Baseline seizure frequency as a predictor of vagus nerve stimulation outcomes in drug-resistant epilepsy: A single-centre cohort study
16.Avrupa Epilepsi Kongresi, Athens, Greece, 5 - 09 September 2026, pp.457, (Summary Text)
- Publication Type: Conference Paper / Summary Text
- City: Athens
- Country: Greece
- Page Numbers: pp.457
- Istanbul University Affiliated: Yes
Abstract
Purpose: Vagus nerve stimulation (VNS) is an established treatment option for patients with drugresistant epilepsy (DRE) who are not candidates for resective surgery. However, predictors of therapeutic response remain unclear. This study evaluated whether baseline seizure frequency is associated with postoperative outcomes following VNS implantation.
Method: In this retrospective single-centre cohort study, 22 patients with DRE who underwent VNS implantation between 2019 and 2024 were analysed. Clinical, radiological, and electrophysiological data were reviewed. Baseline seizure frequency was categorised as low (<10 seizures/day) or high (>10 seizures/day). Postoperative seizure outcomes were assessed using the ILAE classification system. Fisher’s exact test, chi-square analysis, odds ratio estimation, and effect size (Cramér’s V) were used to evaluate the association between seizure frequency and treatment response.
Results: Of the 22 patients, 11 (50%) achieved responder status (ILAE Class 1–4). Patients with low baseline seizure frequency demonstrated a higher responder rate than those with high frequency (58.8% vs. 20%). Although this trend was not statistically significant (Fisher’s exact p = 0.3107), the odds of a favourable response were higher in the low-frequency group (OR 5.71; 95% CI 0.52–62.6). Effect size analysis suggested a small-to-moderate association (Cramér’s V = 0.218).
Conclusion: Baseline seizure frequency was not significantly associated with postoperative VNS response; however, a clinically meaningful trend favoured patients with fewer than ten seizures per day. These findings suggest potential prognostic relevance of seizure burden and underscore the need for larger, multicentre studies to clarify predictors of VNS efficacy in refractory epilepsy.