Sleep in the elderly: a practical approach

Journal of Family Practice, Nov, 1989 by Jeffrey L. Susman

Sleep and watchfulness, both of these when immoderate

constitute disease.

-Hippocrates

Though physiologists still debate the purpose of sleep, its importance in health and disease has been noted since the time of Hippocrates. The debilitating effects of sleep deprivation, including fatigue, memory deficits, personality changes, and difficulty in concentration, are striking.(1) Perhaps it is of little wonder 30% to 45% of the elderly complain of insomnia and up to 14% use sleeping pills habitually.(1) To understand the role of the family physician in treating sleep disorders in the elderly, a brief background of sleep physiology is important.

Physiologists divide sleep into stages based upon characteristic electroencephalographic changes. Sleep may be divided into non-rapid-eye-movement (non-REM) and rapid-eye-movement (REM) sleep.(1)

Non-REM consists of four stages that can be simplified into light and deep sleep. During non-REM sleep, motor tone is preserved, eye movements are rare, and physiologic factors are stable.

During REM sleep, atonia of the major antigravity muscles occurs, rapid conjugate eye movements are typical, and physiologic variables fluctuate widely. Increased oxygen requirements and increased autonomic activity occur during this sleep stage. Dreaming and penile tumescence are also characteristic of REM Sleep. These distinctions between REM and non-REM sleep are important in understanding specific sleep disorders.

Certain characteristic changes occur in sleep architecture with aging.(1-5) There is an increased sleep latency (time from lights out until sleeping). Light sleep is increased, whereas deeper sleep is decreased. The percentage of time spent in REM is almost the same in older patients as in younger patients, but there is decreased total REM sleep. Generally the number of nocturnal awakenings increases, especially very brief ones, but the elderly tend to get back to sleep more quickly than younger adults. Sleep is generally less efficient; in other words, there is more time spent in bed with less time spent sleeping. Total sleep time is usually less, but there is wide intra-individual variability. Thus, sleep is generally a less efficient and lighter process in the aged. EVALUATION OF SLEEP DISORDERS It is important to recognize that insomnia is a symptom, not a diagnosis or a disease. To assess accurately the cause of insomnia, a thorough history is of primary importance. A sleep history should include an interview with both the patient and his or her bed partner, if pertinent. A sleep diary and a tape recording (if snoring or unusual noises are a problem) can be valuable. Information concerning habits, including alcohol and caffeine use, activities prior to bedtime, and the quality of sleep are all important. The patient should also record the occurrence of snoring, unusual movements, dreams, daytime sleepiness, and naps, as well as how rested he or she feels upon awakening.

In evaluating patients with insomnia, it is important to remember that nocturnal awakenings and difficulty in falling asleep are common in older patients. Furthermore, while the average length of sleep is about 7 to 71/2 hours, this length varies from individual to individual and in the same person over time. The patient should be advised to correct environmental problems such as excessive noise or extreme temperatures. The physician must also explore transient psychophysiologic factors, including stress, anxiety, or depression. indeed, depression may be one of the most commonly overlooked causes of geriatric sleep disturbance, especially in the family practice setting. Loss and change in status such as retirement can also influence sleep. Such life stresses, combined with decreased hearing, vision, and functional ability, can lead to decreased interaction with the outside world, boredom, and disordered sleep patterns. Moreover, a thorough drug, alcohol, and caffeine history is extremely valuable because such factors play a role in 10% to 20% of sleep disorders.(1) Caffeine, sympathomimetics, bronchodilators, alcohol, and a variety of other prescription medications can provoke wakefulness, whereas anticholinergics, tricyclic antidepressants, and antihistamines may cause excessive somnolence. Diuretics are obvious causes of nocturia and sleep difficulties. Finally, tricyclic antidepressants, antiparkinsonism agents, and antihypertensive medications (most classically, propranolol) can induce nightmares.(1)

Next, the physician should rule out treatable medical disorders, including causes of pain, paresthesia, cough, breathlessness, or other troublesome symptoms. Arthritic conditions, gastrointestinal reflux, diabetic neuropathy, prostatism, and congestive heart failure can all present as insomnia and are best treated by correcting the underlying disease, not by prescribing hypnotics or referring the patient for a sleep laboratory evaluation. WHEN TO SUSPECT PRIMARY SLEEP DISORDERS

Serious sleep disorders are of increasing prevalence in the aged, and the family physician needs a working knowledge for their diagnosis. The Association of Sleep Disorder Clinics has divided primary sleep disorders into the following categories: