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 1cm 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.