title: Effects of deep brain stimulation of dorsal versus ventral subthalamic nucleus regions on gait and balance in Parkinson's disease.
abstract: OBJECTIVE
  Deep brain stimulation (DBS) of the subthalamic nucleus (STN) improves motor function, including gait and stability, in people with Parkinson's disease (PD) but differences in DBS contact locations within the STN may contribute to variability in the degree of improvement. Based on anatomical connectivity, dorsal STN may be preferentially involved in motor function and ventral STN in cognitive function.
  
  
  METHODS
  To determine whether dorsal DBS affects gait and balance more than ventral DBS, a double blind evaluation of 23 PD patients with bilateral STN DBS was conducted. Each participant underwent gait analysis and balance testing off Parkinson's medication under three DBS conditions (unilateral DBS in the dorsal STN region, unilateral DBS in the ventral STN region and both stimulators off) on 1 day.
  
  
  RESULTS
  Improvements were seen in Unified Parkinson's Disease Rating Scale (UPDRS)-III scores and velocity in walking trials as fast as possible (Fast gait) and preferred pace (Pref gait), as well as stride length for Fast and Pref gait, with dorsal and ventral stimulation compared with the off condition (post hoc tests, p<0.05). However, there were no differences with dorsal compared to ventral stimulation. Balance, assessed using the multi-item mini-Balance Evaluation Systems Test (mini-BESTest), was similar across conditions.
  
  
  CONCLUSIONS
  Absence of differences in gait and balance between the dorsal and ventral conditions suggests motor connections involved in gait and balance may be more diffusely distributed in STN than previously thought, as opposed to neural connections involved in cognitive processes, such as response inhibition, which are more affected by ventral stimulation.
authors.affiliation: Program in Physical Therapy, Washington University School of Medicine, St Louis, MO 63108, USA.
authors.forename: M E
authors.initials: ME
authors.lastname: McNeely
authors.forename: T
authors.initials: T
authors.lastname: Hershey
authors.forename: M C
authors.initials: MC
authors.lastname: Campbell
authors.forename: S D
authors.initials: SD
authors.lastname: Tabbal
authors.forename: M
authors.initials: M
authors.lastname: Karimi
authors.forename: J M
authors.initials: JM
authors.lastname: Hartlein
authors.forename: H M
authors.initials: HM
authors.lastname: Lugar
authors.forename: F J
authors.initials: FJ
authors.lastname: Revilla
authors.forename: J S
authors.initials: JS
authors.lastname: Perlmutter
authors.forename: G M
authors.initials: GM
authors.lastname: Earhart
mesh_terms: D000368:Aged; D000978:Antiparkinson Agents / Q000627:therapeutic use; D046690:Deep Brain Stimulation / Q000379:methods*; D004311:Double-Blind Method; D005260:Female; D005684:Gait; D006801:Humans; D008297:Male; D008875:Middle Aged; D009474:Neurons / Q000473:pathology; D010300:Parkinson Disease / Q000503:physiopathology* / Q000628:therapy*; D004856:Postural Balance; D020531:Subthalamic Nucleus / Q000503:physiopathology*; D016896:Treatment Outcome
chemical_list: D000978:Antiparkinson Agents