Current Source Analysis of Interictal Spikes in Two Patients With Gelastic Epilepsy-Hypothalamic Hamartoma Syndrome

ABSTRACT

BACKGROUND: Interictal spikes in gelastic epilepsy-hypothalamic hamartoma syndrome are mainly in the fronto-temporal area. Current source analysis of the interictal spikes has not been done enough. We tried the current source analysis in 2 patients with gelastic epilepsy-hypothalamic hamartoma syndrome using both of the discrete and distributed models. METHODS: Twenty 1 sec epochs including the negative peak of the spikes, were selected from one or two electroencephalographic recordings respectively in each patient. These 20 epochs were averaged into a single spike. The current dipole sources of the averaged spike were analyzed and located on a spherical head model. The current source density of the negative peak point of the averaged spike was located on the Talairach human brain map. RESULTS: The current dipole sources were in the right subcallosal gyrus, or the right or left anterior cingulate gyri. The current source density was distributed in the bilateral medial frontal area including the anterior cingulate gyri. CONCLUSIONS: The interictal spikes of patients with gelastic epilepsy-hypothalamic hamartoma syndrome may be generated by the current sources located in the bilateral medial frontal area.