Optimal stimulation site and fiber tracts in subthalamic deep brain stimulation for Meige syndrome.

Background: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) has emerged as an effective therapy for Meige syndrome (MS). However, the optimal stimulation site within STN and the most effective stimulation fiber tracts have not been investigated.

Methods: Based on the discovery cohort (n = 65), we first identified the optimal stimulation site within the STN using the sweet spot mapping method. Second, we screened for the fiber tracts accounting for optimal clinical outcomes by the fiber filtering approach. Third, based on the above findings, we constructed outcome prediction models and estimated their predictive performance in the discovery cohort and an independent validation cohort (n = 20). Finally, we introduced two prospective cases to illustrate if and how the optimal stimulation site and fiber tracts could facilitate precise electrode targeting and postoperative programming.

Results: The optimal stimulation site was mapped to the anterodorsal portion of the STN-motor subregion. Superior STN-DBS outcomes were positively correlated with stimulation of the fibers projecting to the primary motor cortices, the supplementary motor areas, and the globus pallidus internus. Notably, spatial overlap between individual stimulation volumes and the resultant sweet spot or fiber filtering models could cross-predict symptom improvement in out-of-model patients. Moreover, the models could guide electrode implantation and active contact selection in prospective cases.

Conclusion: Our study underscores the potential of optimizing stimulation sites and fibers to predict clinical improvement, and provides new insights into the ongoing efforts of precise surgical targeting and computer-assisted DBS programming.