50: Sleep Disorders

The Institute of Medicine’s report, “Sleep Disorders and Sleep Deprivation: An Unmet Public Health Problem,” highlighted the prevalence and associated deleterious health consequences of these issues. Sleep difficulties and several primary sleep disorders increase in prevalence with age. However, in older adults, insomnia is most often associated with other conditions, rather than presenting as a primary insomnia. This “comorbid insomnia” often coexists with and can exacerbate or lead to additional medical and psychosocial conditions. For this reason, sleep disorders in older adults should often be approached as a geriatric syndrome as the causes are generally multifactorial.

The prevalence of sleep difficulties varies based on how these problems are identified and defined, but studies suggest that more than 50% of community-dwelling older persons and >65% of long-term care facility residents experience sleeping difficulties. Many community-dwelling older persons use nonprescription or prescribed sleeping medications.

Sleep architecture can be described based on findings of polysomnography, which involves multiple channels (eg, electroencephalogram, electrooculogram, electromyogram) of physiologic recording during sleep. Based on polysomnography, sleep can be categorized into 2 states: nonrapid eye movement (NREM) and rapid eye movement (REM) sleep. NREM sleep is further divided into 3 stages, where N1 is the lightest sleep, N2 is where the majority of sleep time is spent, and N3 is deep sleep. N1 and N2 sleep increase with age, whereas N3 sleep decreases. Altered sleep patterns include decreased sleep efficiency (time asleep as percentage of time in bed), decreased total sleep time, increased sleep latency (time to fall asleep), more arousals during the night, more daytime napping, and other changes.

Patients may not report sleep complaints unless specifically asked. Presenting symptoms overlap significantly among common sleep disorders (Figure 50–1).

Clinical Findings

Symptoms & Signs

Occasional difficulty falling asleep or staying asleep is common. To diagnose insomnia, the International Classification of Sleep Disorders—2nd edition (ICSD2), requires that the individual must have a sleep complaint (ie, difficulty initiating sleep, difficulty maintaining sleep, waking up too early, or sleep that is nonrestorative or of poor quality), the sleep complaint must occur despite adequate opportunity and circumstances for sleep, and there must be daytime impairment related to the nighttime sleeping difficulty (eg, fatigue or malaise, mood disturbance or irritability, daytime sleepiness). Insomnia can be classified based on symptom duration, but definitions based on duration vary. Generally, insomnia must be present for at least a month to be considered a chronic insomnia.

Patient History

A detailed history is essential in determining the causes of insomnia. Key factors include recent stressors, and symptoms of depression, anxiety, or other psychiatric disorders.

Special Tests

Instruments that can be helpful in the evaluation of insomnia include sleep questionnaires, sleep logs, symptom checklists, psychological screening tests, and interviews of bed partners. Examples of self-administered questionnaires are the Insomnia Severity Index (specific to insomnia) and the Pittsburgh Sleep Quality Index (a general questionnaire of sleep problems). Polysomnography and/or wrist actigraphy (which estimates sleep and wakefulness based on wrist movements) are not indicated for the routine evaluation of insomnia unless suggested by signs and symptoms of comorbid sleep disorders. Laboratory tests should be similarly guided based on signs or symptoms of comorbid conditions that appear associated with the insomnia.

Differential Diagnosis

In older adults, psychological problems, symptoms related to underlying medical illnesses, and the effects of medications are common causes of insomnia. Often, multiple factors may contribute to insomnia in the older patient.

Many medical conditions can interfere with sleep, including chronic pain, dyspnea, gastroesophageal reflux disease, and nocturia. Medications reportedly account for 10% to 15% of cases of insomnia. Table 50–1 lists common offending agents. Many other agents can disrupt sleep, including caffeine and nicotine. Caffeine is an ingredient in many nonprescription medications and foods, and many people are unaware that they are ingesting caffeine-containing products. Nighttime alcohol use, while causing initial drowsiness, can interfere with sleep architecture later in the night and worsen sleep. Withdrawal from sedative–hypnotic agents can also lead to worsening insomnia.

Treatment

Behavioral

Most published guidelines recommend psychological and behavioral treatments as first-line therapy for the management of chronic insomnia. Cognitive–behavioral therapy for insomnia generally combines several treatments, including stimulus control, sleep restriction and cognitive therapy. Stimulus control promotes behaviors such as establishing regular morning rising and bedtimes, using the bedroom only for sleep and sexual activity, going to bed only when sleepy and getting out of bed if unable to fall asleep, and avoiding or limiting naps. Sleep restriction therapy seeks to improve sleep efficiency by causing modest sleep deprivation (by limiting time in bed) and then gradually increasing time in bed as sleep efficiency improves. Cognitive therapy focuses on correcting inaccurate ideas and thoughts about sleep. Cognitive–behavioral therapy for insomnia is generally provided by a psychologist with expertise in behavioral sleep medicine, but simpler approaches have been developed and tested for use by other personnel, such as nurses.

Sleep hygiene is often a component of more comprehensive behavioral interventions for insomnia. Sleep hygiene addresses lifestyle and environmental factors (Table 50–2). However, simple sleep hygiene alone is rarely effective in the patient with a longstanding, severe chronic insomnia. Other behavioral interventions may include meditation and relaxation techniques to guide patients in recognizing and relieving tension and anxiety.

Pharmacologic

Prescription medications—

Pharmacologic agents (Table 50–3) can be considered if behavioral interventions are not fully successful, or the patient has an acute problem with insomnia and the benefits appear to outweigh the risks of these medications. Thoughtful selection of agents to minimize adverse side effects and drug interactions is reached by evaluating symptom types (eg, problem with sleep onset vs. awakening during the night), agent characteristics, comorbid conditions, and cost. In older adults, the starting dose should be the lowest available. Patient dosage self-adjustment should be discouraged.

Benzodiazepines and related drugs are commonly prescribed for sleep. Long-acting benzodiazepines (eg, flurazepam) should not be used in older patients because of the risk of daytime carryover (sedation), falls, and fractures. Short- and intermediate-acting benzodiazepines can be used in older people; however, caution is warranted because of the risk of tolerance to the hypnotic effects of the medication and the potential for rebound insomnia on withdrawal. These agents also result in an increased risk of falls, and their half-life can be longer in older people.

Nonbenzodiazepine hypnotics may have fewer side effects, and less daytime carryover, compared with benzodiazepines. Although structurally different from benzodiazepines, these agents also act at the gamma-aminobutyric acid (GABA) benzodiazepine receptor, but perhaps with greater specificity for sedative effects. In the United States, currently available nonbenzodiazepine agents include zolpidem, zaleplon, and eszopiclone (see Table 50–3). Caution is also warranted in the use of these newer sleeping medications for the management of chronic insomnia in older adults.

The melatonin receptor agonist ramelteon is approved for sleep-onset insomnia. It is not a scheduled agent. With a half-life of 2.6 hours, it has been shown to reduce sleep latency and to increase total sleep time without rebound or withdrawal effects.

There is some evidence for using a low-dose sedating antidepressant at night (with a more stimulating antidepressant during the day) for depressed patients who also report insomnia. Most published guidelines discourage use of a sedating antidepressant for insomnia unless the patient has failed other agents, or has an indication for an antidepressant. Low-dose doxepin is the only antidepressant that has been FDA approved for insomnia. However, like other sedating tricyclic antidepressants (eg, amitriptyline), it is not recommended for use in older patients because of its strong anticholinergic side effects.

Nonprescription medications—

Nonprescription sleeping aids often contain a sedating antihistamine (eg, diphenhydramine) alone or in combination with an analgesic. Diphenhydramine and similar compounds are not recommended for older people because of potent anticholinergic effects and the development of tolerance to sedating effects over time. A bedtime dose of an analgesic agent alone (eg, acetaminophen) may be safe and helpful if pain disrupts sleep. The herbal product valerian does not have sufficient evidence to support routine use. However, there is some evidence for use of prolonged-release melatonin.

General Principles in Older Adults

Sleep apnea is the repetitive cessation (or marked decrease) of airflow during sleep. In obstructive sleep apnea (OSA), the cessation or decrease in breathing is associated with continued ventilatory effort.

Clinical Findings

Symptoms & Signs

Increased body mass index is an important predictor of sleep apnea, although the relationship between obesity and OSA is not as strong in older adults, and many older adults with OSA are not obese. The prevalence of OSA is higher in men than women, and in older age groups. Prevalence rates of OSA of up to 40% are reported in people age 65 years and older. There is also a higher prevalence of OSA among older adults with dementia. OSA is common among patients presenting with insomnia, although excessive daytime sleepiness is the most frequent complaint. Other associated signs or symptoms include poorly controlled hypertension and morning headache. The bed partner may be very helpful in reporting loud snoring, choking and gasping sounds, or apneic periods.

The clinical consequences of sleep apnea are related to sleep fragmentation, hypoxia, and hypercapnia. Sleep apnea, especially if untreated, is associated with cardiovascular diseases such as hypertension and coronary artery disease, and increased mortality rates. Other adverse consequences include cognitive impairment and a higher rate of motor vehicle accidents.

Screening Methods

Polysomnography in an overnight sleep laboratory remains the gold standard in diagnosing OSA. If unavailable, an ambulatory (home-based, outpatient) approach is an alternative. The optimal patients for home testing are those with high suspicion for OSA with no comorbidities (eg, chronic obstructive pulmonary disease and congestive heart failure) that may require medical attention during the study period. Limitations may include the need for a repeat or formal laboratory study to confirm negative results or resolve technical issues (such as monitoring leads slipping off during sleep). In addition, most ambulatory sleep monitoring systems do not screen for other sleep disorders, such as parasomnias (eg, abnormal nocturnal movements and REM behavior disorder).

Treatment

Positive airway pressure (PAP) is the treatment standard for moderate-to-severe OSA as defined by the apnea-hypopnea index (AHI), the sum of apneas and hypopneas per hour of sleep. One classification suggests that AHI >30 per hour denotes severe OSA, 16–30 per hour that of moderate OSA, and 5–15 per hour for mild OSA. Consistent PAP use improves hypertension and congestive heart failure treatment responses and may also rectify some metabolic problems such as lipid abnormalities. The primary challenge with PAP usage is adherence. Initial experience with PAP is predictive of use as adherence is often established as early as the first week. Initial close follow-up to resolve issues interfering with regular use may promote long-term adherence.

Auto-adjusting positive airway pressure (APAP) is gaining more interest for use in uncomplicated moderate-to-severe OSA. Instead of supplying a continuous fixed pressure (as in continuous PAP), APAP titrates to the minimum pressure that will sustain airway patency. Effective pressure can vary with body position and weight fluctuation.

Alternatively, some patients may respond better to bi-level PAP. A sleep specialist will use polysomnography results to determine the most appropriate treatment.

Patients should be advised to avoid alcohol and sedative use, and to lose weight if obese. For those who fail or are unable to tolerate PAP treatment, other approaches may be considered. Oral–dental devices that reposition the jaw or tongue can be tried. Surgical procedures (eg, laser-assisted uvuloplasty, mandibular-maxillary advancement) offer mixed results, with little evidence for use in older adults. Although rarely performed for this indication, tracheostomy may be appropriate for those with severe life-threatening OSA who do not respond to other therapies.

General Principles in Older Adults

Among older adults, the prevalence of periodic limb movements during sleep (PLMS) ranges from 20% to 60% and for restless leg syndrome (RLS) from 2% to 15%. RLS may cause insomnia and nighttime restlessness and discomfort. RLS and PLMS often coexist; the latter are present in 80% of patients with RLS. Prevalence of PLMS increases with age and appears to be higher in those of Northern and Western European descent and lower in Asians. The cause of both conditions is unknown, but increased age, family history, uremia, and low iron stores have been suggested as risk factors.

Clinical Findings

Symptoms & Signs

PLMS is characterized by recurring episodes of stereotypic rhythmic movements during sleep, generally involving the legs. The diagnosis of PLMS is reserved for individuals with PLMS that causes a sleep disturbance that is not explained by the presence of another disorder. Many patients who exhibit PLMS-like movements are asymptomatic or may have another sleep disorder (eg, OSA).

RLS has 4 features: (a) an uncontrollable urge to move the legs, usually accompanied or caused by uncomfortable and unpleasant sensations in the legs, (b) symptoms begin or worsen during periods of rest or inactivity, (c) symptoms are partially or entirely relieved with movement, and (d) symptoms are worse in the evening or night.

Special Tests

The diagnosis of PLMS, but not RLS, requires polysomnography. RLS is diagnosed clinically based on history. Subjective scales such as the International RLS Rating Scale may help evaluate RLS severity and assess treatment outcomes. Patients with RLS should be screened for iron deficiency with a serum ferritin test.

Treatment

The treatment of PLMS depends on the severity of symptoms and their impact on the patient’s general well-being. If another sleep disorder is present (eg, OSA), that disorder should be treated first, as PLMS-like movements may improve with treatment of that disorder.

RLS may improve with leg stretching, and avoidance of caffeine, alcohol, and medications that precipitate symptoms, such as antihistamines, antidepressants, and promotility agents. A low ferritin should prompt iron replacement (and appropriate evaluation of iron deficiency) as RLS symptoms may resolve after iron replacement.

Pharmacotherapy should be considered for RLS when these maneuvers are ineffective or when symptoms are severe. Medication choice should depend on evidence of effectiveness and comorbid conditions. Dopaminergic agents are the best studied agents for both RLS and PLMS and are considered to be the treatment of choice in older patients. Treatment near bedtime with a dopamine agonist (eg, pramipexole 0.125 mg, ropinirole 0.25 mg or higher) may be effective for both RLS and PLMS. Adverse effects of dopamine agonists include excessive daytime sleepiness, hallucinations and compulsive behaviors (eg, uncontrolled shopping, gambling, eating, and sexual urges). Carbidopa-levodopa (one-half to 1 full tablet of 25/100-mg tablets, or higher) has also been suggested. Rebound symptoms (which occur as the medication wears off) or augmentation (shift of symptoms to early in the day) can occur with treatment. Augmentation is more common with carbidopa-levodopa than with the dopamine agonists. Both rebound and augmentation resolve with medication discontinuation. There is also some evidence for use of gabapentin in RLS. Opioids such as oxycodone and hydrocodone may help patients with severe symptoms unresponsive to other therapies, but the side effects of these agents may limit their usefulness for RLS in the older patient.

General Principles in Older Adults

Narcolepsy is a disorder of recurrent, uncontrollable, brief episodes of sleep that interfere with wakefulness, and which are often associated with hypnagogic hallucinations (which occur near the onset of sleep or awakening), cataplexy, and sleep paralysis. This disorder generally presents in adolescence or young adulthood, and only rarely presents for the first time in old age.

Clinical Findings

Symptoms & Signs

The key clinical features of narcolepsy are excessive daytime sleepiness and cataplexy (a sudden and transient loss of muscle tone triggered by emotions). Other common symptoms include sleep paralysis (a transient inability to move or speak during the transition between sleep and wakefulness) and hypnagogic hallucinations (ie, vivid perceptions at the onset of sleep).

Special Tests

Polysomnography typically reveals a shortened sleep latency and sleep-onset REM (ie, REM sleep present soon after sleep onset). A structured daytime sleep study, the Multiple Sleep Latency Test (MSLT), is performed to determine the extent of daytime sleepiness and to identify sleep episodes with early onset of REM. In patients without typical cataplexy, the diagnosis of narcolepsy requires performance of nighttime polysomnography and MSLT.

Differential Diagnosis

Narcolepsy can be complicated by other sleep disorders, including sleep apnea, periodic limb movements, and REM behavior disorder. These other disorders would generally be identified during polysomnography.

Treatment

Nonpharmacologic interventions involve maximizing nighttime sleep, supplemented by scheduled daytime naps, and avoiding emotional situations that precipitate attacks. Various medications are available including stimulants such as modafinil, selective serotonin reuptake inhibitors (SSRIs), serotonin–norepinephrine reuptake inhibitors, tricyclic antidepressants, and sodium oxybate for severe cataplexy. Treatment of narcolepsy typically requires input from a sleep specialist.

General Principles in Older Adults

Circadian rhythm sleep disorders (CRSDs) may be primarily intrinsic (eg, advanced sleep phase, delayed sleep phase) or situational, as in time zone change (jet lag) syndrome or shiftwork disorders. Correlations have been made between changes in circadian rhythms and advancing age.

Clinical Findings

Symptoms & Signs

Commonly, older people experience an advanced sleep phase, which leads to a pattern of an early bedtime and early morning awakening. The alteration in circadian rhythm can be marked in people who are bed-bound. When the internal clock is completely desynchronized, as may occur in severe neurodegenerative disorders, the sleep–wake cycles become irregular, with sleep occurring during the day and wakefulness at night or alternating periods of sleep and wakefulness throughout the 24-hour period. This irregular pattern is particularly common among nursing home residents.

Special Tests

Wrist actigraphy and/or sleep logs can be used for making a diagnosis and for monitoring treatment response. Polysomnography is indicated when the diagnosis is unclear or another sleep disorder is suspected.

Treatment

Depending on the specific CRSD, treatments may include appropriately timed bright light exposure, appropriately timed melatonin use, prescribed sleep scheduling, and other measures. Special expertise is generally needed in the management of severe, chronic CRSDs.

General Principles in Older Adults

Although rare in the general population, REM behavior disorder (RBD) usually presents in late life, more commonly in men than women.

Clinical Findings

Symptoms & Signs

RBD presents with symptoms of dream enactment behavior along with a lack of the normal muscle atonia present during REM sleep. Patients act out dreams with forceful movements and behaviors during sleep. They usually present for medical care as a result of injury to themselves or their bed partners; these injuries can be quite severe. Medications such as SSRIs or other antidepressants can precipitate RBD. It has also has been associated with brain disorders, including dementia and stroke. It is particularly common among the neurodegenerative disorders termed synucleinopathies, including Parkinson disease, Lewy body dementia, and multiple system atrophy.

Special Tests

Polysomnography is required to confirm the diagnosis and to rule out other conditions.

Treatment

Environmental measures should be taken to make the sleeping environment safe for the patient and the bed partner. Evidence-based guidelines suggest the use of nighttime clonazepam for RBD. However, caution is warranted in using clonazepam in older adults, especially if there is comorbid OSA, dementia, or gait disorders. There is some evidence for using melatonin in older adults and acetylcholinesterase inhibitors (eg, donepezil) to treat RBD in older patients with neurodegenerative disorders.

Sleep Patterns In Dementia

Most research on sleep problems with dementia has focused on Alzheimer disease. Compared with older people without dementia, those with dementia have more sleep disruption, more arousals and lower sleep efficiency. Sundowning, a worsening of confusion or agitated behaviors at night, is present in 12% to 20% of patients with dementia. Their inability to voice their symptoms or actively participate in their care may also compound sleep difficulties. Antipsychotic and sedative hypnotic agents have not been consistently effective. Sensory interventions (aromatherapy, thermal bath and calming music with hand massage) may be beneficial. Polysomnography does not appear to be clinically useful in diagnosing sleep changes with dementia, but may be useful in select cases where primary sleep disorders (eg, OSA) are suspected and if treatment would be warranted.

Sleep Disturbance in Long-Term Care Facility Residents

Superimposed on the multifactorial etiologies leading to sleep problems in older adults, long-term care residents have other factors that may contribute to sleep disturbance. The common pattern of sleep disturbance among these residents involves frequent nighttime arousals and daytime sleeping. Many factors seem to affect quality of sleep, including multiple physical illnesses and medications that can interfere with sleep, debility and inactivity, increased prevalence of primary sleep disorders, minimal sunlight exposure, and environmental factors, including frequent nighttime noise and light and disruptive nighttime nursing care activities.

An increase in daytime activity levels to enhance wakefulness may lead to improved nighttime sleep in nursing home residents. Socialization and exercise programs are modestly helpful. Bright light therapy may also improve total nighttime sleep and decrease daytime sleeping. Reduction of nighttime noise and consistent sleep hygiene practices are also recommended. Application of multicomponent nonpharmacological interventions to improve sleep/wake patterns in nursing home residents may have some modest effect but results are mixed.

American Academy of Sleep Medicine. http://www.aasmnet.org

National Institutes of Health National Center on Sleep Disorders Research. http://www.nhlbi.nih.gov/sleep

National Sleep Foundation. http://www.sleepfoundation.org

Sleep Research Society. http://www.sleepresearchsociety.org

Sleep Questionnaires

Insomnia Severity Index. http://www.journalsleep.org/ViewAbstract.aspx?pid=28127

Pittsburg Sleep Quality Index. http://www.sleep.pitt.edu/content.asp?id=1484

International Restless Leg Rating Scale. http://www.medicine.ox.ac.uk/bandolier/booth/RLS/RLSratingscale.pdf