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Information ⬇

[Section Outline]

Disorders of sleep are among the most common problems seen by clinicians. More than one-half of adults experience at least intermittent sleep disturbances, and 50-70 million Americans suffer from a chronic sleep disturbance which can adversely affect daytime functioning as well as physical and mental health.

APPROACH TO THE PATIENT

Sleep Disorders

Pts may complain of (1) difficulty in initiating and maintaining sleep at night (insomnia); (2) excessive daytime sleepiness or tiredness; (3) unusual behaviors during sleep (parasomnias); or (4) circadian rhythm disorders associated with jet lag, shift work, and delayed sleep phase syndrome. Careful history of sleep habits is a cornerstone of diagnosis (e.g., ask when pt typically goes to bed, falls asleep, and wakes up; also note if he/she awakens during sleep, feels rested in the morning, and naps during the day). Reports from the sleep partner (e.g., heavy snoring, falling asleep while driving) are also important. Pts with excessive sleepiness should be advised to avoid driving until effective therapy is achieved. Completion of a day-by-day sleep-work-drug log for 1-2 weeks is often helpful. Work and sleep times (including daytime naps and nocturnal awakenings) as well as drug and alcohol use, including caffeine and hypnotics, should be noted each day. The physical examination may show a small airway, large tonsils, or a neurologic or medical disorder that contributes to the complaint. Objective sleep laboratory recording is necessary to evaluate specific disorders such as sleep apnea, periodic limb movements, and narcolepsy.

Insomnia !!navigator!!

Insomnia is the complaint of poor sleep and usually presents as difficulty initiating or maintaining sleep. People with insomnia are dissatisfied with their sleep and feel it impairs their ability to function well. Affected individuals often experience fatigue, decreased mood, irritability, malaise, and cognitive impairment. Chronic insomnia, lasting >3 months, occurs in about 10% of adults. Acute or short-term insomnia affects over 30% of adults and is often precipitated by stressful life events. Most insomnia begins in adulthood, but many pts may be predisposed and report easily disturbed sleep predating the insomnia, suggesting that their sleep is lighter than usual.

All insomnias can be exacerbated and perpetuated by behaviors that are not conducive to initiating or maintaining sleep. Inadequate sleep hygiene is characterized by a behavior pattern prior to sleep, and/or a bedroom environment, that is not conducive to sleep. In preference to hypnotic medications, the pt should attempt to avoid stressful activities before bed, reserve the bedroom environment for sleeping, and maintain regular rising times.

Psychophysiologic Insomnia !!navigator!!

These pts are preoccupied with a perceived inability to sleep adequately at night. Rigorous attention should be paid to sleep hygiene and correction of counterproductive, arousing behaviors before bedtime. Behavioral therapies are the treatment of choice.

Drugs and Medications !!navigator!!

Caffeine is the most common pharmacologic cause of insomnia although a wide range of psychoactive drugs can interfere with sleep, including alcohol and nicotine. Numerous medications, including antidepressants, stimulants, and glucocorticoids, can produce insomnia. Severe rebound insomnia can result from the acute withdrawal of hypnotics, especially following the use of short-acting benzodiazepines.

Movement Disorders !!navigator!!

Pts with restless legs syndrome (RLS) complain of creeping dysesthesias deep within the calves or feet associated with an irresistible urge to move the affected limbs; symptoms are typically worse at night. RLS is very common, affecting 5-10% of adults and is more common in women and older adults. Iron deficiency, renal failure, and peripheral neuropathies can cause secondary RLS, and symptoms can worsen by pregnancy, caffeine, alcohol, antidepressants, lithium, neuroleptics, and antihistamines. One-third of pts have multiple affected family members. Treatment is with dopaminergic drugs (pramipexole 0.25-0.5 mg daily at 7 PM or ropinirole 0.5-4.0 mg daily at 7 PM). Periodic limb movements of sleep (PLMS) consist of stereotyped extensions of the great toe and dorsiflexion of the foot recurring every 20-40 s during non-REM sleep. Treatment options include dopaminergic medications.

Other Neurologic Disorders !!navigator!!

A variety of neurologic disorders produce sleep disruption through both indirect, nonspecific mechanisms (e.g., neck or back pain) or by impairment of central neural structures involved in the generation and control of sleep itself. Common disorders to consider include dementia from any cause, epilepsy, Parkinson's disease, and migraine.

Psychiatric Disorders !!navigator!!

Approximately 80% of pts with mental disorders complain of impaired sleep. The underlying diagnosis may be depression, mania, an anxiety disorder, or schizophrenia.

Medical Disorders !!navigator!!

In asthma, daily variation in airway resistance results in marked increases in asthmatic symptoms at night, especially during sleep. Treatment of asthma with theophylline-based compounds, adrenergic agonists, or glucocorticoids can independently disrupt sleep. Inhaled glucocorticoids that do not disrupt sleep may provide a useful alternative to oral drugs. Chronic obstructive pulmonary disease, pain from rheumatologic disorders or neuropathy, cystic fibrosis, hyperthyroidism, menopause, and gastroesophageal reflux are other causes.

TREATMENT

Insomnia

Primary insomnia is a diagnosis of exclusion.

  • Treatment of a medical or psychiatric disease that may be contributing should be addressed first.
  • Attention should be paid to improving sleep hygiene and avoiding counterproductive behaviors before bedtime (Table 58-1 Methods to Improve Sleep Hygiene in Insomnia Pts).
  • Cognitive behavioral therapy emphasizes understanding the nature of normal sleep, the circadian rhythm, the use of light therapy, and visual imagery to block unwanted thought intrusions.
  • Pharmacotherapy is reserved for instances when insomnia persists after treatment of contributing factors. Antihistamines are the primary active ingredient in most over-the-counter sleep aids. Benzodiazepine receptor agonists are effective and well tolerated; options include zaleplon (5-20 mg), zolpidem (5-10 mg), triazolam (0.125-0.25 mg), eszopiclone (1-3 mg), and temazepam (15-30 mg). Heterocyclic antidepressants such as trazodone (25-100 mg) are often used due to their lack of abuse potential and lower cost. Limit use to a short period of time for acute insomnia or intermittent use for chronic insomnia. All sedatives increase the risk of falls and confusion in the elderly, and therefore if required these medications should be used at the lowest effective dose.

Disorders of Excessive Daytime Sleepiness !!navigator!!

Differentiation of sleepiness from subjective complaints of fatigue may be difficult. Quantification of daytime sleepiness can be performed in a sleep laboratory using a multiple sleep latency test (MSLT), the repeated daytime measurement of sleep latency under standardized conditions. An approach to the evaluation is summarized in Table 58-2 Evaluation of the Pt with Excessive Daytime Sleepiness.

Sleep Apnea Syndromes !!navigator!!

Respiratory dysfunction during sleep is a common cause of excessive daytime sleepiness and/or disturbed nocturnal sleep, affecting an estimated 24% of middle-aged men and 9% of middle-aged women. Episodes may be due to occlusion of the airway (obstructive sleep apnea), absence of respiratory effort (central sleep apnea), or a combination of these factors (mixed sleep apnea). Obstruction is exacerbated by obesity, supine posture, sedatives (especially alcohol), nasal obstruction, and hypothyroidism. Sleep apnea is particularly prevalent in overweight men and in the elderly and is undiagnosed in most affected individuals. Treatment consists of correction of the above factors, positive airway pressure devices, oral appliances, and sometimes surgery or neurostimulation (Chap. 140 Sleep Apnea).

Narcolepsy !!navigator!!

A disorder of excessive daytime sleepiness and intrusion of REM-related sleep phenomena into wakefulness (cataplexy, hypnagogic hallucinations, and sleep paralysis). Cataplexy, the abrupt loss of muscle tone in arms, legs, or face, is precipitated by emotional stimuli such as laughter or sadness. Symptoms of narcolepsy typically begin in the second decade. The prevalence is 1 in 2000. Narcolepsy has a genetic basis; almost all narcoleptics with cataplexy are positive for HLA DQB1*06:02. Hypothalamic neurons containing the neuropeptide hypocretin (orexin) regulate the sleep/wake cycle and loss of these cells, possibly due to autoimmunity, has been implicated in narcolepsy. Diagnosis is made with sleep studies confirming a short daytime sleep latency and a rapid transition to REM sleep.

TREATMENT

Narcolepsy

  • Somnolence is treated with modafinil (200-400 mg/d given as a single dose each morning).
  • Older stimulants such as methylphenidate (10-20 mg bid) or dextroamphetamine (10 mg bid) are alternatives, particularly in refractory pts.
  • Cataplexy usually responds to antidepressants that increase noradrenergic or serotonergic tone. Venlafaxine (37.5-150 mg each morning) and fluoxetine (10-40 mg each morning) are often effective. The tricyclic antidepressants, such as protriptyline (10-40 mg/d) or clomipramine (25-50 mg/d), are potent suppressors of cataplexy, but their anticholinergic effects, including sedation and dry mouth, make them less attractive. Alternatively, sodium oxybate, given at bedtime and 3-4 h later, is also effective.
  • Adequate nocturnal sleep time and the use of short naps are other useful preventative measures.

Circadian Rhythm Sleep Disorders !!navigator!!

Insomnia or hypersomnia may occur in disorders of sleep timing rather than sleep generation. Such conditions may be (1) organic-due to a defect in the circadian pacemaker, or (2) environmental-due to a disruption of exposure to entraining stimuli (light/dark cycle). Examples of the latter include jet-lag disorder and shift work. Shift work sleepiness can be treated with modafinil (200 mg) or armodafinil (150 mg) taken 30-60 min before the start of each night shift as well as properly timed exposure to bright light. Safety programs should promote education about sleep and increase awareness of hazards associated with night work.

Delayed sleep-wake phase syndrome is characterized by late sleep onset and awakening with otherwise normal sleep architecture. Bright-light phototherapy in the morning hours or melatonin therapy during the evening hours may be effective.

Advanced sleep-wake phase syndrome moves sleep onset to the early evening hours with early morning awakening. These pts may benefit from bright-light phototherapy during the evening hours. Some autosomal dominant cases result from mutations in genes (PER2 or casein kinase I delta) involved in regulation of the circadian clock.

Outline ⬆

Section 3. Common Patient Presentations