This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nervous system, Subject name: Anatomy
What is the histological appearance of brain in Creutzefeldt Jakob disease 
Select and explain. 
A. Neuronophagia, B. Spongiform change in brain, C. Microabscess, D. Demylination
B: Spongiform change in brain
Answer: B: Spongiform change in brain 
Explanation: 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.