Vagus nerve stimulation as an add-on therapy in patients with epilepsy: a prospective, multicenter, real-world study in China
Vagus nerve stimulation (VNS) has been proven as an effective and safe adjunct therapy for epilepsy, but real-world evidence is limited. This study aimed to evaluate outcomes of VNS and its cumulative effect through a prospective, multicenter, real-world survey in China, with dynamic follow-up. A total of 83 sites in China participated and 124 epilepsy patients enrolled. Visits were scheduled at 1, 3, 6, 9, and 12 months after VNS. Primary outcomes included seizure response rate (≥ 50% frequency reduction) and seizure-free rate. Secondary outcomes assessed changes in the 31-item Quality of Life in Epilepsy Inventory (QOILE-31) score, overall anti-seizure medication (ASM) load, and adverse events. The responder rates were 35.5%, 41.6%, 62.2%, 64.2%, and 76.6% at 1, 3, 6, 9, and 12 months after VNS, respectively. Seizure-free rates were 2.4%, 2.7%, 9.2%, 8.6%, and 10.9% at 1, 3, 6, 9, and 12 months, respectively. No significant differences were observed in overall ASM load between baseline and any follow-up visit. Significant improvements were noted in QOLIE-31 from baseline to each follow-up visit, with mean (± SD) score improvements as follows: 1 month (2.93 ± 8.65), 3 months (4.27 ± 9.84), 6 months (4.69 ± 11.5), 9 months (6.68 ± 12.5), and 12 months (9.32 ± 13.8). A significant trend toward improved seizure outcomes and change in quality of life was observed with longer treatment durations. Adverse events occurred in 34 patients (27.4%). VNS is an effective and safe adjunctive treatment for epilepsy, reducing seizure frequency and significantly improving quality of life, with a cumulative effect over time.