Spectral analysis of EEG in the late course of primary generalized myoclonic-astatic epilepsy. I. EEG and clinical data.

The EEG of 38 patients suffering from primary generalized myoclonic astatic epilepsy since early childhood is studied in late stages of the disease. Spectral analysis shows that parietal 4-7 cps rhythms (theta rhythms) which are typical of the EEG in the early stages of the disorder can still exist in the EEG of the adult. The rhythms seem to be related to the course of the epilepsy. In the EEG of patients who still have seizures rhythms occur more often than in the EEG of patients who are free of seizures in the two years before the reexamination of their EEG. The functional anomaly producing a 4-7 cps rhythmization of the parietal EEG seems to be one pathogenetic factor in some epileptic disorders of early childhood, especially in primary generalized myoclonic-astatic epilepsy.