Epilepsy surgery outcomes and their determinants : a systematic review and individual patient data meta-analysis

Avigdor, Tamir and Ho, Alyssa and Moye, Matthew and Davalan, William and Minato, Erica and Hannan, Sana and Holden, Tamzin and Bouchet, Tasha and Wang, Yingqi Laetitia and Jaber, Kassem and Khweileh, Mays and Kaplan, Samantha and Travnicek, Vojtech and Carlson, David and Frauscher, Birgit (2026) Epilepsy surgery outcomes and their determinants : a systematic review and individual patient data meta-analysis. Journal of Neurology, Neurosurgery and Psychiatry. ISSN 0022-3050

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Abstract

Background Despite advances in epilepsy surgery, seizure freedom is achieved in only ~50–70% of cases, highlighting the need to better understand factors driving surgical success. Methods A preregistered systematic review and individual patient data meta-analysis was conducted on studies reporting clinical outcomes in epilepsy surgery, based on a comprehensive literature search through August 2024. Data were extracted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Unique patient data from 385 studies were pooled, yielding 5588 patients with outcomes, localisation, demographics, pathology and other findings. Surgical success rates (% Engel 1/ILAE 1–2) were reported with 95% Wald CIs. Associations with patient- and disease-specific factors were assessed using chi-squared tests (p<0.05), effect sizes with Cramer’s V, and post hoc comparisons adjusted using the false discovery rate. Results Surgical success varied by lobar anatomy (χ²=52, p<0.001, V=0.12), with the highest success rates in temporal (68.6% (67.0% to 70.1%)) and insular lobes (66.2% (55.4% to 77.0%)). Multilobar resections had lower success rates, with outcomes varying by lobar combination (χ²=25, p=0.02, V=0.22). Variability in outcomes was influenced by histopathology and MRI findings (χ²=121, p<0.001, V=0.16; highest success in tumours (78.2% (74.9% to 81.6%))) and by surgical intervention (χ²=30.5, p<0.001, V=0.07; lowest success with corpus callosotomy (43.4% (35.4% to 51.5%))). Overall surgical success rates remained stable over time (r=0.25, p=0.13), despite surgery being extended to more complex patients. Conclusions These findings inform surgical planning for drug-resistant epilepsy, emphasising individual patient characteristics to guide personalised treatment, improve outcomes and reflect the growing complexity of intersecting factors. PROSPERO registration number CRD42024530397.