Cognitive function in Parkinson's disease: in relation to motor symptoms.

The performance of patients with Parkinson's disease (PD) on selective neuropsychological tests was examined in regard to the applicability of such examinations to diagnosis. Thirty-six patients with PD, and twenty age- and education-matched controls were given a battery of tests designed to assess motor and intellectual functions. The PD group displayed significantly lower scores on all tests than those in the control group. Correlation analyses on the several motor and neuropsychological results in PD group revealed that there was a significant negative correlation between bradykinesia and visuospatial tests, and rigidity and memory tests. Results are discussed with respect to the involvement of dopaminergic pathways in the central nervous system.