Lennox-Gastaut syndrome in the elderly?

The Lennox-Gastaut syndrome (LGS) is an electro-clinical syndrome of early childhood that consists of mental retardation, intractable generalized epilepsy with multiple seizure types, and typical EEG findings. We report a 64-year-old woman who was referred for presurgical evaluation with a diagnosis of intractable temporal lobe epilepsy since the age of 14 years, consisting of staring and unresponsiveness, sudden falls, and generalized convulsions. The average seizure frequency was 1-4 per month. Mental status and neurological examination were normal. There was no known etiology and magnetic resonance imaging (MRI) of the brain was normal. Interictal EEG showed findings characteristic of LGS: generalized slow spike-wave complexes, multifocal sharp waves, generalized polyspikes and paroxysmal fast activity during sleep. Despite the absence of mental retardation and the presence of normal alpha rhythm, the patient fulfills most diagnostic criteria for LGS, with unusually late onset and extremely delayed diagnosis. This case illustrates the controversial nosologic boundaries of the syndrome. Prolonged EEG video monitoring may be of value even in the elderly. The LGS and other varieties of secondary generalized epilepsy should be considered in the syndromic diagnosis of epilepsy in the elderly.