Efficacy comparison and outcome predictors of GPi- and STN-targeted deep brain stimulation for Meige syndrome: a systematic review of individual patient data.

Objective: The aim of this study was to evaluate outcomes of deep brain stimulation (DBS) for Meige syndrome, compare the efficacy of globus pallidus internus (GPi) and subthalamic nucleus (STN) as targets, and identify potential outcome predictors.

Methods: The PubMed, Embase, and Web of Science databases were systematically searched to collect individual data from patients with Meige syndrome receiving DBS. Outcomes were assessed using the Burke-Fahn-Marsden Dystonia Rating Scale motor (BFMDRS-M) and disability (BFMDRS-D) scores. Data were analyzed using pooled meta-analysis. The study is registered in the PROSPERO database.

Results: The analysis included 233 patients from 26 studies, with significant publication bias (p = 0.008, Egger's test), but showed significant improvements in BFMDRS-M (65.09% ± 26.65%) and BFMDRS-D (53.48% ± 42.44%) scores at the final follow-up (mean duration 27.10 ± 33.64 months). No significant differences were observed in BFMDRS-M score improvement (mean difference -2.58%, 95% CI -15.84% to 10.69%; p = 0.430) or risk difference for response (-0.97%, 95% CI -10.08% to 8.15%; p = 0.835) between the GPi and STN target groups at the final follow-up across all follow-up periods (0 to ≤ 6, > 6 to ≤ 12, > 12 to ≤ 24, > 24 to ≤ 36, and > 36 months). Multiple regression analysis revealed a negative correlation between disease duration and treatment efficacy and a positive correlation between preoperative BFMDRS score and treatment outcome.

Conclusions: DBS significantly improves motor symptoms and disability in patients with Meige syndrome, with GPi and STN targets providing comparable efficacy. The efficacy of DBS diminishes with longer disease duration, underscoring the importance of early intervention.