Clinical and electroencephalographic studies of postencephalitic epilepsy.

We retrospectively reviewed the clinical features and results of investigation of 62 patients with acute encephalitis or encephalopathy in the acute phase to identify the prognostic factors in the development of postencephalitic epilepsy. Patients who later developed epilepsy showed more marked disturbance of consciousness, convulsions, and seizure activities on EEG during the acute phase than those who did not. There was no relation between CSF abnormalities and postencephalitic epilepsy. Control of convulsions during the acute phase, especially of status epilepticus, seems to be important to improve the prognosis.