Treatment of the Lennox syndrome with ACTH: a clinical and electroencephalographic study.

In 45 cases of Lennox syndrome treated with ACTH, the immediate and long-term effects and the various factors affecting them were investigated by a follow-up study. 1) Regarding the immediate effect, 23 (51.1%) of the 45 cases became "seizure free" for over 10 days. 2) As to the long-term prognosis of these 23 cases, 10 cases relapsed into Lennox syndrome within 6 months and in the remaining 13 cases, seizures were suppressed for over 6 months; out of these 13, seizure relapse was observed in eight cases from 9 months to 7 years later, and the other five cases followed a very favorable course without relapse. 3) The favorable factors related to the effect of ACTH for Lennox syndrome are: a) age at ACTH treatment: up to 4 years old, b) time lag between onset of Lennox syndrome and initiation of ACTH treatment: the shorter the better; at least within 1 year, preferably within 3 months, c) presumptive causes and underlying diseases: idiopathic cases are best, d) mental defects before treatment: the slighter the better, e) seizure patterns: without tonic seizures, and f) EEG findings: disorganized diffuse slow spike-waves without asymmetry. 4) It is desirable to continue the ACTH treatment as long as possible, with the goal of the disappearance of seizure discharges, or at least the disappearance of diffuse seizure discharges.