Gelastic epilepsy and hypothalamic hamartoma.

The clinical, electro-encephalographic and neuroradiological findings in 2 boys with gelastic epilepsy are described. Both patients had hypothalamic masses thought to be hamartomas, and 1 had precocious puberty. These 2 cases are compared with a previously published case of gelastic epilepsy with a left temporal focus. It was not possible to differentiate the hypothalamic lesions from the left temporal lesion on clinical grounds. The laughter in the hypothalamic group did not lack affect, as described by some other authors. Interictal EEGs in the patients with hypothalamic lesions showed generalized wave-spike activity, whereas localized abnormality was present in the patient with a left temporal EEG focus. Ictal recordings were the same in both groups. The combination of gelastic epilepsy and precocious puberty is rare. Only 10 cases have been reported in the literature, our patient being the 11th.