Frontal Lobe Syndromes & Disorders - Pgepsychiatry.com
Frontal Lobe Syndromes & Disorders - Pgepsychiatry.com
Frontal Lobe Syndromes & Disorders - Pgepsychiatry.com
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<strong>Frontal</strong> <strong>Lobe</strong> <strong>Syndromes</strong><br />
& <strong>Disorders</strong><br />
Joseph Tham<br />
BC Neuropsychiatry Program<br />
(Resident Presentation)<br />
josephth@interchange.ubc.ca
I. History<br />
Harlow J M (1868)<br />
• Case report of Phineas Gage (1823-1860)<br />
• Foreman of a railroad construction crew, Vermont<br />
• Setting explosives<br />
• Iron bar blown upward into his left maxilla (Sept 13, 1848)<br />
• Point exited to the left of the midline of the frontal skull<br />
• <strong>Frontal</strong> lobe injury
Freeman Transorbital <strong>Frontal</strong><br />
Leukotomy / Lobotomy
prefrontal<br />
cortex<br />
Major <strong>Frontal</strong> Divisions<br />
dorsolateral<br />
region<br />
orbitofrontal<br />
region<br />
premotor cortex<br />
Broca's area<br />
FRONTAL LOBE ANATOMY<br />
Motor Cortex<br />
precentral gyrus<br />
central sulcus
Prefrontal Cortex<br />
► 3 Subdivisions of the PREFRONTAL cortex:<br />
Dorsolateral region<br />
► Superior, middle, and inferior frontal gyri<br />
Dorsomedial region<br />
► Superior frontal gyrus<br />
► Cingulate gyrus<br />
Orbitofrontal region<br />
► Gyrus rectus (medial)<br />
► Orbital gyrus (lateral)
Superior <strong>Frontal</strong><br />
Gyrus<br />
Middle <strong>Frontal</strong><br />
Gyrus<br />
Inferior <strong>Frontal</strong><br />
Gyrus<br />
Dorsolateral Region
Dorsolateral Region (2)<br />
► Connections: Motor & sensory convergence areas,<br />
thalamus, basal ganglia (GP, caudate, SN)<br />
Lateral<br />
Prefrontal<br />
DL<br />
Caudate<br />
DM Globus<br />
Pallidus<br />
Substantia<br />
Nigra<br />
VA, MD<br />
Thalamus<br />
► Function: Executive Cognitive Functions (ECFs) [Fogel,<br />
2001]<br />
► Develop & execute plans for <strong>com</strong>plex goal-directed activities<br />
► Conform behaviour to social contingencies<br />
► Lesion: executive dysfunction, disinterest / emotional<br />
reactivity, inattention to relevant stimuli
Superior <strong>Frontal</strong> Gyrus<br />
Cingulate Gyrus<br />
Dorsomedial Region
Gyrus rectus<br />
Orbitofrontal gyrus<br />
Orbitofrontal Region
Phenomenology<br />
► 1. Emotional make-up & personality<br />
► 2. Abstraction & judgment<br />
► 3. Attention & memory<br />
► 4. Language
Phenomenology: Abstraction and<br />
Judgment<br />
– Awareness undisturbed<br />
– Concrete thinking<br />
– Diminished insight<br />
– Defect in planning / executive control
Sample Recency Memory Test<br />
(Gazzaniga, 2002)
Formal Tests<br />
– Wisconsin Card Sorting Test<br />
• Attention, working memory, visual processing,<br />
abstract thinking and set shifting; L > R hemisphere<br />
– Trail Making (Trails B)<br />
• Visuospatial & motor tracking, conceptualization, set<br />
shift<br />
– Stroop Color & Word Test<br />
• attention, shift sets; L > R hemisphere<br />
– Tower of London Test<br />
• planning
Tower of London<br />
In as few steps as possible, rearrange the pegs to resemble the<br />
configuration below.
Diseases Affecting <strong>Frontal</strong> <strong>Lobe</strong>s<br />
Traumatic brain injury<br />
– Gunshot wound<br />
– Closed head injury<br />
• Widespread stretching and shearing of fibers throughout.<br />
(Diffuse Axonal Injury / Traumatic Axonal Injury)<br />
• Orbito-frontal (and temporal) lobe more vulnerable<br />
• Shearing against underlying skull, SAH<br />
• Contusions and intracerebral hematomas<br />
<strong>Frontal</strong> <strong>Lobe</strong> seizures<br />
– Usually secondary to trauma<br />
– Difficult to diagnose: can be odd (laughter, crying, verbal automatism,<br />
<strong>com</strong>plex gestures)
Diseases (2)<br />
Vascular disease<br />
– Common cause especially in elderly<br />
– ACA territory infarction<br />
• Damage to medial frontal area<br />
– MCA territory<br />
• Dorsolateral frontal lobe<br />
– ACom aneurysm rupture<br />
• Personality change, emotional disturbance<br />
• Confabulation - <strong>com</strong>bination of damage to<br />
basal forebrain and frontal damage
Tumors<br />
– Gliomas, meningiomas<br />
Diseases (3)<br />
– Subfrontal and olfactory groove meningiomas: profound<br />
personality changes and dementia<br />
Multiple Sclerosis<br />
– <strong>Frontal</strong> lobes 2 nd highest number of plaques<br />
– Mood lability, memory problems, cognitive and<br />
behavioral effects… (see MS talk)
Diseases (4)<br />
Psychiatric Illness – proposed associations<br />
– Depression<br />
– Schizophrenia<br />
– OCD<br />
– ADHD<br />
– PTSD
Neurotransmitters…<br />
Glutamate - main excitatory<br />
GABA - main inhibitory<br />
Serotonin<br />
► 5HT1 - main transmitter in basal ganglia<br />
► 5HT3 - anterior cingulate (also hippocampus, amygdala)<br />
Dopamine<br />
► D1 - inhibitory (direct loop)<br />
► D2 - inhibitory (indirect loop)<br />
► D3, D4, D5 - region specific<br />
Acetylcholine - basal forebrain
► Cannabinoids<br />
Nabilone (Cesamet)<br />
∆ 9 THC (Marinol)<br />
Sativex - full plant extract<br />
► Anti-androgen<br />
Treatment (2)<br />
Cyproterone acetate, cimetidine
Take Home Message<br />
► Limited knowledge around biology & behavioural<br />
correlates.<br />
► Grossly speaking, 3 main neuropsychiatric<br />
syndromes - know them!<br />
► Neuropsychological testing may be essential in<br />
objective measurement of functional disturbance.<br />
BUT: Clinical judgment just as important (eg. WCST<br />
may be inaccurate)<br />
► Symptomatic treatments only…
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