Argentophilic Plaques in Creutzfeldt-Jakob Disease

One of the important diagnostic features of Creutzfeldt-Jakob disease is the absence of senile plaques and Alzheimer neurofibrillary changes. Two consecutive cases of Creutzfeldt-Jakob disease were recently diagnosed on the basis of clinical signs and symptoms. At postmortem examination, these diagnoses were confirmed. Both showed neuronal loss, sponginess, and astrocytic gliosis in the cerebral cortex and basal ganglia. In addition, argentophilic plaques were found throughout the cerebral cortex and part of the basal ganglia in numbers exceeding those expected in the brains of normal old people. Alzheimer neurofibrillary tangles were virtually absent except for a number seen in Ammon's horn. Histochemical changes seen in the plaques were similar to those observed in Alzheimer's disease. Electron microscopically, the plaques appeared to be composed of distended neuronal processes filled with abnormal accumulations of various organelles.