title: The impact of subthalamic deep brain stimulation on bradykinesia of proximal and distal upper limb muscles in Parkinson's disease.
abstract: OBJECTIVE
  To assess the differential effects of bilateral deep brain stimulation of the subthalamic nucleus on proximal and distal muscle groups of the upper limb in Parkinson's disease.
  
  
  METHODS
  Eight parkinsonian subjects with chronic bilateral stimulation of the subthalamic nucleus performed index finger tapping (differentially drawing upon distal arm muscles), horizontal pointing (differentially drawing upon proximal arm muscles) and a complex reach-to-grasp task with cubes of different sizes, which involved both proximal and distal arm muscles. An ultrasound based system was used for kinematic motion analysis. Subjects were investigated in two clinical conditions: on and off subthalamic nucleus stimulation. Clinical symptom severity was rated with the Unified Parkinson's Disease Rating Scale (UPDRS) motor subscore.
  
  
  RESULTS
  Stimulation of the subthalamic nucleus improved the UPDRS motor subscore (68 %). Bradykinesia of index finger tapping and horizontal pointing were equally improved by subthalamic nucleus stimulation. In contrast, in a complex reach-to-grasp task bradykinesia was differentially ameliorated for the grasp component.
  
  
  CONCLUSIONS
  The data suggest that bilateral stimulation of the subthalamic nucleus improves bradykinesia of both distal and proximal muscles of the arm and hand in Parkinson's disease; however, dependent upon task complexity proximal and distal movement components may be affected differentially. Kinematic motion analysis is an efficient tool to objectively evaluate the beneficial effects of subthalamic nucleus stimulation on dexterity in Parkinson's disease.
authors.affiliation: Dept. of Neurology, University Hospital, University of Cologne, Cologne, Germany. m.dafotakis@fz-juelich.de
authors.forename: Manuel
authors.initials: M
authors.lastname: Dafotakis
authors.forename: Gereon R
authors.initials: GR
authors.lastname: Fink
authors.forename: Niels
authors.initials: N
authors.lastname: Allert
authors.forename: Dennis A
authors.initials: DA
authors.lastname: Nowak
mesh_terms: D000328:Adult; D000368:Aged; D001696:Biomechanical Phenomena; D003627:Data Interpretation, Statistical; D046690:Deep Brain Stimulation; D005260:Female; D005385:Fingers / Q000502:physiology; D018737:Hand Strength / Q000502:physiology; D006801:Humans; D018476:Hypokinesia / Q000209:etiology* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000503:physiopathology*; D010300:Parkinson Disease / Q000150:complications / Q000503:physiopathology* / Q000628:therapy*; D011597:Psychomotor Performance / Q000502:physiology; D013028:Space Perception / Q000502:physiology; D020531:Subthalamic Nucleus / Q000502:physiology*; D014110:Touch / Q000502:physiology; D034941:Upper Extremity