Virtual Responsive Neurostimulation Implantation: From Intracranial Connectivity to Optimized Lead Placement

Responsive neurostimulation (RNS) is an implanted device that delivers direct brain stimulation for drug-resistant focal epilepsy. The study included 49 patients with drug-resistant epilepsy from three epilepsy centers who underwent intracranial EEG and RNS implantation. Researchers developed a functional connectivity score based on Spearman correlation, combining standard deviation and kurtosis of interictal EEG. The score was tested on a training group (18 patients) and validated on two independent groups (17 and 14 patients). The accuracy of the score in predicting clinical outcome was 72% at the group level and 61% at the individual patient level. The research showed that interictal functional connectivity can predict individual RNS response, and three-dimensional maps derived from this biomarker could prospectively guide electrode implantation toward favorable brain regions.