A 72-year-old woman has progressive memory loss, motor neuron signs, and 14-3-3 protein in CSF. Brain MRI shows cortical ribboning on DWI. She deteriorates rapidly and dies within 6 months. Autopsy shows spongiform vacuolation of cerebral cortex, neuronal loss, astrogliosis, and PrP-immunopositive plaques. The diagnosis is:

• A Alzheimer disease
• B Frontotemporal dementia (Pick disease)
• C Lewy body dementia
• D Creutzfeldt-Jakob disease (CJD) ✓

Explanation

Sporadic Creutzfeldt-Jakob disease (sCJD) is the most common human prion disease, featuring rapidly progressive dementia, myoclonus, cerebellar ataxia, and death within 12 months. The triad of spongiform change (vacuolation), neuronal loss, and astrogliosis without inflammation is pathognomonic; PrP-immunopositive deposits confirm prion disease. CSF 14-3-3 protein and RT-QuIC are biomarkers. DWI MRI shows cortical ribboning and basal ganglia signal change. Alzheimer disease has neurofibrillary tangles and amyloid plaques; Pick disease has Pick bodies (FTLD-tau); Lewy body dementia has synuclein-positive Lewy bodies.

Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.

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Written and medically reviewed by the StethoPrep medical team.