Efficacy of vagus nerve stimulator during transition to adulthood in patients with treatment‐resistant epilepsy

OBJECTIVE: To evaluate the efficacy of vagus nerve stimulation (VNS) as an adjunctive treatment in pediatric patients with treatment-resistant epilepsy during the transition to adolescence. METHODS: We performed a retrospective cohort study of 30 children (ages 2-18 years) with medication-resistant epilepsy who underwent VNS implantation between January 2019 and January 2023 at a tertiary epilepsy center. Clinical data included demographics, epilepsy etiology and syndrome, age at implantation, seizure frequency and severity (McHugh classification), number of antiseizure medications (ASM), magnet use, and EEG findings. Outcomes were assessed at the last available follow-up, with a minimum duration of 12 months post-implantation. Statistical analyses comprised chi-squared or Fisher's exact tests, Spearman rank correlation, and logistic regression; significance was set at p < 0.05. RESULTS: At the last follow-up, 20 of 30 patients (66.7%) achieved ≥50% reduction in seizure frequency, and 73% of patients experienced a significant decrease in seizure severity. Status epilepticus (SE) incidence fell from 67% pre-VNS to 17% post-VNS (p = 0.024). The number of ASMs decreased in 57% of patients. Successful magnet activation strongly predicted responder status (OR 10.8, 95% CI 1.2-95.4; p = 0.024). Among females, 12 of 16 (75%) experienced a transient seizure worsening around menarche. Earlier VNS implantation correlated with better seizure reduction (ρ = -0.43; p = 0.015). EEG improvement-defined as reduced interictal epileptiform activity or background normalization-was observed in 23% of patients, predominantly in males and pre-menarche females. SIGNIFICANCE: VNS is an effective adjunctive therapy in pediatric treatment-resistant epilepsy, yielding substantial reductions in seizure frequency and severity, lowering status epilepticus risk, and simplifying medication regimens. Pubertal status and magnet responsiveness modulate outcomes. Early VNS intervention and proactive management during adolescence may optimize therapeutic benefit.