Lennox–Gastaut syndrome is an epileptic encephalopathy with onset in childhood. The classical triad of diagnostic criteria well known: 1) presence various types refractory seizures (tonic, atypical absences, myoclonic, tonic/atonic drop attacks, generalized tonic-clonic, focal); 2) cognitive disorders frequent behavioral (not always evident by the beginning seizures); 3) generalized, slow (≤2.5...