True about Prion disease is all except:
Ans. (a) Myoclonus is seen in 10% of the patients Most patients with CJD exhibit myoclonus that appears at various times throughout the illness. Prion is proteinaceous infectious paicle that lacks nucleic acid and causes slow progressing disease. MC human prion disease is sporadic CJD. Clinical Features of CJD Most patient present with deficits in higher coical function which almost always progress to dementia. 90% patient exhibit myoclonus which persist during sleep in comparison of other involuntary movements. Also present with visual impairment or cerebellar gait, coordination deficit, extrapyramidal dysfunction, pyramidal signs, seizures. Diagnosis Constellation of dementia, myoclonus and peirodic electrical burst in an afebrile 60 years old patient generally indicates CJD. Only specific diagnostic test for CJD is measurement of PRPsc In humans the diagnosis of CJD as established by brain biopsy if PRPsc is detected. There is no abnoramlity on gross examination of brain. Pathologic hallmarks are spongiforms degeneration (in cerebral coex, putamen, etc.) and Astrocytic gliosis. - 10% of CJD patient have amyloid plaques. Sequencing the PRNP gene. CJ finding may be normal or show coical atrophy. CSF is nearly always normal but may show minimal protein elevation.
Myoclonus is seen in 10% of the patients
Caused by infectious protein
Brain biopsy is diagnostic
Commonly manifests as dementia