Gelastic epilepsy: Symptomatic and cryptogenic cases

Purpose: To describe the etiology, characteristics, and clinical evolution of epilepsy in patients with gelastic seizures (GSs). Methods: Nine patients whose seizures were characterized by typical laughin g attacks were observed between 1986 and 1997. Patients were selected based on electroencephalogram (EEG) or video-EEG recordings of at least one GS a nd on magnetic resonance imaging (MRI) study. Results: Five patients were affected by symptomatic localization-related ep ilepsy (LRE), with four of the patients' disorders related to a hypothalami c hamartoma (HH) and one to tuberous sclerosis (TS) without evident hypotha lamic lesions. In four patients (the cryptogenic cases) MRI was negative al so in these cases, clinical and EEG data suggested a focal origin of the se izures. The epileptic syndrome in the HH cases was usually drug-resistant, and was surgically treated in two of the patients. The patient with TS beca me seizure free with vigabatrin. In the cryptogenic cases, the ictal, clini cal, and EEG semiology were similar to the symptomatic cases; the clinical evolution was variable, with patients having transient drug resistance or p artial response to treatment. No cognitive defects were observed in the cry ptogenic patients. None of the nine patients had precocious puberty. Conclusions: We confirm the frequent finding of HHs in GSs and further unde rline how GSs may also be observed in patients without MRI lesions and with normal neurologic status. In these patients, clinical and EEG seizure semi ology is similar to symptomatic cases, but the clinical evolution is usuall y more benign.