Outcomes of resections that spare vs remove an MRI‐normal hippocampus

Objective To characterize seizure and cognitive outcomes of sparing vs removing an magnetic resonance imaging (MRI)–normal hippocampus in patients with temporal lobe epilepsy. Methods In this retrospective cohort study, we reviewed clinical, imaging, surgical, and histopathological data on 152 individuals with temporal lobe epilepsy and nonlesional hippocampi categorized into hippocampus‐spared (n = 74) or hippocampus‐resected (n = 78). Extra‐hippocampal lesions were allowed. Pre‐ and postoperative cognitive data were available on 86 patients. Predictors of seizure and cognitive outcomes were identified using Cox‐proportional hazard modeling followed by treatment‐specific model reduction according to Akaike information criterion, and built into an online risk calculator. Results Seizures recurred in 40% within one postoperative year, and in 63% within six postoperative years. Male gender (P = .03), longer epilepsy duration (P