Early impairment of cognitive functions in Parkinson's disease.

Background: Impairment in non-motor functions such as disturbances of some executive functions are also common events in Parkinson's disease patients.

Objective: To verify the performance of Parkinson's disease patients in activities requiring visuoconstructive and visuospatial skills.

Method: Thirty elderly patients with mild or moderate stages of Parkinson's disease were studied. The assessment of the clinical condition was based on the unified Parkinson's disease rating scale (56.28; SD=33.48), Hoehn and Yahr (2.2; SD=0.83), Schwab and England (78.93%), clock drawing test (7.36; SD=2.51), and mini-mental state examination (26.48; SD=10.11). Pearson's correlation and stepwise multiple regression were used for statistical analyses.

Results: The patients presented deterioration in visuospatial and visuoconstructive skills.

Conclusion: The clock drawing test proved to be a useful predictive tool for identifying early cognitive impairment in these individuals.