Sleep and Neurodegeneration.
OBJECTIVE This article discusses the relationship between sleep and neurodegenerative disorders. LATEST DEVELOPMENTS Sleep disorders disrupt neurotransmitters, facilitating the progression of neurodegenerative changes. Sleep impairment promotes amyloid-β aggregation, propagating memory impairment in neurodegenerative disorders. The use of biomarkers for early diagnosis of neurodegenerative disorders may include sleep features. Sleep apnea is associated with an increased risk of Parkinson disease. ESSENTIAL POINTS Sleep disorders, such as obstructive sleep apnea, are five times more likely in people with Alzheimer disease. Notably, individuals with genetic factors, including carriers of APOE4, are found to have decreased overall regulation of regions within the brain that control sleep. External factors that increase the risk of dementia include long-term use of antihistamines. The risk of mild cognitive impairment is reduced with the intake of 200 mg/d of caffeine, which aligns the circadian activity of suprachiasmatic nucleus cells. People diagnosed with idiopathic rapid eye movement (REM) sleep behavior disorders have more than a 90% risk of developing an α-synucleinopathy at 14 years follow-up.