0521779407-17 CUNY1086/Karliner 0 521 77940 7 June 4, 2007 21:19
1218 Prion Disorders■Progression to akinetic mutism or coma typically over months
■Accounts for 85% of all cases of CJD
Transmissible Form: Rare
■Human-to-human transmission
➣Cannibalism
➣Corneal transplantation
➣Improperly sterilized surgical instruments
➣Human growth hormone
■Animal to human transmission
➣New variant CJD (or bovine spongiform encephalopathy)
➣Characterized by early onset (mean age 30 yr)
➣More prolonged course than sporadic CJD
➣Prominent psychiatric abnormalities
Familial Forms
■Fatal familial insomnia (dementia & ataxia)
■Gerstmann-Straussler-Scheinker syndrome (disturbance of sleep,
autonomic & endocrine function)
■Signs & symptoms include memory loss, behavioral abnormalities,
myoclonus (often induced by startle), extrapyramidal signs (rigidity,
bradykinesia, tremor, dystonia, chorea or athetosis), pyramidal signs,
cerebellar signs
tests
■Diagnosis made clinically
■Lab tests: blood & urine unremarkable
■EEG may show a typical but nonspecific pattern of periodic sharp
waves or spikes
■CSF protein may be mildly elevated
■Brain MRI may show mildly increased signal in the basal ganglia on
T2 images
■Biopsy: detection of PrPsc protein in brain or tonsillar tissue is diag-
nostic
■Genetic testing (research): available in familial formsdifferential diagnosis
■Alzheimer’s disease, Parkinson’s disease, progressive supranuclear
palsy excluded by history
■Hashimoto’s encephalopathy, drug intoxication (lithium), toxic
exposure (bismuth) and sedative drug withdrawal may be differen-
tiated by lab evaluation
■Intracerebral mass lesion excluded by brain imaging