Motor and non-motor symptoms of Parkinson's disease and their impact on quality of life and on different clinical subgroups

Introduction: The aim of the present study is to analyse the influence that motor and non-motor symptoms have on the quality of life (QoL) of patients with Parkinson's disease (PD), and to study the relationship between the two types of symptoms. Material and methods: This cross-sectional study included 103 patients with PD (55 men and 48 women). Quality of life was measured on the PDQ-39 scale. The UPDRS scale (I-IV) was also used, and different items were grouped to analyse the presence of tremor, rigidity, bradykinesia, and axial symptoms. The non-motor symptoms scale (NMSS) was administered to assess non-motor symptoms. We performed correlation analyses between different scales to analyse the influence of motor and non-motor symptoms on QoL. Results: Correlations were observed between the PDQ-39 summary index (PDQ39 SI) and the NMSS (correlation coefficient [cc], 0.56; P