Managing sleep issues in Parkinson's disease: an up-to-date review

IntroductionIn Parkinson's disease (PD), sleep-wake problems are disease-related symptoms that occur throughout the day and have a negative impact on patients' quality of life to an extent that is equal to or greater than that of typical motor symptoms.Areas coveredInsomnia due to fragmented sleep and excessive daytime sleepiness (EDS) worsen as PD progresses. Nighttime wearing-off and early morning-off should be considered first when fragmented sleep is reported in PD patients. If the main complaint of patients with insomnia is difficulty falling asleep, restless legs syndrome should be differentiated first. Obstructive sleep apnea causes sleep quality deterioration and fragmented sleep. For rapid eye movement sleep behavior disorder (RBD), preventative measures against sleep-related trauma are necessary. RBD has also attracted attention as a PD precursor state and as a disease progression marker that is associated with specific PD clinical subtypes. In PD patients, the sleep-wake phase may advance/delay or become irregular due to circadian dysfunction.Expert opinionImportantly, sleep-wake problems are core symptoms related to the pathogenesis and progression of PD, and addressing a wide range of these symptoms will improve patients' quality of life.