title: Effects of levodopa on motor sequence learning in Parkinson's disease.
abstract: BACKGROUND
  Dopaminergic therapy with levodopa improves motor function in PD patients, but the effects of levodopa on cognition in PD remain uncertain.
  
  
  OBJECTIVE
  To use H(2)(15)O and PET to assess the effect of levodopa infusion on motor sequence learning in PD.
  
  
  METHODS
  Seven right-handed PD patients were scanned "on" and "off" levodopa while performing a sequence learning task. The changes in learning performance and regional brain activation that occurred during this intervention were assessed.
  
  
  RESULTS
  During PET imaging, levodopa infusion reduced learning performance as measured by subject report (p < 0.05). This behavioral change was accompanied by enhanced activation during treatment in the right premotor cortex and a decline in the ipsilateral occipital association area (p < 0.01). Levodopa-induced changes in learning-related activation responses in the occipital association cortex correlated with changes in learning indexes (p < 0.01).
  
  
  CONCLUSIONS
  Levodopa treatment appears to have subtle detrimental effects on cognitive function in nondemented PD patients. These effects may be mediated through an impairment in brain activation in occipital association cortex.
authors.affiliation: Center for Neurosciences, North Shore-Long Island Jewish Research Institute, Manhasset, NY 11030, USA. asfeigin@aol.com
authors.forename: A
authors.initials: A
authors.lastname: Feigin
authors.forename: M F
authors.initials: MF
authors.lastname: Ghilardi
authors.forename: M
authors.initials: M
authors.lastname: Carbon
authors.forename: C
authors.initials: C
authors.lastname: Edwards
authors.forename: M
authors.initials: M
authors.lastname: Fukuda
authors.forename: V
authors.initials: V
authors.lastname: Dhawan
authors.forename: C
authors.initials: C
authors.lastname: Margouleff
authors.forename: C
authors.initials: C
authors.lastname: Ghez
authors.forename: D
authors.initials: D
authors.lastname: Eidelberg
mesh_terms: D000368:Aged; D000978:Antiparkinson Agents / Q000494:pharmacology*; D001921:Brain / Q000000981:diagnostic imaging / Q000187:drug effects / Q000503:physiopathology; D003071:Cognition / Q000187:drug effects; D015259:Dopamine Agents / Q000494:pharmacology*; D005260:Female; D006801:Humans; D007858:Learning / Q000187:drug effects; D007980:Levodopa / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000523:psychology*; D011597:Psychomotor Performance / Q000187:drug effects*; D014055:Tomography, Emission-Computed
chemical_list: D000978:Antiparkinson Agents; D015259:Dopamine Agents; D007980:Levodopa