Comparison of Deep Brain Stimulation of the Hippocampus to Thalamic Targets and Responsive Neurostimulation for Adult Intractable Epilepsy: A Systematic Review and Meta-Analysis

Abstract

Objective: Stereotactic neuromodulation, such as deep brain stimulation (DBS) and responsive neurostimulation (RNS), have emerged as some of the more promising means for managing drug-resistant epilepsy. This study serves as a comprehensive analysis of DBS of the anterior nucleus of the thalamus (ANT), centromedian nucleus of the thalamus, and hippocampus and RNS for seizure reduction in adult intractable epilepsy.

Methods: Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a systematic review was conducted of PubMed, Cochrane Library, and Embase databases from January 2000 to January 2024 to objectively assess the effectiveness of the various neuromodulation modalities on seizure reduction. Different software such as EndNote and Rayyan was used to organize the 1996 total reviewed studies and to run a blinded multiphase review process.

Results: A total of 25 studies were included for review with 21 studies and 166 patients suitable for the meta-analysis. DBS ANT, DBS hippocampus, and RNS were all found to have significant individual seizure reductions of 54.0%, 70.0%, and 63.5%, respectively. DBS centromedian nucleus of the thalamus was excluded since only 1 study met inclusion criteria and was, therefore, not suitable for meta-analysis. Furthermore, the 3 analyzed procedures were found to be not significant when compared to one another. Focal versus general epilepsy in DBS ANT also had no significant difference. DBS hippocampus had a significantly higher reduction rate in patients with mesial temporal sclerosis compared to patients with normal imaging findings.

Conclusions: These results provide a vast amount of supporting data for these neurostimulation procedures while also indicating no significant difference between operations. Therefore, in this target population, operative decisions can be made based on surgeon preference and patient circumstance without affecting seizure reduction outcomes.

Keywords: ANT; CMT; DBS; Epilepsy; Hippocampus; RNS.