title: Clinical motor outcome of bilateral subthalamic nucleus deep-brain stimulation for Parkinson's disease using image-guided frameless stereotaxy.
abstract: BACKGROUND
  Image-guided neuronavigation has largely replaced stereotactic frames when precise, real-time anatomic localization is required during neurosurgical procedures. However, some procedures, including placement of deep-brain stimulation (DBS) leads for the treatment of movement disorders, are still performed using frame-based stereotaxy. Despite the demonstration of comparable accuracy between frame-based and "frameless" image-guided approaches, the clinical efficacy of frameless DBS placement has never been reported.
  
  
  OBJECTIVE
  To analyze the outcomes of subthalamic nucleus (STN) DBS using the frameless technique for the treatment of Parkinson's disease (PD).
  
  
  METHODS
  Of 31 subjects (20 men) with PD for 10 ± 4 years, 28 had bilateral STN DBS and 3 had unilateral STN DBS. The Unified Parkinson's Disease Rating Scale (UPDRS) motor scale (III) and total medication doses were assessed before surgery on and off medication and off medication/ON DBS (off/ON) after 6 to 12 months of STN DBS.
  
  
  RESULTS
  There was a 58% improvement from bilateral STN DBS in the UPDRS III (40 ± 16 preoperatively off, 17 ± 11 off/ON) 9.6 ± 1.9 months after surgery (P < .001). This compared favorably with the published outcomes using the frame-based technique. All motor subscores improved significantly (P < .01). The mean reduction in medication was 50%. No intraoperative complications occurred, but one subject with hypertension died of a delayed hemorrhage postoperatively. Two subjects developed postoperative infections that required lead removal and antibiotics.
  
  
  CONCLUSIONS
  Bilateral STN DBS for PD performed by an experienced team using a frameless approach results in outcomes comparable to those reported with the use of the frame-based technique.
authors.affiliation: Departments of Neurology and Neurological Sciences and of Neurosurgery, Stanford University, Stanford, California 94305-5327, USA. hbs@stanford.edu
authors.forename: Helen
authors.initials: H
authors.lastname: Brontë-Stewart
authors.forename: Stephanie
authors.initials: S
authors.lastname: Louie
authors.forename: Sara
authors.initials: S
authors.lastname: Batya
authors.forename: Jaimie M
authors.initials: JM
authors.lastname: Henderson
mesh_terms: D000368:Aged; D046690:Deep Brain Stimulation / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D007839:Functional Laterality; D006801:Humans; D019018:Imagery, Psychotherapy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000628:therapy*; D013238:Stereotaxic Techniques; D020531:Subthalamic Nucleus / Q000502:physiology*; D014057:Tomography, X-Ray Computed / Q000379:methods; D016896:Treatment Outcome