Efficacy and safety following two or more years of vagus nerve stimulation (VNS Therapy) in pediatric patients with drug‐resistant epilepsy enrolled in a Russian VNS Registry

INTRODUCTION: Following approval in 2009 of vagus nerve stimulation (VNS Therapy) for drug‐resistant epilepsy (DRE) in the Russian Federation, this is the first multicenter study across Russia to evaluate the safety and efficacy of adjunctive VNS Therapy. METHODS: The retrospective, observational registry included 58 pediatric patients with DRE (5–17 years old at implantation) who had ≥2 years of VNS. To ensure a robust evaluation process, changes in seizure frequency were evaluated for all seizure types as well as “most disabling” seizures (defined as seizures accompanied by falls, physical trauma, and/or incontinence in the absence of preventative measures). RESULTS: With 2 years of VNS Therapy, 37 of 49 patients (76%) experiencing the most disabling epileptic seizures had a >50% decrease in frequency of such seizures, and 16 (33%) reported no longer experiencing the “most disabling” seizure type. In addition, based on the McHugh Outcome scale, VNS Therapy had a positive outcome on both frequency and severity of all epileptic seizure types, with a >50% decrease in frequency of all epileptic seizure types noted in 37 of 58 patients (64%), and 31% of patients had a Class I outcome, including 11 patients (19%) who achieved seizure freedom. VNS Therapy also had a positive effect on the frequency of status epilepticus: 13 patients (22%) had status epilepticus prior to implantation with a mean rate of 9.4 ± 17.7 events per year (range, 0–52), and after VNS Therapy, only one patient continued to experience status epilepticus (at 1 event per 4–6 months). VNS Therapy had an acceptable safety profile and no adverse events leading to VNS discontinuation were reported. CONCLUSIONS: The results demonstrate that VNS Therapy is being safely and effectively applied to pediatric patients in the Russian healthcare system.