title: [Cognition deterioration in Parkinson's disease: associated risk factors].
abstract: BACKGROUND
  Frequency estimation of dementia in Parkinson's disease (PD) has often been the source of controversy owing to variations in the case selection methods and diagnosis criteria used. We examined the frequency of dementia and differences found in some clinical features between PD patients with or without cognitive impairment, to determine the risk factors for incident dementia in PD patients.
  
  
  METHODS
  A diagnosis of PD was taken according to the United Kingdom Parkinson's Disease Society Brain Bank criteria. Subjects were considered as affected from cognitive impairment if Minimental State Examination score was below to 21.
  
  
  RESULTS
  Cognitive impairment was present in 36% of PD patients. The mean age was higher in PD patients with cognitive impairment (76 vs 69 years old, respectively; p < 0.001). The age onset of PD was higher in patients with cognitive impairment (68 vs 63 years old, respectively; p < 0.01). The rate of PD patients with low educational level were higher in patients with cognitive impairment (59 vs 30%, respectively; p < 0.01). Patients with cognitive impairment had higher rating scale score (p < 0.001).
  
  
  CONCLUSIONS
  Cognitive impairment was present in 36% of examined PD patients, based in our operative diagnostic criteria. The cognitive status decrease continuously with age. It's also evidence an inverse relation between educational level and rating scale score with cognitive impairment.
authors.affiliation: Servicio de Neurología, Hospital Comarcal de Barbastro, Huesca, España.
authors.forename: J M
authors.initials: JM
authors.lastname: Errea
authors.forename: J R
authors.initials: JR
authors.lastname: Ara
mesh_terms: D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D003072:Cognition Disorders / Q000175:diagnosis / Q000209:etiology*; D005260:Female; D006304:Health Status; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology; D012720:Severity of Illness Index; D017678:Sex Distribution; D013030:Spain / Q000453:epidemiology