[Nosological limits of the Lennox-Gastaut syndrome (author's transl)]

Some results of a follow-up study concerning 103 observations of chronic and transitory Lennox-Gastaut syndrome (SLG) are presented. The full-blown syndrome in the chronic SLG (mean duration 21 years and 2 months) is in 100% of the cases characterized by tonic seizures and 'complex absences', mental retardation and abnormal EEG with slow spike-waves and 10 c/sec recruiting bursts. Slow spike-waves are not the most specific EEG pattern of SLG with chronic outcome. The statement is discussed.