[Lennox-Gastaut syndrome]

Abstract

Introduction: The Lennox-Gestaut syndrome is classified as an epileptic syndrome shown by the presence of various types of generalized seizures (tonic, atonic and atypical absences) which appear at a certain age (1-8 years), with an interictal EEG showing an abnormally slow basic rhythm interrupted by slow spike-and-wave complexes (< 3 Hz) and progressive mental deterioration.

Development: From the aetiological point of view there are cryptogenic (25%) and symptomatic (75%) forms. There is a previous history of West syndrome in 9.4-30% of the symptomatic cases. The commonest types of seizures are tonic (17-95%), atypical absences (17-60%) and atonic (25-56%). The mixed form of an epileptic state with typical absences and tonic seizures is the most frequent (27%). Follow-up studies show that in 90% and 100% of cryptogenic and symptomatic patients, respectively, mental retardation develops and the initial seizures persist in 67% and 45% of the patients with cryptogenic and symptomatic forms respectively, when they become adults.

Conclusions: There is still no successful treatment for these seizures and progressive mental deterioration occurs even when using the newer anti-epileptic drugs. Electrical stimulation of the vagus nerve seems a promising possibility but further experience is necessary.