We report the results of a prospective, multicenter study with open-label, blinded, as well as self-assessed evaluations to investigate the efficacy and safety of bilateral GPi DBS in patients with primary dystonia. Twenty-four patients from ten different hospitals were included and followed for one year. Clinical assessments were done through blinded scoring of video recordings, open-label evaluations, and self-assessment scales. One year after surgery, baseline motor scores were significantly reduced as revealed by both open and blinded assessments. A similar reduction in disability and pain associated with dystonia was also observed. A marked reduction of anti-dystonic medications was observed postoperatively. At six months and one year follow-up, we found correlation between improvement of both motor and functional BFMDRS scores and the age of patients at the moment of surgery. Significant improvement was also seen in quality of life. Despite global improvements in the majority of our dystonic patients, these were not associated with any significant changes in caregiver burden. Six of the 24 patients in this study presented adverse events.
GPi DBS is an effective symptomatic treatment in patients with primary dystonia refractory to medical treatment; younger age at the moment of surgery correlates positively with motor and functional outcome.