Spongiform changes in astrocytic tumor with neuronal loss is seen in?

Prion diseases are a large group of related neurodegenerative conditions, which affect both animals and humans. These diseases all have long incubation periods but are typically rapidly progressive once clinical symptoms begin. Prion diseases are unique in that they can be inherited, they can occur sporadically, or they can be infectious. The infectious agent in the prion disease is composed mainly or entirely of an abnormal conformation of a host-encoded glycoprotein called the prion protein. Pathophysiology: A unifying feature of all the prions is their neuropathology. These illnesses tend to affect the gray matter of the central nervous system (CNS), producing neuronal loss, gliosis, and characteristic spongiform change. The latter is vacuolation of the neuropil and to a variable degree of the neurons. This also shows mild parenchymal vacuolation and prominent reactive astrocytosis. Ref: medscape