Different patterns of dipole source localization in gelastic seizure with or without a sense of mirth.

Dipole source localization corresponding to interictal spikes were estimated using EEG dipole tracing with a realistic three-shell head model in three patients with cryptogenic gelastic epilepsy. The dipole sources in two patients, whose gelastic seizures were accompanied by a subjective feeling of mirth, were estimated in the right or left medio-basal temporal regions. In the other patient, with gelastic seizures without a sense of mirth, the dipole sources were localized in the right frontal region corresponding to the anterior cingulate. The results suggest that the neural activities in hippocampal regions are involved with the generation of gelastic seizures with a sense of mirth and those in the cingulate might be associated with the motor act of laughter.