Cerebral cortex dendritic degeneration in subacute sclerosing panencephalitis (SSPE).

Biopsy fragments from the frontal cortex of three patients with subacute sclerosing panencephalitis (SSPE) were studied by light- and electronmicroscopy. Special attention was given to the neuropil. Electron-dense degenerating dendrites were observed in all cortical layers, more abundantly in layers. I, II, and III. Mitochondria, with electron-dense deposits between disrupted cristae, were often recognized within these dendrites. The deposits were enzymatically extracted by pronase. These findings are in keeping with recent alterations found in dendrites of patients with other cerebral disorders, and they may be related to the mental changes seen in SSPE.