Many individuals may struggle with sleep at various points in their lives and impaired sleep may impact upon quality of life. Less understood is the long-term impact of prolonged sleep deprivation. Sleep serves a restorative function in the brain, and has a critical role in our ability to process information and think clearly. However, could there be potentially more harmful and longer-term impacts of sleep deprivation? Alzheimer’s Disease International (ADI) published a report last year on potential modifiable risk factors relating to the onset of dementia; the report suggested decreased sleep may be a potential risk factor for cognitive decline, but indicated in the summary that these studies were limited and had a short follow time (WHO Dementia and Risk Reduction 2014). More generally, lack of sleep has been associated with poorer cognitive performance (Tworoger SS et al 2006) and increased rates of mortality (Gallicchio & Kalesan 2008).
Evidence suggests that there may be a number of complex neural processes at play which impact on the long term function of the brain. One theory suggests that lack of sleep may increase the risk of amyloid plaque formation (Holtzman et al 2013), which is part of the pathology of Alzheimer’s disease. Another study found that daytime sleepiness may be correlated with the onset of vascular dementia (Elwood et al 2011). Research in this area suggests that where causal relationships can be determined interventions may be possible to aid and encourage sleep, in order to delay the possible onset of dementia. Despite these individual research papers, the jury is still out on a definitive correlation between lack of sleep and the onset of dementia.
Whilst the research on the long term impact of poor quality sleep is interesting, the priority of services is the daily management of sleep difficulties, particularly for people with a level of cognitive decline or dementia, where sleep difficulties exasperate their difficulties. Where there are cognitive demands, lack of sleep only adds to the disorientation. Therefore, sleep can impact significantly on quality of life, can increase emotional distress, and can in some cases lead to transition to residential care (Pollak et al 1990). For many services working with people with dementia who experience sleep difficulties, it has become an expensive problem, often requiring higher levels of staffing during the night, or staff manpower to review increasing incidences of emotional distress and challenging behaviour during the day.
There are a number of different sleep disorders, and, whilst the prevalence of these disorders remains unclear, there has been some correlations between the type of disorder and the type of dementia (figure 1). One study showed that up to 70% – 80% of residents that live in a long-term facility experience sleep apnoea (Ancoli-Israel S 2006). Sleep apnoea is a sleep disorder which is characterised by disrupted breathing. There are other forms of sleep disorders experienced by people living with dementia, such as Restless Legs Syndrome, REM Behaviour Disorder and Periodic Limb Movement Disorder.
Figure 1 (Clin Geriatr Med. 2008 Feb; 24(1): 39–vi.)
|Alzheimer’s disease||Sleep Disordered Breathing|
|Dementia with Lewy Bodies||Restless Legs Syndrome
REM behaviour disorder: this is part of diagnostic criteria – a suggestive feature – can occur years prior to onset.
Periodic Limb Movement Disorder
|Parkinson’s disease with dementia||Restless Legs Syndrome
REM Behaviour Disorder
Periodic Limb Movement Disorder
Sleep Disordered Breathing
|Vascular dementia||Sleep Disordered Breathing|
Restless Legs Syndrome is where an individual experiences discomfort in their legs, relieved by moving them; it may cause difficulties in falling asleep.
Periodic Limb Movement Disorder is when a person’s arms and legs move about during sleep. Often movements are repetitive and can be every 20 to 40 seconds, so can significantly disrupt sleep for the individual and family carer.
REM Behaviour Disorder is a condition in which individuals physically act out dreams during REM sleep, particularly in the second half of the night (Boeve BF 2004). This occurs because the normal mechanism for paralysis during sleep is disrupted. This can be dangerous and frightening for the individual with dementia, as well as a significant safety concern for families. It can lead to injuries at night. REM Behaviour Disorder can occur years prior to the onset of Lewy Body Dementia.
Sleep apnoea is part of a group of difficulties called Sleep Disordered Breathing. It is where your breathing is disrupted, with one or more pauses of breathing.
A common challenge for services is ‘Sundowning’. Sundowning may be caused by states being between sleep and wakefulness, possibly caused by sleep deprivation (Klaffke & Staedt 2006). The person may become agitated and disorientated. Presenting changes in behaviour may also be as a consequence of changing light levels, which triggers a reaction to the environmental clues. For example, a change in light levels may indicate to a person that it is time to finish work and return home; the person may then become agitated, particularly when they find it difficult to return home. When considering interventions to minimise agitation, this should always be done in the context of the person’s reality.
If the environment is too hot or too cold; too light or too dark; if the environment is unfamiliar (potentially as a consequence of transitions in care, or as a consequence of memory problems), this can be distressing, and cause significant anxiety impacting on a person’s ability to fall asleep. Night time may also be a lonely experience for many people with dementia.
Some of the main interventions to treat sleep disorders are pharmacological. However, side effects of medications can exasperate cognitive difficulties and increase the risk of adverse outcomes such as falls (Aviden et al 2005). There has been some research linking the use of benzodiazepine to an increased risk of Alzheimer’s disease (Sophie Billioti de Gage et al 2014). Commonly used medications like Donezepil can stimulate the cholinergic nervous system increasing the risk of disturbed dreams (Kitabayashi 2006). Medication prescribed for a number of co-morbid conditions can also interfere with sleep.
There are a number of other factors which may impact on the quality of sleep: pain, depression, anxiety, diabetes, depression, arthritis and renal failure. A medical review of co-morbid conditions may help to address some concerns. 72% of people living with dementia also live with another condition.
Research carried out in a community setting in New Zealand (Gibson, Gander and Jones 2014) found that there were 3 main areas for developing coping strategies: 1) strategies related to the sleeping environment 2) safety issues surrounding sleep and night time waking 3) techniques to relax at night and stay awake during the day. Services could benefit from distinguishing these categories as a useful framework for possible interventions.
Another area of interest in the treatment and support of sleep disorders is the use of ‘bright light therapy’. The mechanism that controls the wake-night cycle is called the circadian rhythm; the daily light–dark cycle is the primary synchronizer responsible for supporting the circadian rhythms to the 24-hour day. Light helps to maintain the circadian rhythm and can be introduced artificially to help reset those rhythms. Bright light therapy has been well researched in the area of dementia care and sleep. One study found favourable results when combined with the use of melatonin (Dowling et al 2007). Melatonin decreases when a person develops Alzheimer’s disease (Liu RY et al 1999). Simple environmental changes can be also be made to ensure that an individual has more access to light during the day; ensuring that there is adequate outdoor space, ensuring that curtains are pulled back during the day and the light fittings are the appropriate strength. Other simple mechanisms include relaxation therapy or having a quiet time before bed. Exercise has also been found to improve sleep (Baehr 2003) and could be potentially used as an effective treatment. A vast range of assistive technologies which enhance safety at night are now widely available.
Support services need to have in place a holistic management plan to respond to sleep disorders; a strategy to not only ensure improvements in quality of life, but also reduce the costs of responding to behavioural disturbances.
Things that you can do:
Environmental adaptations, such as noise and light levels
Assistive technologies which help with safety at night
Bright light therapy
Increased activity in the day
Avoiding caffeine and alcohol
Review of life history
Environmental adaptations to support orientation
Provide night time activities programme