[Electroencephalographic aspects of classic agyria-pachygyria]

Four infants had agyria confirmed by CT scan. All were mentally retarded, microcephalic, 3 of them having characteristic facial dysmorphy and 2 infantile spasms. EEG was characterized by very high amplitude rhythms in the alpha range, associated with delta waves and with infrequent spikes. The tracing was poorly modified by sleep. Drugs reduced its amplitude and rapid rhythms appeared with benzodiazepines. The authors point to the usefulness of the EEG in suggesting diagnosis before the CT scan, as was the case in 2 patients. They point to the urgent need of studying infantile epilepsies according to etiology, and not only to seizure types.