What is the histological appearance of brain in Creutzefeldt Jakob disease

Refer Robbins page no 1282MORPHOLOGY The progression of the dementia in CJD is usually so rapid that there is little if any grossly evident brain atrophy. The pathog- nomonic finding is a spongiform transformation of the cerebral coex and, often, deep gray matter structures (caudate, putamen); this multifocal process results in the uneven forma- tion of small, apparently empty, microscopic vacuoles of varying sizes within the neuropil and sometimes in the perikaryon of neurons (Fig. 28-32A). In advanced cases there is severe neu- ronal loss, reactive gliosis, and sometimes expansion of the vacuolated areas into cystlike spaces ("status spongiosus"). Inflammation is notably absent. Electron microscopy shows the vacuoles to be membrane-bound and located within the cyto- plasm of neuronal processes. Kuru plaques are extracellular deposits of aggregated abnormal protein; they are Congo red- and PAS-positive and usually occur in the cerebellum (Fig. 28-32B), but are abundant in the cerebral coex in cases of vCJD (Fig. 28-32C). In all forms of prion disease, immuno- histochemical staining demonstrates the presence of protein- ase K-resistant PrPsc in tissue.