History of Lennox–Gastaut Syndrome: An electro-clinical voyage in search of an epileptic syndrome

Lennox-Gastaut syndrome (LGS), one of the most severe childhood epileptic encephalopathies, was described stepwise in the United States and France. Gibbs (1938) and Gibbs et al. (1939) identified a characteristically slow spike-and-wave pattern, which they called the 'petit mal variant,' as opposed to typical spike-and-waves at 3 Hz observed in 'petit mal.' Shortly after participating in the description of this pattern, William G. Lennox reported children with 1) diffuse slow spike-and-waves, 2) mental deficiency, and 3) three seizure types with-myoclonic jerks-a variant of petit mal absences described as brief episodes of immobility-and drops of the head on the chest or of the whole body on the ground. Henri Gastaut arranged three symposia over six years in Marseille to discuss the entity conceptualized by Lennox. Charlotte Dravet's medical dissertation (1965) was the basis of a paper published in Epilepsia by Gastaut et al. (1966), enriched with 50 new cases. Gastaut et al. proposed describing this epileptic syndrome under the name 'Lennox syndrome.' They preferred this designation over 'petit mal variant' because of the term's exclusive electroencephalographic significance that cannot be employed to designate a clinical syndrome. Furthermore, Henri Gastaut wanted to use the term 'Lennox syndrome' in the same manner as 'West syndrome' was used to describe infantile myoclonic encephalopathy with hypsarrhythmia. Margaret Lennox-Buchthal, daughter of William Lennox, co-chaired the second meeting dedicated to the concept developed by her father, held in Marseille in September 1966 and suggested that the syndrome be called the LGS in honor of her father's first description, later confirmed and completed by the Marseille school. Nowadays, the clinical and EEG characteristics of the LGS are well-defined. The Marseille school stressed the importance of sleep electroencephalographic recording to highlight bilateral fast epileptic rhythms and axial tonic seizures. The eponym LGS should be restricted to a relatively homogeneous entity, clinical expression, and prognosis, with multiple possible etiologies.