Dementia and Sleep

 Around 5.8 million people in the US alone are currently experiencing Alzheimer’s disease and related dementias³. The number of Alzheimer’s disease and related dementias is expected to have the largest increase between 2015 and 2060³. This is due to the amount of people aged over 65 years increasing as healthcare aids in the rising average life expectancy. Certain factors such as low education level, higher poverty rate, adversity and discrimination may increase risk for Alzheimer’s and around 2/3 of dementia patients are women³. Other research articles explain how healthy lifestyle behaviors can prevent dementia even with a genetic predisposition from family history. Recognizing potential initial signs of dementia and/or an early diagnosis may help the patient in addition to the family and friends of the individual. 

Lewy body dementia (LBD), the second most common type of progressive dementia, is caused by the abnormal presence of Lewy body proteins in brain cells³. Lewy body proteins are protein inclusions with disaggregated oligomers³. These deposits are found in brain regions that control memory and muscle movement such as cerebral cortex, limbic cortex, hippocampus, substantia nigra, and the brain stem³. Lewy body dementia causes issues with sleep, behavior, perception, mood, awareness, alertness, problem-solving and movement³. Researchers are discovering that these movement issues in Lewy body dementia patients can begin as early as 10 years before formal diagnosis². Symptoms of LBD may present initially as REM sleep disorder². REM sleep disorder is when a person acts out their dreams, including sudden vocal sounds and physical movements in the REM stage of sleep². Presence of REM sleep disorder has been shown to increase risk for LBD up to five times³.

In Phyllis Zee’s paper, “Circadian disruption and human health”, she discusses how sleep has a bidirectional relationship with health meaning that sleep is disrupted by diseases and low quality/quantity of sleep leads to future health conditions. “Circadian disruption and human health” talks about dementia and Alzheimer’s association with circadian disruption as well². In her paper, Zee mentions how sleep behavior modifications are increasing in popularity in care for Alzheimer’s disease. Some examples of sleep behavior modifications include reduced screen time before bed, appropriate lighting in the bedroom, and allowing for an optimal amount of sleep. Although Zee’s paper explains the association of dementia and Alzheimer’s disease with circadian disruption as an effect from loss of suprachiasmatic nucleus (SCN) neurons and impaired function of light input pathways, it still emphasizes how there is a relationship between Alzheimer’s and Dementia and sleep quality. The news article from Mirror discussing the Mayo Clinic’s new research explains the unidirectional relationship of dementia causing sleep problems as an early indicator of the disorder. What the news article from Mirror didn’t mention was if this was a bidirectional relationship, although Zee does explore how sleep could cause dementia in her research. 

 

References:

(1)  Fishbein, A. B., Knutson, K.L., & Zee, P.C. (2021). Circadian disruption and human health. Journal of Clinical Investigation. https://www.jci.org/articles/view/148286

(2)  Hodgson, F. (2023, February 20). Dementia warning sign that strikes in your sleep years before diagnosis. Mirror.https://www.mirror.co.uk/news/health/dementia-warning-sign-strikes-your-29265042

(3)  Okolo, S. (2022, May 26). Dementia Is On The Rise Worldwide, Here’s How to Stop it. Forbes. https://www.forbes.com/sites/sophieokolo/2022/05/26/dementia-is-on-the-rise-worldwide-heres-how-to-stop-it/?sh=7317e3e34327