The frequency and associated risk factors for dementia in patients with Parkinson's disease

Arch Neurol. 1995 Jul;52(7):695-701. doi: 10.1001/archneur.1995.00540310069018.


Objectives: To estimate the frequency and determine the risk factors for incident dementia in community-dwelling patients with Parkinson's disease (PD) and in control subjects.

Design: Prospective cohort study. During a 3.5-year period, 140 patients with idiopathic PD without evidence of dementia and 572 nondemented control subjects were identified in the community of Washington Heights-Inwood in New York, NY. All subjects underwent neurological and neuropsychological evaluations and follow-up examinations.

Results: Twenty-seven patients with PD (19.2%) became demented throughout 2 years, as compared with 87 (15.2%) of the control subjects. The relative risk (RR) for the development of dementia with PD was 1.7 (95% confidence interval [CI], 1.1 to 2.7) after adjusting for age, education, and gender. Predictive features of incident dementia were an extrapyramidal score greater than 25 (RR, 3.56; 95% CI, 1.4 to 8.9) and a Hamilton Depression Rating Scale score greater than 10 (RR, 3.55; 95% CI, 1.6 to 7.9).

Conclusion: Patients with PD, especially those with severe extrapyramidal signs, have almost twice the risk for the development of dementia than do community-dwelling control subjects.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Cohort Studies
  • Dementia / etiology*
  • Dementia / psychology
  • Depressive Disorder / complications
  • Depressive Disorder / psychology
  • Female
  • Humans
  • Male
  • Middle Aged
  • Neuropsychological Tests
  • Parkinson Disease / complications*
  • Parkinson Disease / psychology
  • Prospective Studies
  • Risk Factors