title: Premotor cognitive status in a cohort of incident Parkinson disease patients (NEDICES).
abstract: BACKGROUND
  A variety of symptoms may precede the classical motor features of Parkinson disease (PD). However, it is not known whether cognitive dysfunction precedes the motor phase of PD. We examined whether patients with incident PD had had global cognitive function disturbances three years prior to diagnosis when compared with matched controls in a cohort of community-dwelling subjects.
  
  
  METHODS
  All participants were age 65 years or older (median 76 years) and were enrolled in the Neurological Disorders in Central Spain (NEDICES) study in central Spain. We identified all participants with incident PD (N=23), diagnosed in the follow-up examination (1997-1998), who had performed an expanded 37-item version of the Mini-Mental State Examination (37-MMSE) at the baseline evaluation (1994-1995). These 23 were 1:4 matched to 92 controls.
  
  
  RESULTS
  Baseline 37-MMSE scores were 27.9±4.9 (28) in PD patients and 28.7±6.5 (31) in controls (p=0.212). There were no patient-control differences in orientation, immediate recall, attention and calculation, memory recall, language, or visuospatial copying. In analyses that adjusted for several possible confounding factors, there were no case-control differences.
  
  
  CONCLUSIONS
  In this population-based sample, patients with incident PD did not have evidence of significant global cognitive function disturbances three years prior to their diagnosis when compared with matched controls. Our data suggest that global cognitive dysfunction does not precede the diagnosis of PD.
authors.affiliation: Department of Neurology, University Hospital 12 de Octubre, Madrid, Spain.
authors.forename: Álvaro
authors.initials: Á
authors.lastname: Sánchez-Ferro
authors.forename: Julián
authors.initials: J
authors.lastname: Benito-León
authors.forename: Alex J
authors.initials: AJ
authors.lastname: Mitchell
authors.forename: Elan D
authors.initials: ED
authors.lastname: Louis
authors.forename: Ignacio J
authors.initials: IJ
authors.lastname: Posada
authors.forename: Rocío
authors.initials: R
authors.lastname: Trincado
authors.forename: Alberto
authors.initials: A
authors.lastname: Villarejo
authors.forename: Félix
authors.initials: F
authors.lastname: Bermejo-Pareja
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D003072:Cognition Disorders / Q000453:epidemiology* / Q000209:etiology*; D015331:Cohort Studies; D018672:Community Health Planning; D018450:Disease Progression; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D009483:Neuropsychological Tests; D016017:Odds Ratio; D010300:Parkinson Disease / Q000150:complications* / Q000453:epidemiology*; D011569:Psychiatric Status Rating Scales; D012189:Retrospective Studies