title: Assessing the effects of subthalamic nucleus stimulation on gait and mobility in people with Parkinson disease.
abstract: OBJECTIVE
  To determine the effects of unilateral and bilateral subthalamic nucleus (STN) stimulation on gait and mobility in persons with Parkinson disease (PD).
  
  
  METHODS
  We examined eight individuals with advanced PD who underwent staged stimulator implantation surgeries. Gait and mobility were assessed in the medication-on state with a variety of clinical and laboratory measures (Unified Parkinson Disease Rating Scale items, Timed Up and Go Test, gait speed) at three time points: prior to surgery, after the first surgery (unilateral stimulation) and after the second surgery (bilateral stimulation).
  
  
  RESULTS
  Despite overall improvements in motor function and reduction of dyskinesia, there were no significant group effects of unilateral or bilateral stimulation on gait and mobility compared to pre-surgical function. However, there were clinically meaningful changes, both improvements and declines, at the individual level.
  
  
  CONCLUSIONS
  Because of the consequences of gait deficits and mobility limitations for people with PD, future research should examine the effects of STN stimulation on gait in the medication-on state using sensitive and specific measures such as gait speed. Accurate assessment of gait changes is necessary to improve the evaluation of STN effects and the prediction of individuals in need of rehabilitation services to manage gait and mobility deficits.
authors.affiliation: Department of Rehabilitation Medicine, University of Washington, Seattle, Washington 98195-6490, USA. vekelly@u.washington.edu
authors.forename: Valerie E
authors.initials: VE
authors.lastname: Kelly
authors.forename: Shawn M
authors.initials: SM
authors.lastname: Israel
authors.forename: Ali
authors.initials: A
authors.lastname: Samii
authors.forename: Jefferson C
authors.initials: JC
authors.lastname: Slimp
authors.forename: Robert
authors.initials: R
authors.lastname: Goodkin
authors.forename: Anne
authors.initials: A
authors.lastname: Shumway-Cook
mesh_terms: D000328:Adult; D000368:Aged; D046690:Deep Brain Stimulation; D004567:Electrodes, Implanted; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D010300:Parkinson Disease / Q000601:surgery / Q000628:therapy*; D020531:Subthalamic Nucleus / Q000502:physiology*; D016896:Treatment Outcome; D016138:Walking / Q000502:physiology