Sleep Disturbances and Pain Subtypes in Parkinson's Disease

Background and Objectives: Sleep and pain are non-motor symptoms encountered frequently in Parkinson's disease (PD). Several subtypes of pain have been identified in PD, with different associations with other non-motor symptoms. To evaluate the prevalence of various subtypes of pain in a PD cohort and their associations with sleep disturbances and quality of sleep. Materials and Methods: In this study, 131 consecutive PD patients were assessed, focusing on pain and sleep using several validated scales and questionnaires. Results: According to KPPQ, the most reported types of pain were musculoskeletal pain (82.44%), nocturnal pain (58.77%), and radicular pain (55.72%). "Bad sleepers" (PSQI score > 5) reported significantly more pain than "good sleepers" regarding all KPPS subdomains, with statistically significant differences observed in the following domains: musculoskeletal pain (5.48 ± 3.50 vs. 2.70 ± 2.67, p < 0.001), chronic pain, specifically central pain (1.19 ± 2.01 vs. 0.15 ± 0.71, p = 0.004), nocturnal pain, specifically pain related to akinesia (2.26 ± 2.74 vs. 0.64 ± 1.22, p = 0.001), and radicular pain (4.35 ± 4.20 vs. 2.45 ± 3.55, p = 0.022). The prevalence of sleep disturbances was higher in patients with nocturnal pain (odds = 1.165, 95% CI: 1.064-1.276, p = 0.001), orofacial pain (odds = 1.108, 95% CI: 1.051-1.167, p < 0.001), and radicular pain (odds = 1.015, 95% CI: 1.015-1.149, p = 0.015). Conclusions: Pain is common in PD patients with sleep disorders. Identifying specific types of pain that are associated with sleep disorders and their correct management may improve sleep quality.