Responsive Neurostimulation Therapy Outcomes in Two Small Bilateral Thalamic and Corticothalamic Subgroups of...

Responsive neurostimulation (RNS) is a neuromodulation option for treatment of drug-resistant epilepsy (DRE). There is limited data reviewing bilateral thalamic and corticothalamic RNS therapy response. We performed a retrospective analysis of 21 patients undergoing RNS implantation with either bilateral thalamic (n = 17) or corticothalamic (n = 4) leads and ≥6 months of follow-up. Patients were classified as responders (≥50% seizure frequency reduction) vs. non-responders (<50% seizure frequency reduction). Among the bilateral thalamic cohort, 12/17 (70.6%) patients were responders, and 15/17 (88.2%) patients reported reduction in seizure severity. Pre-RNS seizure frequency was higher in bilateral thalamic nonresponders, although not found to be significant (median 13 vs. 30 seizures per month, p = 0.20). Among the corticothalamic cohort, 3/4 (75.0%) patients were responders, and all patients demonstrated improvement in seizure severity. These findings suggest that although bilateral thalamic targets were selected at our center more often, both bilateral thalamic and corticothalamic RNS approaches provided seizure frequency reduction. The majority of patients, including non-responders, reported seizure severity alleviation.