Your sleeping habits can directly impact your brain’s health, and the health of your brain can affect how you sleep. So when your body is experiencing one or multiple chronic sleep disturbances, it could potentially signal something deeper ― including dementia.
“The relationship between sleep disturbances and dementia is an important dynamic, and rapidly evolving area of investigation,” said Dr. Arman Fesharaki-Zadeh, assistant professor of neurology at Yale School of Medicine. “There’s a strong association between sleep disruption ― particularly impairment of slow-wave sleep (SWS), also referred to as deep sleep ― and an increased risk of developing dementia. Alterations in sleep architecture, including reductions in SWS, may serve as early biomarkers of neurodegenerative disease.”
Your brain has a network called the glymphatic system that clears toxins while you sleep. These toxins include amyloid beta, a protein that builds up in the brain as dementia develops. So if you are experiencing sleep disturbances that significantly alter your sleep-wake cycle, your body could be giving you an early warning sign.
Additionally, memories form in your brain in three stages: encoding, consolidation and retrieval. “Consolidation is critically supported by deep and REM sleep and stabilizes and integrates newly acquired information, including emotional contextualization. Retrieval enables access to stored memory traces,” according to Fesharaki-Zadeh. “Disruption of sleep, particularly during consolidation stages, can contribute to persistent memory impairment.”
Dementia affects multiple brain functions, including memory, circadian rhythm, and behavior. “So early disease can disrupt the body clock and normal sleep architecture,” said board-certified neurologist Dr. Rob Nawaz Khan.
What exactly does this look like? Ahead, experts break down the sleep problems that could be signs of dementia.
Severe Insomnia
A little sleeplessness from time to time isn’t alarming, but a sudden onset of insomnia should be evaluated for deeper meaning. New, severe insomnia can include extreme difficulty falling asleep and staying asleep, as well as severe daytime impairment, like intense feelings of fatigue and frequent and unusual mood changes.
“In Alzheimer’s disease, difficulty falling asleep, frequent nighttime awakenings, behavioral changes at night, and daytime sleepiness are common as the brain networks that regulate the sleep-wake cycle gradually deteriorate,” said neurologist Dr. Fawad Mian.
Falling Asleep At Odd Times
A sleep-wake cycle, also known as your circadian rhythm, regulates your daily patterns of being awake and alert, and of being tired.
When this is disturbed, your body is out of sync with the environment, and a person may “sleep more during the day and be awake at night. These changes are often associated with confusion and behavioral changes. ” Mian explained. “This comes about because neurodegeneration affects the brain’s internal clock.”
Someone experiencing this may also notice repeated wakings, accompanied by disorientation or agitation at night. This is also known as sundowning, which occurs in the late afternoon and evening.
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Acting Out Dreams
Known as REM Sleep Behavior Disorder, acting out in your dreams may be an early sign of certain dementias, “particularly Lewy body dementia and Parkinson’s,” Mian said.
Someone who is experiencing REM Sleep Behavior Disorder may engage in shouting, swearing, punching, kicking or jumping from bed as they sleep. This is often a response to an action-filled or scary dream.
“This happens years before memory symptoms occur, as the brainstem regions that control muscle paralysis during dreaming are affected early,” Mian said.
Wandering Around At Night
Getting up from bed and wandering around your house at night, often confused, can be a sign of dementia.
When this happens, your circadian rhythm is disrupted, and your body feels restless or sometimes in pain. Your mind may be more awake and active at night, leading to a lack of sleep and rest for your brain.
This sleep disturbance can “reduce the brain’s ability to clear waste proteins overnight, which, over time, may contribute to cognitive decline,” Khan said.
It’s important to remember that sleep issues alone do not mean someone has dementia.
If you’re experiencing persistent or worsening sleep disturbances, especially when you have memory changes or have difficulty managing daily activities, it’s important to speak with a neurologist. However, if you’re just experiencing sleep disruption and no other side effects, consulting a sleep specialist is your best bet for nailing down a problem.