Broad Impairment of Executive Functions in Patients with Parkinson’s disease: A Meta-Analysis

Objective: Executive functions (EF) impairments have been observed in patients with Parkinson’s disease (PD). However, the pattern of EF deficits in this population remains unclear. This article aimed to examine the influence of PD on different EF domains through meta-analysis of published data. Methods: This article aimed to compare the EFs of PD patients with those of healthy controls (CON) in different EF domains. We searched electronic databases for articles reporting comparisons of EF performance between non-demented/non-depressed PD patients and CON. Accordingly, we identified 140 studies investigating 6 EF domains (attention, inhibition, planning, reasoning, shifting and working memory) in 4683 PD patients and 4247 CON. Results Results showed that PD patients exhibited impaired attention (Hedges’ g= -0.48), inhibition (Hedges’ g=-0.48), planning (Hedges’ g = -0.49), reasoning (Hedges’ g = -0.31), shifting (Hedges’ g = -0.55) and working memory (Hedges’ g = -0.53). They exhibited a moderately impaired overall EF (Hedges’ g = -0.49). EF deficits were not moderated by age, years of education, disease severity, motor deficits, disease duration, medication dose or global cognition. Conclusions: The findings suggest that among PD patients, EFs in which reasoning is least affected are broadly impaired