Impact of motor and nonmotor symptoms in Parkinson disease for the quality of life: The Japanese Quality-of-Life Survey of Parkinson Disease (JAQPAD) study

Abstract Introduction Parkinson's disease (PD) is characterized by a range of classic motor symptoms and heterogeneous nonmotor symptoms that affect patients' quality of life (QoL). Studies have individually reported the effect of either motor or nonmotor symptoms on patients' QoL; however, a thorough assessment of the symptoms that have the greatest influence on QoL is limited. This JAQPAD study examined the effect of both motor and nonmotor symptoms and patient demographics on QoL in a large population of patients with PD in Japan. Methods All members of the Japan Parkinson's Disease Association were invited to participate in the study. Questionnaires assessing wearing-off symptoms (the 9-item Wearing-Off Questionnaire [WOQ-9]), nonmotor symptoms (Non-Motor Symptoms Questionnaire [NMSQ]) and QoL (the 8-item Parkinson's Disease Questionnaire [PDQ-8]) were included. Multiple regression analyses assessed the effect of clinical factors on the PDQ-8 Summary Index (PDQ-8 SI). Spearman rank correlation coefficient (r) estimated the correlation between each subdomain score of nine NMSQ domains and the PDQ-8 SI. Results A total of 3022 patients were included in the analysis. The PDQ-8 SI score correlated with off-time, age, duration of PD, work status, and the NMSQ total score and subdomain scores. Memory problems correlated most strongly with the PDQ-8 SI score (r = 0.4419), followed by mood (r = 0.4387) and digestive problems (r = 0.4341; p  Conclusions Physicians tend to focus on motor symptoms, while nonmotor symptoms often go under-recognized in clinical practice. This JAQPAD study highlights the importance of recognition and management of both motor and nonmotor symptoms, which together significantly affect patient QoL.