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.