Pallidus internus versus subthalamic nucleus deep brain stimulation for Meige syndrome: a randomized, controlled, double-blind multicenter trial

OBJECTIVE: The aim of this randomized, controlled, double-blind multicenter trial was to compare the safety and efficacy of globus pallidus internus (GPi) and subthalamic nucleus (STN) deep brain stimulation (DBS) in patients with Meige syndrome (MeS). Additionally, the authors explored the optimal site of DBS and identified predictors of clinical outcomes. METHODS: The primary outcome was improvement in motor function as assessed by the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS). The secondary outcomes included mood, global cognitive function, and quality of life (QOL). The optimal stimulation site for DBS was investigated using Lead-DBS. RESULTS: A total of 62 patients with MeS were randomized to receive GPi-DBS (n = 31) or STN-DBS (n = 31), and all completed the 1-year follow-up. In the GPi-DBS group, the mean improvement rates in BFMDRS movement scores were 54.9%, 57.3%, and 59.7% at 3, 6, and 12 months, respectively. In the STN-DBS group, the corresponding rates were 57.1%, 59.0%, and 59.9%. There was no significant difference in the efficacy of motor symptoms, depression, anxiety, and QOL between the two groups during follow-up. The total electrical energy delivered in the GPi-DBS group was significantly greater than that in the STN-DBS group. The adverse event rates were comparable between the GPi-DBS (16.1%) and STN-DBS (12.9%) groups (p > 0.99). The "sweet spot" for GPi-DBS was found to be located in the posterolateral dorsal pallidum (ρ = 0.76, p = 0.001), while the sweet spot for STN-DBS was found to be situated in the dorsal subthalamic nucleus (ρ = 0.66, p = 0.005). Preoperative BFMDRS movement subscores for speech/swallowing were identified as an independent predictor negatively associated with DBS efficacy (p = 0.025). CONCLUSIONS: GPi-DBS and STN-DBS demonstrate comparable safety and efficacy in patients with MeS. STN-DBS requires lower stimulation parameters than GPi-DBS. The optimal stimulation sites are the posterolateral dorsal GPi and the dorsal STN. Greater preoperative speech/swallowing impairment predicts poorer outcomes.