Sleep disturbance and autonomic symptoms in Parkinson’s disease

Abstract

Parkinson’s disease (PD) is the most common neurodegenerative movement disorder. Although striking motor features characterize PD (e.g., bradykinesia, resting tremor, and rigidity), numerous nonmotor symptoms often precede motor symptoms. Sleep disturbances are observed in 60%–90% of patients with PD, impacting their quality of life. Sleep disturbances are influenced by many clinical factors, including disease-related neurodegeneration, nocturnal motor/nonmotor symptoms, medications, coexisting sleep disorders, aging, and other complications. Rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia characterized by dream-enacting behavior and loss of normal atonia during REM sleep. The sublaterodorsal tegmental nucleus and ventromedial medulla oblongata, which play an important role in generating muscle atonia during REM sleep, are considered to have degenerated in patients with RBD. Isolated RBD is a strong risk factor for predicting future phenoconversion to neurodegenerative diseases, especially synucleinopathies. Patients with PD complicated by RBD may exhibit distinct clinical presentations compared to those without RBD. Various autonomic symptoms often precede motor symptoms in PD, and Lewy body pathology is observed in the central and peripheral autonomic nervous systems. The severity of autonomic symptoms may affect the subsequent outcomes of PD. This review outlines sleep disturbances and autonomic symptoms in PD.