Stereoelectroencephalography-Guided Radiofrequency Thermocoagulation for Drug-Resistant Epilepsy: A Single-Arm Meta-Analysis of 517 Patients' Data

Introduction: In patients with focal-drug resistant epilepsy (DRE) , resective epilepsy surgery has shown to produce high rates of remission. However, in cases where the epileptic region is deemed surgically-inaccessible, or when it involves a complex network, Stereo-electroencephalography-guided radiofrequency thermocoagulation (sEEG-guided RF-TC) might be an effective therapeutic strategy. However, most of the available evidence are limited to small observational studies. A meta-analysis is warranted to provide a comprehensiveassessment of sEEG-guided RF-TC in patients with DRE.

Methods: Databases were searched until Sept 9th, 2023, to identify published studies reporting on the effectiveness of sEEG-guided RF-TC in patients with DRE. The primary outcomes of interest were 1-year seizure-freedom and a 50% seizure reduction at 1-year (response rate). These outcomes were pooled using the inverse variance, and a random-effects model.

Results: Initially, 187 articles were identified and a total of 20 retrospective studies involving 517 patients were included. The pooled seizure-free rate after 1-year was found to be 36.3% (95% Confidence Interval [CI]=26.2%-46.4%), while the seizure response rate after 1-year was 66.7% (95% CI=53.2%-83.1%). There was a high heterogeneity among the included studies. Subgroup analysis revealed that patients with Nodular Heterotrophic (NH) achieved higher rates of seizure freedom (59.3% [95% CI=46.2%-72.4%]) compared to those with Cortical Dysplasia and MRI-negative conditions. Furthermore, Hippocampal Sclerosis patients exhibited higher seizure freedom rates (44.2% [95% CI=29%-59%]) than those with Cortical Dysplasia (14.1% [95% CI=5.5%-22%]).

Conclusion : SEEG-guided RF-TC might be a feasible option for seizure control in patients with DRE who are not candidates for surgical intervention while decreasing treatment costs, particularly in cases with NH. This study highlights the need for well-designed clinical trials to deepen our understanding of sEEG-guided RF-TC compared to other therapeutic modalities.