Pain, poor sleep quality, restless legs syndrome (RLS), and other symptoms are frequently reported by patients with Parkinson's disease (PD). However, the impact that pain severity and interference has on non-motor symptoms (NMS) has not been extensively studied. The objective of the present study is to explore the relationship between sleep quality in PD to pain and other NMS that affect quality of life.
The study included 100 PD patients and 100 age and gender-matched controls assessed for pain severity and pain interference using the Brief Pain Inventory and sleep quality using the Pittsburgh Sleep Quality Index. Participants were also evaluated for their subjective levels of anxiety and depression using the Hospital Anxiety and Depression Scale.
PD patients with poor sleep quality had greater pain severity and pain interference than controls and PD patients with good or borderline sleep quality. PD patients with poor sleep quality also had the greatest case-ness and severity for depression and anxiety. However, RLS was not significantly correlated with depression, anxiety or pain.
Poor sleep quality in PD patients is related to greater pain severity, pain interference, and more radiating and paresthestic pain that is independent of RLS. There is a higher prevalence of depression and anxiety in PD patients compared to controls, especially in PD patients with poor sleep quality. Our findings suggest a relationship between poor sleep quality in PD with pain, anxiety and depression. Prospective studies are warranted to investigate the causal relationship.