Prognostic Value of Qualitative Magnetic Resonance Imaging Hippocampal Abnormalities in Patients Undergoing Temporal Lobectomy for Medically Refractory Seizures

Summary: In patients with temporal lobe epilepsy (TLE), high‐resolution, magnetic resonance imaging (MRI) frequently demonstrates hippocampal atrophy and increased hippocampal signal. To assess the prognostic value of these findings, we studied 51 patients evaluated prospectively by a radiologist blinded to other preoperative evaluations. Thirty‐one of 51 (61%) patients undergoing temporal lobectomy had visually apparent hippocampal atrophy o r increased hippocampal signal on MRI (25 ipsilateral 3 contralateral, and bilateral to the operated site). Patients with ipsilateral abnormalities became seizure‐free more frequently than patients with normal scans [24 of 25 (96%) vs. 10 of 20 (50%) p < 0.015]. Both ipsilateral hippocampal atrophy and ipsilateral increased hippocampal signal independently predicted a seizure‐free outcome. Qualitative MRI provides important prognostic information in patients undergoing temporal lobectomy.