Deep brain stimulation of the thalamus for intractable epilepsy (FRANCE study): A randomized clinical trial

This study was undertaken to evaluate the efficacy and safety of deep brain stimulation (DBS) of the anterior nucleus of the thalamus (ANT) compared with best medical treatment (BMT) in patients with drug-resistant epilepsy (DRE).

This randomized, open-label, phase 3 controlled trial was conducted across 14 specialized epilepsy and DBS centers. Eligible participants were adults with focal or multifocal DRE who had previously failed vagus nerve stimulation (VNS). Sixty-one patients were randomized 1:1 either to receive continuous bilateral ANT-DBS (n = 30) or to continue BMT, including VNS (n = 31), for 12 months. Afterward, patients in the BMT group were offered delayed ANT-DBS and followed for an additional year. The primary outcome was the change in monthly severe seizure frequency (defined on the modified Chalfont Scale) at 12 months. Safety outcomes were also recorded.

Among 67 screened patients, 61 were enrolled. At 12 months, median seizure reduction was greater in the DBS group (-44%, interquartile range [IQR] = -67 to 0) versus the BMT group (-6%, IQR = -56 to 20; p = .09); 44.5% of patients in the DBS group achieved a ≥50% reduction in seizure frequency compared to 27% in the BMT group. Within-group analyses showed significant seizure reductions in the DBS group at both 12 months (-44%, p < .001) and 24 months (-46%, p < .001), as well as in the delayed DBS group at 12 months (-36%, IQR = -73 to -4; p < .001). No significant differences in quality of life were observed between groups, and no major DBS-related adverse events were reported.

Our study suggests a potential benefit rather than demonstrating superiority of ANT-DBS over medical therapy. However, within-group improvements and favorable safety profile support the use of ANT-DBS as a palliative treatment option in patients with DRE who have failed VNS.