Insomnia in Older Adults with Dementia
Sleep disturbances are frequently seen among older adults with dementia, leading to significant distress for both patients and their caregivers. It is likely that neuronal loss in key areas of the brain contributes to sleep disturbances in this population. When evaluating older adults with dementia and insomnia, try to obtain information regarding all details of their sleep, and determine whether medical, psychiatric, or environmental factors may be contributors. In treating sleep disturbances in older adults with dementia, behavioural interventions should first be used to improve sleep hygiene. At the present time, there are not enough data to standardize recommendations for pharmacological treatment of insomnia in this population, so treatment should be guided by attempting to minimize potential side effects and interactions with other medications.
Key words: sleep, dementia, older adults, sleep hygiene, pharmacological treatment of insomnia.
Introduction
Sleep disturbances are common among individuals with dementia--about 50% of this population experience sleep difficulties of some kind.1 The prevalence of insomnia among older adults with dementia living in the community is similar to that of those living in long-term care (LTC) facilities.2 Insomnia is not an invariable sequela of dementia, but it can have devastating consequences for these individuals and their caretakers. Indeed, sleep difficulties in older people with insomnia are a frequent cause of behavioural disturbances and falls and are often cited as primary reasons for caregiver burden and LTC placement.3
Physiology of Sleep in Dementia
Sleep disturbances among people with Alzheimer’s disease (AD) may be in part the result of neuronal losses in the suprachiasmatic nucleus, a region in the hypothalamus that regulates sleep and circadian rhythms.4 Sleep changes in this population include decreased total sleep time, increased sleep latency and nighttime awakenings, and decreased slow wave sleep, sleep spindles, and K complexes.5,6 Older adults with AD also have decreased rapid eye movement (REM) sleep, which may be related to diminished cholinergic activity in the brain.7
Electroencephalographic findings such as decreased amounts of slow wave (Stages 3 and 4) and REM sleep may correlate with dementia severity (Figure 1).8 As a result, many individuals with dementia have problematic sleep-wake cycle disturbances including increased daytime sleepiness and napping, which create further sleep difficulties at night. Most problematic may be late-day episodes of increased confusion, agitation, and psychosis known as sundowning.9 Among individuals with AD, sundowning has been shown to be associated with increased rates of cognitive decline and caregiver distress.10
Clinical Evaluation of Insomnia
Given how common sleep disturbances are in the older adult with dementia, it is recommended that clinicians ask about sleep at least during their initial evaluation (but preferably at each visit). When evaluating someone who has dementia for a sleep disorder, it is crucial that the clinician obtain collateral information from a family member or caretaker who lives with the patient and is able to characterize the specifics of the problem (see Table 1). There is no universally used screening test for insomnia in patients with dementia. Thus, when possible, it is helpful to have the caretaker keep a sleep diary to record 24-hour sleep-wakefulness patterns. This should