The impact of Parkinson’s disease severity on performance of activities of daily living: an observational study

INTRODUCTION. Parkinson’s disease (PD) affects the ability to perform activities of daily living (ADL), increasing with disease progression. The study of the association between PD severity and occupational performance skills may improve the understanding of the functional impairment associated with this pathology. Objective. To study the relationship between PD severity and the loss of functional performance. PATIENTS AND METHODS. 49 non-demented PD patients were assessed with The Assessment of Motor and Process Skills (AMPS) scale, the Hoehn & Yahr scale (HY), the section III of the Unified Parkinson Disease Rating Scale (UPDRS), and the Schwab & England scale. RESULTS. PD severity was related to the AMPS scale (p < 0.001). There was a strong correlation between the AMPS motor skills and the HY scale (p < 0.001) and UPDRS III (p < 0.001), as well as between process skills and the Schwab & England E scale (p < 0.001). A moderate correlation was found between Schwab & England scale and AMPS motor skills, while a strong correlation was found with the process skills. Finally, a weak correlation was found between the AMPS scale and disease duration, yet only in the motor section. CONCLUSIONS. The severity of PD is closely related to the impairment of functional skills measured with the AMPS scale in non-demented PD patients. A strong correlation was found with the motor skills. A strong correlation was found between the AMPS process skills scale and Schwab & England ADL scale. A weak correlation was found between the AMPS motor scale and disease duration. The AMPS scale might be a useful tool to monitoring the PD progression through the observation of ADL performance.