[Periodic discharges and diagnosis of central nervous system diseases].

Periodic discharges are easily identified on conventional EEG traces. Proper interpretation requires systemic analysis of their spatial, temporal and morphological characteristics. These EEG changes are always abnormal and can be observed in various CNS diseases. Periodic discharges were found in 127 patients from a total number of 3212 patients suffering from 9 different CNS diseases. This study confirms the high incidence of periodic discharges in subacute sclerosing panencephalitis (89%), in acute necrotizing encephalitis (85%) and in Creutzfeldt-Jakob disease (75%). Their prognostic value and their relationship to epilepsy is shortly discussed.