title: Cognitive profile of patients with newly diagnosed Parkinson disease.
abstract: OBJECTIVE
  To determine the frequency and pattern of cognitive dysfunction in patients with newly diagnosed Parkinson disease (PD) and to identify its demographic and clinical correlates.
  
  
  METHODS
  A cohort of 115 consecutive patients with newly diagnosed PD and 70 healthy controls underwent a comprehensive neuropsychological assessment including tests of psychomotor speed, attention, language, memory, executive and visuospatial functions, as well as measures of affective status. Patients also received quantitative ratings of motor symptom severity and functional status. Neuropsychological performance of PD patients was compared with that of healthy controls and with available normative data. Independent demographic and clinical predictors of cognitive impairment were identified with multiple logistic regression analysis.
  
  
  RESULTS
  Relative to controls, PD patients performed significantly worse on most cognitive measures. However, further analysis revealed that group differences in cognitive performance could mainly be explained by measures of immediate memory and executive function. Comparison with normative data showed that impairments were most frequent on measures of executive function, memory and psychomotor speed. In all, 24% of PD patients (4% of controls) displayed defective performance on at least three neuropsychological tests and were classified as cognitively impaired. Late onset of disease was an independent predictor of cognitive dysfunction in PD.
  
  
  CONCLUSIONS
  Cognitive impairments are common even in newly diagnosed Parkinson disease patients, with deficits being most prominent in the domains of memory and executive functions. Older age at disease onset is likely to be an important determinant of cognitive dysfunction in Parkinson disease.
authors.affiliation: Department of Neurology, Academic Medical Center, University of Amsterdam, The Netherlands. d.muslimovic@amc.uva.nl
authors.forename: Dino
authors.initials: D
authors.lastname: Muslimovic
authors.forename: Bart
authors.initials: B
authors.lastname: Post
authors.forename: Johannes D
authors.initials: JD
authors.lastname: Speelman
authors.forename: Ben
authors.initials: B
authors.lastname: Schmand
mesh_terms: D000342:Affective Symptoms / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D017668:Age of Onset; D000368:Aged; D003072:Cognition Disorders / Q000175:diagnosis / Q000453:epidemiology* / Q000523:psychology*; D015331:Cohort Studies; D015897:Comorbidity; D005260:Female; D006801:Humans; D007806:Language Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D008297:Male; D008569:Memory Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D008875:Middle Aged; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000175:diagnosis / Q000453:epidemiology* / Q000523:psychology*; D011237:Predictive Value of Tests; D015995:Prevalence; D011597:Psychomotor Performance / Q000502:physiology