Clinical Outcomes and Prognostic Factors of Vagus Nerve Stimulation in Drug-Resistant Epilepsy: A Single-Center Retrospective Cohort Study.

Abstract

Vagus nerve stimulation (VNS) has emerged as a well-established therapeutic option for drug-resistant epilepsy (DRE). This study aims to assess treatment outcomes and prognostic factors in DRE patients undergoing VNS therapy. We conducted a single-center retrospective analysis of 44 consecutive DRE patients who underwent VNS implantation between 2017 and 2023. Primary efficacy endpoints were as follows: 1) absolute seizure reduction (SR) percentage and 2) responder rate (≥50% SR), evaluated during routine follow-up of 7 years. Secondary outcomes included safety, assessed through adverse event monitoring and quality of life in epilepsy-31, measured using standardized metrics. Multivariable logistic regression models were used to examine associations with 3 clinical predictors: gender, age at implantation, and preoperative epilepsy duration. The mean SR from baseline was 49.15%, with 21 patients (47.7%) meeting the responder criterion. Regression analysis identified a significant inverse relationship between epilepsy duration and treatment response (β = -0.1819, P = 0.0119 for age threshold 18; β = -0.1299, P = 0.0743 for age threshold 12). Device-related complications requiring surgical revision occurred in 2 cases (4.5%). Postoperative quality of life in epilepsy-31 scores averaged 59.95 (±14.35) on standardized assessments. Our findings demonstrate the sustained efficacy of VNS in managing DRE, with nearly half of the patients achieving clinically meaningful seizure control. The observed inverse association between disease duration and treatment response highlights the potential benefits of earlier VNS intervention. Together with its favorable safety profile, these results support the role of VNS as an integral component of comprehensive epilepsy management.