Wisconsin Card Sorting Test variables in relation to motor symptoms in Parkinson's disease

The Wisconsin Card Sorting Test, a standard test for the assessment of executive function and free of a motor component, was employed for the assessment of 37 nondemented patients with idiopathic Parkinson's Disease and 37 matched normal controls. The symptoms of the patients were clinically assessed by means of the Unified Parkinson's Disease Rating Scale, which yielded scores for the cardinal symptoms of the disease as well as a total motor score. The Wisconsin Card Sorting Test was administered in all subjects in its original form (128 cards), and it was scored to yield 16 measures according to the instruction of the Wisconsin Card Sorting Test revised manual. Patients with Parkinson's Disease had significantly lower scores on the following test variables: number of trials administered, perseverative responses, percent perseverative responses, and failure to maintain set. The correlations between the last three variables and total motor score were statistically significant. Of the four cardinal symptoms of the disease, only rigidity correlated significantly with the number of perseverative responses and percent perseverative responses. These findings provide a clue that the lower performance of these patients on certain variables of the Wisconsin Card Sorting Test may be related to the process of the disease.