| Characteristic | Variant CJD | Classic CJD |
| Median age at onset | 29 years | 65 years |
| Median duration of illness | 13 to 14 months | 4 to 6 months |
| Clinical signs and symptoms | Early onset of prominent psychiatric/behavioral symptoms and painful sensory symptoms; other neurologic signs develop later | Presents with dementia; early neurologic signs |
| Periodic sharp waves on electroencephalogram | Often absent | Often present |
| Pulvinar sign on MRI | Present in >75% of cases | Not reported |
| CSF RT-QuIC | Typically negative | Positive in >90% of cases |
| Posterior thalamic neuronal loss | Severe | Minimal |
| Florid plaques on neuropathology | Present in large numbers | Absent |
| PrP immunohistochemistry | Widespread cluster plaques | Cluster plaques not identified |
| Presence of agent in lymphoid tissue | Readily detected | Not readily detected |
| Immunoblot analysis of protease-resistant prion protein | Overrepresentation of diglycosylated protein fragments | Predominance of monoglycosylated protein fragments |
