The clinical spectrum and natural history of gelastic epilepsy-hypothalamic hamartoma syndrome

Purpose: To delineate the clinical spectrum and patterns of evolution of epilepsy with gelastic seizures related to hypothalamic hamartoma (HH). Patients and methods: We evaluated patients with HH, observed between 1986 and 2002 for whom at least one ictal video-EEG or EEG recording of gelastic seizures was available. Results: Six subjects (four male, two female) with sessile HH between 0.8 and 1.7 cm in diameter were identified. The onset of gelastic seizures was between 2 months and 20 years. It evolved to secondary generalized epilepsy in one case, and to drug-resistant partial epilepsy in the other five from 2 to 13 years after onset. No patient showed precocious puberty. Severe cognitive impairment developed in the patient with secondary generalized epilepsy, and a mild cognitive defect in two others. Patients with an HH below 1 cm did not show neuropsychological or behavioural disturbances. Drug resistance occurred in all cases. Surgical removal of HH markedly improved the clinical evolution in two patients. Conclusions: Gelastic epilepsy-HH syndrome can differ in severity and evolution. A catastrophic evolution and drug resistance can be reversed by surgical or by gamma-knife ablation of HH.