Sleep and Dementia.

Neurocognitive and sleep problems are common, underdiagnosed, and frequently co-morbid. Sleep disruption, and fatigue, predict cognitive impairment. Cognitive impairment, in turn, can worsen sleep hygiene. In dementia patients, sleep disorders are common, and dementia medications affect sleep. Emerging insights on the brain's glymphatic system suggests that sleep may drive clearance of Aβ peptide to affect Alzheimer pathophysiology. Parkinsonian dementias are linked with REM behavior disorder, a highly treatable problem that predicts future conversion into dementia.