Combined Surgical Resection and Responsive Neurostimulation for Drug-Resistant Epilepsy: A Case Series

Surgical resection offers the highest seizure freedom rates in appropriately selected patients with drug-resistant epilepsy (DRE). However, complete resection may not be feasible if the epileptogenic zone is diffuse, multifocal, or eloquent. Responsive neurostimulation (RNS) reduces seizure frequency in patients who are not candidates for complete resection but rarely results in complete seizure freedom. For patients requiring subtotal resection because of eloquent cortex involvement, we pursued a hybrid approach using RNS to target the remaining unresectable regions of the putative seizure onset zone. We hypothesized that neuromodulation of unresected areas would improve seizure control beyond subtotal resection alone and conducted a retrospective analysis investigating partial resection plus RNS (R + RNS) efficacy in DRE.

We conducted a retrospective study of patients with focal DRE who underwent R + RNS at our institution between 2020 and 2022 and had at least 6 months of follow-up. We assessed relative seizure frequency, severity, seizure-free periods, and subjective improvements.

Seven patients underwent R + RNS with a mean follow-up of 20.7 months. The mean seizure frequency reduction was 79.3% (range 0%-100%). Three patients (42.9%) achieved seizure freedom postresection but experienced recurrence; RNS activation restored sustained seizure freedom in all three. One additional patient with initial seizure relapse achieved near seizure-freedom through RNS programming optimization. Overall, 3 patients (42.9%) were seizure-free at the final follow-up. Patients reported decreased seizure severity and improved sleep. No complications occurred.

In our case series, R + RNS yielded substantial seizure reductions for patients with DRE. This combined approach may serve as a beneficial strategy for patients who cannot undergo a complete resection of their seizure onset zone because of the involvement of eloquent areas or secondary foci.