Safety in epilepsy surgery: a multicenter analysis of surgery-related complications and seizure outcome in 1167 cases of mesial temporal lobe epilepsy

OBJECTIVE: Despite advances in technical approaches, microsurgical resection remains the gold standard for treating drug-resistant mesial temporal lobe epilepsy (MTLE). However, current multicenter data on the risk of new focal neurological deficits following MTLE surgery and on factors predicting the likelihood of seizure freedom postsurgery are limited. This study aimed to evaluate the safety and efficacy of surgery by providing reliable data on the predictors of favorable postoperative outcomes. METHODS: The authors conducted a retrospective multicenter analysis across 20 epilepsy centers on 5 continents. Detailed standardized clinical data were collected, encompassing the preoperative status of patients, presurgical diagnostics, surgical techniques, complications, and neurological outcomes. Predictive factors for postoperative neurological deficits and a satisfactory response to surgery (defined as International League Against Epilepsy [ILAE] classes 1 and 2) were analyzed using a logistic regression model. Additionally, the authors assessed the relationship between neurological deficits, seizure outcomes, and neuropsychological performance. RESULTS: A total of 1167 patients were included in this study. Postoperative new neurological deficits were observed in 22.2% of cases, with new quadrantanopia being the most common (11.2%). No in-hospital mortality or 30-day mortality was recorded. Surgical revision was necessary in 4.3% of cases within the 1st year. A younger age and surgical intervention on the nondominant brain hemisphere were associated with a reduced risk of postoperative neurological deficits. After 1 year, 74.2% of patients achieved seizure outcomes classified as ILAE class 1 or 2. Known positive predictors of seizure outcomes, such as identifiable MRI lesions and a history of febrile seizures, were supported by data. Furthermore, even after adjusting for preoperative MRI findings, hemisphere dominance, occurrence of bilateral tonic-clonic seizures, age, and sex, anterior temporal lobe resection was linked to improved seizure outcomes. CONCLUSIONS: This study offers extensive multicenter data on outcomes following MTLE surgery from a large international patient cohort. The authors' analysis indicates a strong safety profile and high efficacy for epilepsy surgery in this patient group. The comprehensive breakdown of results facilitates the assessment of individual success prospects and improves informed patient counseling.