Gelastic epilepsy--a case report with SPECT studies.

A 24 years male presented with daily episodes of uncontrollable laughter followed by urinary incontinence since the age of nine years. Some of these attacks progressed to generalized tonic-clonic seizures. General and neurological examination did not reveal any abnormality. Ictal and interictal video EEGs were normal. MRI showed a hypothalamic hamartoma. Interictal SPECT scan showed normal perfusion in the hamartoma. SPECT scan obtained four minutes after beginning of seizure showed that the perfusion increased in right cingulate gyrus but not in the hamartoma, suggesting the involvement of the cingulate gyrus in the seizure origin or pathway.