Medically refractory dystonia has recently been treated using deep brain stimulation (DBS) targeting the globus pallidus internus (GPI). Outcomes have varied depending on the features of the dystonia. There has been limited literature regarding outcomes for refractory dystonia following DBS of the subthalamic nucleus (STN).
Four patients with medically refractory, predominantly cervical dystonia underwent STN DBS. Intraoperative assessments with the patients in a state of general anesthesia were performed to determine the extent of fixed deformities that might predict outcome. Patients were rated using the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) and the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) preoperatively and 3 and 12 months following surgery by a rater blinded to the study. Mean changes and standard errors of the mean in scores were calculated for each subscore of the two scales. Scores were also analyzed using analysis of variance and probability values were generated. Neuropsychological assessments and quality of life ratings using the 36-Item Short Form Health Survey (SF-36) were evaluated longitudinally.
Significant improvements were seen in motor (p = 0.04), disability (p = 0.02), and total TWSTRS scores (p = 0.03). Better outcomes were seen in those patients who did not have fixed deformities. There was marked improvement in the mental component score of the SF-36. Neuropsychological function was not definitively impacted as a result of the surgery.
Deep brain stimulation of the STN is a novel target for dystonia and may be an alternative to GPI DBS. Further studies need to be performed to confirm these conclusions and to determine optimal candidates and stimulation parameters.
Abbreviations used in this paper:BFMDRS = Burke-Fahn-Marsden Dystonia Rating Scale; DBS = deep brain stimulation; GPI = globus pallidus internus; MCS = Mental Component Summary; MR = magnetic resonance; PCS = Physical Component Summary; QOL = quality of life; ROM = range of motion; SF-36 = 36-Item Short Form Health Survey; STN = subthalamic nucleus; TWSTRS = Toronto Western Spasmodic Torticollis Rating Scale.
Address reprint requests to: Galit Kleiner-Fisman, M.D., Morton and Gloria Shulman Movement Disorders Center, Toronto Western Hospital, University of Toronto, 399 Bathurst Street, McL-7, Toronto, Ontario, M5T 2S8 Canada. email:
DetanteO, , VercueilL, , KrackP, , ChabardesS, , BenabidAL, & PollackP: Off-period dystonia in Parkinson's disease but not generalized dystonia is improved by high-frequency stimulation of the subthalamic nucleus. Adv Neurol94:309–314, 2004
DetanteO, VercueilL, KrackP, ChabardesS, BenabidAL, PollackP: Off-period dystonia in Parkinson's disease but not generalized dystonia is improved by high-frequency stimulation of the subthalamic nucleus. Adv Neurol94:309–314, 2004)| false
SunB, , LiD, & SunC: Target selection for primary dystonia deep brain stimulation: Gpi or STN. Proceedings from the American Society for Stereotactic and Functional Neurosurgery Quadrennial MeetingMay 18–21New York2003. (Abstract)
SunB, LiD, SunC: Target selection for primary dystonia deep brain stimulation: Gpi or STN. Proceedings from the American Society for Stereotactic and Functional Neurosurgery Quadrennial MeetingMay 18–21New York2003. (Abstract))| false