Ultrastructural study of three cases of encephalopathy with hypsarrhythmia

Summary We report a morphological study of three cases of infantile hypsarrhythmia. The cerebral cortex lesions consisted of a diffuse neuropile microspongiosis, corresponding ultrastructurally to vacuolized and enlarged neuronal processes, particularly postsynaptic bags. The morphological aspects and the high cell fusion index in one case resemble those described in transmissible subacute spongiform encephalopathies.