Mohammed T. Abou-Saleh

336 PRINCIPLES AND PRACTICE OF GERIATRIC PSYCHIATRYTable 60.3 Focal central nervous system lesions associated withneuropsychiatric symptomsLocation of the lesionRight hemisphere (especiallytemporal lobe and central lesions)Temporal lobeCentral lesionsParietal lobe (left)Occipital lobe (left)Frontal lobeLeptomeningealMultifocal brain metastasesTemporal lobeOccipital lobe (right)Frontal lobeTemporal lobeCentral lesionsParietal lobe (left)Frontal lobeTemporal lobeCentral lesionsLeptomeningealOccipital lobe (left)Frontal lobeTemporal lobeCorresponding sign or symptomDelusions; schizophrenia-likebehavior; maniaHallucinationsDelirium; encephalopathy; abuliaAnxiety; irritabilityDepressionMemory impairmentEuphoria; facetiousnessof the tumor. Distractibility, indifference, disinhibition,euphoria or mania 43,62 , facetiousness, memory impairment52,53,55 , abulia, depression 31,43,45,54,64–67,73 and confusionare common in frontal lobe tumors 24,31,42,43,68,69 . Temporallobe lesions can produce memory dysfunction (especially inthe dominant hemisphere) 70–72 , depression, and intellectualimpairment 31,61,73,74 . Anxiety attacks, irritability, dissociativestates, altered sexual behavior, mania (in right-sided orbilateral lesions) 32,60,62,75 , and schizophrenic symptoms24,35,46,76–79 have also been noted. The delusions whichoccur in this setting are usually paranoid in content and lesscomplex in nature than those seen in true schizophrenia 80 .Non-epileptic visual and auditory hallucinations developoccasionally with frontal, temporal, parietal and occipitaltumors, and probably represent ‘‘release’’ phenomena 82,83 .They are frequently prolonged, non-stereotyped and complex,in contrast to hallucinations produced by a seizure.Tumors involving the limbic system, thalamus, basal ganglia,and diencephalon produce the next highest frequency ofpsychiatric symptoms 33,46,84–92 . Memory deficits 63 , including Korsakoff’ssyndrome 90 , depression 53 , apathy and psychomotorslowing, have been described. Delusions, visual hallucinations,disinhibition, childish behavior, mania 59,75,91,93,94 and violent oremotional outbursts are also common 92 .A smaller number of patients (20–30%) with tumorsconfined to the parietal lobe develop psychiatric symptoms 33,61 .Intellectual impairment, depression and (with right-sidedlesions) mania 34,44,60,95 are typical. Tumors of the occipitallobe are occasionally accompanied by behavioral symptoms 96 ,including memory impairment, irritability and visual hallucinations82,96,97 . Behavioral disturbance is a relatively unusualfinding in infratentorial tumors, although irritability, apathy,poor concentration and encephalopathy have all beenreported 31,46,98 and a well-characterized ‘‘cognitive affectivesyndrome’’ can occur in the setting of cerebellar tumors ortumor surgery 99 .Leptomeningeal carcinomatosis is heralded by confusion,memory loss and cognitive impairment in at least 20% of patients,and mental symptoms ultimately develop in the majority ofpatients 14,17,100–102 . While myelopathy, radiculopathy and pain arethe hallmarks of spinal cord and epidural tumors, psychiatricsymptoms have also been reported 103 .SeizuresSeizures are the presenting sign of primary and metastatic braintumors in one-quarter to one-third of patients, and occur in halfof such patients at some point 14,30,104,105 . For patients withleptomeningeal disease, the corresponding frequencies are 6–7%and 14–26% 14,16,17,30 . Tumors located in the frontal and temporallobes are most often associated with seizures; occipital lobe fociare uncommon; lesions in the basal ganglia, brainstem andcerebellum rarely if ever produce seizures 30,104,105 . Focal orgeneralized motor seizures are the most frequent and easilyrecognized seizure type; however, seizures may have solelybehavioral manifestations 105 . Confusion may be the only observedmanifestation of a seizure arising from any location. Visual andolfactory hallucinations may arise from frontal, temporal oroccipital lobe foci. Memory lapses 106 , feelings of anxiety orfearfulness 107 , aggressive, inappropriate or psychotic behavior 108and distortions of sound, space or size occur with temporal andfrontal lobe seizures 109–113 . Rarely, the sensation of fear can be sooverpowering that patients will run from a vaguely perceivedthreat (‘‘cursive’’ epilepsy) 114 . Visual, auditory and olfactoryhallucinations may be poorly formed (flashes of light, hissing orbuzzing, unpleasant smells) or quite elaborate 115 . Patients maydescribe familiar (de´ja` vu) or unfamiliar (jamais vu) pictures orsituations, snatches of music or overpowering (but inappropriate)feelings 112 . Disinhibition and feelings of compulsion 116 can occurwith frontal lobe seizures. Schizophrenic 101,116 and manic–depressivesymptoms 112–117 have been reported with temporal lobe foci inthe dominant and non-dominant, hemispheres, respectively.Depression, weeping or laughter (‘‘gelastic’’ epilepsy) alsooccur 114–118 . Although controversial, interictal behavioral abnormalitiesprobably develop in a higher percentage of epileptic thannon-epileptic patients 119–124 .Paraneoplastic DisordersPsychiatric disturbances can also be produced by a number ofindirect effects of cancer on the nervous system (Table 60.1). Ofthese, the neurologic paraneoplastic syndromes are the mostdifficult to diagnose 125–129 . These are seen much more frequently inthe setting of systemic cancer than with primary brain tumors,and produce identifiable syndromes resulting in profoundneurologic disability, in the absence of other causes. One type of‘‘remote effect’’, paraneoplastic encephalomyelitis (PEM), frequentlyproduces behavioral symptoms 129–132 . PEM is aninflammatory disorder of grey matter that may involve any levelof the CNS, including the limbic system, cerebellum and spinalcord. With limbic encephalitis, the gradual (average 10.5 months)onset of anxiety, depression, hallucinations, bizarre behavior,paranoia and marked impairment of recent memory, progressingto dementia (the ‘‘Ophelia syndrome’’) 132 , are characteristic. Inone-third of cases, behavioral symptoms precede the diagnosis ofcancer. Small cell carcinoma of the lung is the most commonunderlying malignancy, followed by breast, ovarian, gastric,testicular, uterine and non-small cell lung cancers and Hodgkin’sdisease. In addition to a characteristic clinical presentation andsetting, well-defined serum antibody markers (Hu, Ma/Ta, CV2)are often present 133–135 and characteristic MRI findings have alsobeen described 136,137 .