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.