make an error; instead, it is important to acknowledge that we all committ 

errors and have an obligation to investigate errors to prevent future recurrence. Failure to disclose the error for 

fear of malpractice lawsuit is inappropriate, as it constitutes concealment. 

References: 

Patient Safety Colloquium. http://www.aan.com/professionals/patient/pdfs/colloquium_syllabi_06.pdf 

Institute for Safe Medical Practices. List of error-prone abbreviations, symbols and dose designations. 

http://www.ismp.org/tools/errorproneabbreviations.pdf. 


Discussion: 

Although advances in understanding the pathophysiology of ALS have stimulated the development of new drug 

therapies, the mainstay of treatment for ALS patients remains symptomatic management. The AAN Practice 

Parameter on the care of the patient with ALS recommends frequent discussions of the goals of care because 

decision making may be subject to change as the disease becomes more severe. Between 40% and 73% of 

patients experience pain in later stages of ALS, and AAN guidelines recommend use of opioids when 

non-narcotic treatment fails. While the use of carefully titrated benzodiazepines to alleviate anxiety and 

respiratory distress is indicated, the use of neuromuscular blockade is not supported by AAN guidelines. Few 

patients on long-term invasive ventilation regret their choice, but because patient satisfaction is higher with 

noninvasive than invasive ventilation, noninvasive ventilation should be considered first. 

References: 

Quality Standards Subcommittee of the American Academy of Neurology. Practice parameter: the care of the 

patient with amyotrophic lateral sclerosis. Neurology 1999; 52:1311-1323. 

http://www.neurology.org/cgi/reprint/52/7/1311.pdf 

Question 332: Contemporary Issues - Driving 

Discussion: 

Determining the ability to drive following stroke is a difficult task. Numerous studies have been performed 

suggesting the most reliable determinant of driving ability is the roadside test. The simulated driving test and the 

roadside test are more predictive than neuropsychological measures and neurologist opinion. 

References: 

Akinwuntan AE, Feys H, De Weerdt W, et al. Prediction of driving after stroke: a prospective study. 

Neurorehabil Neural Repair 2006;20:417-423. 

Akinwuntan AE, De Weerdt W, Feys H, et al. The validity of a road test after stroke. Arch Phys Med Rehabil 

2005;86:421-426. 


Discussion: 


The American Medical Association has recently published guidelines regarding the ethical use of 

industry-sponsored funds for social gatherings and other offerings provided by pharmaceutical companies to 

physicians in the interest of endorsing products. Pharmaceutical companies are restricted from providing strictly 

meals or entertainment to physicians or their families. It is appropriate to accept educational grants from 

pharmaceutical companies if the source is disclosed, the educational content and speakers are selected by the 

47

pharmaceutical companies if the source is disclosed, the educational content and speakers are selected by the 

program director, and the presentation is free from bias. 

References: 

Accreditation Council for Continuing Medical Education. The Standards for Commercial Support. 

http://www.accme.org/dir_docs/doc_upload/ 69466f45-ca31-4cc0-b88e-a38d10de5ee2_uploaddocument.doc 

Question 372: Contemporary Issues - Business 

Discussion: 

When choosing an ICD-9-CM diagnosis code for a diagnostic test, the code most consistent with the test result 

or confirmed diagnosis should be used. A principle rule for choosing an ICD-9-CM code is to code to the highest 

level of specificity. Based on the history and clinical findings, the most specific choice is carpal tunnel 

syndrome. Codes that describe symptoms and signs as opposed to diagnoses are acceptable for reporting 

purposes when a related definitive diagnosis has not been established or confirmed. V-codes are considered by 

Medicare as "Supplementary Classification of Factors Influencing Health Status and Contact With Health 

Services” and are not used for diagnoses. 

References: 

CMS. ICD-9-CM Official Guidelines for Coding and Reporting. Available online at: 

http://www.cdc.gov/nchs/datawh/ftpserv/ftpicd9/icdguide05.pdf 


Discussion: 

In the NICU, implied consent to medical treatment is suitable in emergency circumstances, as patients would 

otherwise be harmed by the delay needed to obtain informed consent from a surrogate. However, the concept of 

implied consent for emergency treatment cannot be expanded to apply to other procedures or interventions 

performed on the same patient in the absence of an emergency. The tracheostomy and percutaneous endoscopic 

gastrostomy (PEG), while necessary, are elective and not emergency procedures, and informed consent from a 

surrogate decision maker is necessary. The hospital attorney does not have the legal authority to approve 

treatment decisions, and, as a representative of the hospital's interests, cannot appropriately advocate for the 

patient's interests. Life-sustaining therapies cannot be withdrawn on the basis of the ICU teams' decision alone. 

Therefore a surrogate decision maker must be found. The ethics consultation team can serve to represent the 

patient's interests and decide whether the treatment recommended by the NICU team is ethically permissible. A 

court of law would take the ethics consultation team's recommendations seriously when approving a guardian 

for the patient. The NICU team may make the same recommendations to the ethics consultation team or 

guardian that would be made to a family in a similar situation, including either withdrawal of life-sustaining 

therapies or insertion of a tracheostomy and PEG. 

References: 

Donatelli LA, Geocadin RG, Williams MA. Ethical issues in critical care and cardiac arrest: clinical research, 

brain death, and organ donation. Semin Neurol 2006;26:452–460. 


Discussion: 

In emergency circumstances where irreversible harm or death would occur by withholding requested treatment, 

it is best to initiate the treatment and then seek consultation from an ethics committee. An ethics consultation can 

rarely be done immediately as there would be insufficient time to gather the information necessary to offer a 

recommendation. Refusals to treat on the basis of medical futility require a due process of evaluation of the 

patient's interests, the family's wishes, and the medical facts of the case, including prognosis. Medical futility 

cannot be determined unilaterally without ethics consultation. Anencephaly is not equivalent to brain death, as 

there is function of the brain stem and there are respiratory efforts. 

References: 


48

Anomynous. In the matter of baby "K" No. 93-1899, No. 93-1923, No. 93-1924. United States Court of Appeals 

16F.3d590; 1994 US app. (LEXIS 2215) 

Question 434: Contemporary Issues - HIPAA 

Discussion: 

The HIPAA Privacy Rule at 45 CFR 164.510(b) specifically permits physicians to share information that is 

directly relevant to the involvement of a spouse, family members, friends, or other persons identified by a 

patient in the patient’s care or payment for health care. If the patient is present or is otherwise available prior to 

the disclosure and has the capacity to make health care decisions, physicians may discuss this information with 

the family and these other persons if the patient agrees or, when given the opportunity, does not object. 

Physicians may also share relevant information with the family and these other persons if they can reasonably 

infer, based on professional judgment, that the patient does not object. In this case, the neurologist does not have 

sufficient information to infer whether the patient would allow this information to be shared with her husband, 

and it is better to ask the patient's permission first. Information can be shared in medical emergencies; however, 

weight gain is not an emergency. HIPAA regulations apply equally to specialists and primary care physicians, 

and HIPAA regulations apply equally to verbal and written communication. 

References: 

United States Department of Health and Human Services. Health Information Privacy and Civil Rights 

Questions & Answers; Disclosure to Family and Friends. 

http://healthprivacy.answers.hhs.gov/cgi-bin/hipaa.cfg/php/enduser/ 

std_alp.php?p_cv=1.7%3B2.u0&%20p_cats=7%2C0&%20cat_lvl1=7&cat_lvl2=0 

United States Department of Health and Human Services Office for Civil Rights--HIPAA. Standards for Privacy 

of Individually Identifiable Health Information [45 CFR Parts 160 and 164]. 

http://www.hhs.gov/ocr/hipaa/guidelines/guidanceallsections.pdf. 

Neuroimaging 

Question 51: Neuroimaging - Stroke 

Discussion: 

Parenchymal hemorrhages can be detected on MRI imaging documented within 2 hours of onset with gradient 

T2 (also called T2*) and EPI sequences due to magnetic susceptibility effects of deoxyhemoglobin, which is the 

earliest step in the breakdown of oxyhemoglobin. 

References: 

Patel M, Edelman R, Warach S. Detection of Hyperacute Primary Intraparenchymal Hemorrhage by Magnetic 

Resonance Imaging. Stroke 1996;27:2321-2324. 

Question 230: Neuroimaging - CSF Circulation Disorders 

Discussion: 

The CT shown is consistent with normal pressure hydrocephalus. The clinical presentation associated with 

normal pressure hydrocephalus consists of gait apraxia, executive function impairment, and urinary 

incontinence. There is no evidence of any lesions to suggest the clinical presentations of aphasia, hemisensory 

neglect, Parkinson's disease, or seizures. 

References: 

Osborne AG. .. Diagnostic Neuroradiology. St Louis: Mosby, 1994. pp. 154-68. neuroradiology. Am] 

Roentgenol 1991; 159:137-47. 

Question 231: Neuroimaging - Critical Care/Trauma 


49

Discussion: 

The scans show multiple small ring-enhancing lesions consistent with cerebral abscesses located at the 

supratentorial gray-white junction. In addition, a posterior occipital enhancing lesion is noted. The appearance is 

most consistent with septic emboli. By the imaging appearance alone, cerebral metastases are not ruled out. In 

the current case, the patient had endocarditis secondary to intravenous drug abuse. Uncomplicated pyogenic 

meningitis typically shows intense meningeal enhancement of the cerebral convexity, tentorium, and falx. 

Multiple sclerosis may show lesions with a similar appearence, but they would not involve the cortex, as seen on 

the sagittal image, and the enhancement ring would tend to open to the side of the gray matter, not the white 

matter as seen in the axial image of this case. 

References: 

Greenberg JO, editor. Neuroimaging: a companion to Adams and Victor's principles of neurology. 2nd ed. New 

York: McGraw-Hill, 1999. 

Question 232: Neuroimaging - Infection 

Discussion: 

CT shows multiple parenchymal calcifications with mild atrophy; this is characteristic of a host of infections, 

including toxoplasmosis, rubella, Cytomegalovirus, and herpes. Calcification seen in Sturge-Weber syndrome is 

typically cortical and gyriform. Although lipomas may calcify, they are extraaxial, usually single, and are 

hypodense on CT. The scan does not show malformations of the sulci or ventricles to suggest schizencephaly or 

colpocephaly. 

References: 

Greenberg JO. Neuroimaging: a companion to Adams and Victor's principles of neurology. New York: 

McGraw-Hill, 1999. 

Question 235: Neuroimaging - Spine 

Discussion: 

MR is the imaging modality of choice for evaluation of spinal infections. The typical MRI appearance is loss of 

distinction between the endplates, disks, and adjacent vertebral bodies on T1-weighted views and increased 

T2-weighted signal. These areas show enhancement. The findings with high sensitivity for spinal infections 

include evidence of paraspinal, or epidural, inflammatory tissues, contrast enhancement of the disc, and 

hyperintensity on fluid-gradient T2-weighted views. Spinal infections rarely involve only one vertebral body 

and adjacent disc or only the epidural space. 

References: 

Gutmann DH, Rasmussen SA, Wolkenstein P, et al. MR Imaging gs in Spinal Infections: Rules or Myths? 

Radiology 2003;228:506-514. 


Discussion: 

A hyperintense signal is seen on both T1-weighted and T2-weighted images, suggesting that the lesion is a 

lipoma. Neurosurgical and radiation therapy consultations are not necessary for the management of this lesion. 

A lumbar puncture and blood cultures are not recommended. Lipomas are benign. 

References: 

Edelman R, Hesselink J, editors. Clinical Magnetic Resonance Imaging. Philadelphia: WB Saunders, 1990. 

Question 238: Neuroimaging - Brain Tumors 

Discussion: 


50

MR is effective in demonstrating a displaced optic chiasm because the optic chiasm is usually slightly more 

intense than pituitary tumors. 

References: 

Daniels DL, Haughton VM, Czervionke LF. MR of the skull base. In: Bradley WG, Stark D. Magnetic 

resonance imaging. St. Louis: Mosby, 1988. 



Question 241: Neuroimaging - Autoimmune Disorders (Non-MS) 

Discussion: 

Leptomeningeal enhancement, parenchymal enhancement, and, especially, pituitary stalk/hypothalamic 

involvement in a patient with cranial nerve symptoms is characteristic of neurosarcoidosis. About 5% to 10% of 

sarcoidosis patients develop CNS involvement. Lack of hemiatrophy and prominent (asymmetrical) choroid 

plexus enhancement make the diagnosis of Sturge-Weber syndrome less likely. No gyral enhancement is 

present. Low CSF pressure would not be limited to one hemisphere and would not have masslike and 

leptomeningeal enhancement. The enhancing lesion is intraaxial and therefore is not a meningioma. 

References: 

Osborn AG. Diagnostic neuroradiology. St. Louis: CV Mosby, 1994. 

Question 242: Neuroimaging - Dementia 

Discussion: 

The most striking change between the two studies is the pronounced decrease in glucose metabolism in the 

frontal and anterior temporal regions. This pattern is characteristic of frontotemporal dementia. Alzheimer’s 

disease tends to decrease metabolism in the parietotemporal association cortex, relatively spared in the scan 

shown. Parkinson’s disease does not cause a decrease in metabolism. As in this case, in Huntington’s chorea 

there is decreased metabolism in the head of the caudate nuclei, but the frontal and temporal lobes are not as 

affected. Finally, diffuse Lewy body disease causes decreased metabolism in the occipital regions, relatively 

spared in this scan. 

References: 

Masdeu JC, Zubieta JL, Arbizu J. Neuroimaging as a marker of the onset and progression of Alzheimer's 

disease. J Neurol Sci 2005;236:55-64. 

Kantarci K, Jack Jr C. Neuroimaging in Alzheimer disease: an evidence-based review. Neuroimaging Clin N 

Am 2003;13:197-209. 

Coleman RE. Positron emission tomography diagnosis of Alzheimer's disease. Neuroimaging Clin N Am 

2005;15:837-846. 


Discussion: 

The most likely diagnosis is glioblastoma multiforme. On the FLAIR image, the lesion presents with mass 

effect, too pronounced for an arteriovenous malformation, choroid plexus calcification, or an infarction. The 

abnormal high-intensity region extends across the corpus callosum to the right hemisphere, a feature common in 

malignant gliomas. The abnormal contrast enhancement suggests that the tumor has abnormal vessels with 

marked permeability, another finding in glioblastoma. However, macroscopically dilated vessels, characteristic 

of an arteriovenous malformation are not present. A choroid plexus papilloma is very unusual in this age group. 

A toxoplasma abscess tends to show enhancement at the periphery and with a more regular appearance than in 

the present case. 

References: 


51

Greenberg JO, editor. Neuroimaging: A Companion to Adams and Victor's Principles of Neurology. 2nd ed. 

New York: McGraw-Hill, 1999. 


Discussion: 

Multiple basal ganglia high-signal foci are seen bilaterally. They are more numerous than normal 

Virchow-Robin spaces. Toxoplasmosis resides also in basal ganglia, but then there is usually also mass effect. 

Cryptococcus enters the intracranial space through the perivascular spaces, and the organisms are surrounded by 

gelatinous material that is seen as high signal foci. This correlates with "soap-bubble" abscesses seen grossly. 

The correct answer is cryptococcus infection. 

References: 


Question 245: Neuroimaging - Developmental/Neurogenetic Disorders 

Discussion: 

Sagittal T1-weighted image shows a Chiari II malformation with deformity of the tectum of the mesencephalon, 

caudalization of the cerebellar vermis into the cervical spinal canal, and a deformity of the medial aspect of the 

cerebral hemisphere, with an absent posterior corpus callosum. The cerebral aqueduct is not visualized, and the 

ventricles do not appear enlarged, suggesting there is aqueductal stenosis and that a functioning shunt should be 

present as was the case. There is a high degree of association between the cerebral changes of Chiari II 

malformation and the presence of a lumbar myelomeningocele, thus the lumbar spine should be and was 

dysraphic. Patients with Chiari II malformations do not have to be and are frequently not mentally retarded. 

There is no evidence of contusion, subdural hematoma, or other forms of trauma on the section shown. 

References: 

McLone DG, Naidich TP. Developmental morphology of the subarachnoid space, brain vasculature, and 

contiguous structures, and the cause of the Chiari II malformation. AJNR Am J Neuroradiol 1992;13(2):463-482. 

Question 246: Neuroimaging - Epilepsy 

Discussion: 

The image shows heterotopic gray matter in the left frontal region. Deformity of the left frontal horn is seen with 

ex-vacuo hydrocephalus. No mass effect is seen to suggest tumor. Rather, the lesion is destructive. Heterotopic 

gray matter refers to cortical neurons in abnormal location. Heterotopia is caused by migrational arrest of the 

affected neuroblasts. The cause of the incomplete migration is unknown. Three kinds of heterotopic gray matter 

have been described: (1) nodular (periventricular), (2) laminar (in deep white matter), like in this patient, and (3) 

band heterotopia (double cortex). 

References: 

Guerrini R, Filippi T. Neuronal migration disorders, genetics, and epileptogenesis. J Child Neurol 

2005;20:287-299. 


Discussion: 


The large vascular malformation is an aneurysm of the vein of Galen. The sagittal time-of-flight image shows 

particularly well the blood backing up into the posterior portion of the superior sagittal sinus, which is markedly 

dilated. The fast flow in the malformation creates a flow void, visible as a dark structure in both the T2- and 

T1-weighted images. The morphology of this malformation is characteristic and differentiates it from the other 

answer options. Cavernous and venous angiomas are much smaller. A dural fistula has an important arterial 

component, absent in this case. A hemangioma has the appearance of a tumor, without the large vessels visible 

in this patient. 

52

References: 




Discussion: 

Diastematomyelia is a rare form of spinal dysraphism. On MRI the cord appears split with a sagittal cleft of 

varying extent. Fiber, cartilaginous, or osseous septums produce complete or incomplete divisions of the spinal 

cord into hemicords. Patients may have neurological defects in the lower limbs such as gait disorders, sphincter 

disturbance, or muscle atrophy. 

References: 

Sami H, Ross E, Walter M, Goli S. Split Spinal Cord (Diastematomyelia). Neurology 2003; 60:491. 


Discussion: 

The distribution of the changes on postendarterectomy MRI are consistent with an acute infarct in the 

distribution of the anterior cerebral artery. 

References: 

Greenberg JO, editor. Neuroimaging: a companion to Adams and Victor's principles of neurology. 2nd ed. New 

York: McGraw-Hill, 1999. 


Discussion: 

The MRI shows a subacute left middle cereberal infarct with a subacute hematoma. The hematoma has increased 

T1 signal and decreased T2 signal. There is mild ipsilateral dilation of the left ventricle indicating an anteceding 

chronic infarct. There is no mass effect or midline shift to indicate an acute left infarct. Chronic hemorrhage 

would cause hypointense signal on both pulse sequences 

References: 

Barnett HJM. Stroke: pathophysiology, diagnosis, and management. New York: Churchill Livingstone, 1992. 


Discussion: 

The axial T2-weighted image shows a symmetrical brain with normal size ventricles. The frontal lobe cortex is 

flat, and the white matter, which is hypointense, does not show the normal interdigitation into the gray matter in 

this region. Thus, the cortex is thick, and the patient has pachygyria. Such an abnormality develops during the 

period of neuronal migration, occurring during the second trimester. 

References: 

Zimmerman RA, Bilaniuk LT. Pediatric central nervous system. In: Stark DD, Bradley WG, editors. Magnetic 

resonance imaging. St. Louis: CV Mosby, 1988. 


Discussion: 


MR images demonstrate dilatation of the cord around a central cystic cavity, consistent with 

syringohydromyelia. Note also on the sagittal images that the inferior portion of the cerebellum has herniated 

53

down into the upper cervical canal, diagnostic of a Chiari malformation. Hydromyelia is commonly seen in 

association with both Chiari type I and Chiari type II malformation. 

References: 



Question 258: Neuroimaging - Multiple Sclerosis 

Discussion: 

The MRI reveals far too much white matter disease for Alzheimer's disease. Metachromatic leukodystrophy 

typically produces by this age more diffuse and confluent areas of demyelination than those shown. Progressive 

multifocal leukoencephalopathy is less common, and large regions (rather than small plaques) of white matter 

signal change are expected. Given the diffuse white matter lesions that are characteristic of multiple sclerosis 

plaques, her age, and gender, multiple sclerosis is the most likely diagnosis. Vasculitis typically involves the 

gray/white matter junction. 

References: 

Benedict RH, Weinstock-Guttman B, Fishman I, et al. Prediction of neuropsychological impairment in multiple 

sclerosis: comparison of conventional magnetic resonance imaging measures of atrophy and lesion burden. Arch 

Neurol 2004;61:226-230. 

Question 259: Neuroimaging - Movement Disorders 

Discussion: 

The patient has cerebellar and pontine atrophy. This finding and the abnormal signal in the pons, in the form of a 

cross, are found in olivopontocerebellar atrophy but not the other diagnostic possibilities. In the Chiari 

malformation the posterior fossa is crowded, the opposite of what happens here. With an arachnoid cyst, the 

subarachnoid space could be dilated but not the fourth ventricle. Finally, the inferior vermis is not atretic as it is 

in the Dandy-Walker syndrome. 

References: 

Srivastava T, Singh S, Goyal V, et al. "Hot cross bun" sign in two patients with multiple system 

atrophy-cerebellar. Neurology 2005;64:128. 


Discussion: 

Anoxia causes increased T2 signal in the globus pallidus, deep portions of the sulci, and superior cerebellum, 

which are all anatomical regions that are susceptible to hypoxia. The necrotic globus pallidus enhances after 

gadolinium administration. 

References: 




Discussion: 


Although the MRI tends to rule out an astrocytoma and ependymoma because there is only mild mass effect, it 

could still be an inflammatory lesion, giving rise to the increased signal on the T2 images. A heavily 

T2-weighted sequence (T2-CISS) shows a cluster of vessels on the dorsal aspect of the cord compatible with 

venous dilation due to arteriovenous shunting by a dural fistula. The selective angiogram confirms this 

impression because the venous system is filled so rapidly by a brief arterial injection that both arterial and 

venous vessels are seen on the same angio frame. This disorder corresponds to the myelopathy of 

54

Foix-Alajouanine. 

References: 



Koch C. Spinal dural arteriovenous fistula. Curr Opin Neurol 2006;19:69-75. 


Discussion: 

The patient was a diabetic with severe vascular disease. The morphology of the hemispheric lesions resembles 

vascular disease more than either multiple sclerosis or a lymphoma. Of the three vessels mentioned in the 

options, the right carotid does not show the flow void characteristic of circulating blood. 

References: 




Discussion: 

The FLAIR MRI image shows an area of high signal intensity in the distribution of the recurrent artery of 

Heubner. It is consistent with an infarct in this tissue. The recurrent artery of Heubner arises from the A1 

segment of the anterior cerebral artery and supplies the anteroinferior portion of the caudate nucleus, the 

putamen, and the anterior limb of the internal capsule. 

References: 

Netter FH. Nervous system anatomy and physiology. New Jersey: CIBA Medical Education Division, 1986. 


Discussion: 

The patient had a subdural hematoma with mixed densities, some corresponding to a more recent bleeding. The 

shape of the lesion and the low density of the deeper portion are uncharacteristic of an epidural hematoma, with 

a lens shape and the high density of fresh blood. The lesion is outside the brain, compressing the cortex of the 

right hemisphere. For this reason, infarction is not an option. A meningioma "en plaque" would be more 

homogeneous and have higher density. 

References: 




Discussion: 

This is a typical location for a colloid cyst. This usually causes low signal in the T2-weighted image; however, 

the MRI signal can be variable. 

References: 

Dalessio DJ. Diagnosing the severe headache. Neurology 1994;44(Suppl 3):S6-S12. 


Discussion: 


55

Pleomorphic xanthoastrocytoma typically produce a large cyst with superficially positioned mural nodule. Most 

lesions arise within the temporal or parietal lobes. This lesion is surrounded with minimal hemosiderin rim but 

no edema, and this excludes abscess and hematomas. The signal characteristics of cavernous hemangioma are 

heterogeneous (popcorn). The mass effect is too little for a hematoma of this size. Porencephalic cysts do not 

exert mass effect. 

References: 

Osborne A. Diagnostic Imaging: Brain. Philadelphia: Elsevier, 2004. 


Discussion: 

Transverse myelitis affects predominantly the thoracic spinal cord and on imaging reflects as an increased signal 

in the spinal cord on T2 images extending several segments. The spinal tap would show lympocytic 

predominance and increased protien. There is no evidence of disc herniation, tumor, or spinal artery stroke on 

the image. Gullain-Barre syndrome would not cause any increased signal in the spinal cord. 

References: 

Edelman R, Hesselink J, editors. Clinical Magnetic Resonance Imaging. Philadelphia: WB Saunders, 1990. 


Discussion: 

Axial image demonstrates a small, constricted spinal canal. This is mainly due to degenerative facet joint 

disease. No disc herniation or synovial cyst is present. The nerve roots are coiled above the narrow area since 

they cannot slide freely though the narrow part. Distal nerve roots are stretched. The correct answer is spinal 

stenosis. 

References: 

Ross J, Zawadzki MB, Chen M, et al. Diagnostic Imaging: Spine. Salt Lake City: Saunders-Elsevier, 2004. 


Discussion: 

The MRI study shows a recent subcortical hemorrhage in the subcortical white matter of the right paracentral 

region. This hemorrhage is responsible for the recent hemiparesis. The subcortical location of the hemorrhage is 

typical of amyloid (or congophilic) angiopathy and very atypical for a hypertensive hemorrhage. Hemorrhages 

do not tend to happen with either CADASIL or subcortical arteriosclerotic encephalopathy. Finally, the pattern 

of multiple lesions in the white matter is not present in frontotemporal dementia. 

References: 

Chao CP, Kotsenas AL, Broderick DF. Cerebral amyloid angiopathy: CT and MR imaging findings. 

Radiographics 2006;26:1517-1531. 




Discussion: 

An intradural, extramedullary mass in the thoracic spine is causing significant cord compression. This 

represents either neurofibroma or meningioma and requires surgical removal. Neither tumor is radiosensitive. 

Imaging with CT or myelography is not likely to add any further useful information. 

References: 


56

Osborn A. Diagnostic Neuroradiology. St. Louis: Mosby, 1994. 


Discussion: 

The internal carotid artery segment shown is immediately proximal to the takeoff of the middle cerebral artery 

(which goes to the right) and the anterior cerebral artery (which goes to the left). 

References: 

Osborn A. Introduction to cerebral angiography. Hagerstown, MD: Harper & Row, 1980. 


Discussion: 

The scan demonstrates findings highly suggestive of acute or subacute herpes simplex virus (HSV) encephalitis 

involving the temporal lobe. The lesion crosses the vascular boundaries of the middle and posterior cerebral 

arteries, making an ischemic insult unlikely. The contrast-enhancing pattern would be unusual for glioblastoma 

or lymphoma. A contusion could occur in this location but would contain evidence of hemorrhage and MR 

evidence of parenchymal blood degradation products, which is not seen in this case. HSV encephalitis primarily 

involves limbic structures. MR typically shows temporal and inferior frontal lobe swelling, with low signal on 

T1-weighted images and high signal on T2-weighted images. Postcontrast studies in the acute and subacute 

setting often show cortical and leptomeningeal enhancement. The lesion may not be hemorrhagic in the early 

stages. 

References: 

de Almeida Magalhaes AC, Bacheschi LA. Viral and nonviral infections of the nervous system. In: Greenberg 

JO, editor. Neuroimaging: a companion to Adams and Victor's principles of neurology. 2nd ed. New York: 

McGraw Hill, 1999. 


Discussion: 

The CT scan shows a collection of air in the right frontal lobe, with the bottom portion having an air fluid level. 

The finding is not consistent with an artifact nor with a vascular event. Infection could be present; however, the 

way in which the air would gain access to the intracranial compartment would have to involve a break in the 

skull, most often in the air containing sinuses of the cranial base. In this case, the air collection entered through 

a fracture of the frontal sinus. In order for the air to occupy as much space within the brain parenchyma as it 

does, there would have to be a loss of substance of the brain focally at the site. This is consistent with the patient 

having had a loss of brain substance (volume) due to a prior focal hemorrhagic contusion. 

References: 

Woodruff WW. Fundamentals of neuroimaging. Philadelphia: WB Saunders, 1993. 


Discussion: 

The correct diagnosis is communicating hydrocephalus. Dilation of the Sylvian fissure and other sulci may 

suggest atrophy. However, this feature is not uncommon in shunt-responsive hydrocephalus, as documented in 

the references. On the coronal images note that the sulci at the high parietal convexity are compressed, as 

compared to the markedly dilated posterior extent of the Sylvian fissure. 

References: 


Kitagaki H, Mori E, Ishii K, et al. CSF spaces in idiopathic normal pressure hydrocephalus: morphology and 

volumetry. AJNR Am J Neuroradiol 1998;19:1277-1284. 

57


Discussion: 

The postinjection T1-weighted MR image shows enhancement of an extra-axial small mass that displaces the 

brain parenchyma away from the inner table of the skull. The inner table of the skull is focally expanded at the 

center of the mass. The findings are characteristic of a meningioma. A "dural tail sign" is present on the 

postcontrast image. An epidural hematoma would have been of high signal intensity on the preinjection study. 

Without expansion of the bone, a depressed fracture would have a plane of cleavage within the calvarium and 

may also have had an underlying cortical contusion. 

References: 

Berry I, Brant-Zawadski M, Osaki L, et al. Gd-DTPA in clinical MR of the brain: extra-axial lesions and normal 

structures. AJNR Am J Neuroradiol 1986;7:789. 

Question 286: Neuroimaging - Multiple Sclerosis 

Discussion: 

Enhancement is circumscribed to the margins of the lesion and affects only the white matter. Several patches of 

enhancement are in subcortical white matter. The overall appearance of the enhancement resembles an open 

ring, a finding characteristic of the large lesion (Schilder's) variety of multiple sclerosis. An infarction would 

give rise to cortical enhancement. The other lesions tend to cause closed rings, and characteristically the gray 

matter tends to enhance more than the white matter if the lesion is as close to the cortex as this one is. In this 

patient the lesion shown improved on steriods. Six months later he developed a similar lesion in the frontal lobe. 

References: 

Masdeu JC, Quinto C, Olivera C, et al. Open-ring imaging sign: highly specific for atypical brain demyelination. 

Neurology 2000;54:1427-1433. 


Discussion: 

A developmental venous anomaly (DVA) or venous angioma is occasionally identified in the work-up of 

patients with neurological symptoms. Headache is the most common symptom. Seizures are also commonly 

associated. There is no real evidence, however, that either headaches or seizures are caused by the DVA, and in 

most instances the DVA is incidental. It is very important to understand that the DVA represents the venous 

drainage of the brain tissue in which it is situated. Removal of the DVA may cause a venous infarction. 

References: 

Rigamonti D, Hsu FPK, Huhn S. Angiographically occult vascular malformations in neurovascular surgery. In: 

Carter PL, Spetzler RF, editors. New York: McGraw-Hill, 1994. 


Discussion: 

There is marked enlargement of the third and lateral ventricles, with a normal-sized fourth ventricle. Note also 

the peculiar configuration of the quadrigeminal plate, which appears displaced and compressed superiorly, but 

normally inferiorly, reflecting dilation of the proximal portion of the aqueduct only. The axial T2 image 

through the midbrain also fails to demonstrate the normal flow void seen at the level of the aqueduct that 

originated from high velocity of CSF traveling through the patent aqueduct. These findings are consistent with a 

diagnosis of obstructive hydrocephalus, with obstruction at the level of the aqueduct (excluding the choices of 

atrophy or communicating hydrocephalus). In this case, there is no evidence of a mass in the quadrigeminal 

plate, and obstruction is due to stenosis. 

References: 


58

Bradley WB, Quencer RM. Hydrocephalus, atrophy, and intracranial CSF flow. In: Stark DD, Bradley WG. 

Magnetic resonance imaging, Vol. 1. 2nd ed. St Louis: CV Mosby, 1992. 


Discussion: 

The sagittal two-dimensional phase contrast venogram with a velocity encoding of 15 cm/s is tailored to 

demonstrate slow flow such as that in the dural venous sinuses. The scan demonstrates practically no flow in the 

superior sagittal sinus (SSS). One prominent cortical vein shows flow. Just adjacent to this cortical vein, minor 

flow is seen in the SSS. This finding is consistent with near occlusion of the SSS. Higher velocity encodings are 

needed to demonstrate arterial flow. 

References: 

Medlock MD, Olivero WC, Hanigan WC, et al. Children with cerebral venous thrombosis diagnosed with 

magnetic resonance imaging and magnetic resonance angiography. Neurosurgery 1992;31:870-876. 


Discussion: 

In the images, the intervertebral disc near a postsurgical foreign body is obliterated, and there is enhancement of 

the sheath of the psoas muscle. These findings are most suggestive of infection. Several MRI patterns have been 

described as indicating spinal infections, including decreased disk height, disk hypointensity on T1-weighted 

images, and hyperintensity on T2-weighted images, disk enhancement, erosion of vertebral endplates, the loss 

of distinction between endplate and disk, along with the adjacent vertebral bodies on T1-weighted signal is most 

frequently seen. These areas show enhancement. Spinal infections are most frequently associated with 

paraspinal or epidural inflammatory tissues. 

References: 

Ledermann HP, Schweitzer ME, Morrison WB, Carrino JA. MR Imaging Findings in Spinal Infections: Rules or 

Myths? Radiology 2003;228:506-514. 


Discussion: 

The ring-enhancing lesion in the lower portion of the precentral region has the characteristics of a brain abscess. 

Corresponding to the ring of enhancement in the gadolinium study is a dark rim in the FLAIR image. This rim 

has a rich vascular network and abundant macrophages. The core of the lesion, containing an excess of water as 

compared to brain, is hyperintense on T2 (FLAIR) and hypointense on T1. Around the ring there is brain 

edema, also hyperintense on T2 and hypointense on T1. None of the other options have similar characteristics. 

Astrocytomas of the types indicated seldom enhance. Areas of enhancement in an infarct tend to involve the 

cortical ribbon whereas in the lesion shown the ring is at the corticomedullary junction, mostly in the white 

matter. The lesion shown is in the brain parenchyma, not outside, as would happen with a meningioma. 

References: 

Kastrup O, Wanke I, Maschke M. Neuroimaging of infections. NeuroRx 2005;2:324-332. 




Discussion: 


The enhanced CT image demonstrates multiple irregular ring-enhancing lesions adjacent to and compressing the 

lateral ventricles. There is extensive white matter vasogenic edema in both hemispheres. This appearance is most 

consistent with a glioblastoma that has spread through the corpus callosum to involve both hemispheres. In 

immunocompromised patients, lymphoma can have a similar appearance, but in immunocompetent patients, 

59

immunocompromised patients, lymphoma can have a similar appearance, but in immunocompetent patients, 

lymphoma is most commonly seen as a homogenously enhancing mass. Herpes encephalitis in adults nearly 

always affects the temporal lobes. Neurocysticercosis can occur in the brain parenchyma or as cysts within the 

ventricles. First seen as cysts in the brain, cysticercosis can incite an inflammatory reaction when the larva dies, 

but the lesions are usually small, well circumscribed, and located at the corticomedullary junction. 

References: 



Discussion: 

The lesion at the tip of the left temporal lobe spares the cortical ribbon and is clearly extraaxial, ruling out old 

head trauma or herpes simplex encephalitis. The signal characteristics are typical of CSF, ruling out a 

metastasis. The lesion on the right perimesencephalic cistern cannot be incisural sclerosis, characterized by 

gliosis not by a CSF-like lesion like the one shown. Both lesions are arachnoid cysts. 

References: 




Discussion: 

Axial CTs show a large mass lesion filling the right orbit, compressing and deforming the posterior margin of 

the globe. The inferior cut through the maxillary sinus shows that the lateral wall of the maxilla is destroyed and 

is associated with the soft tissue mass. Metastatic disease commonly involves bone and adjacent soft tissue, as in 

this case. Facial trauma does not produce a disappearance of bone but fractures it. Fibrous dysplasia expands 

bone but does not destroy it. Hemangioma may involve bone and soft tissue, but is not a destructive process. In 

the orbit, capillary hemangiomas are commonly found in the cutaneous tissues and periorbita but do not extend 

retroglobar and do not destroy bone. Cavernous hemangiomas are discrete masses that may be found intraorbital 

or extraorbital but do not usually cross these margins. 

References: 

Zimmerman RA, Bilaniuk LT. Computed tomography of the orbit. In: Lee S, Rao K, editors. Cranial 

computerized tomography. New York: McGraw-Hill, 1983. 


Discussion: 

The scans show active spondylitis at L4-L5 and remote spondylitis at L2-L3. Spondylitis may include 

osteomyelitis, discitis, and epidural abscess formation, each of which are seen in the current case at L4-L5. The 

enhancement and T2 hyperintensity of the L4-L5 disc is consistent with active discitis. In contrast, metastatic 

disease usually spares and does not cross the disc space. Remote spondylitis often results in the changes seen in 

the current case at L2-L3; the disc space is markedly narrowed, and the adjacent vertebral bodies show 

degenerative changes. Incidental note is made of scoliosis, which is maximal at L2. 

References: 



Discussion: 


The lesion in the left temporal lobe is isodense on T1 and enhances with gadolinium. It is outside the temporal 

lobe. It causes compression of the tip and medial aspect of the temporal lobe, with partial herniation of the 

60

parahippocampal gyrus. These features are characteristic of a meningioma. Both Alzheimer’s disease and 

frontotemporal dementia would present with atrophy, not mass effect. Both an astrocytoma and a glioblastoma 

are intraparenchymal tumors. 

References: 




Discussion: 

Dissection and total occlusion of the left internal carotid are incorrect because there is no evidence for 

dissection. Emergency surgery is not required and it is clear that there is a large ulcerated plaque, not a 

dissection. The ulcerated plaque could have resulted from the accident, but it is far more likely that it happened 

spontaneously. If plaque material from within a crater this large had broken off and embolized during the 

accident, the patient would have had serious neurological morbidity. Therefore, the correct answer is that the 

accident did not cause the findings. 

References: 

Watridge CB, Muhlbauer MS, Lowery RD. Traumatic carotid artery dissection: diagnosis and treatment. Journal 

of Neurosurgery 1989;71(6):854-857. 


Discussion: 

The most likely diagnosis is subarachnoid hemorrhage. The high density of the recent bleeding outlines the 

subarachnoid space around the brain. Its shape rules out the other types of hemorrhage mentioned as options. 

There is hydrocephalus, but it is not idiopathic; rather, it is caused by the subarachnoid hemorrhage. The air with 

pneumocephalus would have a much lower density than any of the structures seen on the image. 

References: 




Discussion: 

Both the clinical picture and the imaging suggest a subacute process, with quick worsening. Of the given 

options, listeriosis and multiple sclerosis usually have a subacute course. Of the two, the imaging is more typical 

of listeriosis, an infection produced by Listeria monocytogenes that has a preference for the brainstem. In the 

second study, the larger abscess in the tegmentum of the pons, visible in the gadolinium-enhanced study, is 

accompanied by a subependymal cluster of smaller abscesses. In addition, there is enhancement of the 

ependymal lining, suggesting the infectious nature of the lesion. 

References: 

Falini A, Kesavadas C, Pontesilli S, et al. Differential diagnosis of posterior fossa multiple sclerosis 

lesions--neuroradiological aspects. Neurol Sci 2001;22 (Suppl 2):S79-S83. 

Antal EA, Loberg EM, Dietrichs E, Maehlen J. Neuropathological findings in 9 cases of listeria monocytogenes 

brain stem encephalitis. Brain Pathol 2005;15:187-191. 


Discussion: 


The lesion in the left hippocampus has the imaging characteristics of a cavernous angioma, with a rim of 

61

low-intensity hemosiderin surrounding a cluster of high-intensity, fluid-containing vessels. The absence of 

draining veins rules out both an arteriovenous malformation and a venous angioma. Astrocytoma and 

oligodendroglioma do not have the imaging characteristics present in this MRI. 

References: 




Discussion: 

The lesion of the left optic nerve is an astrocytoma. Neurofibromatosis type 1 (NF1) is associated with the 

development of both benign and malignant tumors. The left optic nerve is thickened, suggesting the presence of 

a tumor, but it does not enhance, suggesting that the lesion is not a meningioma, neurofibroma, or schwannoma. 

Astrocytomas (glioma) are seen in 15% to 20% of these individuals. The most common locations include the 

optic nerve, optic chiasm, hypothalamus, and, less often, the posterior fossa. 

References: 

Gutmann DH, Rasmussen SA, Wolkenstein P, et al. Gliomas Presenting After Age 10 in Individuals with 

Neurofibromatosis Type 1 (NF1). Neurology 2002; 59: 759-761. 


Discussion: 

This extra-axial lesion diffusely and homogenously enhances with contrast. It sits on the dura. The morphology 

and location make less likely the diagnoses of acoustic neurinoma and trigeminal schwannoma. Astrocytoma 

and hemangioma are intra-axial tumors. This is an en-plaque variant meningioma. 

References: 

Mohr JP, Gautier JC, editors. Guide to Clinical Neurology. New York: Churchill Livingstone, 1995. 

Question 309: Neuroimaging - Metabolic 

Discussion: 

The high subcortical signal in T2, affecting multiple gyri, suggests increased vascular permeability, as it happens 

in all the conditions listed as possible answers. However, only eclampsia fails to have other findings and causes 

white matter changes with the topography and shape present in the images. Multiple sclerosis tends to cause 

sharper lesions, with a periventricular distribution. In abscesses, there are round, cystic collections. There is no 

evidence of nodular deposits of choriocarcinoma. Emboli in these locations would be accompanied by cortical 

necrosis, not evident in this image. 

References: 

Orrison WW. Neuroimaging. Philadelphia: WB Saunders, 2000. 


Discussion: 


The CT and MRI scan findings are highly consistent with Sturge-Weber syndrome (SWS). Cerebral lesions in 

SWS are most frequently found in the parieto-occipital area. On CT scans, parenchymal calcification is found 

adjacent to the leptomeningeal lesions in a pericapillary distribution in the fourth cortical layer, possibly 

secondary to chronic tissue hypoxia. Noncontrast MR images in SWS typically show unilateral cerebral atrophy 

with enlargement of the ipsilateral subarachnoid spaces and ventricular cavities. Enlarged tubular regions of 

flow void and gyriform hypointensities (decreased signal on T1-weighted and T2-weighted images) reflect 

venous collateralization and cortical "serpentine" calcification, respectively. Contrast-enhanced MRI is best for 

demonstrating the salient CNS vascular abnormalities in SWS. The leptomeninges show intense enhancement 

62

overlying the involved cortical region secondary to leptomeningeal (pial) angiomatosis or a compromised 

blood-brain barrier secondary to chronic cortical ischemia. This meningeal enhancement often extends well 

beyond the region of parenchymal atrophy. 

References: 

Provenzale JM, Tavares JM. Clinical cases in neuroradiology. Philadelphia: Lea & Febiger, 1994. 


Discussion: 

Pituitary apoplexy is a syndrome of infarction or hemorrhage of the pituitary gland. It is associated with 

headache, ophthalmoparesis, visual defects, and encephalopathy. It may occur acutely or subacutely and can be 

associated with coma or death. It occurs more often in pituitary adenomas. 

References: 

Rogg JM, Tung GA, Anderson G, Cortez S. Pituitary Apoplexy: Early Detection with Diffusion Weighted MR 

Imaging. AJNR Am J Neuroradiol 2002;23:1240-1245. 

Question 347: Neuroimaging - Technical 

Discussion: 

The internal cerebral vein, which is one of the major components of the deep draining system of the brain, is 

located in the roof of the third ventricle between the leaflets of the veli interpositi. 

References: 


Question 356: Neuroimaging - Technical 

Discussion: 

Of the medical devices and conditions listed, only cardiac pacemakers constitute an absolute contraindication for 

MRI. Many heart valves are MR compatible, particularly those produced in the last decade. Middle ear 

prosthesis are not considered hazardous to patients, but the device itself can be damaged. An MRI can be 

performed in a patient with an aneurysm clip depending on the material used for the clip. Pregnancy is a relative 

but not absolute contradiction to MRI. It should be used with caution in the first trimester. 

References: 

Bushong SC. Magnetic resonance imaging: physical and biological principles. St. Louis: CV Mosby, 1996. 


Discussion: 

Luxury perfusion refers to increased perfusion in the periphery of an ischemic area. It is best documented with 

PET or SPECT. Some authors have used the term to refer to gray matter enhancement, which is best seen on 

MRI 3 days to several weeks after a cerebral infarct and results from contrast leaking into the perivascular space 

in an area of ischemic insult. 

References: 

Bakshi R, Ketonen L. Brain MRI in clinical neurology. In: Joynt RJ, Griggs RC, editors. Baker’s clinical 

neurology. Philadelphia: Lippincott, Williams & Wilkins, 2001. 

Pathology 

Question 17: Pathology - Demyelinating Disease 


63


Discussion: 

Neuromyelitis optica antibody is a newly developed serum antibody test that identifies up to 70% of cases of 

neuromyelitis optica (Devic's disease). The test is negative in standard cases of multiple sclerosis and in other 

demyelinating and disorders disorders. 

References: 

Lennon VA, Wingerchuk DM, Kryzer TJ, et al. A serum autoantibody marker of neuromyelitis optica: 

distinction from multiple sclerosis. Lancet 2004;364:2106-2112. 


Discussion: 

Huffing glue causes diffuse leukoencephalopathy, not neuronal necrosis in either cerebral or cerebellar cortices. 

References: 

Graham DI, Lantos PL. Greenfield's neuropathology. 7th ed. London: Arnold, 2002. 

Question 73: Pathology - Cerebrovascular Disease 

Discussion: 

Dolichoectasia (fusiform aneurysm) most commonly affects the supraclinoid segment of the internal carotid 

artery and the basilar artery, and is seen in patients with advanced cerebral atherosclerosis. Berry aneurysms are 

associated with both coarctation of the aorta and arteriovenous malformations (3% to 9% of patients with 

intracranial AVMs have berry aneurysms), but fusiform aneurysms are not. Fungi cause arteritis and aneurysmal 

change but not the elongated vessel distention of dolichoectasia. HIV occasionally is associated with but perhaps 

not the direct cause of smaller vessel vasculitis. 

References: 


Question 80: Pathology - Epilepsy 

Discussion: 

Although the etiology of hippocampal (Ammon's horn sclerosis) is controversial, with some authors contending 

the lesions are the cause, and others the result, of the seizures, the lesion is nonetheless the most common 

pathology found in patients with tissue resected for temporal lobe epilepsy. Seizure control after temporal 

lobectomy is best with hippocampal sclerosis but is also very good with neoplasms and vascular malformations, 

although these are less common causes of temporal lobe epilepsy. End folium sclerosis with neuronal loss 

confined to the CA4 sector of the hippocampus is rare, as is Rasmussen's encephalitis. 

References: 

Burger P,Scheithauer B,Vogel FS. Surgical Pathology of the Nervous System and Its Coverings. 4th ed. 

Philadelphia: Churchill Livingstone, 2002. 

Question 93: Pathology - Critical Care/Trauma 

Discussion: 

Hemorrhage and necrosis of the central core of the spinal cord usually results from traumatic subluxation injury 

of the cervical spine. Rarely, hematomyelia can also result from intraspinal vascular malformations. 

References: 



64

Question 104: Pathology - Epilepsy 

Discussion: 

Of the tumor types listed, the most likely to show a superficial cystic appearance and to occur in the temporal 

lobe of a young adult is the pleomorphic xanthoastrocytoma (PXA), a WHO grade II tumor. Eosinophilic 

granular bodies are histological features most commonly found in low grade gliomas, such as pleomorphic 

xanthoastrocytoma. They are small aggregates of eosinophilic, hyaline material situated in the processes of 

astrocytes. 

References: 



Question 133: Pathology - Tumors 

Discussion: 

Angiotropic (intravscular) lymphoma is a disease of multiple organs that involves the central nervous system in 

greater than 30% of cases. It is usually a B cell lymphoma by immunophenotyping, and causes multiple small 

brain infarcts, often of deep white matter. A patient with CNS involvement by angiotropic lymphoma may show 

lymphoma cells only within the blood vessels and may not have either intraparenchymal lymphomatous masses 

or significant meningeal involvement. The old name for this tumor prior to the advent of specific 

immunohistochemical markers for lymphoma was "malignant angioendotheliomatosis", reflceting the erroneous 

belief that the tumor cells were endothelial in origin. 

References: 


Question 135: Pathology - Toxic/Metabolic Disease 

Discussion: 

Peripheral neuropathies can be caused by inorganic arsenic, lead, mercury, and thallium. Aluminum intoxication 

can produce an encephalopathy but does not produce a neuropathy. Cyanide, manganese, and bismuth do not 

cause peripheral neuropathy. 

References: 


Question 139: Pathology - Hypothalmus/Pituitary 

Discussion: 

Bromocriptine (Parlodel) and cabergoline are dopamine agonists that function by the same mechanism as 

prolactin inhibitory factor (PIF, which is dopamine) to inhibit prolactin synthesis and release by 

prolactin-secreting pituitary adenomas (prolactinomas). Bromocriptine or cabergoline treatment causes a 

decrease in the tumor cell cytoplasmic volume without actually killing the adenoma cells. Therefore, the 

prolactinoma may reexpand if bromocriptine is withdrawn. Bromocriptine has no significant role in 

neuro-oncology other than in suppression of prolactin-secreting tumors. 

References: 



Question 156: Pathology - Neurodegenerative Disease 

Discussion: 


65

Familial frontotemporal dementia that arises from a mutation on chromosome 17 results in a mutation of the 

gene encoding for tau protein. 

References: 

Ellison D, Love S, Chimelli L, et al. Neuropathology: A Reference Text of CNS Pathology. 2nd ed. Edinburgh: 

Mosby, 2004. 


Discussion: 

Critical care myopathy is an underrecognized disorder characterized by selective loss of myosin from myofibers. 

Also known as myosin-losing myopathy, this disorder is most commonly seen in critically ill patients treated 

with corticosteroids and neuromuscular blockers. 

References: 

Ruff RL. Why do ICU patients become paralyzed? Ann Neurol 1998;43:154-155. 


Discussion: 

Hemorrhagic necrosis of the putamen is characteristic of methanol poisoning. Methanol may be ingested as an 

alcohol substitute. There is selective vulnerability of the putamen, among the choices listed. 

References: 

Schochet SS, Gray F. Acquired Metabolic Disorders. In: Gray F, De Girolami U, Poirier J. Escourolle and 

Poirier Manual of Basic Neuropathology. 4th ed. Boston: Butterworth Heinemann 2004; 198. 


Discussion: 

Corticobasal degeneration classically presents with progressive asymmetric apraxias, rigidity, and/or aphasia due 

to neuronal loss and atrophy of the peri-Sylvian region. Ballooned neurons and astrocytic plaques with 

tau-immunoreactivity are a diagnostic feature of corticobasal degeneration. 

References: 


Questions 224 - 228: Pathology - Neuromuscular Disease 

Discussion: 

Perifascicular atrophy is virtually pathognomonic of dermatomyositis and is particular characteristic of juvenile 

dermatomyositis. The image is of an onion bulb or hypertrophic neuropathy and best matches a clinical scenario 

suggestive of an indolent demyelinating neuropathy such as Charcot-Marie-Tooth disease 1a. The figure depicts 

a ragged-red fiber as are seen in some, but not all mitochondrial encephalomyopathies. The ocular system, 

including the eye and ocular muscles are frequently involved in mitochondrial disease. This shows an H&E 

stained muscle fiber with a rimmed vacuole, characteristic of the most common inflammatory in older adults, 

inclusion body myositis. Neurogenic atrophy (group atrophy) of skeletal muscle is characteristic of spinal 

muscular atrophy type I (Werdnig-Hoffman disease). 

References: 


Lidov H, De Girolami U, Gherardi R. Skeletal muscle diseases. In: Gray F, De Girolami U, Poirier J. Escourolle 

and Poirier Manual of Basic Neuropathology. 4th ed. Boston: Butterworth-Heinemann, 2004; 

287,302-304,309-312,308-310. 

Vallat J-M, Anthony D, De Girolami U. Peripheral Nerve Diseases. In: Gray F, De Girolami U, Poirier J. 

66

Escourolle and Poirier Manual of Basic Neuropathology. 4th ed. Boston: Butterworth-Heinemann 2004; 337-338. 

Question 229: Pathology - Developmental 

Discussion: 

This brain shows multiple areas of cavitation (liquefaction necrosis) involving the deeper cortical layers and 

underlying white matter, a condition known as multicystic encephalopathy or multicystic encephalomalacia. 

The lesions are most pronounced in the distribution of the anterior and middle cerebral arteries. They are the 

result of circulatory disturbances during the latter half of pregnancy or the neonatal period. 

References: 

Nelson J, Mena H, Parisi JE, Schochet SS, editors. Principles and Practice of Neuropathology. 2nd ed. New 

York: Oxford University Press, 2003. 


Discussion: 

The biopsy of a right parietal lobe mass showed a tumor composed of cells with monotonous round nuclei 

surrounded by prominent perinuclear halos ("fried egg" apppearance). These features are characteristic of 

oligodendroglioma. Of the other choices listed, ependymomas and astroblastomas characteristically show 

perivascular pseudorosettes, with stout nontapering cytoplasmic processes in the latter. Fibrillary astrocytomas 

and gemistocytic astrocytomas show eosinophilic cytoplasm rather than the clear perinuclear halos of 

oligodendrogliomas, with multiple elongated cytoplasmic processes in fibrillary astrocytomas and large rounded 

globular cytoplasm in gemistocytic astrocytomas. 

References: 




Discussion: 

The microscopic appearance is that of a capillary-rich neoplasm with abundant foamy cells containing lipid. This 

is a hemangioblastoma. The cell origin of the hemangioblastoma is still unknown, despite many investigative 

efforts. The tumor arises independently or in conjunction with von Hippel-Lindau disease. The most common 

location is in the cerebellum, but the spinal cord can also be a site of origin. Pilocytic astrocytomas, also 

commonly found in the cerebellum, are composed of astrocytes with elongate, bipolar, eosinophilic cell 

processes; these tumors often show Rosenthal fibers. Medulloblastomas are malignant small blue cell tumors of 

neuronal origin that manifest little visible cytoplasm. Ependymomas are glial tumors which show formation of 

ependymal canals, or more commonly, perivascular pseudorosettes. 

References: 




Discussion: 

Autosomal dominant cerebral cavernous angioma (malformation) (CCM1) syndrome occurs in Hispanic 

individuals and is characterized by intraparenchymal cavernous malformations that can produce seizures, 

impairment of function, or hemorrhage. The photograph illustrates a multi-channeled vascular malformation 

composed of closely juxtaposed hyalinized, non-arterial vessels. 

References: 



67

Mosby, 2004. 

Question 249: Pathology - Neuromuscular Disease 

Discussion: 

The muscle biopsy specimen shows a necrotizing vasculitis with fibrinoid necrosis of the vessel walls, not 

amyloid angiopathy. Vasculitis may be seen in amphetamine-induced vasculitis, polyarteritis nodosa, rheumatoid 

vasculitis, and Wegener's granulomatosis, but not in polymyalgia rheumatica which is associated with temporal 

arteritis and usually type II fiber atrophy in the muscle biopsy, not vasculitis. Takayasu's arteritis affects large 

blood vessels such as aortic arch, not small intramuscular vessels. ALS causes no inflammation of intramuscular 

blood vessels, but does show neurogenic atrophy. 

References: 




Discussion: 

The lesion shown in this image is a remote infarct. The preservation of the outer layer of the cortex would argue 

against a remote contusion. An old hematoma cavity would be smoother, and would not necessairly be confined 

to the vascular distribution territory of a branch of the middle cerebral artery as this lesion is. Both an abscess 

and metastatic carcinoma would be accompanied by brain swelling rather than shrinkage; note the lack of mass 

effect on the ventricular system. 

References: 



Discussion: 

The gross findings are those of a remote hemorrhagic stroke. Microscopically, the blood vessels of the meninges 

and cortex showed amorphous eosinophilic material indicative of cerebral amyloid angiopathy. Neither primary 

or secondary systemic amyloidoses cause amyloid deposits within cerebral blood vessels. Cerebral autosomal 

dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) deposits would not stain 

with amyloid stains such as thioflavin S or Congo red and would not be as homongeneous or affect the 

superficial cortex and meninges. Chronic hypertension causes thickened walls of small blood vessels due to 

hyalinization and lipohyalinosis; no amyloid is deposited. 

References: 



Discussion: 

The defect is anencephaly, the most common of the neural tube closure defects. Folate supplementation has been 

known to lower the recurrence risk of these defects however a recent report also documents the presence of 

anti-folate receptor antibodies in some pregnancies complicated by neural tube closure defects. 

References: 


Rothenberg SP, da Casta M, Sequeira J, et al. Autoantibodies against Folate Receptors in Women with a 

Pregnancy Complicated by a Neural-Tube Defect. N Engl J Med 2004;350:134-142. 

Encha-Razavi F, Folkerth R, Harding B. Congenital Malformations and Perinatal Diseases. In: Gray F, De 

Girolami U, Poirier J. Escourolle and Poirier Manual of Basic Neuropathology. 4th ed. Boston: 

68

Butterworth-Heinemann, 2004; 250. 


Discussion: 

The graphic shows an acute subdural hematoma. Subdural hematomas result from disruption of bridging veins 

and are seen more commonly in older persons with cortical atrophy with resultant tension on these veins. The 

inciting trauma often is a fall, but may not be recalled. 

References: 



Discussion: 

The photograph shows syringomyelia. The lesion consists of a large cystic space, which would not be seen with 

subacute combined degeneration, AIDS-associated myelopathy, or mutliple sclerosis. Syringomyelia is a cystic 

lesion in the spinal cord that interrupts the crossing pain fibers and damages anterior horn cells. Muscle atrophy, 

often results but vibratory, position, and touch senses are usually spared. 

References: 


Question 271: Pathology - Infectious Disease 

Discussion: 

The photograph shows abundant exudate, especially along vessels, in the subarachnoid space on the dorsal 

surface of the brain. This is most consistent with purulent leptomeningitis. Hemophilus influenzae rarely causes 

meningitis in the adult, and pneumococcal meningitis is more common than meningococcal meningitis in the 

elderly patient. With this history of alcoholism and asplenism, the most likely diagnosis is pneumococcal 

meningitis. 

References: 



Question 273: Pathology - Basic Reactions 

Discussion: 

The photograph shows Wallerian degeneration, with shrinkage of one medullary pyramid and atrophy of the 

ipsilateral cerebral peduncle. The Wallerian degeneration is secondary to destruction of the corticospinal tract 

above this level, such as an infarction in the posterior limb of the internal capsule. 

References: 



Discussion: 

The gross photograph of the brain shows lobar atrophy. Lobar atrophy of the frontal and temporal lobes is 

typical of Pick's disease. Microscopically, intracytoplasmic argyrophilic neuronal inclusions and gliosis are 

observed in Pick body Pick's disease. 

References: 


69



Discussion: 

The spinal cord shows tract degeneration in the dorsal spinocerebellar columns and posterior columns, with 

myelin loss highlighted by the Luxol fast blue-periodic acid Schiff stain for myelin. Tract degeneration is seen in 

Friedreich's ataxia, but not multiple sclerosis or acute disseminated encephalomyelitis. Tabes dorsalis affects the 

posterior columns of the spinal cord, but not the dorsal spinocerebellar tracts. 

References: 


Question 282: Pathology - Prion Disease 

Discussion: 

The image shows spongiform change of the cerebral cotex consistent with a prion disease. Neuronal loss and 

gliosis complete the classic histologic triad. Prion diseases are caused by misfolding of a normal cellular protein 

PrP. Such misfolding may be induced by mutation or by exposure of normal cellular prion protein to pathogenic 

prions. Misfolding alters the secondary structure such that the protein becomes highly resistant to chemical or 

thermal methods of strerilization. 

References: 



Discussion: 

The brain shows severe atherosclerosis of intracranial vessels as well as bilateral remote anterior cerebral artery 

infarctions. The ventricles are slightly enlarged due to hydrocephalus ex vacuo. This patient actually had a 

single, unpaired anterior cerebral artery, accounting for the bilateral nature of the infarctions. Bilateral anterior 

cerebral artery territory infarcts often result in profound apathy, lack of motivational intent, akinetic mutism, 

weakness of the lower extremities and urinary incontinence. 

References: 


Mosby, 2004. 


Discussion: 

The photograph shows a massive basal ganglionic hemorrhage with rupture into the ventricular system. The 

location of this hematoma is common for hypertensive intracerebral hemorrhage. Hypertension is a major risk 

factor for this type of hemorrhage, and hypertension is associated with pathologic and electrocardiographic 

evidence of left ventricular hypertrophy. Prostate cancer only rarely metastasizes to brain parenchyma and is 

usually not hemorrhagic. Visceral cysts are not relevant to intracerebral hemorrhage, but are frequently seen in 

von Hippel-Lindau disease with associated CNS hemangioblastoma. 

References: 



Discussion: 


70

Fungal infections with Coccidioides occur in regions of semiarid climate. In the United States, the Southwest 

and California are the most common locations for these infections. Mature fungi in tissue are endospores, such 

as the one pictured, which are round and have a refractile wall. 

References: 




Discussion: 

This photograph of a coronal section of immature brain shows small foci of dystrophic calcification in white 

matter corresponding to periventricular leukomalacia (PVL). This is the principal ischemic lesion of 

prematurity. Microscopy would show coagulative necrosis, dystrophic calcifications, microglial activation, and 

axonal injury. 

References: 

Encha-Razavi F, Folkerth R, Harding B. Congenital Malformations and Perinatal Diseases. In: Gray F, De 

Girolami U, Poirier J. Escourolle and Poirier Manual of Basic Neuropathology. 4th ed. Boston: 

Butterworth-Heinemann, 2004; 267. 


Discussion: 

The lesion is seen in the cortex of the gyri to the right of midline in this coronal section and is a typical example 

of laminar necrosis due to hypoxic/ischemic injury. 

References: 

Schochet SS, Gray F. Acquired Metabolic Disorders. In: Gray F, De Girolami U, Poirier J. Escourolle and 

Poirier Manual of Basic Neuropathology. 4th ed. Boston: Butterworth Heinemann 2004; 198. 


Discussion: 

Marburg's disease, also known as acute multiple sclerosis, can cause severe cerebral damage and render a 

patient comatose within a few weeks. The patient does not go into remission and may die within weeks or 

months after onset of the demyelinating disorder. 

References: 

Fernandez H, Eisenschenk S, Yachnis AT, Okun MS. Ultimate review for the neurology boards. 1st ed. New 

York: Demos Medical Publishing, 2006. 


Discussion: 

The nucleus of Onufrowicz of the sacral cord is spared in motor neuron disease. The remaining motor nuclei are 

involved to varying degrees in amyotrophic lateral sclerosis. 

References: 



Discussion: 


71

In tabes dorsalis, the degeneration is confined to the dorsal columns, whereas in AIDS myelopathy, amyotrophic 

lateral sclerosis, Friedreich's ataxia, and pernicious anemia degeneration occurs in other tracts. 

References: 



Discussion: 

Choline acetyltransferase is the synthetic enzyme for acetylcholine and is a marker of the axonal termini of 

cholinergic neurons. The neurons of the basal nucleus are the major cholinergic projections to the cerebral 

cortex, and with depopulation of this projection nucleus there is a corresponding reduction in cortical choline 

acetyltransferase. 

References: 



Discussion: 

Paraneoplastic cerebellar degneration is most commonly associated with ovarian carcinoma and some breast 

tumors. It can also be seen with Hodgkin's lymphoma and small cell carcinoma of the lung. 

References: 


Mosby, 2004. 


Discussion: 

Ethylene glycol toxicity has birefringent calcium oxalate deposits in and around blood vessels. Oxalic acid 

crystals may be detected in the urine. 

References: 



Discussion: 

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) 

results from missense mutations of the Notch 3 gene on chromosome 19. The small deep white matter vessels 

show replacement of the media by eosinophilic, periodic acid-Schiff positive, Congo red negative, granular 

material. Ultrastructurally, there is compact electron-dense material known as granular osmophilic material 

surrounding myocytes in the arterial media. Although the predominant effects of CADASIL are on the central 

nervous system, it is a systemic vasculopathy that can be appreciated on skin or nerve biopsy. Vasculitis is not 

seen in CADASIL. 

References: 


Mosby, 2004. 


Discussion: 


72

Patients with tuberous sclerosis have a variety of systemic and CNS tumors. In the brain, astrocytic hamartomas 

called tubers and candle gutterings are present. Subependymal giant cell astrocytomas are true neoplasms arising 

in the vicinity of the foramen of Monro. These tumors may produce CSF obstruction, and they may rarely 

undergo malignant degeneration. 

References: 



Kleihues P, Cavenee WK, editors. Pathology and genetics of tumors of the nervous system. 2nd ed. New York: 

Oxford University Press, 2000. 


Discussion: 

The injury described above fits best with a contrecoup type injury. The individual decelerates when he falls and 

strikes the back of his head. Because the head was in motion and he struck his occiput, the contrecoup sites will 

be the frontal lobes and temporal tips. The irregular bony contours within the cranial vault in the anterior and 

middle fossae exacerbate the injury. 

References: 




Discussion: 

Rhabdoid meningioma is a variant of meningioma that often has aggressive clinical behavior with numerous 

recurrences and the potential for metastasis. It is a World Health Organization (WHO) grade III tumor. Many 

meningiomas have distinctive histological appearances, such as secretory, fibrous, and psammomatous subtypes, 

but have no adverse prognosis associated specifically with their morphology and are usually WHO grade I 

tumors. 

References: 



Question 426: Pathology - Basic Reactions 

Discussion: 

The type of edema seen with acute, obstructive, high-pressure hydrocephalus is interstitial edema. Hydrostatic 

edema is seen when high arterial pressures overcome cerebrovascular resistance and drive water across the 

capillary walls into the extracellular space. Vasogenic edema is the most frequent type of edema and is seen 

around tumors or traumatic lesions. Hypo-ostomic edema occurs with marked reduction in serum osmolality, 

and cytotoxic edema is most commonly caused by hypoxia. 

References: 


Question 445: Pathology - Hypothalmus/Pituitary 

Discussion: 


Neurosarcoidosis is uncommon, even in patients with systemic sarcoidosis. Of the anatomic sites mentioned, the 

hypothalamus is most commonly affected. It may be assoicated with a peripheral neuropathy or myopathy and 

on biopsy is a histological diagnosis of exclusion. Specifically, fungi and tuberculosis must be eliminated as 

73

diagnoses in cases with granulomatous inflammation. 

References: 


Mosby, 2004. 

Pharmacology/Chemistry 

Question 5: Pharmacology/Chemistry - Movement Disorders 

Discussion: 

Suboptimal doses of carbidopa are a frequent cause of nausea/vomiting at the initiation of levodopa therapy. It 

takes 100 mg to 150 mg of carbidopa per day to saturate the peripheral aromatic aminoacid decarboxylase 

enzyme to prevent peripheral side effects of levodopa. Promethaziine and metaclopramide block dopamine 

receptors and may worsen the parkinsonism. 

References: 

Roger E, Kurlan JB. Treatment of movement disorders. Philadelphia: Lippincott, 1995. 

Question 18: Pharmacology/Chemistry - Neuromuscular Disorders 

Discussion: 

Vitamin B12 (cobalamin) plays an important role in DNA synthesis and neurologic function. Deficiency can lead 

to a wide spectrum of hematologic, neurologic, and psychiatric manifestations. It is a common cause of 

macrocytic (megaloblastic) anemia and, in advanced cases, pancytopenia. Neurologic sequelae from vitamin B12 

deficiency include paresthesias, peripheral neuropathy, and demyelination of the corticospinal tract and dorsal 

columns (subacute combined systems disease). The diagnosis of vitamin B12 deficiency has traditionally been 

based on low serum vitamin B12 levels, usually less than 200 pg per mL (150 pmol per L), along with clinical 

evidence of disease. However, studies indicate that older patients tend to present with neuropsychiatric disease in 

the absence of hematologic findings.Furthermore, measurements of metabolites such as methylmalonic acid and 

homocysteine have been shown to be more sensitive in the diagnosis of vitamin B12 deficiency than 

measurement of serum B12 levels alone 

References: 

Oh RC, Brown DL. Vitamin B12 Deficiency. Am Fam Physician 2003; 67(5):979-986. 

Question 20: Pharmacology/Chemistry - Headache 

Discussion: 

Giant cell emporal arteritis is a vasculitis can lead to devastating ophthalmic and systemic complications. Jaw 

claudication, superficial temporal artery tenderness, fever, and visual loss are seen. Treatment primarily to 

prevent visual loss requires extended management with corticosteroids - initially at a high dose (e.g. Prednisone 

80-100 mg/d). 

References: 

Bhatti MT, Tabandeh H. Giant cell arteritis: diagnosis and management. Curr Opin Ophthalmol 

2001;12(6):393-399. 


Discussion: 


Sumatriptan and other triptans are felt to provide acute relief for migraine by acting as 5HT1 receptors, 

specifically 1b and 1d, resulting in decreased activity in the trigeminovascular system. Drugs acting at 

adrenergic, specifically beta and alpha, receptors provide prophylactic effects. 

74

References: 

Tepper SJ, Rapoport AM, Sheftell FD. Mechanisms of action of the 5-HT1B/1D receptor agonists. Arch Neurol 

2002;59(7):1084-1088. 

Question 25: Pharmacology/Chemistry - Other Pain Syndromes 

Discussion: 

Transient receptor potential (TRP) ion channels are molecular gateways in sensory systems, an interface between 

the environment and the nervous system. Several TRPs transduce thermal, chemical, and mechanical stimuli 

into inward currents, an essential first step for eliciting thermal and pain sensations. Precise regulation of the 

expression, localization, and function of the TRP channels is crucial for their sensory role in nociceptor 

terminals, particularly after inflammation when they contribute to pain hypersensitivity by undergoing changes 

in translation and trafficking as well as diverse posttranslational modifications. 

References: 

Story GM, Gereau RW 4th. Numbing the senses: role of TRPA1 in mechanical and cold sensation. Neuron 

2006;50(2):177-180. 

Wang H, Woolf CJ. Pain TRPs. Neuron 2005;46(1):9-12. 


Discussion: 

Cluster headache will often respond acutely to oxygen inhalation at a flow rate of 8 L/min to 10 L/min via face 

mask. It may be triggered or exacerbated by vasodilating substances such as nitroglycerin, histamine, and 

ethanol. Drugs such as triptans, steroids, and dihydroergotamine may also be helpful in acute headache 

management. Verapamil, lithium, and methysergide can be effective prophylactic agents for cluster headaches. 

Oral analgesics such as codeine are generally ineffective in treating cluster headache, as are anticonvulsants and 

diuretics. 

References: 

Campbell JK, Caselli RJ. Headache and other craniofacial pain. In: Bradley WG, Daroff RB, Fenichel GM, et al, 

editors. Neurology in clinical practice. 2nd ed. Boston: Butterworth-Heinemann, 1996. 

Question 32: Pharmacology/Chemistry - Cerebrovascular Disease 

Discussion: 

Cessation of electrical activity due to hyperpolarization that occurs acutely after an ischemic insult is the result 

of activation of potassium (K+) membrane channels. 

References: 

Dugan LL, Kim-Han JS. Hypoxia-ischemic brain injusry and oxidative stress. In: Siegel GJ, Albers RW, Brady 

ST, Price DL, editors. Basic Neurochemistry: molecular, cellular, and medical aspects. Boston: Elsevier, 

2006;559-573. 

Question 50: Pharmacology/Chemistry - Epilepsy 

Discussion: 

Praziquantel is effective in treating cerebral cysticercosis. Active uninflamed cysts are responsive. Praziquantel 

will produce inflammation and edema as it kills the larva, which may temporarily result in symptoms such as 

headache. 

References: 


Garcia HH, Evans CA, Nash TE, et al. Current consensus guidelines for treatment of neurocysticercosis. Clin 

75

Microbiol Rev 2002;15(4):747-756. 


Discussion: 

Dyskinesias are more commonly associated with levodopa than direct dopamine agonists (DDAs). 

Hallucinations more commnon with the DDAs. Nausea, orthostatic hypotension roughly equal. Peripheral 

edema is not uncommon with DDAs, but rarely if ever seen with levodopa. 

References: 

Tintner R, Jankovic J. Dopamine agonists in Parkinson's disease. Expert Opin Investig Drugs 

2003;12(11):1803-1820. 


Discussion: 

Midodrine is a prodrug that is transformed in the liver to a potent agonist of alpha receptors in arteries and veins. 

Given its predictable absorption and peak effect, it is the sympathomimetic of choice for treatment of 

neurogenic orthostatic hypotension. One common side effect is scalp pruritus, a manifestation of alpha 

adrenergic mediated piloerection. Its most potentially serious side effect is supine hypertension. Midodrine 

should not be administered late in the evening and patients taking the drug should avoid lying flat. 

References: 

Jankovik J, Gilden JL, Hiner BC, et al. Neurogenic orthostatic hypotension: a double-blind, placebo-controlled 

study with midodrine. Am J Med 1993;95:38-48. 

Bradley WG, Daroff RB, Fenichel GM, et al, editors. Neurology in clinical practice. 3rd ed. New York: 



Discussion: 

Restless legs syndrome (RLS) is clinically defined as an urge to move the legs with or without paresthesia, 

worsening of symptoms with rest and transient improvement with activity, and worsening of symptoms in the 

evening and night. It is often genetic but may also occur in the setting of iron deficiency, uremia, pregnancy, 

neuropathy, and possibly other conditions. Among the current treatment options offered for the treatment of 

RLS, dopaminergic agents have provided the best evidence for efficacy in symptom relief. 

References: 

Ondo WG. Restless legs syndrome. Neurol Clin 2005;23(4):1165-1185, viii. 

Chahine LM, Chemali ZN. Restless legs syndrome: a review. CNS Spectr 2006;11(7):511-520. 


Discussion: 

Iron deficiency can cause (secondary) restless legs syndrome (RLS). In addition, evidence suggests that there is 

an abnormality in brain iron that somehow translates to a hypodopaminergic state in idiopathic RLS. 

References: 

Sun ER, Chen CA, Ho G, et al. Iron and the restless legs syndrome. Sleep 1998;21(4):371-377. 


Discussion: 


76

Type 1 (Andrade) familial amyloidosis, inherited as an autosomal dominant, is associated with amyloid 

deposition in peripheral nerves. It is characterized by progressive loss of pain and temperature sensation, 

lancinating pain, and severe generalized autonomic failure. Mutations have been demonstrated in the gene that 

codes for transthyretin, the protein that transports thyroxine and retinol binding protein. 

References: 

Bosch EP, Smith BE. Disorders of peripheral nerves. In: Bradley WG, Daroff RB, Fenichel GM, et al, editors. 

Neurology in clinical practice. 3rd ed. Boston: Butterworth-Heinemann, 2000. 

Question 88: Pharmacology/Chemistry - Neurogenetics 

Discussion: 

Dopa-responsive dystonia (DRD), in classic cases, manifests in early childhood with walking problems due to 

dystonia of the lower limbs. The dystonia is frequently accompanied by parkinsonian features such as reduced 

facial expression or slowing of fine finger movements. Biochemically, the disorder is typically characterized by 

low levels of the neurotransmitter metabolite homovanillic acid and reduced levels of neopterin and 

tetrahydrobiopterin (BH4) in the cerebrospinal fluid. This is due to heterozygote mutations of the GTP 

cyclohydrolase I gene, which is the rate-limiting enzyme in the synthesis of BH4. BH4 is an essential cofactor 

for tyrosine hydroxylase (TH), the rate-limiting enzyme in the synthesis of dopamine. Reduced levels of BH4 

lead to the dopamine-deficit syndrome DRD because of reduced TH activity. Other genes implicated in the 

pathogenesis of this disorder are the TH gene itself and the parkin gene. 

References: 

Bandmann O, Wood NW. Dopa-responsive dystonia -- the story so far. Neuropediatrics 2002;33(1):1-5. 


Discussion: 

Postherpetic neuralgia is the persistence of the pain of herpes zoster virus more than 3 months after resolution 

of the rash and is relatively common, affecting 10% to 15% of those with herpes zoster. Zoster-associated pain 

is used to describe the continuum of pain from acute herpes zoster to the development of postherpetic neuralgia. 

The time interval used in the clinical case definition of postherpetic neuralgia varies in the literature from 1 to 6 

months after resolution of the rash. The incidence of postherpetic neuralgia increases with age. Administration 

of antiviral agents within 72 hours of the onset of herpes zoster can reduce the intensity and duration of acute 

illness and can prevent postherpetic neuralgia. Efforts at prevention of herpes zoster and postherpetic neuralgia 

are important in that 40% to 50% of those with postherpetic neuralgia do not respond to any treatment. 

However, tricyclic antidepressants (amitriptyline, nortriptyline, desipramine, and maprotiline), gabapentin, 

pregabalin, opioids, and topical lidocaine patches are effective in reducing pain and improving quality of life and 

should be used in the treatment of postherpetic neuralgia. Aspirin in cream is possibly effective in the relief of 

pain in patients with postherpetic neuralgia, but the magnitude of benefit is low, as is seen with capsaicin. The 

effectiveness of carbamazepine, nicardipine, biperiden, chlorprothixene, ketamine, He:Ne laser irradiation, 

intralesional triamcinolone, cryocautery, topical piroxicam, extract of Ganoderma lucidum, dorsal root entry 

zone lesions, and stellate ganglion block are unproven in the treatment of postherpetic neuralgia. 

References: 

Dubinsky R, Kabbani H, El-Chami Z, et al. Practice Parameter: Treatment of postherpetic neuralgia: An 

evidence-based report of the Quality Standards Subcommittee of the American Academy of Neurology. 

Neurology 2004;63:959-965. 


Discussion: 


Oxcarbazepine is a derivative of carbamazepine and shares many similarities with carbamazepine, including its 

mechanism of action, ability to induce hepatic metabolism of oral contraceptives and other drugs, risk of 

hyponatremia, and indication for treatment of partial epilepsy. Unlike carbamazepine, oxcarbazepine is reduced 

to 10-monohydroxy-carbamazepine and does not undergo oxidation to an epoxide. This may explain its fewer 

77

side effects as compared to carbamazepine. 

References: 

Schmidt D, Elger CE. What is the evidence that oxcarbazepine and carbamazepine are distinctly different 

antiepileptic drugs? Epilepsy Behav 2004;5(5):627-635. 

Question 115: Pharmacology/Chemistry - Cerebrovascular Disease 

Discussion: 

The structural basis of the blood-brain barrier (BBB) is the presence of tight junctions (zonula occludens) 

between capillary endothelial cells. Tight junctions consist of macromolecular complexes, including the 

transmembrane proteins occludin and claudin, and the associated zonula occludens (ZO) proteins and cingulin. 

References: 

Huber JD, Egleton R, Davis TP. Molecular physiology of tight junctions in the blood-brain barrier. Trends 

Neurosci 2001;24:719-726. 

Question 117: Pharmacology/Chemistry - Neuromuscular Disorders 

Discussion: 

The findings are most consistent with propofol infusion syndrome. Propofol impairs mitochondrial fatty acid 

oxidation and oxidative phosphorylation. Propofol raises levels of malonylcarnitine that inhibits CPT1, blocking 

long chain fatty acid transport into mitochondria. Complex II function is secondarily inhibited. Children have 

limited carbohydrate stores, and require larger doses of propofol for sedation, thus placing them at higher risk of 

this syndrome than adults. Inadequate caloric intake before or during the infusion further increases the risk, by 

leading to inability to meet metabolic demands and suppress fat metabolism. Hemofiltration has been shown to 

correct the metabolic abnormalities in propofol infusion syndrome. Carbohydrate intakes of 6 mg/kg/min to 8 

mg/kg/min during propofol infusion might prevent it. 

References: 

Wolf A, Weir P, Segar P, et al. Impaired fatty acid oxidation in propofol infusion syndrome. Lancet 

2001;357:606-607. 


Discussion: 

Opioid withdrawal resembles severe influenza with the additional features of mydriasis, lacrimation, rhinorrhea, 

piloerection, yawning, sneezing, anorexia nausea, vomiting, and diarrhea. Delirium tremens and seizures do not 

occur. Classic withdrawal techniques utilize long-acting oral agents such as methadone. Studies of aggressive 

(rapid) withdrawal regimens used over 5 days have found that the least severe symptoms and shortest duration 

of withdrawal was achieved with a combination of naltrexone, clonidine, and buprenorphine. 

References: 

Kosten TR, O'Connor PG. Management of drug and alcohol withdrawal. N Engl J Med 2003;348:1786-1795. 


Discussion: 


Autosomal dominant hypokalemic periodic paralysis typically presents in the first 3 decades with episodes of 

weakness occurring following rest after exercise, particularly if the subject is exposed to high-carbohydrate 

meals, emotional stress, or cold. The respiratory and cardiac muscles are almost always spared, and attacks last 

for hours. Symptoms often resolve in later life, although patients may be left with residual weakness. Most 

patients have mutations in the skeletal muscle calcium channel gene, although mutations may be found in 

sodium and potassium channels in the remainder. Secondary hypokalemic paralysis occurs in older patients with 

chronic medical problems predisposing them to hypokalemia. Preventive treatment with acetazolamide is usually 

78

effective in abolishing or attenuating episodes, and oral potassium supplements may be helpful during acute 

attacks. Some patients require the use of potassium-sparing diuretics such as spironolactone or triamterene. 

Nephrolithiasis is a complication of long-term therapy with acetazolamide and should be screened for with 

annual ultrasound examinations. 

References: 

Jones HR, De Vivo DC, Daras BT, editors. Neuromuscular disorders of infancy, childhood and adolescence. 

Philadelphia: Butterworth-Heinemann, 2003. 

Question 136: Pharmacology/Chemistry - Dementia 

Discussion: 

Frontotemporal dementia (FTD) is the most common syndrome in which the focus of neurodegeneration is the 

frontal lobes. FTD is frequently familial. It is also often due to a susceptibility locus on chromosome 17q21-22. 

Some 17q21-22-linked families have mutations in the tau gene and most have microscopically visible aggregates 

of hyperphosphorylated tau. Demonstrating that mutations in tau can produce neurodegeneration will necessitate 

a reassessment of the role of tau in the pathogenesis of the many diseases in which tau biology is disrupted. 

References: 

Wilhelmsen KC. Frontotemporal dementia genetics. J Geriatr Psychiatry Neurol 1998; 11(2):55-60. 


Discussion: 

Chronic paroxysmal hemicrania is considered a syndrome with two pivotal characteristics: (1) unilateral 

headache of moderate intensity, with episodes lasting under 45 minutes on average, occurring multiple times 

throughout the day, and at a 3:1 ratio female:male; and (2) absolute response to indomethacin. Patients may also 

complain of a continuous low-grade headache in between the more severe attacks (hemicrania continua). 

References: 

Pareja JA, Antonaci F, Vincent M. The hemicrania continua diagnosis. Cephalalgia 2001;21(10):940-946. 


Discussion: 

Anticholinergic agents such as trihexyphenidyl have been used in the treatment of Parkinson's disease (PD) since 

the 19th century. Anticholinergic drugs are typically used in younger PD patients (

Question 174: Pharmacology/Chemistry - Aging, Degenerative Diseases 

Discussion: 

Midodrine is a prodrug that is converted in the liver to an alpha agonist. Its predictable absorption and 

pharmacokinetics makes it the drug of choice for treatment of orthostatic hypotension unresponsive to 

fludrocortisone. 

References: 

Riley DE. Orthostatic hypotension in multiple system atrophy. Curr Treat Options Neurol 2000;2(3):225-230. 

Question 181: Pharmacology/Chemistry - Sleep Disorders 

Discussion: 

Beagles with inherited narcolepsy-cataplexy were intially shown to have defective orexin receptors. In humans, 

where narcolepsy is associated with human leucocyte antigen (HLA) abnormalities, recent studies have shown 

that narcolepsy with cataplexy is usually caused (>90%) by the lack of two related brain chemicals called 

hypocretin-1 and hypocretin-2. The cause of narcolepsy without cataplexy is still under investigation. Over 90% 

of patients with narcolepsy-cataplexy carry HLA-DQB1*0602. This marker is more specific and sensitive than 

the old marker HLA-DR2, and so it is speculated that patients with narcolepsy-cataplexy probably have an 

autoimmune disorder. 

References: 

Zeitzer JM, Nishino S, Mignot E. The neurobiology of hypocretins (orexins), narcolepsy and related therapeutic 

interventions. Trends Pharmacol Sci 2006;27(7):368-374. 


Discussion: 

A-delta nociceptive fibers use glutamate as their fast transmitter. C-fiber slower transmitted nociception involves 

a number of neurotransmitters and neuromodulators, the most important of which is substance P. 

References: 

Costigan M, Scholz J, Samad T, Woolf CJ. Pain. In: Siegel GJ, Albers RW, Brady ST, Price DL, editors. Basic 

Neurochemistry: molecular, cellular, and medical aspects. Boston: Elsevier, 2006;927-937. 

Questions 209 - 213: Pharmacology/Chemistry - Neuromuscular Disorders 

Discussion: 


1. Unrecognized copper deficiency appears to be a common cause of idiopathic myelopathy in adults. The 

clinical picture bears striking similarities to the syndrome of subacute combined degeneration associated with 

vitamin B12 deficiency. Early recognition and copper supplementation may prevent neurological deterioration. 

2. Juvenile myoclonic epilepsy is a common type of epilepsy with onset occurring during adolescence. This is a 

fairly common type of epilepsy, which can develop between 8 and 26 years of age but usually starts between 

ages 12 and 16. Historically, the large majority of patients become seizure-free when treated with valproate. 3. 

Neuromyotonia is a rare condition of spontaneous and continuous muscle fiber activity of peripheral nerve 

origin. It represents the more severe phenotype of peripheral nerve hyperexcitability and, when acquired, is often 

associated with antibodies to voltage-gated potassium channels. There are no specific published 

electromyographic or clinical diagnostic criteria for this disorder. Carbamazapine, topiramate, and gabapentin 

have all shown efficicacy. 4. Hyperkalemic periodic paralysis involves attacks of muscle weakness or paralysis, 

alternating with periods of normal muscle function. Attacks usually begin in early childhood. They tend to occur 

while resting after exercise or exertion. Attacks may also be triggerd by cold expsoure or eating small amounts 

of potassium. It is not associated with low potassium in the bloodstream (serum potassium). Glucose or other 

carbohydrates (sugars) given during an attack may reduce the severity. Intravenous calcium or diuretics such as 

furosemide may need to be given to stop sudden attacks. Intravenous glucose and insulin cause potassium to 

move into the cell and may reduce weakness without a loss of total body potassium. A high-carbohydrate diet 

may be recommended. Acetazolamide, a medication that prevents attacks of familial periodic paralysis, is also 

80

may be recommended. Acetazolamide, a medication that prevents attacks of familial periodic paralysis, is also 

effective in preventing attacks of hyperkalemic periodic paralysis. Thiazide diuretics such as chlorothiazide are 

also effective and have fewer side effects than acetazolamide. 5. Tourette syndrome (TS) is a neurological 

disorder characterized by repetitive, stereotyped, involuntary movements and vocalizations called tics. Tics are 

classified as either simple or complex. Neuroleptics are the most consistently useful medications for tic 

suppression; a number are available but some are more effective than others (for example, haloperidol and 

pimozide). Alfa-adrenergic agents such as guanifencine and clonidine are first-choice treatments for TS; typical 

antipsychotics are more effective but are troublesome because of their long-term side effect profiles. 

References: 

Verrotti A, Manco R, di Marco G, et al. The treatment of juvenile myoclonic epilepsy. Expert Rev Neurother 

2006;6(6):847-854. 

Jurkat-Rott K, Lerche H, Lehmann-Horn F. Skeletal muscle channelopathies. J Neurol 2002;249(11):1493-1502. 

Maddison P. Neuromyotonia. Clin Neurophysiol 2006;117(10):2118-2127. 

Shavitt RG, Hounie AG, Rosario Campos MC, Miguel EC. Tourette's Syndrome. Psychiatr Clin North Am 

2006;29(2):471-486. 

Kumar N, Gross JB Jr, Ahlskog JE. Copper deficiency myelopathy produces a clinical picture like subacute 

combined degeneration. Neurology 2004;63(1):33-39. 


Discussion: 

Cabergoline, pergolide, bromocriptine, and dihydroergocriptine are all ergot-derived dopamine agonists that 

have been associated with serosal fibrosis syndromes. Ropinirole is a nonergoline and does not have this adverse 

effect. 

References: 

Tintner R, Manian P, Gauthier P, Jankovic J. Pleuropulmonary fibrosis after long-term treatment with the 

dopamine agonist pergolide for Parkinson Disease. Arch Neurol 2005;62(8):1290-1295. 


Discussion: 

Vigabatrin enhances GABAergic transmission by inhibiting GABA transaminase, thus increasing GABA 

concentration at the synapse. The other agents listed inactivate sodium channels. 

References: 

Mcnamara JO. Drugs effective in the therapy of the epilepsies. In: Hardman JG, Limbierd LE, Goodman AG, 

editors. Goodman and Gilman's The Pharmacological Basis of Therapeutics, 10/e. New York: McGraw-Hill, 

2001;521-547. 


Discussion: 


Familial periodic paralyses are typical channelopathies (ie, caused by functional disturbances of ion channel 

proteins). The episodes of flaccid muscle weakness observed in these disorders are due to underexcitability of 

sarcolemma leading to a silent electromyogram and the lack of action potentials even upon electrical 

stimulation. Interictally, ion channel malfunction is well compensated so that special exogenous or endogenous 

triggers are required to produce symptoms in the patients. An especially obvious trigger is the level of serum 

potassium (K+), the ion responsible for resting membrane potential and degree of excitability. The clinical 

symptoms can be caused by mutations in genes coding for ion channels that mediate different functions for 

maintaining the resting potential or propagating the action potential, the basis of excitability. The phenotype is 

determined by the type of functional defect brought about by the mutations rather than the channel effected 

81

ecause the contrary phenotypes hyperkalemic periodic paralysis (HyperPP) and hypokalemic periodic paralysis 

(HypoPP) may be caused by point mutations in the same gene. Still, the common mechanism for inexcitability 

in all known episodic-weakness phenotypes is a long-lasting depolarization that inactivates sodium ion (Na+) 

channels, initiating the action potential. 

References: 

Jurkat-Rott K, Lerche H, Lehmann-Horn F. Skeletal muscle channelopathies. J Neurol 2002;249(11):1493-1502. 


Discussion: 

Restless legs syndrome (RLS) is clinically defined as an urge to move the legs with or without paresthesia, 

worsening of symptoms with rest and transient improvement with activity, and worsening of symptoms in the 

evening and night. It is often genetic but may also occur in the setting of iron deficiency, uremia, pregnancy, 

neuropathy, and possibly other conditions. Effective treatments include dopaminergics and narcotics. Its 

underlying pathogenesis is presently unknown. Women are more affected than men and early-onset disease is 

associated with familial cases. The excellent response to dopaminegic drugs points to a central role of dopamine 

in the pathophysiology of RLS. Iron may also represent a primary factor in the development of RLS, as 

suggested by recent pathological and brain imaging studies. However, the way dopamine and iron, and probably 

other compounds, interact to generate the circadian pattern in the occurrence of RLS and periodic limb 

movement symptoms remains unknown. Altered circadian rhythmicity in dopamine metabolism and enhanced 

circadian variations in dopaminergic functions have been reported in the disorder. Dysfunction or atrophy of 

cells from the diencephalic-spinal dopamine system has been suggested to explain the efficacy of dopaminergic 

drugs in relieving RLS symptoms and the circadian rhythmicity of RLS. Studies support the hypothesis that 

these dopaminergic neurons and spinal pathways may be more involved in the pathophysiology of RLS than the 

nigrostriatal system. Among the current treatment options offered for the treatment of RLS, dopaminergic agents 

have provided the best evidence for efficacy in symptom relief. 

References: 

Ondo WG. Restless legs syndrome. Neurol Clin 2005;23(4):1165-1185, viii. 

Clemens S, Rye D, Hochman S. Restless legs syndrome: revisiting the dopamine hypothesis from the spinal 

cord perspective. Neurology 2006 Jul 11;67(1):125-130. 

Barriere G, Cazalets JR, Bioulac B, et al. The restless legs syndrome. Prog Neurobiol 2005;77(3):139-165. 


Discussion: 

Drugs that inhibit carbamazepine metabolism results in elevated levels and toxicity. These include phenytoin, 

cimetidine, diltiazem, erythromycin, verapamil, fluoxetine, and isoniazid. Alternately, carbamazapine can 

accelerate hepatic breakdown of a number of drugs, including its own metabolism. The most common 

interaction is with oral contraceptives, sodium valproate, ethosuximide, corticosteroids, anticoagulants, 

antipsychotics, cyclosporine, and methylphenidate. Meperidine and methylphenyldate can lower the seizure 

threshold in epilepsy patients resulting in worsening seizures independent of antiepileptic therapy. 

References: 

Ruffmann C, Bogliun G, Beghi E. Epileptogenic drugs: a systematic review. Expert Rev Neurother 

2006;6(4):575-589. 

Pauwels O. Factors contributing to carbamazepine-macrolide interactions. Pharmacol Res 2002;45(4):291-298. 

Question 353: Pharmacology/Chemistry - Demyelinating Disorders 

Discussion: 


Interferon-beta-1b (Betaseron, Betaferon) is a nonglycosylated recombinant human interferon-beta approved for 

high-frequency subcutaneous (SC) administration in the treatment of multiple sclerosis (MS). Its mechanism of 

82

action is unknown but may involve modulation of the autoimmune pathogenic processes of MS. In a 

randomized, double-blind trial in patients with relapsing-remitting MS (RRMS), SC interferon-beta-1b 250 

micrograms (8 million International Units [MIU]) every other day reduced the annual relapse rate and increased 

the proportion of relapse-free patients compared with placebo. It also reduced relapse severity, hospitalizations, 

and disease activity assessed by MRI and increased the time to first relapse. 

References: 

Jacobs LD, Beck RW, Simon JH, et al. Intramuscular interferon beta-1a therapy initiated during a first 

demyelinating event in multiple sclerosis. CHAMPS Study Group. N Eng J Med 2000;343(13):898-904. 

Question 367: Pharmacology/Chemistry - Dementia 

Discussion: 

Loss or dysfunction of the acetylcholine projection to the cerebral cortex has been shown experimentally in 

humans and animals to result in cognitive disturbance. Loss of neurons from the nucleus Basalis of Meynert was 

shown early on to characterize patients with Alzheimer's disease. Recent studies however have shown that the 

depletion of cortical acetylcholine has been significantly more severe in patients with dementia with Lewy 

bodies that even in Alzheimer's disease. Neither fund a temporal dimension or Huntington's disease has 

significant loss of cortical cholinergic projections, at least in early to moderate stages. Vascular dementia shows 

variable loss, depending on where the vascular lesions are; in addition, many of these patients have mixed 

Alzheimer's/vascular pictures. 

References: 

Samuel W, Alford M, Hofstetter CR, Hansen L. Dementia with Lewy bodies versus pure Alzheimer disease: 

differences in cognition, neuropathology, cholinergic dysfunction, and synapse density. J Neuropathol Exp 

Neurol 1997;56(5):499-508. 

Question 380: Pharmacology/Chemistry - Aging, Degenerative Diseases 

Discussion: 

Amyotrophic lateral sclerosis (ALS) is a chronic neurodegenerative disease of upper and lower motor neurons. 

Clinically, patients present with skeletal muscle weakness, muscle atrophy, and hyperreflexia. Symptoms 

progress to death in 50% of those affected within 3 to 5 years after symptom onset. Death is usually related to 

respiratory failure. Ten percent of cases are inherited and 20% of these are linked to mutations of the superoxide 

dismutase 1 gene. 

References: 

Miller RG, Rosenberg JA, Gelinas DF, et al. Practice Parameter: The care of the patient with amyotrophic lateral 

sclerosis (an evidence-based revew): Report of the Quality Standards Subcommittee of the American Academy 

of Neurology. Neurology 1999;52:1311. 


Discussion: 


Patients with newly diagnosed epilepsy who require treatment can be initiated on standard antiepileptic drugs 

(AEDs), such as carbamazepine, phenytoin, valproic acid, phenobarbital, or on the new AEDs, lamotrigine, 

gabapentin, oxcarbazepine, or topiramate. The choice of the AED should depend on the characteristics of the 

patient, including potential interaction with concomitant medications. Carbamazapine, topiramate, valproic acid, 

gabapentin, and lamotrogine have reported efficacy as monotherapy or as adjunct therapy for newly diagnosed 

epilepsy. In addition, studies have demonstrated that carbamazepine, valproate, and lamotrigine are also 

effective in the treatment of acute mania and suggest efficacy as maintenance therapy in bipolar disorder. Recent 

studies do not support the efficacy of topiramate as monotherapy or adjunct therapy of acute mania or mixed 

episodes in adults with bipolar I disorder. Topiramate has also been associated with changes in serum lithium 

levels and lithium toxicity and therefore would not be indicated for primary treatment of epilepsy in bipolar 

patients well controlled on lithium. 

83

References: 

Gajwani P, Forsthoff A, Muzina D, et al. Antiepileptic drugs in mood-disordered patients. Epilepsia 

2005;46(Suppl 4):38-44. 

Abraham G, Owen J. Topiramate can cause lithium toxicity. J Clin Psychopharmacol 2004;24(5):565-567. 

Vasudev K, Macritchie K, Geddes J, et al. Topiramate for acute affective episodes in bipolar disorder. Cochrane 

Database Syst Rev 2006 Jan 25;(1):CD003384. 


Discussion: 

Dystrophin is a membrane-bound protein distributed along the intracellular surface of the sarcolemma and is a 

member of the superfamily of cytoskeletal proteins; dystrophin interacts with actin and may contribute to 

structural and functional stability of the plasma membrane. 

References: 

Jones HR, De Vivo DC, Darras BT, editors. Neuromuscular disorders of infancy, childhood and adolescence. 

Philadelphia: Butterworth-Heinemann, 2003. 


Discussion: 

Valproate can produce hair loss that rarely requires discontinuation of the drug. 

References: 

Holland KD. Efficacy, pharmacology, and adverse effects of antiepileptic drugs. Neurol Clin 2001;19:313-345. 


Discussion: 

For migraine prevention, individual medications have been put into treatment groups based on their established 

clinical efficacy, significant adverse events, safety profile, and clinical experience of the US Headache 

Consortium participants: Group 1 medications (amitryptiline, divalproex sodium, propranolol/timolol) have 

proven high efficacy and mild to moderate adverse events. Group 2 medications (verapamil, nonsteroidal 

anti-inflammatory drugs, gabapentin, vitamin B2) with lower efficacy (ie, limited number of studies, studies 

reporting conflicting results, efficacy suggesting only “modest” improvement) and mild to moderate adverse 

events. Group 3 medication (topiramate, diltiazam, antidepressants) are used based on opinion, not randomized 

controlled trials, and may have low to moderate or frequent or severe adverse events. Group 4 medication 

(methysergide) has shown proven efficacy but frequent or severe adverse events (or safety concerns) or complex 

management issues. Group 5 (tegretol, clonidine, clonazepam) medications are proven to have limited or no 

efficacy. 

References: 

Silberstein S. Practice parameter: Evidence-based guidelines for migraine headache (an evidence-based review). 

Report of the Quality Standards Subcommittee of the American Academy of Neurology. Neurology 2000; 55: 

754-763. 


Discussion: 

Mutations of the FIL-1 gene in chromosome Xq28, encoding for filamin-1, produce periventricular heterotopy. 

This reflects a complete failure of neuronal migration that may cause seizures. It is dominant in females and 

lethal in males. Filamin-1 interacts with actin and is critically involved in the early phases of migration. 

References: 


84

Gleeson JG, Walsh CA. Neuronal migration disorders: from genetic disease to developmental mechanisms. 

Trends Neurosci 2000; 22:402-410. 


Discussion: 

Pseudoseizures represent the opposite end of the spectrum from seizures that mimic psychiatric disorders: they 

are paroxysmal changes in behavior that resemble epileptic seizures but are without organic cause and expected 

EEG changes. Accurately distinguishing pseudoseizures from epilepsy and other illnesses is difficult because of 

the breadth and overlap of symptoms seen in each condition and because of the frequent co-occurrence of 

pseudoseizures and epilepsy. For the assessment of true seizure versus pseudoseizure, EEG is indicated in the 

peri-ictal evaluation. Emergent or urgent neuroimaging should be considered if there is a new seizure pattern or 

new seizure type or prolonged postictal confusion or worsening mental status. Elevated serum prolactin assay, 

when measured in the appropriate clinical setting at 10 to 20 minutes after a suspected event, is a useful adjunct 

for the differentiation of generalized tonic–clonic or complex partial seizure from psychogenic nonepileptic 

seizure among adults and older children. However, the use of serum prolactin assay has not been established in 

the evaluation of status epilepticus, repetitive seizures, and neonatal seizures. 

References: 

Chen D, So Y, Fisher R. The use of serum prolactin level in diagnosisng epileptic seizures. Report of the 

Therapeutics and Technology Assessment Subcommittee of the American Academy of Nuerology. Neurology 

2005;65:668-675. 

Physiology 

Question 24: Physiology - EMG 

Discussion: 

Common peroneal nerve divides into superficial and deep branches. Injury to the deep branch weakens the toe 

and foot dorsiflexors, with sensory changes over the web of the skin between the first and second toe.Lesion of 

the superficial branch affects the everters, with sensory deficit over most of the dorsum of the foot. Injury to the 

femoral nerve weakens the quadriceps muscle. Injury to the obturator nerve weakens the adductors, internal and 

external rotators of the thigh. Injury to the tibial nerve weakens the foot inverters, dorsiflexors and intrinsic foot 

muscles. 

References: 

Question 28: Physiology - EEG 

Discussion: 

Although periodic waveforms can be seen in other conditions, the presence of generalized periodic 1 Hz sharp 

waves with progressive dementia is strongly suggestive of Creutzfeldt-Jakob disease. 

References: 

Niedermeyer E, Lopes da Silva F, editors. Electroencephalography: basic principles, clinical applications, and 

related fields. 4th ed. Philadelphia: Lippincott, Williams & Wilkins, 1998. 


Discussion: 

Drowsiness in a normal adult will slow background rhythm on the EEG to theta activity and sometimes bursts of 

generalized moderate-to-high amplitude 5 Hz to 7Hz theta can be seen. Frontocentral beta activity will increase 

in prominence during drowsiness (16 Hz to 20 Hz) and occasionally bursts of faster activity can be seen. 

References: 


85

Daly DD, Pedley TA. Current practice of clinical electroencephalography. 2nd ed. New York: Raven Press, 

1990. 

Question 30: Physiology - Autonomic Studies 

Discussion: 

The Valsalva maneuver evaluates the baroreflex arc and its sympathetic and parasympathetic responses. The 

maneuver consists of four phases. In phase 4, there is overshoot of the blood pressure due to the persistent 

increase in peripheral resistance, normalization of venous return, and stroke volume. The mean blood pressure 

can increase by more than 10 mm Hg. If the blood pressure does not increase, this indicates dysfunction of the 

sympathetic response. 

References: 

Hilz MJ, Dutsch M. Quantitative studies of autonomic function. Muscle Nerve 2006;33:6-20. 


Discussion: 

The presence of periodic lateralized sharp wave discharges in a patient with a recent febrile illness and onset of 

seizures would strongly suggest herpes simplex encephalitis. 

References: 




Discussion: 

Early signs of Guillain-Barre syndrome include diminished or lost muscle stretch flexes. Electrophysiological 

studies reveal slowing of peripheral conduction velocity as well as increased central conduction time, including 

prolonged F-waves and distal motor latencies. Interestingly, the disease tends to spare the sural nerve sensory 

action potential, often regarded as one of the first affected in other neuropathies. Reduction of amplitude of 

compound muscle action potentials with distal stimulation implies a poor prognosis. 

References: 

Kimura J. Electrodiagnosis in diseases of nerve and muscle: principles and practice. 2nd ed. Philadelphia: Davis, 

1989;470-472. 

Murray NMF, Wade DT. The sural sensory action potential in Gullain-Barre syndrome. Muscle Nerve 

1980;3:444. 


Discussion: 

Long-term use of chlorpromazine has been reported to lead to generalized paroxysmal bursts in EEGs. 

References: 

Engel J, Pedley TA, editors. Epilepsy - a comprehensive textbook. Philadelphia: Lippincott-Raven, 1998. 


Discussion: 


Lesions of the upper trunk of the brachial plexus will cause weakness in proximal upper extremity with 

abnormal SNAPs on NCS in the radial and median nerves. The deltoid muscle is innervated by the axillary 

86

nerve which arises from the upper trunk/posterior cord. The biceps muscle is innervated by the 

musculocutaneous nerve which arises from the upper trunk/lateral cord. 

References: 

Kimura J. Electrodiagnosis in disease of nerve and muscle. 3rd ed. New York: Oxford University Press, 2001. 


Discussion: 

Increased jitter is seen in a variety of neuromuscular disorders and is not specific to any particular disease. Jitter 

is not increased in metabolic myopathies and steroid myopathies. 

References: 

Stalberg E, Trontelj JV. Single fiber electromyography. 2nd ed. New York: Raven Press, 1994. 


Discussion: 

Myotonic discharges may be present as spontaneous activity on EMG in myopathies. End plate spikes originate 

from the motor end plate. Fasciculations, myokymia and neuromyotonia all originate from the motor axon. 

References: 

Preston DC, Shapiro BE. Electromyography and neuromuscular disorders: clinical-electrophysiologic 

correlations. 2nd ed. Philadelphia: Elsevier, 2005. 


Discussion: 

Fascioscapulohumeral dystrophy patients have weakness of the facial muscles, shoulder and upper arm muscles 

(sparing deltoids usually), and foot dorsiflexors, frequently with asymmetry. EMG is not specific but can often 

show fibrillation potentials and short-duration, low amplitude, polyphasic motor unit action potentials. 

References: 



Discussion: 

In a postsynaptic disorder (ie, myasthenia gravis), rapid repetitive stimulation causes no change in the 

compound muscle action potential. There would typically be a >10% decrement seen on slow repetitive 

stimulation. A significant increment on rapid repetitive stimulation is typically seen in presynaptic disorders 

(Lambert-Eaton myasthenic syndrome, botulism). 

References: 

Katirji B, Kaminski HJ. Electrodiagnostic approach to the patient with suspected neuromuscular junction 

disorder. Neurol Clin N Am 2002;20:557-586. 


Discussion: 

Generalized beta activity (activity over 14 Hz) can be seen as a consequence of drug use, particularly 

benzodiazepines or barbiturates. 

References: 


87




Discussion: 

In compression neuropathies, sensory fibers are usually affected first with conduction changes. The median 

palmar sensory latency prolongation is the earliest change seen on EMG/nerve conduction studies in patients 

with mild carpal tunnel syndrome. 

References: 



Discussion: 

Favorable prognostic factors on EEG are variability, reactivity to external stimuli, varying sleep patterns, 

increase in background frequencies. Poor prognostic factors are invariant pattern, no reactivity, monorthythmic 

pattern, burst suppression, generalized periodic discharges, very low voltage tracing, and generalized 

suppression. Over 96% of the patients with poor prognostic findings on the EEG following a cardiac arrest 

either die within a few days after the cardiopulmonary arrest or if they survive, do so in a persistent vegetative 

state. 

References: 

Daube JR, editor. Clinical Neurophysiology. New York: Oxford University Press, 2002;98-101. 

Daube JR, editor. Clinical Neurophysiology. Continuum: Lifelong Learning in Neurol 1998:4(5);41. 

Question 91: Physiology - Sleep 

Discussion: 

The goal of the multiple sleep latency test is to quantitate physiological sleepiness during waking hours and to 

determine the occurrence of REM sleep near sleep onset. The goal of polysomnography is to quantitate the 

amount of time spent in various stages of sleep during the night and to document clinically relevant events such 

as cardiopulmonary abnormalities or sleep-related abnormal motor activity. Electro-oculogram, surface 

electromyography of all four limbs, and EEG recording are all used while performing polysomnography and 

multiple sleep latency test. 

References: 



Discussion: 

Preganglionic separation of the cell bodies with lesions at the root level preserves the anatomic and physiologic 

integrity of the peripheral axon. Despite sensory loss, nerve stimulation elicits a normal sensory action potential. 

A preganglionic involvement spares the sensory nerve action potential, although degeneration of the motor 

axons leads to muscle atrophy and reduction in amplitude of compound muscle potentials. The deep cervical 

muscles receive innervation from the posterior, as opposed to anterior rami of the spinal nerves. Evidence of 

denervation here indicates an intraforaminal lesion affecting the root or spinal nerve prior to the division into 

the two rami. 

References: 


Kimura, J. Electrodiagnosis in diseases of nerve and muscle: principles and practice. 2nd ed. Philadelphia: 

Davis, 1989;448-449. 

88


Discussion: 

Femoral nerve innervates the hip flexors and knee extensor muscles. 

References: 



Discussion: 

In elderly patients in coma, EEG showing diffuse spike-and-wave discharges is most consistent with 

nonconvulsive status epilepticus. Barbiturate overdose will show excessive beta activity on EEG. Alpha coma 

will show diffuse nonreactive alpha rhythm. Metabolic encephalopathy usually shows diffuse slowing. 

Pseudoseizures would have a normal EEG pattern. 

References: 




Discussion: 

Alzheimer’s disease is associated with a decrease or loss of alpha and beta activity at an earlier stage than other 

disorders associated with dementia. Generalized periodic sharp waves and invariant alpha pattern are poor 

prognostic indicators on EEG and are usually seen after cardiopulmonary arrest. Triphasic waves are seen in 

50% of patients with hepatic coma. Excessive beta activity may been seen due to medications like 

benzodiazepines or barbiturates. 

References: 



Discussion: 

Isolated visible muscle twitching for several years with no other concurrent symptoms is most consistent with 

fasciculation potentials as seen in benign fasciculation syndrome. 

References: 



Discussion: 

The H-reflex is the electrophysiological equivalent of the monosynaptic tendon stretch reflex at the ankle. 

References: 



Discussion: 


Polio is a motor neuron disease. Adults who had polio when they were younger may have large polyphasic 

89

Polio is a motor neuron disease. Adults who had polio when they were younger may have large polyphasic 

motor unit action potentials, due to reinnervation. They may also have some fibrillation and fasciculation 

potentials. 

References: 



Discussion: 

The patient's examination localizes to the right L5 root. Both the gluteus medius and peroneus longus muscles 

receive their major innervation from the L5 nerve root. 

References: 

Brown WF, Bolton CF, editors. Clinical electromyography. 2nd ed. Boston: Butterworth-Heinemann, 1993. 


Discussion: 

Inclusion body myositis is an inflammatory myopathy with common clinical presentation of distal upper 

extremity and proximal lower extremity weakness. It occurs more frequently in older patients. EMG shows 

diffuse irritability and fibrillation potentials, as in amyotrophic lateral sclerosis, but the motor unit action 

potentials are small and polyphasic. 

References: 

Day JW, Ranum LPW. Myotonic Disorders in Neuromuscular Disorders. In: Katirji B, Kaminski HJ, Preston 

DC, et al, editors. Clinical Practice. Woburn, Mass: Butterworth-Heinemann, 2002;1078-1091. 


Discussion: 

The short head of the biceps femoris muscle is the only muscle proximal to the knee to receive innervation via 

the peroneal division of the sciatic nerve. 

References: 



Discussion: 

Light sensitivity manifested by photomyoclonus induced by photic stimulation can occur with abrupt alcohol 

withdrawal. 

References: 

Niedermeyer E, Lopes da Silva F. Electroencephalography. 4th ed. Baltimore: Lippincott, Williams & Wilkins, 

1998. 


Discussion: 

The pattern most commonly seen in children between the ages of 3 and 10 who have absence seizures is 

generalized 3 Hz spike-and-wave discharges. 

References: 


90

Pedley TA, Mendiratta A, Walczak TS. Seizures and epilepsy. In: Ebersole JS, Pedley TA, editors. Current 

Practice of Clinical Electroencephalography. 3rd ed. Philadelphia: Lippincott, Williams & Wilkins, 2003; 

506-587. 


Discussion: 

First dorsal interosseus muscle is innervated by the ulnar nerve and C8 and T1 nerve roots. 

References: 



Discussion: 

Hereditary neuropathy with liability to pressure palsies may present in childhood. Other family members may or 

may not be symptomatic. Electrophysiologic studies reveal conduction blocks at sites of pressure and mild 

diffuse slowing. 

References: 

Jones HR, Bolton CF, Harper CM. Pediatric clinical electromyography. Philadelphia: Lippincott, Wiliams & 



Discussion: 

Lennox-Gastaut syndrome is characterized clinically by frequent generalized seizures of mixed type in 

association with mental retardation and a slow spike-and-wave EEG pattern with increasing disorganization 

during sleep. 

References: 


1998. 

Question 168: Physiology - Basic Physiology 

Discussion: 

Depolarization of action potentials causes an initial negative departure from baseline due to rapid opening of 

voltage-sensitive sodium channels. Closing of these channels due to an intrinsic inactivation time constant as 

well as slow opening of voltage-sensitive potassium channels results in repolarization of the wave. 

References: 



Discussion: 

The extensor indicis proprius (EIP) is innervated by the posterior interosseous nerve. This is derived from the 

posterior cord, lower trunk of the brachial plexus. The ulnar and median innervated muscles of the hand are 

supplied by the lower trunk, medial cord of the brachial plexus. Thus, if the EIP is involved, then the medial 

cord could not be the primary site of the lesion. 

References: 



91

correlations. 2nd ed. Philadelphia: Elsevier, 2005; 59-64. 


Discussion: 

Alpha rhythm is normal background rhythm seen in posterior head regions in adults. It ranges from 8 Hz to 13 

Hz. 

References: 


1990. 


Discussion: 

Vertex or V-waves are high-voltage sharp-contoured waveforms that can occur with phase reversals on a bipolar 

montage over the central areas. 

References: 

Klass DW, Westmoreland BF. Electroencephalography: general principles and adult electroencephalograms. In: 

Daube JR, editor. Clinical Neurophysiology. Philadelphia: FA Davis, 1996. 


Discussion: 

Photic stimulation is performed to assess for EEG evidence of susceptibility to photosensitive seizures, which is 

manifested as an epileptiform response, and for the occipital driving response. 

References: 

Fisch BJ, So EL. Activation methods. In: Ebersole JS, Pedley TA, editors. Current practice of clinical 

electroencephalography. 3rd ed. Philadelphia: Lippincott, Williams & Wilkins, 2003;246-270. 


Discussion: 

Focal polymorphic delta is seen with hemispheric lesions such as infarct or tumor and is nonspecific as to 

etiology. It generally is seen with processes involving white matter. Subdural hematoma will typically produce 

attenuation of EEG amplitude in the region of the lesion. 

References: 

Klass DW, Westmoreland BF. Electroencephalography: general principles and adult electroencephalograms. In: 

Daube JR, editor. Clinical neurophysiology. Philadelphia: FA Davis, 1996. 


Discussion: 

The EEG shows typical centrotemporal spikes, often associated with benign rolandic epilepsy of childhood, 

which is manifested by clonic movements of the face and hand that often progress to a more generalized seizure. 

References: 


1998. 



92

Discussion: 

Anterior eyeblinks (first second of the page), facial muscle EMG artifact (throughout the page), and an occipital 

dominant alpha rhythm (throughout the page) are characteristic of wakefulness. 

References: 

Blume WT, Kaibara M. Atlas of adult electroencephalography. New York: Raven Press, 1995. 


Discussion: 

An EEG showing triphasic waves is consistent with a metabolic encephalopathy, most commonly hepatic 

encephalopathy. 

References: 




Discussion: 

The EEG was recorded in drowsiness and shows positive sharp waves in occipital leads. These are positive 

occipital sharp transients and are normal phenomenon in sleep. 

References: 


1990. 


Discussion: 

Subacute sclerosing panencephalitis is associated with periodic long-interval diffuse discharges in the EEG that 

recur every 4 to 15 seconds. 

References: 

Klass DW, Westmoreland BF. Electroencephalography: principles and adult electroencephalograms. In: Daube 

JR, editor. Clinical neurophysiology. Philadelphia: FA Davis, 1996. 


Discussion: 

This EEG shows generalized polyspikes and spike-wave discharges, the EEG correlate of primary generalized 

epilepsy syndromes, which are variously characterized by generalized tonic-clonic seizures, generalized 

myoclonic seizures, or absence seizures. 

References: 

Pedley TA, Mendiratta A, Walczak TS. Seizures and epilepsy. In: Ebersole JS, Pedley TA, editors. Current 

Practice of Clinical Electroencephalography. 3rd ed. Philadelphia: Lippincott, Williams & Wilkins, 2003; 

506-587. 


Discussion: 


Stage REM is identified by relatively mixed frequency EEG and the presence of rapid eye movements. In some 

93

subjects, a characteristic sawtooth pattern is intermittently observed in the EEG. EMG drops to the lowest level 

of recording. 

References: 

Rechtschaffen A, Kales A. Manual of standardized terminology, techniques and scoring systems for sleep stages 

of human subjects. Los Angeles: UCLA Brain Information Service/Brain Research Institute, 1968. 


Discussion: 

The minimum duration required for a respiratory event to be called as obstructive apnea or hypopnea is 10 

seconds in an adult. 

References: 

Pack AI. Advances in sleep-disordered breathing. Am J Respir Crit Care Med 2006;173:7-15. 

Chesson A, Ferber R, Fry J, et al. Practice parameters for the indications for polysomnography and related 

procedures. Sleep 1997;20:406. 


Discussion: 

While managing a patient with obstructive sleep apnea, current symptoms, especially daytime sleepiness, AHI, 

and co-morbid cardio/cerebro-vascular, metabolic, and pulmonary disorders should be taken into consideration. 

As indicated by the AHI, he has moderate obstructive sleep apnea (OSA), co-morbid poorly controlled 

hypertension and diabetes with significant daytime sleepiness. Therefore, his OSA should be aggressively 

managed to decrease the daytime sleepiness, and possibly better control the hypertension and diabetes. Among 

the options listed, CPAP if used appropriately, is 100 % effective and thus would be the best option. Surgery 

has a success rate of ~ 50% with a high relapse rate. A dental appliance is good for only mild obstructive sleep 

apnea. Weight loss should be encouraged in all sleep apnea patients with BMI > 25; however, it is not helpful by 

itself. Hypnotic use by itself in moderate to severe obstructive sleep apnea might worsen sleep apnea and thus is 

not the best option. 

References: 

Pack AI. Advances in sleep-disordered breathing. Am J Respir Crit Care Med 2006;173:7-15. 

Chesson A, Ferber R, Fry J, et al. Practice parameters for the indications for polysomnography and related 

procedures. Sleep 1997;20:406. 


Discussion: 

Frontal intermittent rhythmic delta activity can be seen with a variety of lesions including posterior fossa lesions, 

encephalopathy, intracranial lesions, and increased intraventricular pressure. REM sleep is associated with a 

low-voltage desynchronized EEG. 

References: 

Niedermeyer E, Lopes da Silva F. Electroencephalography. 3rd ed. Baltimore: Williams & Wilkins, 1993. 


Discussion: 

Electrocerebral inactivity is defined as no EEG activity over 2 microvolts. 

References: 



94



Discussion: 

Normal variants during drowsiness and sleep include 14 Hz and 6 Hz positive waves, small sharp spikes, wicket 

spikes, 6 Hz spike-and-wave, and rhythmic temporal theta. Subclinical rhythmic electrographic discharges of 

adults (SREDA) is a normal variant during wakefulness. 

References: 



Discussion: 

Tetanus toxin targets synaptobrevins in the presynaptic nerve terminal, blocking docking of the vesicle and 

release of neurotransmitters. Alpha-bungarotoxin and curare bind to the nicotinic AChR in muscle. Brevetoxin 

primarily causes prolonged sodium channel opening. Tetrodotoxin blocks sodium channels. 

References: 



Kandel ER, Schwartz JH, Jessel TM. Principles of neural science. 4th ed. New York: McGraw-Hill, 2000. 


Discussion: 

Both Guillain-Barré syndrome (GBS) and chronic inflammatory demyelinating polyneuropathy (CIDP) are 

acquired demyelinating autoimmune neuropathies. The CSF and electrodiagnostic findings are quite similar, and 

cannot distinguish one from the other. The interval between onset of symptoms and disease plateau is the main 

distinguishing feature, with the vast majority of GBS patients reaching a plateau within four weeks of disease 

onset. 

References: 



Discussion: 

An incremental response to tetanic stimulation indicates a presynaptic defect at the neuromuscular junction. In 

an infant, the most likely reason for developing this is from intestinal botulism. 

References: 

Jones HR, Bolton CF, Harper CM. Pediatric clinical electromyography. Philadelphia: Lippincott, Wiliams & 



Discussion: 

The blink reflex is elicited by stimulation of the supraorbital nerve. Stimulation elicits an R1 response on the 

side of stimulation and R2 responses bilaterally. In a unilateral trigeminal lesion, the ipsilateral R1 and both R2 

latencies will be prolonged; stimulation on the normal side will show normal latencies of all responses. 

References: 


95


correlations. 2nd ed. Philadelphia: Elsevier, 2005; 59-64. 


Discussion: 

Ethosuximide, used to treat absence seizures, binds to calcium channels in the thalamus. 

References: 

Harden CL. New antiepileptic drugs. Neurology 1994;44:787-795. 


Discussion: 

Nerve impulses conduct faster at a higher body temperature. Lower temperature augments the amplitude of the 

nerve and the muscle potential. Both motor and sensory fibers conduct substantially more slowly in the legs than 

in the arms. The nerve impulse propagates faster in the proximal than in the distal nerve segments. A reduction 

in the mean conduction rate of about 10% is seen at age of 60 and above. Aging also causes a diminution in 

amplitude and changes in the shape of the evoked potential. Nerve conduction velocities are higher in large 

myelinated fibers. 

References: 

Kimura, J. Electrodiagnosis in diseases of nerve and muscle: principles and practice. 2nd ed. Philadelphia: 

Davis, 1989;94-97. 


Discussion: 

The electrical fields that generate EEG signals are the result of inhibitory and excititory postsynaptic potentials 

(IPSPs and EPSPs) on the apical dendrites of cortical neurons. Pyramidal neurons contribute the plurality of the 

signal. 

References: 

Swanson TH. Basic cellular and synaptic mechanisms underlying the electroencephalogram. In: Levin KH, 

Lüders HO, editors. Comprehensive clinical neurophysiology. Philadelphia: WB Saunders, 2000;349-385. 


Discussion: 

Myotonic dystrophy is a multisystem disease that can cause cardiac conduction defects, early cataracts, frontal 

balding, ptosis, facial weakness, hip girdle and finger flexor weakness as well as hypogammaglobulinemia, 

endocrine and CNS abnormalities. Electrophysiologic studies demonstrate myotonic discharges, even when there 

is minimal to no clinical myotonia elicitable. 

References: 



Question 388: Physiology - Evoked Potentials 

Discussion: 


A reduced P100 amplitude of a pattern reversal evoked potential on one side is most likely due to decreased 

visual acuity in that eye. 

96

References: 

Chiappa KH. Evoked potentials in clinical medicine. 3rd ed. New York: Lippincott-Raven, 1997. 


Discussion: 

The EEG record is generated by recording electrical potential differences between pairs of electrodes. The 

universal convention is that negative potential differences are represented by a deflection above the baseline, ie, 

up. 

References: 

Hamer HM, Lüders HO. Electrode montages and localization potentials in clinical electroencephalography. In: 

Levin KH, Lüders HO, editors. Comprehensive clinical neurophysiology. Philadelphia: WB Saunders, 

2000;358-386. 


Discussion: 

In Bell’s palsy, facial nerve conduction studies assess the facial nerve distal to the stylomastoid foramen only. 

Blink reflexes allow assessment of the nerve proximal to the stylomastoid foramen, including the intraosseus 

portion. 

References: 



Discussion: 

In upper extremity somatosensory evoked potential (SEP), after stimulation of the median or ulnar nerve in the 

wrist, activity can be recorded at the elbow, erbs point cervical spine, and scalp. The N5 potential is recorded in 

the median or ulnar nerve. The N9 potential is recorded at the Erb’s point. The N11 potential is recorded at the 

dorsal root entry zone. The N13 potential is created by dorsal column of the cervical cord and N14 potential 

represents activity in the nucleus cuneatus or medial lemniscus at the cervicomedullary junction. The activity 

recorded over the frontal lobe is seen by the N30 peak. 

References: 



Discussion: 

Damage to the long thoracic nerve can occur with neck surgical procedures, resulting in scapular winging due to 

weakness of the serratus anterior muscle. 

References: 



Discussion: 


Brainstem auditory evoked potentials (BAEPs) have five measurable waves. Presumed anatomical location for 

the source of these waves are as follows: wave I - distal action potential of CN VIII; wave II - ipsilateral 

proximal CN VIII or cochlear nucleus; wave III - ipsilateral superior olivary nucleus; wave IV - nucleus or axon 

of lateral lemniscus; wave V - inferior colliculus; wave VI - medial geniculate body; wave VII - thalamocortical 

97

pathways. In brain death, peak I may still be present. 

References: 

Daube JR, editor. Clinical neurophysiology. Philadelphia: FA Davis, 1996. 

Question 420: Physiology - Autonomic Studies 

Discussion: 

Painful neuropathies and significant reflex sympathetic dystrophy can both cause persistent or “hung up” sweat 

responses with the quantitative sweat testing (QSART). 

References: 



Discussion: 

In hepatic coma, the EEG often shows a triphasic wave pattern consisting of medium to high-voltage broad 

triphasic waves that occur rhythmically and bilaterally synchronous and symmetrical fashion over the two 

hemispheres. They have a fronto-occipital or occipitofrontal time lag [2]. The triphasic waves usually have a 

frontal predominance[3]. 

References: 


Kass D, Westmoreland B. Electroencephalography: general principles and adult electroncephalograms In: 

Daube JR, editor. Clinical neurophysiology. New York: Oxford University Press, 2000;98. 

Bickfor RG, Butt HR. Hepatic coma: the electroencephalographic pattern. J Clin Invest 1955;34:790-799. 

Fisch BJ, Klass DW. The diagnostic specificity of triphasic wave patterns. Electroencephalogr Clin 

Neurophysiol 1988;70:1-8. 

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