Creutzfeldt-Jakob disease (CJD) and other prion diseases share a common pathological hallmark. The characteristic 'spongiform change' in prion diseases is caused by:

• A Intra-axonal accumulation of prion fibrils causing axonal swelling and vacuolization
• B Astrocytic swelling and degeneration from tau aggregation in astrocytes
• C Perivascular inflammatory edema with microglial phagocytosis of myelin
• D Intraneuronal accumulation of misfolded PrPSc in synaptic terminals and neuronal soma causing intracytoplasmic vacuolation ✓

Explanation

Spongiform change in prion diseases (CJD, Gerstmann-Sträussler-Scheinker, Fatal Familial Insomnia, kuru) results from intracytoplasmic vacuolation of neuronal soma and their synaptic processes (dendrites and axon terminals). This is caused by the accumulation of PrPSc (misfolded, beta-sheet-rich, protease-resistant isoform of normal cellular PrPC) within neurons, particularly at synaptic terminals. The vacuoles represent membrane-bound compartments containing accumulating PrPSc. The spongiform pattern corresponds to the characteristic 'swiss cheese' appearance on H&E. There is no inflammation (distinguishing it from viral encephalitides), and the pathological triad of prion disease is: spongiform vacuolation, astrogliosis, and neuronal loss — without inflammation.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.