The Efficacy, Safety, and Outcomes of Brain-responsive Neurostimulation (RNS® System) therapy in older adults

Objectives The gold standard for the management of drug-resistant focal epilepsy (DRE) is resection of epileptogenic zone. However, some patients may not be candidates for resection. Responsive neurostimulation is approved in patients above 18 years of age for such patients. We aimed to investigate whether RNS outcomes and safety varied based on age. Methods We performed a single-center retrospective cohort study of patients with DRE who were treated with RNS between May 2008 and February 2020. We included patients who had been implanted with RNS for >6 months (N = 55), dividing them into older (N = 11) and younger adults (N = 44) depending on implantation age (>= 50 and <50 years, respectively). Results Mean age at implantation in older adults was 54.9 +/- 3.5 years. Seizure onset age, epilepsy duration, and comorbidities were significantly higher in older adults ( P < .01). Stimulation parameters, treatment duration, and median seizure frequency reduction (76% in older vs 50% in younger adults) were statistically comparable between the two cohorts. Posttreatment, antiseizure medication burden was significantly decreased in older compared with younger adults (P = .048). Postoperative and delayed adverse events among older adults were mild. Compared with three younger adults, none of the older adults required device explantation due to surgical site infection. Conclusion Our study suggests that older adults treated with the RNS System achieve seizure outcomes comparable to younger adults with the additional benefit of a significant postimplantation medication reduction. With efficacy and safety similar to younger adults, brain-responsive neurostimulation was well-tolerated in older adults.