Thalamic deep brain stimulation for treatment-refractory Tourette syndrome

Abstract

BACKGROUND: Eighteen patients with severe and refractory Tourette syndrome (TS) underwent bilateral thalamic deep brain stimulation (DBS). OBJECTIVE: To assess the long-term outcome on tics, behavioral symptoms, and cognitive functions in the largest case series of thalamic DBS for TS to date. METHODS: In this prospective cohort study, 15 of the original 18 patients were evaluated before and after surgery according to a standardized protocol that included both neuropsychiatric and neuropsychological assessments. RESULTS: In addition to marked reduction in tic severity (p = 0.001), 24-month follow-up ratings showed improvement in obsessive-compulsive symptoms (p = 0.009), anxiety symptoms (p = 0.001), depressive symptoms (p = 0.001), and subjective perception of social functioning/quality of life (p = 0.002) in 15 of 18 patients. There were no substantial differences on measures of cognitive functions before and after DBS. CONCLUSIONS: At 24-month follow-up, tic severity was improved in patients with intractable Tourette syndrome (TS) who underwent bilateral thalamic deep brain stimulation. Available data from 15 of 18 patients also showed that neuropsychiatric symptoms were improved and cognitive performances were not disadvantaged. Controlled studies on larger cohorts with blinded protocols are needed to verify that this procedure is effective and safe for selected patients with TS. LEVEL OF EVIDENCE: This study provides class IV evidence that bilateral thalamic deep brain stimulation reduces global tic severity measured 24 months after implantation in patients with severe intractable Tourette syndrome.