Purpose: Ictal intracranial EEG recordings obtained during continuous preoperative monitoring are often used to localize the region of seizure onset for purposes of surgical resection in patients with extrahippocampal seizures. Whether interictal epileptiform abnormalities during long-term monitoring can predict surgical outcome in this group is not established.Methods: Intracranial EEGs of patients who underwent extrahippocampal resective epilepsy surgery were reviewed for interictal epileptiform abnormalities before medication discontinuation or first seizure occurrence. Interictal abnormalities were categorized as within or beyond the confines of surgical resection. We correlated these findings with the region of seizure onset, the pathologic substrate, and surgical outcome (by using Engel criteria) at I-year minimum follow-up.ResuZts: Of I3 patients with interictal epileptiform abnormalities, six patients had interictal epileptiform discharges extending beyond the confines of surgical resection. These pa-