Executive cognitive tests for the evaluation of patients with Parkinson's disease

Parkinson's disease (PD) is characterized by changes in movement, which are later followed by cognitive, behavioral and psychological changes. The objective of the present study was to correlate different tests used to examine executive functions in PD patients followed at a specialized outpatient clinic.

Thirty-five patients with idiopathic PD aged 63.0 years on average and with mean schooling of 5.5±4.2 years, were examined using the following tests: Mattis Dementia Rating Scale (MDRS), Scales for Outcomes of Parkinson's Disease-Cognition (SCOPA-COG), Wisconsin Card Sorting Test (WCST), Frontal Assessment Battery (FAB), Digit Span - Inverse Order (IO) (a subtest of the WAIS III) and Verbal Fluency Test (category animals).

Significant correlations were detected between FAB and MDRS Conceptualization (0.814), MDRS Initiation/Perseveration (I/P) and SCOPA-COG Executive Function (0.643), FAB and MDRS I/P (0.601), FAB and Verbal Fluency (0.602), MDRS I/P and MDRS Conceptualization (0.558), Verbal Fluency and MDRS I/P (0.529), MDRS Attention and SCOPA-COG Executive Function (0.495), MDRS Conceptualization and SCOPA-COG Executive Function (0.520), FAB and Digit Span (OI) (0.503), Verbal Fluency and MDRS Conceptualization (0.501), and WCST perseverative errors and FAB (-0.379), WCST perseverative errors and MDRS Conceptualization (0.445), WCST perseverative errors and MDRS I/P (-0.407) and WCST categories completed and MDRS Conceptualization (0.382).

The results demonstrated strong correlations between most of the tests applied, but no associations were detected between the WCST and the other tests, a fact that may be explained by the heterogeneity of scores obtained in the tests by the patients evaluated. A difficulty of the present study was the lack of a control groups for the establishment of adequate standards for this population.