Implantable vagus nerve stimulation for the treatment of disorders of consciousness with epilepsy: a retrospective propensity score-matched clinical study
Background: Disorders of consciousness (DoC) have limited effective therapies. Implantable vagus nerve stimulation (VNS) is established for epilepsy but remains underexplored for DoC with comorbid epilepsy. Objectives: To evaluate whether VNS is associated with improved consciousness recovery in DoC patients with epilepsy and to explore factors related to response. Design: Retrospective propensity score-matched cohort study. Methods: Ninety DoC patients with epilepsy received implantable VNS or conservative management. The primary outcome was clinically meaningful improvement at 1 year (Coma Recovery Scale-Revised (CRS-R) increase ⩾3 points). Propensity score matching (1:1) balanced baseline characteristics (23 per group). Longitudinal CRS-R trajectories were assessed using linear mixed-effects models with Type III ANOVA. Logistic regression within the VNS cohort explored factors associated with responder status; adverse events were extracted from operative and follow-up records. Results: The 1-year responder rate was higher with VNS than with conservative management (34.78% vs 4.35%; two-sided Fisher’s exact test, p = 0.022). Longitudinal analyses showed a significant group × time interaction (χ2 = 43.535, p < 0.001) with greater CRS-R gains from 3 months onward in the VNS group. Within the VNS cohort, responder status was associated with baseline minimally conscious state (aOR = 9.750, 95% confidence interval (CI) 1.592–59.695; p = 0.014) and better seizure control (McHugh classification; aOR = 22.667, 95% CI 3.140–163.629; p = 0.002). Traumatic etiology was not associated with 12-month net CRS-R improvement after adjustment for baseline CRS-R (β = 0.893, 95% CI −1.583 to 3.369; p = 0.466). Five patients reported stimulation-related hoarseness/dysphonia, and two had surgical-site complications; no device removal occurred. Conclusion: Implantable VNS was associated with higher 1-year clinically meaningful improvement and greater longitudinal CRS-R gains than conservative management in DoC patients with epilepsy. Prospective controlled studies are warranted.