Progression of non-motor symptoms in Parkinson's disease among different age populations: A two-year follow-up study

Background: Non-motor symptoms (NMS) are gaining increasing relevance in the management of Parkinson's disease (PD), but little is known about their progression, especially among patients with different ages. Methods: A total of 117 PD patients who were divided into four age groups (<50, 50-60, 60-70, and >70 years old) were included to assess NMS at baseline and follow-up visit (21.6 +/- 5.6 months). The frequency and severity of NMS were assessed using the Non-Motor Symptom Scale (NMSS). Results: After adjusting for confounding factors, patients at the last visit had significantly higher frequency of Difficulty falling asleep item (p = 0.034) and Urinary domain (p = 0.017), and higher total NMSS score (p = 0.011) as well as scores for Sleep/fatigue (p = 0.013) and Sexual dysfunction (p = 0.014) domains and scores for Fatigue (p = 0.004), Lack of motivation (p = 0.033), Interest in sex (p = 0.014) and Problems having sex (p = 0.031) items than patients at baseline. The frequency changes of each NMS among four age groups exhibited an anfractuous result, while the annual severity changes of each NMS were not significant different among four age groups. Multinomial logistic regression model indicated that age had no correlation with the changes of NMS frequency and severity. Conclusions: The severity of NMS in PD tends to become progressively worse with the course of the disease. Age is not related to the progression of NMS in PD. (C) 2015 Elsevier B.V. All rights reserved.