Impact of Alzheimer's on Sleep Patterns
Alzheimer's disease (AD), the most common type of dementia, is characterised by profound sleep disturbances that contribute to cognitive decline. A complex and reciprocal relationship exists between the accumulation of beta-amyloid (Aβ) protein and disruption of the circadian rhythm in the brain.
The accumulation of Aβ protein, a hallmark of AD, disrupts neuronal function and plasticity in brain regions that regulate sleep, such as the suprachiasmatic nucleus (SCN), the brain's internal clock. This impairment leads to fragmented and reduced deep and REM sleep stages, which are crucial for memory preservation [1][2].
Damage to the SCN and altered expression of clock genes in AD patients causes an impaired 24-hour sleep-wake cycle, resulting in excessive daytime sleepiness and insomnia at night [1][3]. This circadian rhythm disruption also reduces the production of brain-derived neurotrophic factor (BDNF), which normally promotes healthy neural function and prevents amyloidogenic processing of APP protein that forms Aβ plaques. Lower BDNF exacerbates Aβ accumulation, creating a vicious cycle of worsening sleep and AD pathology [2].
Moreover, sleep itself helps clear neurotoxic waste, including Aβ, from the brain. Poor sleep or fragmented sleep impairs this clearance process, accelerating Aβ buildup and cognitive decline [2]. Sleep disturbances can also damage brain blood vessels, further contributing to cognitive impairment and AD progression [5].
In an attempt to manage sleep difficulties in people with AD, establishing a routine, including a bedtime routine, can help the individual recognise the time of day and prepare for sleep. Reviewing medications and their side effects with a doctor can also be beneficial [4]. Identifying other medical conditions like sleep apnea or restless legs syndrome can further aid in managing sleep issues [6].
Keeping a clock visible can help individuals with AD distinguish between nighttime and daytime, while maintaining regular routines, getting morning sunlight exposure, getting regular exercise, effectively treating pain, and making sure the bedroom is a comfortable temperature can also improve sleep quality [7]. Using the bed only for sleep and avoiding alcohol, caffeine, and nicotine can further promote restful sleep.
In severe cases, a doctor may recommend sleep medications for a short period if other treatments have not helped. Sleeping on the side may also help support the glymphatic system, a waste clearance system in the central nervous system, potentially protecting against AD [8].
Various treatments can address AD symptoms and help an individual manage sleeping difficulties. For instance, using a bed exit pad can signal if an individual with AD wanders from their bed during the night, allowing caregivers to assist them in getting back into bed as soon as possible. Treatment options also include addressing issues like confusion, incontinence, and anxiety that can affect sleep [9].
Despite these challenges, it is crucial to remember that people with AD can still enjoy restful sleep and maintain a good quality of life with the right care and support.
Key points:
- Aβ accumulation impairs neuronal and synaptic function in circadian and sleep-regulating brain regions [1][2].
- Damage to the SCN and altered clock gene expression disrupts the normal circadian sleep-wake cycle in AD [3].
- Reduced BDNF from circadian dysregulation promotes more Aβ formation and worsens cognitive function [2].
- Sleep disruption impairs Aβ clearance, accelerating its buildup and AD progression [2].
- Fragmented sleep also damages brain blood vessels, further promoting cognitive decline in AD [5].
- Establishing a routine, including a bedtime routine, can help manage sleep difficulties in people with AD.
- Reviewing medications and their side effects with a doctor can help manage sleep difficulties in people with AD.
- Identifying other medical conditions like sleep apnea or restless legs syndrome can help manage sleep issues in people with AD.
- Keeping a clock visible can help individuals with AD distinguish between nighttime and daytime.
- Maintaining regular routines, getting morning sunlight exposure, getting regular exercise, effectively treating pain, and making sure the bedroom is a comfortable temperature can improve sleep quality in people with AD.
- Using the bed only for sleep and avoiding alcohol, caffeine, and nicotine can promote restful sleep in people with AD.
- In severe cases, a doctor may recommend sleep medications for a short period if sleep problems are severe and other treatments have not helped.
- Sleeping on the side may help support the glymphatic system and protect against AD due to its role in waste clearance in the central nervous system.
- Various treatments can address AD symptoms and help an individual manage sleeping difficulties.
- Using a bed exit pad can signal if an individual with AD wanders from their bed during the night, allowing caregivers to assist them in getting back into bed as soon as possible.
- Treatment options for sleep schedule disruptions due to AD may include addressing issues like confusion, incontinence, and anxiety that can affect sleep.
- Alzheimer's disease (AD) is marked by a disruption of sleep due to the accumulation and impairment of neurons and synaptic function in circadian and sleep-regulating brain regions.
- Damage to the suprachiasmatic nucleus (SCN) and altered clock gene expression in AD patients lead to an improper 24-hour sleep-wake cycle, causing excessive daytime sleepiness and insomnia at night.
- Reduced production of brain-derived neurotrophic factor (BDNF) from circadian dysregulation in AD exacerbates the accumulation of beta-amyloid (Aβ) protein, creating a vicious cycle of worsening sleep and AD pathology.
- Sleep disruption impairs Aβ clearance, accelerating its buildup and contributing to AD progression and cognitive decline.
- Establishing a routine, including a bedtime routine, can help manage sleep difficulties in people with AD, promoting restful sleep and improving sleep quality.
- In severe cases, sleep medications and addressing issues like confusion, incontinence, and anxiety may be recommended to manage sleep difficulties in people with AD, ensuring they can still enjoy restful sleep and maintain a good quality of life.
