ð ç« æ«éèš
- Prion: protein-only infectious agent (PrPSc); causes TSE (transmissible spongiform encephalopathy)
- Sporadic CJD (85%): rapid dementia + myoclonus + ataxia; median survival 4-6 mo
- vCJD: BSE-related; younger onset 28 yr; tonsil + appendix biopsy+
- MRI: cortical ribbon + basal ganglia hyperintensity (DWI/FLAIR); âhockey stick signâ in vCJD
- EEG: periodic sharp wave complexes (PSWC) in sCJD
- CSF: RT-QuIC (most sensitive + specific) + 14-3-3 + tau
- No treatment; universally fatal
- Special prion decontamination for surgical instruments
- Differential: rule out treatable causes (autoimmune encephalitis, HSV, etc.)
- CWD in deer/elk â no documented human transmission but vigilance
ç§é«åž« hint
- Rapidly progressive dementia + myoclonus + ataxia â CJD considered; RT-QuIC + MRI + EEG; rule out treatable (autoimmune encephalitis especially)
- Family history of dementia â genetic CJD / familial prion testing
- UK resident 1980-1996 + neurodegeneration â vCJD consideration
- DONâT MISS treatable causes of rapidly progressive dementia