Abstract
Epilepsy is a chronic neurological disorder affecting millions of people around the world. Even though the majority of patients gain seizure control with antiseizure medications (ASMs), many subjects may have drug-resistant epilepsy (DRE). Deep brain stimulation (DBS) is a promising alternative, showing effectiveness in reducing seizures for some patients. This systematic review and meta-analysis aim to evaluate DBS's efficacy in DRE. A comprehensive search in PubMed, CENTRAL, Medline, Ovid, and Scopus was performed up to August 31, 2024, using the terms 'Drug-resistant Epilepsy' AND 'Deep Brain Stimulation'. Two independent researchers screened titles, abstracts, and full texts. The data extracted included study details, sample size, age at surgery, seizure duration, follow-up duration, seizure reduction (SR), responder rate (RR), and adverse events. Quality assessment was conducted using the Risk of Bias 2 (ROB2) tool (https://methods.cochrane.org/bias/resources/rob-2-revised-cochrane-risk-bias-tool-randomized-trials), and data analysis was performed using Jamovi software (https://www.jamovi.org). The search yielded 707 studies that were initially screened. Out of them, 29 articles were retrieved for full-text screening, and 5 randomized controlled trials (RCTs) were included in the review and meta-analysis. The meta-analysis showed that the pooled effect size for SR was 0.51 (95% CI, 0.35-0.68; P < 0.001), and the pooled effect size for RR was 0.54 (95% CI, 0.35-0.74; P < 0.001), demonstrating significant improvements in seizure control. The pooled effect size for adverse events was 0.21 (95% CI, 0.08-0.34; P = 0.001). The risk-of-bias assessment revealed a low risk of randomization for most studies. However, concerns were noted in areas such as deviations from the intended intervention and missing outcome data. In conclusion, DBS is a viable intervention for DRE, with significant reductions in seizure frequency and a favorable safety profile. However, the variability in efficacy and RRs across studies underscores the need for continued research to refine patient selection criteria, optimize stimulation parameters, and explore the differential effects of targeting various thalamic nuclei.