title: Activity enhances dopaminergic long-duration response in Parkinson disease.
abstract: OBJECTIVE
  We tested the hypothesis that dopamine-dependent motor learning mechanism underlies the long-duration response to levodopa in Parkinson disease (PD) based on our studies in a mouse model. By data-mining the motor task performance in dominant and nondominant hands of the subjects in a double-blind randomized trial of levodopa therapy, the effects of activity and dopamine therapy were examined.
  
  
  METHODS
  We data-mined the Earlier versus Later Levodopa Therapy in Parkinson's Disease (ELLDOPA) study published in 2005 and performed statistical analysis comparing the effects of levodopa and dominance of handedness over 42 weeks.
  
  
  RESULTS
  The mean change in finger-tapping counts from baseline before the initiation of therapy to predose at 9 weeks and 40 weeks increased more in the dominant compared to nondominant hand in levodopa-treated subjects in a dose-dependent fashion. There was no significant difference in dominant vs nondominant hands in the placebo group. The short-duration response assessed by the difference of postdose performance compared to predose performance at the same visit did not show any significant difference between dominant vs nondominant hands.
  
  
  CONCLUSIONS
  Active use of the dominant hand and dopamine replacement therapy produces synergistic effect on long-lasting motor task performance during "off" medication state. Such effect was confined to dopamine-responsive symptoms and not seen in dopamine-resistant symptoms such as gait and balance. We propose that long-lasting motor learning facilitated by activity and dopamine is a form of disease modification that is often seen in trials of medications that have symptomatic effects.
authors.affiliation: Department of Neurology, The University of Chicago, Chicago, IL, USA. unkang@uchicago.edu
authors.forename: Un Jung
authors.initials: UJ
authors.lastname: Kang
authors.forename: Peggy
authors.initials: P
authors.lastname: Auinger
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D000368:Aged; D000978:Antiparkinson Agents / Q000008:administration & dosage*; D015259:Dopamine Agents / Q000008:administration & dosage*; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D005260:Female; D007839:Functional Laterality; D006801:Humans; D007980:Levodopa / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000188:drug therapy* / Q000503:physiopathology*; D013647:Task Performance and Analysis
chemical_list: D000978:Antiparkinson Agents; D015259:Dopamine Agents; D007980:Levodopa