Long-term seizure outcome of surgery versus no surgery for drug-resistant partial epilepsy: a review of controlled studies

Abstract

A majority of patients with formerly drug-resistant temporal lobe epilepsy become seizure-free after surgery. However, apart from one 12-month randomized trial, it is unclear how many become seizure-free because of surgery. To determine the net benefit of surgery, we performed a systematic review and meta-analysis of the published evidence of how many patients in similar studies become seizure-free without surgery. Of 155 potentially eligible articles reviewed in full text, 29 (19%) fulfilled eligibility criteria. After excluding 9 publications, 20 studies form the base of evidence. Overall, 719 of 1,621 (44%) of patients with mostly temporal lobe surgery were seizure-free compared to 139 of 1113 (12%) of nonoperated controls [pooled random effects relative risk (RR) 4.26, 95% confidence interval (CI) 3.03-5.98]. The pooled risk difference in favor of surgery was 42% (95% CI 32-51%). We found no comparative outcome data in patients with extratemporal lobe epilepsy only. The available evidence from mostly nonrandomized observational studies indicates that in appropriately selected patients with drug-resistant temporal lobe epilepsy, the combination of surgery with medical treatment is 4 times as likely as medical treatment alone to achieve freedom from seizures.