Optimal Stimulation Sites and Long-Term Efficacy of Pallidal Deep-Brain Stimulation for Patients With Tardive Dystonia.

Abstract

Objective: Globus pallidus internus deep brain stimulation (GPi-DBS) is an established treatment for dystonia, but its specific efficacy for tardive dystonia (TD) remains insufficiently documented. To evaluate the long-term clinical outcomes of GPi-DBS and to identify optimal stimulation sites in patients with medically refractory TD.

Methods: We retrospectively analyzed data from 26 patients with TD who underwent bilateral GPi-DBS. Clinical outcomes were assessed using the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS). Optimal stimulation sites were identified using voxelwise sweet spot analysis.

Results: At an average follow-up time of 42 months (range 12-4 months), the mean BFMDRS score improvement was 81.5%. The optimal stimulation sites were located in the posteroventral region of the GPi. Two patients experienced sustained symptom remission after DBS cessation. Complications included device-related infection (n=2), dysarthria (n=4), and gait imbalance (n= 1); no severe permanent complications occurred.

Conclusion: GPi-DBS is effective and safe for patients with medically refractory TD, providing significant long-term symptom relief. The optimal stimulation sites were located in the posteroventral GPi, which is consistent with those reported for patients with other dystonia types.