In patients with drug-resistant focal epilepsy(DRE) in whom resective surgery is not feasible, responsive neurostimulation(RNS) is a potential treatment option for seizure reduction. The average age of RNS patients is ~35 years in literature. Its utility has not been studied specifically in older adults.

We performed a single center retrospective study of patients who were treated with RNS for >6 months. Patients were divided into older(≥50 years) and younger groups. Change in seizure frequency compared to pre-implant baseline was the primary outcome. Secondary outcomes included RNS-related complications, subsequent resections and changes in seizure medications. Data was analyzed using Student’s t-test, Mann-Whitney U test and Fisher’s exact test.

A total of 57 patients were included with 12(21%) who were >50 years old at the time of RNS implantation. Mean age at implantation was 54.9 among older versus 30.2 years among younger adults. Older adults had seizure onset later in life(p< 0.01) and had a long duration of epilepsy(p< 0.01). There was no differences in MRI findings, prior resections, prior VNS implantations, prior intracranial evaluations, and median number of AEDs prior to RNS implantation among the two groups. Eight (67%) of the older adults had > 50% seizure reduction, of whom 3 (25%) became seizure free. Twenty three (52%) of the younger adults had > 50% seizure reduction of whom 5 (11%) became seizure free. Younger adults had more RNS related complications in comparison to older adults (4 versus 0;p< 0.001).

Our findings show that RNS is a feasible, and safe therapy for older adults with DRE who cannot undergo epilepsy surgery. The outcomes are comparable to their younger counterparts. Multi-center, larger studies are needed to better elucidate the efficacy and utility of RNS in this patient population.