Sleep Disorders

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Definition

Sleep disorders are a group of syndromes characterized by disturbance in the patient's amount of sleep, quality or timing of sleep, or in behaviors or physiological conditions associated with sleep. There are about 70 different sleep disorders. To qualify for the diagnosis of sleep disorder, the condition must be a persistent problem, cause the patient significant emotional distress, and interfere with his or her social or occupational functioning.

Although sleep is a basic behavior in animals as well as humans, researchers still do not completely understand all of its functions in maintaining health. In the past 30 years, however, laboratory studies on human volunteers have yielded new information about the different types of sleep. Researchers have learned about the cyclical patterns of different types of sleep and their relationships to breathing, heart rate, brain waves, and other physical functions. These measurements are obtained by a technique called polysomnography.

There are five stages of human sleep. Four stages have non-rapid eye movement (NREM) sleep, with unique brain wave patterns and physical changes occurring. Dreaming occurs in the fifth stage, during rapid eye movement (REM) sleep.

• Stage 1 NREM sleep. This stage occurs while a person is falling asleep. It represents about 5% of a normal adult's sleep time.
• Stage 2 NREM sleep. In this stage, (the beginning of "true" sleep), the person's electroencephalogram (EEG) will show distinctive wave forms called sleep spindles and K complexes. About 50% of sleep time is stage 2 REM sleep.
• Stages 3 and 4 NREM sleep. Also called delta or slow wave sleep, these are the deepest levels of human sleep and represent 10–20% of sleep time. They usually occur during the first 30–50% of the sleeping period.
• REM sleep. REM sleep accounts for 20–25% of total sleep time. It usually begins about 90 minutes after the person falls asleep, an important measure called REM latency. It alternates with NREM sleep about every hour and a half throughout the night. REM periods increase in length over the course of the night.

Sleep cycles vary with a person's age. Children and adolescents have longer periods of stage 3 and stage 4 NREM sleep than do middle aged or elderly adults. Because of this difference, the doctor will need to take a patient's age into account when evaluating a sleep disorder. Total REM sleep also declines with age.

The average length of nighttime sleep varies among people. Most people sleep between seven and nine hours a night. This population average appears to be constant throughout the world. In temperate climates, however, people often notice that sleep time varies with the seasons. It is not unusual for people in North America and Europe to sleep about 40 minutes longer per night during the winter.

Description

Sleep disorders are classified based on what causes them. Primary sleep disorders are distinguished from those that are not caused by other mental disorders, prescription medications, substance abuse, or medical conditions. The two major categories of primary sleep disorders are the dyssomnias and the parasomnias.

Dyssomnias are primary sleep disorders in which the patient suffers from changes in the amount, restfulness, and timing of sleep. The most important dyssomnia is primary insomnia, which is defined as difficulty in falling asleep or remaining asleep that lasts for at least one month. It is estimated that 35% of adults in the United States experience insomnia during any given year, but the number of these adults who are experiencing true primary insomnia is unknown. Primary insomnia can be caused by a traumatic event related to sleep or bedtime, and it is often associated with increased physical or psychological arousal at night. People who experience primary insomnia are often anxious about not being able to sleep. The person may then associate all sleep-related things (their bed, bedtime, etc.) with frustration, making the problem worse. The person then becomes more stressed about not sleeping. Primary insomnia usually begins when the person is a young adult or in middle age.

Hypersomnia is a condition marked by excessive sleepiness during normal waking hours. The patient has either lengthy episodes of daytime sleep or episodes of daytime sleep on a daily basis even though he or she is sleeping normally at night. In some cases, patients with primary hypersomnia have difficulty waking in the morning and may appear confused or angry. This condition is sometimes called sleep drunkenness and is more common in males. The number of people with primary hypersomnia is unknown, although 5-10% of patients in sleep disorder clinics have the disorder. Primary hypersomnia usually affects young adults between the ages of 15 and 30.

Nocturnal myoclonus and restless legs syndrome (RLS) can cause either insomnia or hypersomnia in adults. Patients with nocturnal myoclonus wake up because of cramps or twitches in the calves. These patients feel sleepy the next day. Nocturnal myoclonus is sometimes called periodic limb movement disorder (PLMD). RLS patients have a crawly or aching feeling in their calves that can be relieved by moving or rubbing the legs. RLS often prevents the patient from falling asleep until the early hours of the morning, when the condition is less intense.

Kleine-Levin syndrome is a recurrent form of hypersomnia that affects a person three or four times a year. Doctors do not know the cause of this syndrome. It is marked by two to three days of sleeping 18–20 hours per day, hypersexual behavior, compulsive eating, and irritability. Men are three times more likely than women to have the syndrome. Currently there is no cure for this disorder.

Narcolepsy is a dyssomnia characterized by recurrent "sleep attacks" that the patient cannot fight. The sleep attacks are about 10–20 minutes long. The patient feels refreshed by the sleep, but typically feels sleepy again several hours later. Narcolepsy has three major symptoms in addition to sleep attacks: cataplexy, hallucinations, and sleep paralysis. Cataplexy is the sudden loss of muscle tone and stability ("drop attacks"). Hallucinations may occur just before falling asleep (hypnagogic) or right after waking up (hypnopompic) and are associated with an episode of REM sleep. Sleep paralysis occurs during the transition from being asleep to waking up. About 40% of patients with narcolepsy have or have had another mental disorder. Although narcolepsy is often regarded as an adult disorder, it has been reported in children as young as three years old. Almost 18% of patients with narcolepsy are 10 years old or younger. It is estimated that 0.02–0.16% of the general population suffer from narcolepsy. Men and women are equally affected.

Breathing-related sleep disorders are syndromes in which the patient's sleep is interrupted by problems with his or her breathing. There are three types of breathingrelated sleep disorders:

• Obstructive sleep apnea syndrome. This is the most common form of breathing-related sleep disorder, marked by episodes of blockage in the upper airway during sleep. It is found primarily in obese people. Patients with this disorder typically alternate between periods of snoring or gasping (when their airway is partly open) and periods of silence (when their airway is blocked). Very loud snoring is a clue to this disorder.
• Central sleep apnea syndrome. This disorder is primarily found in elderly patients with heart or neurological conditions that affect their ability to breathe properly. It is not associated with airway blockage and may be related to brain disease.
• Central alveolar hypoventilation syndrome. This disorder is found most often in extremely obese people. The patient's airway is not blocked, but his or her blood oxygen level is too low.
• Mixed-type sleep apnea syndrome. This disorder combines symptoms of both obstructive and central sleep apnea.

Circadian rhythm sleep disorders are dyssomnias resulting from a discrepancy between the person's daily sleep/wake patterns and demands of social activities, shift work, or travel. The term circadian comes from a Latin word meaning daily. There are three circadian rhythm sleep disorders. Delayed sleep phase type is characterized by going to bed and arising later than most people. Jet lag type is caused by travel to a new time zone. Shift work type is caused by the schedule of a person's job. People who are ordinarily early risers appear to be more vulnerable to jet lag and shift work-related circadian rhythm disorders than people who are "night owls." There are some patients who do not fit the pattern of these three disorders and appear to be the opposite of the delayed sleep phase type. These patients have an advanced sleep phase pattern and cannot stay awake in the evening, but wake up on their own in the early morning.

PARASOMNIAS. Parasomnias are primary sleep disorders in which the patient's behavior is affected by specific sleep stages or transitions between sleeping and waking. They are sometimes described as disorders of physiological arousal during sleep.

Nightmare disorder is a parasomnia in which the patient is repeatedly awakened from sleep by frightening dreams and is fully alert on awakening. The actual rate of occurrence of nightmare disorder is unknown. Approximately 10–50% of children between three and five years old have nightmares. They occur during REM sleep, usually in the second half of the night. The child is usually able to remember the content of the nightmare and may be afraid to go back to sleep. More females than males have this disorder, but it is not known whether the sex difference reflects a difference in occurrence or a difference in reporting. Nightmare disorder is most likely to occur in children or adults under severe or traumatic stress.

Sleep terror disorder is a parasomnia in which the patient awakens screaming or crying. The patient also has physical signs of arousal, like sweating, shaking, etc. It is sometimes referred to as pavor nocturnus. Unlike nightmares, sleep terrors typically occur in stage 3 or stage 4 NREM sleep during the first third of the night. The patient may be confused or disoriented for several minutes and cannot recall the content of the dream. He or she may fall asleep again and not remember the episode the next morning. Sleep terror disorder is most common in children four to 12 years old and is outgrown in adolescence. It affects about 3% of children. Fewer than 1% of adults have the disorder. In adults, it usually begins between the ages of 20 and 30. In children, more males than females have the disorder. In adults, men and women are equally affected.

Sleepwalking disorder, which is sometimes called somnambulism, occurs when the patient is capable of complex movements during sleep, including walking. Like sleep terror disorder, sleepwalking occurs during stage 3 and stage 4 NREM sleep during the first part of the night. If the patient is awakened during a sleepwalking episode, he or she may be disoriented and have no memory of the behavior. In addition to walking around, patients with sleepwalking disorder have been reported to eat, use the bathroom, unlock doors, or talk to others. It is estimated that 10–30% of children have at least one episode of sleepwalking. However, only 1-5% meet the criteria for sleepwalking disorder. The disorder is most common in children eight to 12 years old. It is unusual for sleepwalking to occur for the first time in adults.

Unlike sleepwalking, REM sleep behavior disorder occurs later in the night and the patient can remember what they were dreaming. The physical activities of the patient are often violent.

In addition to the primary sleep disorders, there are three categories of sleep disorders that are caused by or related to substance use or other physical or mental disorders.

SLEEP DISORDERS RELATED TO MENTAL DISORDERS. Many mental disorders, especially depression or one of the anxiety disorders, can cause sleep disturbances. Psychiatric disorders are the most common cause of chronic insomnia.

SLEEP DISORDERS DUE TO MEDICAL CONDITIONS. Some patients with chronic neurological conditions like Parkinson's disease or Huntington's disease may develop sleep disorders. Sleep disorders have also been associated with viral encephalitis, brain disease, and hypoor hyperthyroidism.

SUBSTANCE-INDUCED SLEEP DISORDERS. The use of drugs, alcohol, and caffeine frequently produces disturbances in sleep patterns. Alcohol abuse is associated with insomnia. The person may initially feel sleepy after drinking, but wakes up or sleeps fitfully during the second half of the night. Alcohol can also increase the severity

of breathing-related sleep disorders. With amphetamines or cocaine, the patient typically suffers from insomnia during drug use and hypersomnia during drug withdrawal. Opioids usually make short-term users sleepy. However, long-term users develop tolerance and may suffer from insomnia.

In addition to alcohol and drugs that are abused, a variety of prescription medications can affect sleep patterns. These medications include antihistamines, corticosteroids, asthma medicines, and drugs that affect the central nervous system.

Pediatricians estimate that 20–30% of children have difficulties with sleep that are serious enough to disturb their families. Although sleepwalking and night terror disorder occur more frequently in children than in adults, children can also suffer from narcolepsy and sleep apnea syndrome.

— Rebecca J. Frey

Sleep is a reversible state during which the individual's voluntary functions are suspended but the involuntary functions, such as circulation and respiration, are uninterrupted; the sleeping subject assumes a characteristic posture with relative immobility and decreased responses to external stimuli.

The sleep state can be divided into nonrapid eye movement (NREM) and rapid eye movement (REM) sleep. NREM sleep is divided into four stages based on electroencephalographic criteria. The first REM in a normal adult occurs 60–90 min after sleep onset, and there are usually four or five NREM-REM cycles, each lasting for 90–110 min. Most dreams occur during REM sleep. The sleep-wake pattern for humans follows a circadian rhythm. An average adult needs approximately 7–8 hours of sleep, but elderly people have frequent awakenings.

Clinical disorders

Sleep disorders are classified as dyssom-nias (intrinsic, extrinsic, or circadian rhythm disorders), para-somnias, and disorders associated with medical, psychiatric, and neurological illnesses. Obstructive sleep apnea syndrome, narcolepsy, psychophysiological and idiopathic insomnia, and restless legs syndrome are examples of intrinsic sleep disorders. Extrinsic sleep disorders include inadequate sleep hygiene, insufficient sleep syndrome, and hypnotic-, stimulant-, and alcohol-dependent sleep disorders. Circadian-rhythm disorders include jet lag and shift-work sleep disorders.

Parasomnias are characterized by abnormal movements or behavior intruding into sleep (for example, sleep walking, sleep terrors, sleep talking, nightmares, sleep paralysis, tooth grinding, and bed wetting).

Excessive daytime sleepiness, insomnia (sleeplessness), and abnormal movements and behavior during sleep are the major sleep complaints. An individual with insomnia may have difficulty initiating or maintaining sleep; repeated awakenings or early morning awakenings; or daytime fatigue and impairment of performance. Individuals with hypersomnia complain of excessive daytime sleepiness. Circadian-rhythm sleep disorders may be associated with either insomnia or hypersomnia.

There are two forms of sleep apnea. In central apnea, both the airflow at the mouth and nose and the effort by the diaphragm decrease. In obstructive apnea, the airflow stops but the effort by the diaphragm continues. Obstructive sleep apnea syndrome is common in middle-aged and elderly obese men.

Narcoleptic sleep attacks usually begin in individuals between the ages of 15 and 25. Narcolepsy is characterized by an irresistible desire to sleep, and the attacks may last 15–30 min. Other symptoms may include fearful dreams or feeling of loss of power at sleep onset or offset. Narcolepsy cannot be cured.

The restless legs syndrome occurs during middle age and is characterized by intense disagreeable feelings in the legs at rest and repose with compulsion to move the legs to get relief. Most individuals with this problem also have periodic limb movements in sleep.

The most common cause of insomnia is psychiatric or psy-chophysiologic disorder (for example, depression, anxiety, or stress), but other causes include medical disorders or pain. Early morning awakening is characteristic of depression.

Diagnosis and treatment

Overnight polysomnography involves recording of brain waves, muscle activities, eye movements, heart activity, airflow at the nose and mouth, respiratory effort, and oxygen saturation. Polysomnography is needed for individuals with excessive daytime sleepiness, narcolepsy, parasomnias, restless legs-period limb movements, and nocturnal seizures. The multiple sleep latency test is important in documenting pathologic sleepiness and diagnosing narcolepsy; it records brain waves, muscle activities, eye movements, and heart activity.

Treatment of obstructive sleep apnea syndrome consists of avoidance of sedatives or alcohol consumption, weight loss, and use of continuous positive airway pressure which will open the upper airway passage. Narcolepsy is treated by stimulants and short naps. Cataplexy is treated with tricyclics. Chronic insomnia can best be treated by sleep hygiene and behavioral modification. Most parasomnias do not require special treatment; however, psychotherapy may be helpful in some cases. Circadian-rhythm disorders may be treated by bright light and chronotherapy. See also Biological clocks; Sleep and dreaming.

The ability to fall asleep, stay asleep, and wake up are all considered inalienable rights. We should neither stuporously wander about our houses nor suddenly decide to jump off our beds into imaginary swimming pools. The child's prayer, ‘Now I lay me down to sleep’, epitomizes the fond hope that sleep is a safe passage across a sea of unconsciousness undisturbed by life-threatening deficits in vital physiological processes. Still, it should have come as no surprise that a system as complicated and differentiated as the brain mechanisms underlying sleep and dreaming would have its own intrinsic propensity for dysfunction and disorder as well as its amazing capacity as a health-conveying operation. And the normal variation in sleep propensity, sleep depth, sleep length, and sleep stage distribution is already proof that such mundane events as excessive daytime sleepiness, or its converse, excessive night-time wakefulness (insomnia) should be viewed at least in part as expressions of extremes of normal physiology.

Yet even the most sophisticated and perspicacious sleep scientists were unprepared for the discovery that breathing sometimes stopped or was blocked in sleep (as it is in sleep apnea) or the recognition that all of the symptoms of the compelling need to sleep (as seen in narcolepsy) could be explained as abnormalities of sleep neurophysiology. More surprising still were the twin discoveries that sleepwalking, sleep-talking, and bedwetting had little to do with dreaming but that a previously unrecognized process, the REM sleep behaviour disorder, was not only dream enactment but the harbinger of degenerative disease of brain motor control systems!

There are three major kinds of sleep problems and each can be understood through sleep physiology:

1. Difficulty falling asleep (which is caused by excessively strong or inadequately suppressed brain drives toward waking) — the classic example is insomnia.
2. Difficulty staying awake (caused by excessively strong or inadequately suppressed brain drives toward sleep). The classic example is narcolepsy.
3. Abnormal movements that occur as the depth of sleep varies over the course of the night. For example, the movement-generating centres of the brain can sometimes become active without the brain's consciousness-generating arousal systems becoming simultaneously activated to waking levels. The classic example is sleepwalking.

The sleep apnea syndromes are an ambiguous but critically important class of sleep disorder with characteristics of all three categories. Victims of this life-threatening tendency to stop breathing when they fall asleep — and then to choke when they make compensatory efforts to wake up and breathe again — may be insomniac (because their bodies will literally not allow them to go to sleep) ; they may have excessive sleepiness by day (because they are chronically sleep deprived) ; and their laboured efforts to breathe while asleep can be seen as a form of chronic abnormal sleep movement, which, in the long term, may prove to be much more physiologically harmful than other sorts of abnormal sleep movements such as sleepwalking.

Sleep apnea sufferers are usually overweight (which makes breathing more difficult as the airway closes normally — causing snoring — at sleep onset) and male (which deprives them of the unexplained protection of sleep breathing afforded by female sex hormones). But they also just exaggerate the surprising normal tendency of men to have long pauses in their breathing efforts, especially during NREM sleep but also in REM. As their oxygen hunger increases and their brain alarm clock arouses them, they make a gasping effort to gulp air, at which point their flaccid, fat-compressed airway closes and they move even closer to self-strangulation. Because treatment is now quite effective it is crucial that any person suspected of having sleep apnea consult a physician or a sleep disorders centre.

Narcolepsy is a rare but instructive illness with four defining attributes: (i) excessive daytime sleepiness and irresistible attacks of sleep; (ii) the sudden loss of postural muscle tone (called cataplexy, often leading to total collapse; (iii) the occurrence of frightening dream hallucinations at sleep onset and upon awakening; and (iv) the persistence of REM sleep motor paralysis, also on arousal from sleep.

All of these symptoms are manifestations of a genetically-determined failure to inhibit REM sleep physiology, which most of us can do quite easily, especially during waking. Like new-borns, many adult narcoleptic patients have prolonged REM sleep bouts at sleep onset. Effective treatment is achieved using drugs that potentiate the brain chemicals responsible for effective waking, and/or suppression of the brain chemicals responsible for REM sleep.

Insomnia is by far the most prevalent disorder of sleep. It is also the most problematic to manage, because none of the myriad sedative drugs available for its relief is a physiological sleep inducer or enhancer. For this reason all of the effective sedatives have one or more defects: undesirable side-effects, diminished efficacy with prolonged use, or a worsening of symptoms upon withdrawal.

Because so much insomnia is psychologically and behaviourally driven, effective treatment should always include attention to such factors as (i) regular, early times of retirement; (ii) elimination of the commonly abused anti-sleep ingestants tobacco and alcohol; (iii) a review of daytime work and interpersonal concerns with special attention to identifying and eliminating the sources of nocturnal rumination and anxiety; (iv) the prescription of sleep-enhancing aerobic exercise; and (v) instruction in systematic body relaxation techniques.

This naturalistic approach to insomnia does not deny its sometimes strong physiological basis, which may demand pharmacological adjuncts, but it is cautious and conservative in warning against the undue expectation and the unacceptable risks of uncritical sedative treatment.

The REM sleep behaviour disorder is easily distinguished from ordinary sleepwalking. Sleepwalking is a self-limited and usually harmless problem of adolescence and early adulthood that occurs in NREM sleep and disappears when that sleep stage declines in the fourth decade. By contrast, the REM sleep behaviour disorder usually begins at that age or later, and reflects the dangerous and prognostically grave failure to inhibit the motor commands of REM sleep that are normally experienced as only the illusion of movement during dreaming.

Early degeneration of the brain (and especially Parkinson's disease) is heralded by REM sleep behaviour disorder, but it has also recently been reported to arise in younger subjects who have been treated for depression with drugs that specifically potentiate serotonin, one of the chemicals that the brain uses to energize itself in waking and to influence the excitability of the motor system in all of its states.

The study of sleep disorders is still a young, rapidly-developing field at the interface of neurology, psychiatry, and internal medicine. Its inventory of disorders, its methods of investigation, and its approaches to treatment can all be expected to change rapidly in the next few decades.

— J. Allan Hobson

See also body clock; sleep; snoring.

Conditions characterized by a disruption in normal sleeping patterns which may be the result of serious medical conditions, including breathing difficulties or thyroid disorders, or external factors such as stress or substance abuse. Manifestations include insomnia, sleep apnea, and narcolepsy.

Definition

Sleep disorders are a group of syndromes characterized by disturbances in the amount, quality, or timing of sleep, or in behaviors or physiological conditions associated with sleep.

Description

Although sleep is a basic behavior in all animals, its functions in maintaining health are not completely understood. In the past 30 years, however, researchers have learned about the cyclical patterns of different types of sleep and their relationships to breathing, heart rate, brain waves, and other physical functions.

There are five stages of human sleep. Four stages are characterized by non-rapid eye movement (NREM) sleep, with unique brain wave patterns and physical changes. Dreaming occurs in the fifth stage during rapid eye movement (REM) sleep.

• Stage 1 NREM sleep. This stage occurs while a person is falling asleep and represents about 5% of a normal adult's sleep time.
• Stage 2 NREM sleep. This stage marks the beginning of "true" sleep. About 50% of sleep time is stage 2 REM sleep.
• Stages 3 and 4 NREM sleep. Also called delta or slow wave sleep, these are the deepest levels of human sleep and represent 10–20% of sleep time. They usually occur during the first 30–50% of the sleeping period.
• REM sleep. REM sleep accounts for 20–25% of total sleep time. It usually begins about 90 minutes after the person falls asleep, an important measure called REM latency. REM sleep alternates with NREM sleep about every hour and a half throughout the night. REM periods increase in length over the course of the night.

The average length of nighttime sleep varies among people. Most adults sleep between seven and nine hours a night.

Sleep disorders are classified according to their causes. Primary sleep disorders are distinguished as those that are not caused by other mental disorders, prescription medications, substance abuse, or medical conditions. The two major categories of primary sleep disorders are the dyssomnias and the parasomnias.

Dyssomnias

Dyssomnias are primary sleep disorders in which the patient suffers from changes in the amount, restfulness, and timing of sleep. The most important dyssomnia is primary insomnia, which is defined as difficulty in falling asleep or remaining asleep that lasts for at least one month. It is estimated that 35% of adults in the United States experience insomnia during any given year. Primary insomnia usually begins during young adulthood or middle age.

Hypersomnia is a condition marked by excessive sleepiness during normal waking hours. The patient has either lengthy episodes of daytime sleep or episodes of daytime sleep on a daily basis even though he or she is sleeping normally at night. The number of people with primary hypersomnia is unknown, although 5–10% of patients in sleep disorder clinics have the disorder. Primary hypersomnia usually affects young adults between the ages of 15 and 30.

Nocturnal myoclonus and restless legs syndrome (RLS) can cause either insomnia or hypersomnia in adults. Patients with nocturnal myoclonus, sometimes called periodic limb movement disorder (PLMD), awaken because of cramps or twitches in the calves and feel sleepy the next day. RLS patients have a crawly or aching feeling in their calves that can be relieved by moving or rubbing the legs. RLS often prevents the patient from falling asleep until the early hours of the morning.

Narcolepsy is a dyssomnia characterized by recurrent "sleep attacks" (abrupt loss of consciousness) lasting 10–20 minutes. The patient feels refreshed by the sleep, but typically feels sleepy again several hours later. Narcolepsy has three major symptoms in addition to sleep attacks: cataplexy (sudden loss of muscle tone and stability), hallucinations, and sleep paralysis. About 40% of patients with narcolepsy have or have had another mental disorder. Although narcolepsy is considered an adult disorder, it has been reported in children as young as three years old. Almost 18% of patients with narcolepsy are 10 years old or younger. It is estimated that 0.02–0.16% of the general population suffers from narcolepsy.

Breathing-related sleep disorders are syndromes in which the patient's sleep is interrupted by problems with his or her breathing. There are three types of breathingrelated sleep disorders:

• Obstructive sleep apnea syndrome is the most common form, marked by episodes of blockage in the upper airway during sleep. It is found primarily in obese people. Patients with this disorder typically alternate between periods of snoring or gasping (when their airway is partly open) and periods of silence (when their airway is blocked). Very loud snoring is characteristic of this disorder.
• Central sleep apnea syndrome is primarily found in elderly patients with heart or neurological conditions that affect their ability to breathe properly.
• Central alveolar hyperventilation syndrome is found most often in extremely obese people. The patient's airway is not blocked, but his or her blood oxygen level is too low.
• Mixed-type sleep apnea syndrome combines symptoms of both obstructive and central sleep apnea.

Circadian rhythm sleep disorders are dyssomnias resulting from a discrepancy between the person's daily sleep/wake patterns and the demands of social activities, shift work, or travel. There are three circadian rhythm sleep disorders: delayed sleep phase (going to bed and arising later than most people); jet lag (traveling to a new time zone); and shift work.

Parasomnias

Parasomnias are primary sleep disorders in which the patient's behavior is affected by specific sleep stages or transitions between sleeping and waking.

Nightmare disorder is a parasomnia in which the patient is repeatedly awakened by frightening dreams. Approximately 10–50% of children between three and five years old have nightmares. They occur during REM sleep, usually in the second half of the night.

Sleep terror disorder is a parasomnia in which the patient awakens screaming or crying. Unlike nightmares, sleep terrors typically occur in stage 3 or stage 4 NREM sleep during the first third of the night. The patient may be confused or disoriented for several minutes and may not remember the episode the next morning. Sleep terror disorder is most common in children 4–12 years old. It affects about 3% of children and fewer than 1% of adults.

Sleepwalking disorder (somnambulism) occurs when the patient is capable of complex movements during sleep, including walking. Sleepwalking occurs during stage 3 and stage 4 NREM sleep during the first part of the night. In addition to walking around, patients with sleepwalking disorder have been reported to eat, use the bathroom, unlock doors, or talk to others. It is estimated that 10–30% of children have at least one episode of sleepwalking. However, only 1–5% meet the criteria for sleepwalking disorder. The disorder is most common in children 8–12 years old.

Sleep Disorders Related to Other Conditions

Substances, living situations, and physical or mental disorders that can cause sleep disorders include:

• Mental disorders, especially depression or one of the anxiety disorders, can cause sleep disturbances. Psychiatric disorders are the most common cause of chronic insomnia.
• Medical conditions like Parkinson's disease, Huntington's disease, viral encephalitis, brain disease, and thyroid disease may cause sleep disorders.
• Such substances as drugs, alcohol, and caffeine frequently produce disturbances in sleep patterns.
• Emotional stress and hormone imbalances can also cause sleep problems.
• Job-related stress is a common factor in sleep disorders. Police officers, firefighters, and other emergency workers have a higher-than-average rate of sleep disorders.
• Sleeping arrangements can be a factor. People who must share a bedroom with someone who snores heavily sometimes develop sleep disorders. In addition, Research has shown that co-sleeping (small children sleeping in the same bed as their parents) is stressful for the children and contributes to sleep disorders.
• Such prescription medications as antihistamines, corticosteroids, asthma medicines, and drugs that affect the central nervous system can affect sleep patterns.

Causes & Symptoms

The causes of sleep disorders have already been discussed with respect to the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) classification of these disorders.

The most important symptoms of sleep disorders are insomnia and sleepiness during waking hours. Insomnia is the more common of the two symptoms and encompasses the inability to fall asleep at bedtime, repeated awakening during the night, and/or inability to go back to sleep once awakened.

Sleep disorders can have a number of negative health consequences in addition to general feelings of tiredness. Studies have shown that people with sleep disorders are at increased risk of having serious motor vehicle accidents and fatal workplace accidents.

Diagnosis

Diagnosis of sleep disorders usually requires a psychological history as well as a medical history. With the exception of sleep apnea syndromes, physical examinations are not usually revealing. The doctor may also talk to other family members in order to obtain information about the patient's symptoms. Psychological tests or inventories are used because insomnia is frequently associated with mood or affective disorders.

Patients may be asked to keep a sleep diary for one to two weeks to evaluate the sleep disturbance. Medications taken, the length of time spent in bed, and the quality of sleep are recorded.

If breathing-related sleep disorders, myoclonus, or narcolepsy are suspected, the patient may be tested in a sleep laboratory or at home with portable instruments. Polysomnography records physiological functions that can be used to help diagnose sleep disorders as well as conduct research into sleep.

Treatment

General Recommendations

General recommendations for getting more restful sleep include:

• Waiting until one feels sleepy before going to bed.
• Not using the bedroom for work, reading, or watching television.
• Arising at the same time every morning.
• Avoiding smoking and drinking caffeinated liquids.
• Limiting fluids after dinner and avoiding alcohol.
• Avoiding high-sugar or high-calorie snacks at bedtime.
• Avoiding highly stimulating activities before bed, such as watching a frightening movie, playing competitive computer games, etc.
• Avoiding tossing and turning in bed. Instead, the patient should get up and listen to relaxing music or read.

Herbal Remedies

Herbal remedies that are helpful in relieving insomnia include:

• catnip (Nepeta cataria): poor sleep
• chamomile (Matricaria recutita): anxiety
• chrysanthemum (Chrysanthemum morifolium): insomnia
• hops (Humulus lupulus): overactive mind
• lime blossom (Tilia cordata): anxiety
• linden (Tilia species): anxiety
• oats (Avena sativa): poor sleep and nervous exhaustion
• passionflower (Passiflora incarnata): anxiety and muscle cramps
• skullcap (Scutellaria lateriflora): nervous tension
• squawvine (Mitchella repens): insomnia
• St. John's wort (Hypericum perforatum): depression
• valerian (Valeriana officinalis): anxiety
• vervain (Verbena officinalis): nervous tension, sleep apnea

According to Prevention magazine, insomnia is the sixth most common condition treated with herbal formulas in the United States; it accounts for 18% of all use of herbal preparations. Some herbs used for insomnia are safer than others. Persons who are using alternative remedies, whether to treat insomnia or other conditions, should always tell their doctor what they are taking, how much, and how often. This warning is important because some herbal preparations that are safe in themselves can interact with prescription medications.

Dietary Supplements and Modifications

Some naturopaths recommend Vitamins B₆, B₁₂, and D for the relief of insomnia. Calcium and magnesium are natural sedatives, which helps to explain the traditional folk recommendation of drinking a glass of warm milk at bedtime. Tryptophan may relieve insomnia; as turkey is high in tryptophan, a turkey sandwich as a bedtime snack may be helpful. Melatonin is widely used to induce sleep although adequate studies of its effectiveness are lacking.

Other Treatments

A wide variety of other alternative treatments that may be helpful in treating sleep disorders include:

• Acupressure. The pressure points on both heels, the base of the skull, between the eyebrows, and on the inside of the wrists can be used to relieve insomnia.
• Acupuncture. The specific treatment for insomnia depends upon the cause.
• Aromatherapy. The use of essential oils of bergamot, lavender, basil, chamomile, neroli, marjoram, or rose promotes relaxation.
• Ayurvedic medicine. Ayurvedic remedies for insomnia include scalp and soles massage with sesame, brahmi, or jatamamsi oils, a warm bath, or a nutmeg ghee paste applied to the forehead and around the eyes. Nightmares are treated with scalp and soles massage with brahmi or bhringaraj oils, tranquility tea (jatamamsi, brahmi, ginkgo, and licorice root), and yoga. Sleep apnea is treated by changing sleep positions, humidifying the air, and nasya (nose drops) with warm brahmi ghee.
• Biofeedback. This technique can promote relaxation.
• Chinese medicine. Practitioners of traditional Chinese medicine usually treat insomnia as a symptom of excess yang energy. Either magnetite or "dragon bones" are recommended for insomnia associated with hysteria or fear.
• Chiropractic. Spinal manipulation can reduce stress upon the nervous system, thus allowing relaxation.
• Colored light therapy. Treatment with true green light can balance the nervous system and may relieve insomnia.
• Homeopathy. Homeopathic remedies are chosen according to the specific causes of insomnia. They may include: Nux vomica (alcohol or substance-related sleeplessness), Ignatia (emotional upset), Arsenicum (anxiety), Passiflora (mental stress, aches, and pains), and Lycopodium (talking and laughing during sleep).
• Light/dark therapy involves making the bedroom very dark at night and exposing the patient to early morning sunlight (or a light box).
• Low-energy emission therapy (LEET) is a clinically proven treatment for chronic insomnia. LEET treatment involves delivering electromagnetic fields through a mouthpiece.
• Massage. Therapeutic massage can relieve the muscular tension associated with chronic insomnia.
• Meditation. Regular meditation practice can counteract emotional stress.
• Reflexology. The use of the reflexology points for the diaphragm, pancreas, ovary/testicle, pituitary, parathyroid, thyroid, and adrenal gland helps to relieve insomnia.
• Visualization may help to promote relaxation.
• Yoga can promote relaxation by releasing muscular tension.

Allopathic Treatment

Treatment for a sleep disorder depends on its cause. In some cases, rearrangement of the bedroom or changes in sleeping arrangements may be all that is needed. Sedative or hypnotic medications are generally recommended only for insomnia related to a temporary stress because of the potential for addiction or overdose. Trazodone, a sedating antidepressant, is often used for chronic insomnia that does not respond to other treatments. Hypnotic agents include lorazepam, temazepam, and zolpidem.

Bright-light therapy, which was originally introduced as a treatment for seasonal affective disorder, is being tried as a treatment for insomnia in elderly adults. Although the results are not conclusive as of 2002, this form of treatment does appear to benefit many patients. In addition, it does not involve medications, which are more likely to produce side effects in the elderly than in younger patients.

Narcolepsy is treated with such stimulants as dextroamphetamine sulfate or methylphenidate. Nocturnal myoclonus has been successfully treated with clonazepam.

Children with sleep terror disorder or sleepwalking are usually treated with benzodiazepines. Children with nightmare disorder may benefit from limits on violent or frightening television programs or movies.

Psychotherapy is recommended for patients with sleep disorders associated with other mental disorders.

Patients with sleep apnea or hypopnea are encouraged to stop smoking, avoid alcohol or drugs of abuse, and lose weight to improve the stability of the upper airway. In children and adolescents, removal of the tonsils and adenoids is a fairly common and successful treatment for sleep apnea. Most sleep apnea patients are treated with continuous positive airway pressure (CPAP). Sometimes an oral prosthesis is used for mild sleep apnea.

Expected Results

The prognosis depends on the specific disorder. Natural remedies often require several weeks to have noticeable effects. Children usually outgrow sleep disorders. Narcolepsy, however, is a lifelong disorder.

Resources

Books

Becker, Philip M. "Sleep Disorders." In Current Diagnosis 9, edited by Rex B. Conn, et al. Philadelphia: W. B. Saunders, 1997.

DeGeronimo, Theresa Foy. Insomnia: 50 Essential Things To Do. New York: Penguin Group, 1997.

Eisendrath, Stuart J. "Psychiatric Disorders: Sleep Disorders." In Current Medical Diagnosis & Treatment 1998, edited by Lawrence M. Tierney, Jr., et al. Stamford, CT: Appleton & Lange, 1997.

Goldson, Edward. "Behavioral Disorders and Developmental Variations: Sleep Disorders." In Current Pediatric Diagnosis & Treatment, edited by William W. Hay, Jr., et al. Stamford, CT: Appleton & Lange, 1997.

Pelletier, Kenneth R., MD. The Best Alternative Medicine, Part II, "CAM Therapies for Specific Conditions: Insomnia." New York: Simon & Schuster, 2002.

Reichenberg-Ullman, Judyth, and Robert Ullman. Homeopathic Self-Care: The Quick and Easy Guide for the Whole Family. Rocklin, CA: Prima Publishing, 1997.

Sanders, Mark H. "Sleep Apnea and Hypopnea." In Conn's Current Therapy. Edited by Robert E. Rakel. Philadelphia: W.B. Saunders, 1998.

"Sleep Disorders." In Diagnostic and Statistical Manual of Mental Disorders. 4th ed., text revision. Washington, DC: American Psychiatric Association, 2000.

Vasant, Lad. The Complete Book of Ayurvedic Home Remedies. New York: Harmony Books, 1998.

Wiedman, John. Desperately Seeking Snoozin': The Insomnia Cure from Awake to Zzzz. Memphis, TN: Towering Pines Press, 1997.

Periodicals

Akerstedt, T., P. Fredlund, M. Gillberg, and B. Jansson. "A Prospective Study of Fatal Occupational Accidents—Relationship to Sleeping Difficulties and Occupational Factors." Journal of Sleep Research 11 (March 2002): 69-71.

Hunsley, M., and E. B. Thoman. "The Sleep of Co-Sleeping Infants When They Are Not Co-Sleeping: Evidence That Co-Sleeping Is Stressful." Developmental Psychobiology 40 (January 2002): 14-22.

Lushington, K., and L. Lack. "Non-Pharmacological Treatments of Insomnia." Israeli Journal of Psychiatry and Related Sciences 39 (2002): 36-49.

Montgomery, P., and J. Dennis. "Bright Light Therapy for Sleep Problems in Adults Aged 60+ (Cochrane Review)." Cochrane Database Systems Review 2002: CD003403.

Neylan, T. C., T. J. Metzler, S. R. Best, et al. "Critical Incident Exposure and Sleep Quality in Police Officers." Psychosomatic Medicine 64 (March-April 2002): 345-352.

Powell, N. B., K. B. Schechtman, R. W. Riley, et al. "Sleepy Driving: Accidents and Injury." Otolaryngology, Head and Neck Surgery 126 (March 2002): 217-227.

Organizations

American Sleep Disorders Association. 1610 14th Street NW, Suite 300. Rochester, MN 55901. (507) 287-6006.

National Sleep Foundation. 1367 Connecticut Avenue NW, Suite 200. Washington, DC 20036. (202) 785-2300.

[Article by: Belinda Rowland; Rebecca J. Frey, PhD]

Definition

Sleep disorders are a group of syndromes characterized by disturbance in the individual's amount of sleep, quality or timing of sleep, or in behaviors or physiological conditions associated with sleep.

Description

Although sleep is a basic behavior in animals as well as humans, researchers still do not completely understand all of its functions in maintaining health. Since 1975, however, laboratory studies on human volunteers have yielded information about the different types of sleep. Researchers have learned about the cyclical patterns of different types of sleep and their relationships to breathing, heart rate, brain waves, and other physical functions. These measurements are obtained by a technique called polysomnography. There are about 70 different sleep disorders. To qualify for the diagnosis of sleep disorder, the condition must be a persistent problem, cause the patient significant emotional distress, and interfere with his or her social, academic, or occupational functioning.

There are five stages of human sleep. Four stages have non-rapid eye movement (NREM) sleep, with unique brain wave patterns and physical changes occurring. Dreaming occurs in the fifth stage, during rapid eye movement (REM) sleep.

• Stage one NREM sleep. This stage occurs while a child is falling asleep. It represents about 5 percent of sleep time.
• Stage two NREM sleep. In this stage, (the beginning of "true" sleep), the child's electroencephalogram (EEG) will show distinctive waveforms called sleep spindles and K complexes. About 50 percent of sleep time is stage two NREM sleep.
• Stages three and four NREM sleep. Also called delta or slow wave sleep, these are the deepest levels of human sleep and represent 10 to 20 percent of sleep time. They usually occur during the first 30 to 50 percent of the sleeping period.
• REM sleep. REM sleep accounts for 20 to 25 percent of total sleep time. It usually begins about 90 minutes after the child falls asleep. It alternates with NREM sleep about every hour and a half throughout the night. REM periods increase in length over the course of the night.

Sleep cycles vary with a person's age. Children and adolescents have longer periods of stage three and stage four NREM sleep than do middle aged or elderly adults. Because of this difference, the doctor needs to consider the individual's age when evaluating a sleep disorder. Total REM sleep also declines with age.

The average length of nighttime sleep varies among individuals. Most people sleep between seven and nine hours a night. This population average appears to be constant throughout the world. In temperate climates, however, people often notice that sleep time varies with the seasons. It is not unusual for people in North America and Europe to sleep about 40 minutes longer per night during the winter. Infants can regularly sleep up to 16 hours a day. The total amount of sleep declines as the infant gets older. Teenagers may actually need more sleep than slightly younger children and often sleep nine or more hours a day.

Sleep disorders are classified based on what causes them. Primary sleep disorders are distinguished as those that are not caused by other mental disorders, prescription medications, substance abuse, or medical conditions. The two major categories of primary sleep disorders are the dyssomnias and the parasomnias.

Dyssomnias

Dyssomnias are primary sleep disorders in which the patient suffers from changes in the amount, restfulness, and timing of sleep. The most important dyssomnia is primary insomnia, which is defined as difficulty that lasts for at least one month in falling asleep or remaining asleep. Primary insomnia can be caused by many things, including a traumatic event related to sleep or bedtime, and it is often associated with increased physical or psychological arousal at night. Children who experience primary insomnia may develop anxiety related to not being able to sleep. The child may come to associate all sleep-related things (their bed, bedtime, etc.) with frustration, making the problem worse. The child may then becomes more stressed about not sleeping.

Hypersomnia is a condition marked by excessive sleepiness during normal waking hours. The individual has either lengthy episodes of daytime sleep or episodes of daytime sleep on a daily basis even though he or she is sleeping normally at night. In some cases, people with primary hypersomnia have difficulty waking in the morning and may appear confused or angry. This condition is sometimes called sleep drunkenness and is more common in males.

The number of people with primary hypersomnia is unknown, although 5 to 10 percent of patients in sleep disorder clinics have the disorder. Primary hypersomnia usually affects young adults between the ages of 15 and 30.

Kleine-Levin syndrome is a recurrent form of hypersomnia that usually starts in late teen years. Doctors do not know the cause of this syndrome. It is marked by excessive drowsiness and for short spells, maybe two to three days, the person sleeps 18 to 20 hours per day, overeats, and is highly irritable. Males are three or four times more likely than females to have the syndrome.

PARASOMNIAS. Parasomnias are primary sleep disorders in which the individual's behavior is affected by specific sleep stages or transitions between sleeping and waking. They are sometimes described as disorders of physiological arousal during sleep.

Nightmare disorder is a parasomnia in which the child is repeatedly awakened from sleep by frightening dreams and is fully alert on awakening. The actual rate of occurrence of nightmare disorder is unknown. Approximately 10 to 50 percent of children between three and five years old have nightmares, as do many older children. The nightmares occur during REM sleep, usually in the second half of the night. The child is usually able to remember the content of the nightmare and may be afraid to go back to sleep. More females than males have this disorder, but it is not known whether the sex difference reflects a difference in occurrence or a difference in reporting. Nightmare disorder is most likely to occur in children under severe or traumatic stress.

Sleep terror disorder is a parasomnia in which the child awakens screaming or crying. The child also has physical signs of arousal, like sweating and shaking. Sleep terror is sometimes referred to as pavor nocturnus. Unlike nightmares, sleep terrors typically occur in stage three or stage four NREM sleep during the first third of the night. The child may be confused or disoriented for several minutes and cannot recall the content of the dream. He or she may fall asleep again and not remember the episode the next morning. Sleep terror disorder is most common in children four to 12 years old and is usually outgrown in adolescence. It affects about 3 percent of children. In children, more males than females have the disorder.

Sleepwalking disorder, which is sometimes called somnambulism, occurs when the child is capable of complex movements during sleep, including walking. Like sleep terror disorder, sleepwalking occurs during stage three and stage four NREM sleep during the first part of the night. If the child is awakened during a sleepwalking episode, he or she may be disoriented and have no memory of the behavior. In addition to walking around, individuals with sleepwalking disorder have been reported to eat, use the bathroom, unlock doors, or talk to others. It is estimated that 10 to 30 percent of children have at least one episode of sleepwalking. However, only 1 to 5 percent meet the criteria for sleepwalking disorder. The disorder is most common in children eight to 12 years old.

Demographics

In the United States, 20 to 25 percent of children have some kind of sleep problem. Nightmares are believed to occur in about 30 percent of children, usually in younger children. Sleepwalking occurs more than once in about 25 to 30 percent of children. The most common age group to experience sleepwalking is children under 10. Insomnia is reported to occur in approximately 23 percent of children. Many other sleep disorders occur less frequently but are still a problem for many children.

Causes and Symptoms

The causes of sleep disorders vary depending on the disorder. Many times, stress, anxiety, or other factors are found to be the cause. Often the underlying cause of the sleep disorder is never found.

The most important symptoms of sleep disorders are insomnia and sleepiness during waking hours. Insomnia is by far the more common of the two symptoms. It covers a number of different patterns of sleep disturbance. These patterns include inability to fall asleep at bedtime, repeated awakening during the night, and/or inability to go back to sleep once awakened.

When to Call the Doctor

If a child does not seem to be getting enough sleep at night or the child wakes frequently or seems tired frequently during the day, it may be helpful to consult a doctor.

Diagnosis

Diagnosis of sleep disorders usually requires a psychological history as well as a medical history. Physical examinations are not usually revealing. The patient's sex and age are useful starting points in assessing the problem. The doctor may also talk to other family members in order to obtain information about the patient's symptoms. The family's observations are particularly important for evaluating sleepwalking, kicking in bed, snoring loudly, or other behaviors that the patient cannot remember.

Psychological Testing

The doctor may use psychological tests or inventories to evaluate insomnia because it is frequently associated with mood or affective disorders. The Minnesota Multiphasic Personality Inventory (MMPI), the Millon Clinical Multiaxial Inventory (MCMI), the Beck Depression Inventory, and the Zung Depression Scale are the tests most commonly used in evaluating this symptom.

Laboratory Studies

If the doctor is considering breathing-related sleep disorders, myoclonus, or narcolepsy as possible diagnoses, he or she may ask the patient to be tested in a sleep laboratory or at home with portable instruments.

POLYSOMNOGRAPHY. Polysomnography can be used to help diagnose sleep disorders as well as conduct research into sleep. In some cases the patient is tested in a special sleep laboratory. The advantage of this testing is the availability and expertise of trained technologists, but it is expensive. Since 2001, however, portable equipment is available for home recording of certain specific physiological functions.

MULTIPLE SLEEP LATENCY TEST (MSLT). The multiple sleep latency test (MSLT) is frequently used to measure the severity of the patient's daytime sleepiness. The test measures sleep latency (the speed with which the patient falls asleep) during a series of planned naps during the day. The test also measures the amount of REM sleep that occurs. Two or more episodes of REM sleep under these conditions indicates narcolepsy. This test can also be used to help diagnose primary hypersomnia.

REPEATED TEST OF SUSTAINED WAKEFULNESS (RTSW). The repeated test of sustained wakefulness (RTSW) measures sleep latency by challenging the patient's ability to stay awake. In the RTSW, the patient is placed in a quiet room with dim lighting and is asked to stay awake. As with the MSLT, the testing pattern is repeated at intervals during the day.

Treatment

Treatment for a sleep disorder depends on what is causing the disorder. For example, if major depression is the cause of insomnia, then treatment of the depression with antidepressants or psychological counseling should resolve the insomnia. The use of antidepressants in minors is a matter of debate. In October 2003, the United States Food and Drug Administration issued an advisory indicating that children being treated with selective serotonin re-uptake inhibitor antidepressants (SSRIs) for major depressive illness may be at higher risk for committing suicide. A similar warning was issued in the United Kingdom. Parents and physicians must weigh the benefits and risks of prescribing these medications for children on an individual basis.

Medications

Medications for sleep disorders are generally not recommended for use by children. In most cases medications are the treatment of last resort. If children with sleep terror disorder or sleepwalking are treated with medication, then they may be given benzodiazepines because this type of medication suppresses stage three and stage four NREM sleep.

Psychotherapy

Psychotherapy is recommended for patients with sleep disorders associated with other mental disorders. In many cases the patient's scores on the Beck or Zung inventories will suggest the appropriate direction of treatment.

Sleep Preparation

Children with sleep disorders such as insomnia may benefit from a regular pattern of pre-bedtime rituals designed to help the child relax and prepare for bed. Fluid intake should usually be limited in the hours before bed to reduce the need to get out of bed and use the toilet. Children should generally not be given caffeine in the evening, as it may make it harder for them to fall asleep. Children with nightmare disorder may benefit from limits on television or movies. Violent scenes or frightening science fiction stories appear to influence the frequency and intensity of children's nightmares.

Alternative Treatment

Some alternative approaches may be effective in treating insomnia caused by anxiety or emotional stress. For some people, meditation practice, breathing exercises, and yoga can break the vicious cycle of sleeplessness, worry about inability to sleep, and further sleeplessness. Yoga can help some people to relax muscular tension in a direct fashion. The breathing exercises and meditation can keep some patients from obsessing about sleep.

Homeopathic practitioners recommend that people with chronic insomnia see a professional homeopath. They do, however, prescribe specific remedies for at-home treatment of temporary insomnia: Nux vomica for alcohol or substance-related insomnia, Ignatia for insomnia caused by grief, Arsenicum for insomnia caused by fear or anxiety, and Passiflora for insomnia related to mental stress.

Melatonin has also been used as an alternative treatment for sleep disorders. Melatonin is produced in the body by the pineal gland at the base of the brain. This substance is thought to be related to the body's circadian rhythms.

Practitioners of traditional Chinese medicine usually treat insomnia as a symptom of excess yang energy. Cinnabar is recommended for chronic nightmares. Either magnetic magnetite or "dragon bones" is recommended for insomnia associated with hysteria or fear. If the insomnia appears to be associated with excess yang energy arising from the liver, the practitioner will give the patient oyster shells. Acupuncture treatments can help bring about balance and facilitate sleep.

Dietary changes such as eliminating stimulant foods (coffee, cola, chocolate) and late-night meals or snacks can be effective in treating some sleep disorders. Nutritional supplementation with magnesium, as well as botanical medicines that calm the nervous system, can also be helpful. Among the botanical remedies that may be effective for sleep disorders are valerian (Valeriana officinalis), passionflower (Passiflora incarnata), and skullcap (Scutellaria lateriflora).

Prognosis

The prognosis depends on the specific disorder. Children usually outgrow sleep disorders. Patients with Kleine-Levin syndrome usually get better around age 40. The prognosis for sleep disorders related to many other conditions depends on successful treatment of the underlying problem. The prognosis for primary sleep disorders is affected by many things, including the patient's age, sex, occupation, personality characteristics, family circumstances, neighborhood environment, and similar factors.

Prevention

There is no known way to prevent sleep disorders, although having a good, regular, sleep schedule with a nighttime ritual intended to reduce stress may help.

Parental Concerns

Children who do not get enough sleep, or do not get good quality sleep, may seem irritable or uncooperative during the day. Lack of sleep reduces the ability to concentrate and decreases mental functioning, so children who are not getting enough good sleep at night may have poor concentration skills and poor academic performance.

Resources

Books

Kryger, Meir H., Thomas Roth, William C. Dement, eds. Principles and Practice of Sleep Medicine, 3rd ed. Philadelphia: Saunders, 2000.

Reite, Martin, John Ruddy, and Kim Nagel. Concise Guide to Evaluation and Management of Sleep Disorders, 3rd ed. Washington, DC: American Psychiatric Publishing, 2002.

Organizations

National Sleep Foundation. 1522 K Street, NW, Suite 500, Washington, DC 20005. Web site: www.sleepfoundation.org.

[Article by: Tish Davidson, A.M. Rebecca J. Frey, PhD]