Synaptic alterations in acoustic cortex in Creutzfeldt-Jacob disease.

The acoustic cortex was studied in electron microscope in 10 cases of Creutzfeldt-Jacob disease. The most prominent finding was the tremendous loss of neurons associated with marked reactive astrocytosis. The so called Cajal-Retzius cell had completely disappeared in the first cortical layer. The neuronal synapses were rare and most of those that were preserved demonstrated marked morphological alterations such as extensive dilatation of the synaptic terminals, synaptic polymorphism, dilatation of the cisternae of the smooth endoplasmic reticulum in the presynaptic terminals and accumulation of fibrillary material in the pre- and postsynaptic terminals. Vacuolization and cavity formation were seen in all the cortical layers resulting in an apparent loss of the lamination pattern of the cortex. Hirano bodies and Pick's bodies were seen in some of the neurons in the acoustic cortex. Amyloid plaques were rare in correlation to the other areas of the temporal isocortex of the same material. Correlating the morphological alterations of the neuronal synapses in acoustic cortex with those seen in other areas of the cortex in case of Creutzfeldt-Jacob disease we believe that acoustic cortex is more seriously affected in Creutzfeldt-Jacob disease than most of the other areas of the temporal isocortex.