Prognostic factors for long-term outcomes of bilateral pallidal deep brain stimulation in the treatment of Meige syndrome

OBJECTIVE: This study aimed to investigate the effects of bilateral globus pallidus internus (GPi) deep brain stimulation (DBS) on both motor and nonmotor symptoms in patients with Meige syndrome and to further explore prognostic factors for postoperative outcomes based on the long-term follow-up results. METHODS: The authors retrospectively reviewed the medical records of a consecutive cohort of patients with refractory Meige syndrome who underwent GPi-DBS at their center from January 2016 to October 2023. Motor function, quality of life, neuropsychological status, and emotional state were assessed using standardized scales at baseline and every 3-6 months thereafter. Univariate and multivariate linear regression analyses were performed to identify independent risk factors affecting long-term motor function after GPi-DBS in patients with steady-state (stable) Meige syndrome. RESULTS: Fifty steady-state patients were ultimately included and assessed, with a mean follow-up duration of 62.9 ± 24.8 months. At the final postoperative evaluation, Burke-Fahn-Marsden Dystonia Rating Scale movement and disability scores showed improvements of 69% (p < 0.001) and 61% (p < 0.001), respectively. A significant improvement from baseline was observed in postoperative scores on the 36-item Short-Form General Health Survey. Throughout continuous neurostimulation, global cognitive function, neuropsychological status, and mood remained stable. Multivariate linear regression analysis revealed that longer disease duration (standardized β-coefficient -0.375, 95% CI -0.033 to -0.011; p < 0.001) and reduced volume of activated tissue within the sensorimotor subregion of the GPi (standardized β-coefficient 0.597, 95% CI 0.002-0.003; p < 0.001) were independently associated with worse long-term motor performance. CONCLUSIONS: Bilateral GPi-DBS is an effective, safe, and promising treatment option for intractable Meige syndrome and provides sustained benefits in motor function and quality of life without inducing cognitive or mood-related side effects. Early intervention and accurate electrode placement in the sensorimotor subregion of the GPi are essential for optimizing long-term therapeutic outcomes.