INTRINSIC EPILEPTOGENESIS OF HYPOTHALAMIC HAMARTOMAS IN GELASTIC EPILEPSY

Hypothalamic hamartomas and gelastic seizures are often associated wit h cognitive deterioration, behavioral problems, and poor response to a nticonvulsant treatment or cortical resections. The origin and pathoph ysiology of the epileptic attacks are obscure. We investigated 3 patie nts with this syndrome and frequent gelastic seizures. Ictal single-ph oton emission computed tomography performed during typical gelastic se izures demonstrated hyperperfusion in the hamartomas, hypothalamic reg ion, and thalamus without cortical or cerebellar hyperperfusion, Elect roencephalograph ic recordings with depth electrodes implanted in the hamartoma demonstrated focal seizure origin from the hamartoma in 1 pa tient. Electrical stimulation studies reproduced the typical gelastic events. Stereotactic radiofrequency lesioning of the hamartoma resulte d in seizure remission without complications 20 months after surgery. The functional imaging findings, electrophysiological data, and result s of radiofrequency surgery indicate that epileptic seizures in this s yndrome originate and propagate from the hypothalamic hamartoma and ad jacent structures.