Sleep

Medical and psychiatric conditions may disrupt sleep, and pharmacological treatments for these conditions are often unrecognized contributors to sleep disruption. Pain is a common symptom of many acute and chronic illnesses that increase in frequency with aging. Conditions such as arthritis, cancer, cardiovascular disease, and musculoskeletal degeneration or injury may be accompanied by pain. Pain can disturb sleep if it is not adequately controlled, and it may be exacerbated by the postures usually adopted during sleep.

Patients with heart disease may awaken out of REM sleep suffering from angina (chest pain) or chest tightness because of changes in heart rate and breathing that occur in this sleep stage. Symptoms of respiratory illnesses (asthma, emphysema) and gastrointestinal conditions (acid reflux) typically worsen during the night and contribute to sleep disruption. Stroke, a common condition in elderly people, may lead to insomnia or daytime drowsiness, depending on a variety of antecedent conditions and the location of the brain damage. In addition, infectious diseases may have a greater impact on older people and may affect sleep patterns.

Many of these serious medical conditions are accompanied by anxiety or depression, both of which can further disrupt normal sleep patterns. Independent of specific medical conditions, both anxiety and depression have important impacts on sleep quality and quantity. Anxiety, and accompanying muscle tension and pain, may make it difficult to initiate and to sustain sleep. Depression often leads to early morning awakening, awakenings during the night, reduced levels of SWS, and a shortened latency to the first nightly REM period.

Several progressive, dementing illnesses (e.g., Alzheimer’s, Parkinson’s, and Huntington’s diseases) increase in both prevalence and severity with increasing age, and they can amplify sleep disruptions in older people. Alzheimer’s disease is the most common of these conditions, and is characterized by disturbances in daily rhythms, including disrupted sleep, daytime napping, and periodic agitation, especially in its later stages. Some studies indicate that the amounts of both SWS and REM sleep decrease in patients with Alzheimer’s, but other studies have not confirmed this observation. Disruption of sleep and daily rhythms in patients with dementia places a further burden on caregivers at home, who may consequently become sleep deprived. The occurrence of nocturnal activity and wandering is often a major consideration in the decision to institutionalize Alzheimer’s patients.