Safety of vagus nerve stimulation and responsive neurostimulation used in combination for multifocal and generalized onset epilepsy in pediatric patients

OBJECTIVE The aim of this study was to assess the safety and efficacy of combined active responsive neurostimula- tion (RNS) and vagus nerve stimulation (VNS) therapies in pediatric patients with drug-resistant epilepsy. METHODS A single-center retrospective chart review was conducted on pediatric patients implanted with the RNS Sys-tem with a concomitant active VNS System (VNS+RNS) between 2015 and 2021. Patients with at least 1 month of over-lapping concomitant VNS and RNS treatment were included. Patients who had an RNS device implanted after 21 years of age, those who had responsive neurostimulators implanted after their VNS was inactivated, or those in whom the VNS battery died and was not replaced before RNS System implantation were excluded. RESULTS Seven pediatric VNS+RNS patients were identified, and their courses of treatment were evaluated. All pa- tients tolerated concurrent VNS and RNS treatment well, no device-device interactions were identified, and no major treatment-related adverse effects were noted. The median follow-up after RNS System implantation was 1.2 years. By electroclinical criteria, all 7 patients achieved 75%-99% reductions in the frequency of disabling seizures after RNS System implantation. By patient and caregiver report, 2 patients (28.6%) had 75%-99% reductions in the frequency of their disabling seizures, 2 patients (28.6%) achieved 50%-74% reductions, 2 patients achieved 1%-24% reduction in frequency of disabling seizures, and 1 patient (14.3%) experienced a 1%-24% increase in seizure frequency. The available VNS magnet swipe data identified 2 patients with 75%-99% reductions in seizure frequency as measured by magnet swipes, one with 25%-49% reductions and the other with 1%-24% increases in seizure frequency as measured by magnet swipes. CONCLUSIONS This study demonstrated that RNS and VNS therapies can safely be used simultaneously in pediatric patients. RNS may potentially augment the therapeutic effects of VNS treatment. Patients in whom a response to VNS has been suboptimal should still be considered for RNS therapy.