Postoperative Parameter Adjustment and Therapeutic Efficacy of Vagus Nerve Stimulation in Drug-Resistant Epilepsy

Vagus nerve stimulation (VNS) is a recognized palliative surgical therapy for drug-resistant epilepsy (DRE). However, optimal postoperative parameter adjustment strategies to maximize efficacy remain an area of active investigation, particularly concerning different etiologies and seizure types. This study was designed to explore the therapeutic efficacy of VNS and postoperative parameter adjustment in patients with DRE.

Eighteen patients with DRE who underwent VNS implantation were retrospectively analyzed. We included patients with focal DRE unsuitable for craniotomy, encephalitis-related DRE, and idiopathic DRE with no identifiable cause. Postoperative stimulation parameters were precisely individualized and adjusted. The efficacy of VNS in controlling seizures was evaluated using the McHugh classification.

Eight patients achieved McHugh class IA efficacy (seizure frequency reduction > 80%), seven achieved class IIA efficacy (> 50% reduction), and three achieved class Ⅲ efficacy (< 50% reduction; ⅢA in two and ⅢB in one).

VNS demonstrated significant therapeutic efficacy in patients with DRE, particularly those with a structural etiology and generalized tonic–clonic seizures. The effect was especially notable in post-traumatic DRE. Postoperative current adjustment proved more complex and influential compared with pulse width and frequency modifications and had a greater impact on seizure control.