Muscle strength and executive function as complementary parameters for the assessment of impairment in Parkinson's disease

Abstract

Objective: To evaluate the relationship between the quantitative results of functional and cognitive performance of patients with Parkin-son's disease (PD) and disease severity; and to study the relationship between patients' functional and cognitive capacity and motor impair-ment (Unified Parkinson's Disease Rating Scale-UPDRS III). Method: Twenty-nine subjects clinically diagnosed with PD were classified into three groups according to disease severity using the modified Hoehn and Yahr Scale (H&Y). They were submitted to functional (Senior Fitness Test) and neuropsychological tests. Stepwise regression analysis showed a significant association between H&Y and upper limb strength (r2=0.30; p=0.005) and executive function (r2=0.37; p=0.004). In relation to UPDRS III, there was a significant association between lower limb strength (r2=0.27; p=0.010) and global cognitive status (r2=0.24; p=0.024). Conclusion: The implementation of simple tests of functional capacity associated with neuropsychological testing can help to assess disease severity and motor impairment, and can be used to monitor the response to treatment in PD.