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&#95;SI) and the NMSS (correlation coefficient [cc], 0.56; p<.001), UPDRS III (cc, 0.44; p< .001) and UPDRS IV (cc, 0.37; p<.001) scores. The strongest correlation was between cognitive symptoms and mood. The analysis pointed to a direct relationship between the NMSS score and axial symptoms (cc, 0.384; p<.01), bradykinesia (cc, 0.299; p<.01), and to a lesser extent, rigidity (cc, 0.194; p<.05). No relationship was observed between presence of tremor and the NMSS score.
Conclusion: Cognitive symptoms and mood exert the most influence on QoL of patients with PD. We found at least two phenotypes; one with predominantly axial symptoms, with significant involvement of non-motor symptoms, and a tremor-associated phenotype in which these symptoms are less prevalent.
(Copyright © 2014 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.)