Importance of focusing on subjective symptoms to maintain quality of life in patients with Parkinson's disease for over 5 years.

Parkinson's disease (PD) is a neurodegenerative disorder that causes a variety of motor and non-motor symptoms (NMS), which affect the patient's quality of life (QOL). This study aimed to compare QOL and background in patients with PD based on the disease duration and investigate the factors affecting QOL. Patients with PD were evaluated based on age, sex, disease duration (≤5 years and > 5 years groups), Mini Mental State Examination (MMSE), Japanese version of Montreal Cognitive Assessment (MoCA-J), Levodopa equivalent daily dose (LEDD), Hoehn and Yahr (HY) severity, movement disorder society-sponsored revision of the unified Parkinson's disease rating scale (MDS-UPDRS) parts I-IV, and QOL using the Parkinson's disease questionnaire (PDQ-8). Overall, 102 patients with PD (58 males; mean age = 70.0 years; mean disease duration = 7.3 years) were included in this study. QOL was significantly correlated (r > 0.30, p < 0.05) with disease duration and MDS-UPDRS parts I-IV total scores. When the PDQ-8 total score was compared with MDS-UPDRS parts I-IV total scores based on disease duration classification, it was positively correlated with the scores for parts I and II in the >5 years group. Moreover, MDS-UPDRS parts I and II total scores appeared to be the factors most significantly affecting QOL. The factors affecting QOL in patients with PD were subjective NMS and motor symptoms. Since, physician-rated motor symptoms were not associated with QOL in patients with >5 years PD, subjective symptoms should be evaluated and treated to maintain QOL.