Creutzfeldt-Jakob Disease Medical Slides

Present the characteristic DWI and FLAIR patterns: cortical ribboning (high signal in cortical gyri in non-vascular distribution), caudate head and putamen hyperintensity, and thalamic pulvinar sign (specific for variant CJD). DWI is more sensitive than FLAIR. Emphasize that these patterns can precede clinical diagnosis and that MRI has >90% sensitivity for sCJD when DWI is included. Common mimics on MRI include status epilepticus, hypoxic-ischemic injury, and autoimmune encephalitis.

Present RT-QuIC as a paradigm shift: this CSF assay detects prion seeding activity with 92-97% sensitivity and 99-100% specificity for sCJD, effectively replacing brain biopsy for antemortem diagnosis. It is now included in the 2017 CDC diagnostic criteria as a supportive investigation. Compare with older markers: 14-3-3 protein (sensitivity 85-95%, poor specificity), total tau >1150 pg/mL (sensitivity 80-90%, specificity 90%). RT-QuIC has made "probable CJD" a clinical diagnosis without tissue confirmation.

Present key differences: vCJD affects younger patients (median age 28 vs 67 for sCJD), has longer duration (14 months vs 5 months), prominent psychiatric/behavioral onset, characteristic MRI "pulvinar sign" (bilateral posterior thalamic hyperintensity), positive tonsil biopsy for PrPSc, and methionine homozygosity at codon 129. Emphasize the epidemiological link to BSE ("mad cow disease") and the ongoing concern about secondary transmission via blood products.