Sleep in Neurodegenerative Disorders

Abstract

Sleep disturbances are common in neurodegenerative disease and impair quality of life. People with Alzheimer’s disease (AD) develop daytime hypersomnia and nighttime insomnia. These symptoms likely result from circadian rhythm disruption due to reduced zeitgeber input, suprachiasmatic nucleus dysfunction, and melatonin alterations. In Parkinson’s disease (PD), various sleep disorders, such as insomnia, hypersomnia, and REM sleep behavior disorder (RBD) are often seen. These problems are related to neurodegeneration of brain structures influencing sleep and wake states, circadian rhythm dysfunction, and motor and non-motor symptoms. RBD can precede PD motor symptoms by several years, and it represents a window of opportunity to treat the disease process when a disease-modifying therapy for PD becomes available in the future. Effective treatments for sleep disturbances in AD and PD are limited. Deeper understanding of sleep and circadian dysfunction is necessary to develop treatments that improve quality of life and potentially alter the degenerative course.