Eight HYPOTHALAMIC HAMARTOMA patients underwent EEG-fMRI. All had gelastic seizures and seven developed other seizure types. Using a general linear model, spike-related activation/deactivation was analyzed individually by applying a hemodynamic response function before, at, and after spike onset. Group analysis was also performed. The sensitivity of EEG-fMRI in identifying the hypothalamic hamartoma interface was compared with SISCOM in hypothalamic hamartoma patients having unilateral hypothalamic attachment.