Problems with sleep are common in dementia. They affect approximately 40% of people with Alzheimer’s disease and up to 90% of people with Lewy body dementia.
Sleep disturbance can include: difficulty falling asleep; difficulty staying asleep at night; restlessness during the night e.g. walking around, acting out dreams, movement disorders, being woken by dreams, hallucinations, needing to go to the toilet; and excessive daytime sleepiness.
Reduced activity and sleeping during the day can also lead to difficulties with sleeping at night. Being disturbed at night on a regular basis can be very distressing and have a significant impact on the well-being of both the person with dementia and those caring for them.
In Lewy body dementia, sleep-related changes often occur months or even years prior to the onset of other symptoms.
Sleep is a natural state of rest occurring each night. It is essential in helping our mind and body to recharge.
Two main factors influence whether we feel tired and ready for sleep or awake and alert.
Melatonin is a natural hormone that is released when it gets dark, to tell the body to prepare for sleep. Once sleep is underway, melatonin slowly decreases in concentration and production usually stops once the body notices it is light. As we age, the body secretes less melatonin which can affect sleep quality.
When we fall asleep our bodies follow a 90-minute sleep cycle that is broken down into 4 stages. During this cycle we experience two different types of sleep – Non-Rapid Eye Movement (non-REM) and Rapid Eye Movement (REM) sleep.
Stages 1 to 3 are non-REM sleep and the final stage is known as REM sleep.
Stage 1 (3-5% of sleep)
Falling asleep – a very short light stage of sleep. You can be easily woken and may experience muscle twitching or jerks.
Stage 2 (45-50%)
A light sleep as your body is preparing for the deep sleep that is about to come. Your heart rate decreases, body temperature drops, and brain activity slows.
Stage 3 (20-25%)
A deeper stage of sleep when it is more difficult to wake. You may feel disorientated if woken from this stage of sleep. This is the most restorative sleep of all the sleep stages.
Stage 4 (20-25%)
Known as rapid eye movement (REM) sleep. During this stage of sleep our brain activity increases and it is when we are mostly likely to dream.
After going through all four stages, we move back to being more alert, and either wake up or move back into another sleep cycle.
A good night’s sleep usually consists of four or five 90-minute cycles, whereas disturbed sleep consists of far fewer. The amount of REM and non-REM sleep we have can also change during each cycle. We need to experience all four stages in order to wake up feeling refreshed and rested.
Stage 3 plays an important part in making us feel rested and restored. Sometimes you can appear to have had a good night’s sleep, but don’t wake up feeling refreshed. This could be a sign that you’re not getting enough deep sleep.
As we get older some people can start to experience a change in the quality and duration of sleep and can experience the following:
It is unusual for disturbed sleep to just have one cause; there are often several factors.
Common causes include pain, anxiety, low mood, noise, being too warm or too cold, or what we eat or drink prior to sleeping.
Other causes include:
In dementia, physical changes in the brain can affect how much or how well someone sleeps. A part of the brain called the ‘supra-chiasmatic nucleus’, which helps regulate sleep by responding to light, can be damaged. As a result people may be unable to follow a 24-hour sleep-wake cycle and instead sleep excessively during the day and sleep much less at night.
A syndrome that affects many people with dementia, particularly at dusk, is known as ‘sundowning’. This is often caused by tiredness and changes in light which can lead to confusion, restlessness, agitation and distress.
In Lewy body dementia reduced levels of dopamine in the brain can disrupt the sleep-wake cycle. The presence of Lewy bodies (abnormal clumps of protein) in certain parts of the brain can result in a number of other symptoms which may affect sleep.
Sleep-related changes in Lewy body dementia include:
REM sleep behaviour disorder (RBD) is more common in Lewy body dementia. This is one of the core symptoms and may have been present for several years before other symptoms appeared.
RBD takes place during ‘rapid eye movement’ (REM) sleep.
Normally during REM sleep, the body experiences temporary paralysis of the muscles while the brain is active and dreaming. This allows us to dream quietly and safely throughout the night. In RBD, paralysis do es not occur. Instead, the body and voice act out dreams during sleep. Dreams may be very distressing and include fears of being attacked.
This can result in injury due to falling out of bed, banging into things or hitting someone whilst acting out the dream.
Disturbed sleep can be common in Parkinson’s due to symptoms of rigidity, stiffness, restless legs, sleep apnoea and increased urination at night. Advice should be sought from a clinician about management of these symptoms.
Parkinson’s symptoms can be worse during an ‘off’ period when the medication level is low. This may lead to stiffness, tremor, pain and difficulty with moving and turning in bed. If medication wears off during the night and causes problems, ask a healthcare professional to review the medication as slow release or longer acting medication may help.
Apathy, loss of motivation or difficulty with initiating activity can be experienced in Lewy body dementia due to changes in the brain.
Feelings of apathy can be overwhelming, making it hard to show interest or emotion in an activity. This may be frustrating for others but it is not deliberate.
The following may help:
Fluctuating cognition differs from apathy. It involves spontaneous alterations in thinking abilities, attention and alertness. This can range from vacant episodes for a few seconds to being completely unresponsive for a period of time. Someone may look asleep, but it could be a fluctuation in cognition.
If you haven’t slept well or are feeling tired, a planned daytime nap can help improve alertness, memory and relieve stress and fatigue.
General napping rules
The Sleep Charity
Trouble sleeping? Every Mind Matters – NHS
Living with Dementia Toolkit
As sleep disturbances can have multiple causes, you may need to try a range of solutions.
The following sleep hygiene tips are recommended:
Exposure to natural light
Some medications used for sleep disturbance can increase drowsiness and the risk of falls, so should be avoided if possible. Ask for a medication review to reduce any medications that can disturb sleep or increase daytime drowsiness. General sleep hygiene approaches should be tried first and advice sought from a clinician about specific sleep problems.
For sleep-related disturbances in Lewy body dementia the following can be discussed with a doctor:
Remember to keep a sleep diary to monitor sleep, noticing any patterns and what helps. This should be brief and record general observations rather than a detailed account. An example can be found on the Sleep Charity website (see Useful resources).
Gadgets or apps to monitor sleep such as watches, may be helpful in monitoring periods of restlessness especially if the person sleeps alone.
Sleep disturbance is common in Lewy body dementia and can significantly affect health and well-being for people with dementia and their caregivers. Sleep-related changes often occur months or even years prior to the onset of other symptoms. In particular REM sleep behaviour disorder (RBD) is one of the core symptoms.
As sleep disturbances can have multiple causes, you may need to try a range of solutions. General sleep hygiene tips are important and keeping a sleep diary can help with identifying possible causes and monitoring different approaches. If sleep problems persist, seek advice from a healthcare professional and request a review of medication.
If you would like to talk to a specialist dementia nurse about sleep disturbance, you can call the Admiral Nurse Dementia Helpline on 0800 888 6678 (Monday-Friday 9am-9pm, Saturday and Sunday 9am-5pm) or email firstname.lastname@example.org
To book a phone or video appointment with a dementia specialist Admiral Nurse in our virtual clinics, please visit www.dementiauk.org/book-an-appointment