title: Early-stage cognitive impairment in Parkinson's disease and the influence of dopamine replacement therapy.
abstract: OBJECTIVE
  The aim of this study was to establish the cognitive profile of newly diagnosed untreated (de novo) patients with Parkinson's disease (PD) and more advanced, treated patients, and to determine the effects of dopamine (DA) replacement therapy.
  
  
  METHODS
  A cohort of 23 de novo patients, 55 mild to moderately advanced, medicated PD patients and 21 healthy controls participated. Cognitive tests included the Cambridge Examination for Mental Disorders and a battery of neuropsychological tests taken from the Cambridge Neuropsychological Test Automated Battery and the Vienna Test System.
  
  
  RESULTS
  De novo patients with PD were more impaired in working memory strategy use than healthy controls and treated patients with PD. Furthermore, the generation of random motor behaviour was more impaired in both de novo and treated PD patients than in healthy controls. Correlation analysis revealed that in treated patients with PD, ascending doses of dopaminergic medication were associated with poorer performance on a pattern recognition task.
  
  
  CONCLUSIONS
  Selective impairments in strategy use and the generation of random motor behaviour are a very early feature of PD and might be of predictive value in further frontal cognitive deterioration. Furthermore, DA replacement therapy seems to improve frontal lobe function (strategy use) and worsen temporal lobe function (visual memory).
authors: Department of Neurology, VU University Medical Center (VUMC), Amsterdam Department of Clinical Neuropsychology, VU University, Amsterdam, The Netherlands. ipmiah@gmail.com
authors: I P
authors: IP
authors: Miah
authors: K T
authors: KT
authors: Olde Dubbelink
authors: D
authors: D
authors: Stoffers
authors: J B
authors: JB
authors: Deijen
authors: H W
authors: HW
authors: Berendse
mesh_terms: D000978:Antiparkinson Agents / Q000008:administration & dosage*; D003072:Cognition Disorders / Q000209:etiology / Q000517:prevention & control*; D004298:Dopamine / Q000008:administration & dosage*; D015259:Dopamine Agents / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000150:complications* / Q000188:drug therapy / Q000523:psychology
chemical_list: D000978:Antiparkinson Agents; D015259:Dopamine Agents; D004298:Dopamine