Adolescent Health Care: A Practical Guide

Chapter 24

Sleep Disorders

Shelly K. Weiss

Sleep is one of our basic needs. It is important for our physical, intellectual, and emotional health. Lack of sleep makes us tired and irritable, decreases short-term memory, and can result in mistakes at work and school, as well as sleep-related accidents. Sleep disturbances are common in adolescents. Many young people acknowledge difficulties with sleep (often not obtaining adequate sleep) when specifically asked, although it may not be their chief complaint.

Sleep disorders are classified into four categories—dyssomnias cover a wide range of disorders including difficulty initiating or maintaining sleep, early morning waking (insomnias), and excessive sleepiness; parasomnias are disorders associated with undesirable physical (motor or autonomic) phenomena that occur exclusively or predominantly during sleep; sleep disorders associated with medical/psychiatric disorders, and proposed sleep disorders (Table 24.1) (International Classification of Sleep Disorders [ICSD-R], 2001). Sleep disturbances in adolescents may represent a reaction to anxiety or depression, inadequate sleep due to busy school or work schedules, and drug use (e.g., stimulants, barbiturates, or use of caffeine, nicotine, alcohol, hallucinogens, or other nonprescription substances). In addition, sleep disturbances can be secondary to a specific sleep disorder.

Sleep Physiology

Sleep is divided into rapid eye movement (REM) sleep and nonrapid eye movement (NREM) sleep. Studies of sleep physiology are carried out using polysomnography, which usually includes electroencephalogram (EEG), electrooculogram, electromyogram, and measures of respiratory function such as airflow, oxygen saturation, and end-tidal PCo₂ levels.

Rapid Eye Movement Sleep

REM sleep occupies 20% to 30% of sleep time in adolescents and is characterized by a high autonomic arousal state including increased cardiovascular and respiratory activity, very low voluntary muscle tone, and rapid synchronous nonpatterned eye movements. The EEG pattern shows a low-voltage variable frequency resembling the awake state. Most dreams occur during REM sleep.

Nonrapid Eye Movement Sleep

NREM sleep occupies 70% to 80% of sleep time in adolescents and is divided into four stages:

1. Stage 1 Very light sleep, characterized on EEG by alpha waves similar to the quiet awake state.
2. Stage 2 Medium-deep sleep, characterized on EEG by the presence of sleep spindles, K-complexes, and a change from alpha waves to slower, higher amplitude brain waves compared to stage 1.
3. Stages 3 and 4: Also called slow-wave sleep; progressively deeper sleep, characterized on EEG by a general slowing of frequency and an increase in amplitude (delta waves). Muscular and cardiovascular activity are decreased and little dreaming occurs.

Sleep Pattern and Changes during Adolescence

Normal sleep usually consists of a brief period of stage 1 and stage 2, followed by a lengthier interval of stages 3 and 4. After approximately 70 to 100 minutes of NREM sleep, a 10- to 25-minute REM period occurs. This cycle is repeated four to six times approximately every 90 minutes throughout the night. The REM periods usually increase by 5 to 30 minutes each cycle.

There are developmental changes in sleep patterns that occur between infancy and adulthood. A meta-analysis of age-related changes in objectively recorded sleep patterns reported a decrease in slow-wave sleep of 7% per 5-year period between the ages of 5 and 15 years. There was a concurrent increase in the lighter stage of NREM (stage 2) sleep (Ohayon et al., 2004).

Another documented change in sleep during adolescence is a delay in the circadian timing system. With progressive adolescent development (documented by increasing sexual maturity ratings), there is a tendency for lengthening the internal day. This coupled with the increasing time devoted to academic, employment, social, and extracurricular activities can cause progressive delay in bedtime (Carskadon et al., 1998).

Adolescents require a minimum of 8.5 to 9.5 hours of sleep per night to awake refreshed and rested. A research study has documented that on school nights, 10- to 11-year

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olds sleep an average of 9.5 hours, 12- to 13-year-olds sleep 9 hours, 14- to 15-year-olds sleep 7.75 hours, 16- to 17-year-olds sleep 7.5 hours, and 18-year-old college freshmen sleep 7 hours. The adolescent often tries to make up for the sleep deficit accumulated during the week by sleeping much longer on weekends.

TABLE 24.1 Classification of Sleep Disorders

From International Classification of Sleep Disorders Revised (ICSD-R). Diagnostic and coding manual. American Sleep Disorders Association, 2001. Dyssomnia: disorders that produce complaints of insomnia (difficulty initiating or maintaining sleep or early morning awakening) and/or excessive daytime sleepiness Parasomnia: disorders in which unusual behavior occurs during sleep, which may not necessarily produce insomnia or complaints of sleepiness Sleep disorders associated with medical/psychiatric disorders Proposed sleep disorders

Sleep History

Any adolescent with a sleep disturbance should be asked about the following:

1. Sleep complaint

• Both the adolescent and the parent should describe the presenting sleep complaint. This is to determine if the perception of the complaint differs between people in the family.
• A description of the complaint should include age at onset, timing during sleep, duration, frequency, and intermittent or continuous nature of the complaint.
• Treatment previously tried, length of trial, and result.

1. General sleep history

• Prior sleep problems
• Description of bedroom environment, bedtime (weekdays and weekends) and bedtime routines—what is done before sleep, sleep onset location, presence of light, noise, television, or computer in bedroom.
• Description of sleep—time to fall asleep, amount of sleep, regularity of sleep and wake schedules.
• Nocturnal arousals—frequency, timing, duration, behavior during arousal, presence of amnesia for event, and response to intervention at time of arousal.
• Snoring, restlessness (this question must be asked of someone who observes the adolescent while sleeping).
• Daytime symptoms—time and mood upon waking, daytime naps, daytime sleepiness, timing and regularity of exercise, intake of caffeine, nicotine, ethanol, and nonprescription drugs.

1. Medical history

• Medical, psychiatric, and surgical history (including history of tonsillectomy and adenoidectomy).
• Medication history including over-the-counter medications, herbal products, dietary supplements, weight-loss products, performance-enhancing substances, and other stimulants.

1. Psychosocial and academic history
2. Family history, including history of sleep problems

Physical Examination

A targeted physical examination should be done depending on the particular sleep complaint.

Sleep Diary

Have an adolescent keep a 1- to 2-week sleep diary, listing bedtimes, nighttime symptoms, time on awakening, daytime fatigue or sleepiness, and daytime naps, can be a very helpful tool in evaluating a sleep disturbance (Fig. 24.1).

Sleep Disorders in Adolescents

In order to appropriately evaluate and manage an adolescent with a sleep disorder, the specific sleep disorder must be determined. Examples of adolescent sleep disorders include the following:

Dyssomnias

Dyssomnia due to Inadequate Sleep

The most common cause of excessive daytime sleepiness in adolescents (and people of all ages) is inadequate sleep. Inadequate sleep may be due to poor sleeping habits or late bedtimes (often due to busy schedules). Adolescents may have rigorous schedules with academic, employment, and extracurricular activities that result in their having less than the required hours of sleep. In addition, in some school districts, high school starting times are earlier than middle school leaving even less time for sleep. This chronic sleep deprivation may cause complaints of fatigue or difficulty staying awake during school or work, adversely affecting performance. This may result in stimulant use to stay awake, moodiness, and even automobile accidents related to falling asleep at the wheel. Drowsiness or fatigue is associated with >100,000 automobile accidents each year and are especially common in the 16- to 25-year-old driver.

Other causes of inadequate sleep include difficulty falling asleep as a result of stress, anxiety, or depression. Adolescents with depression frequently have sleep onset or sleep maintenance insomnia. Other less common causes of insomnia include any physical illness associated with pain or discomfort and substance abuse or withdrawal (particularly stimulants, alcohol, or sedatives). Medications may

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also cause insomnia, including selective serotonin reuptake inhibitors (SSRIs), stimulants, sympathomimetics, and corticosteroids.

FIGURE 24.1 Sleep diary. (From The National Sleep Foundation. 1999 sleep in America poll results. Washington, DC: The National Sleep Foundation, 1999, with permission.)

Dyssomnia due to Delayed Sleep Phase Syndrome

Daytime sleepiness can result from delayed bedtime resulting in extreme difficulty in waking in the morning. Adolescents are particularly prone to this problem because of their busy evening schedules and an intrinsic biological preference for a later bedtime.

A delayed sleep phase syndrome is a circadian phase disorder in which the timing of sleep is delayed. The adolescent has difficulty falling asleep and waking at an expected time; the person tends to fall asleep 3 to 6 hours later than the desired bedtime. If the adolescent is allowed to sleep for a normal length of time, he/she will wake refreshed but will have a difficult time waking for work, school, or social needs because the timing of waking will also be delayed by 3 to 6 hours. If the adolescent is awakened to attend school, he/she may have difficulty arising and may experience daytime sleepiness due to inadequate sleep. If the adolescent is asked to fall asleep at a normal bedtime, he/she will have sleep-onset insomnia.

Dyssomnia due to Obstructive Sleep Apnea Syndrome

The main cause of sleep-disordered breathing (SDB) is obstructive sleep apnea syndrome (OSAS). This is the presence of complete or partial obstruction of the upper airway during sleep and is associated with the following history:

• Habitual snoring with labored breathing
• Observed apnea
• Restless sleep
• Daytime neurobehavioral abnormalities or sleepiness

Even if obstructive sleep apnea is present, there may be no abnormalities seen on physical examination. Physical examination may reveal evidence of the following (American Academy of Pediatrics, 2002):

• Growth abnormalities
• Signs of nasal obstruction
• Adenoidal facies
• Enlarged tonsils
• Increased pulmonic component of second heart sound

Risk factors include obesity, African-American heritage, and other respiratory factors such as chronic cough, occasional and persistent wheezing, sinus problems, and asthma.

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Sleep studies are used to evaluate for apnea (defined as the absence of any effective airflow into the lungs) or hypopneas (defined as incomplete apnea). A sleep study in a person with obstructive sleep apnea demonstrates a pause in breathing, lasting >10 seconds with an associated decrease in oxygen saturation. An apnea-hypopnea index (AHI) divides the number of respiratory events by the estimated sleep time. Different thresholds are used with little consensus. An AHI of 10 is a reasonable cutoff for adolescents.

Narcolepsy

Narcolepsy is a chronic neurological disorder characterized by two major abnormalities—excessive and over-whelming daytime sleepiness and intrusion of REM sleep phenomenon into wakefulness. The age at onset is usually between 10 and 25 years.

Symptoms

The first and primary manifestation of narcolepsy is excessive daytime sleepiness. The disorder is characterized by the following four classic symptoms:

• Sleep attacks: Intrusive and debilitating periods of sleep during the day that may last anywhere from a few seconds to 30 minutes. These periods are often precipitated by sedentary, monotonous activity, and are more frequent after meals and later in the day. Sleepiness is transiently relieved after short naps, but will gradually increase again within the 2 to 3 hours following the nap.
• Cataplexy: Abrupt, brief (seconds to minutes), bilateral loss or reduction of postural muscle tone while conscious, precipitated by intense emotions (e.g., anger, fright, surprise, excitement, or laughter). This is the most valuable symptom in the diagnosis of narcolepsy.
• Sleep paralysis: Temporary loss of muscle tone occurring with the onset of sleep or upon awakening.
• Hypnagogic and hypnopompic hallucinations: Hallucinations that can be visual, auditory, tactile, or kinetic (with sensation of movement) with the onset of sleep (hypnagogic) or upon awakening (hypnopompic). People without narcolepsy may have occasional sleep paralysis and/or hypnagogic hallucinations. In addition, people with narcolepsy may have automatic activity during periods of altered consciousness.

Frequency of components:

• Sleep attacks: 100%
• Sleep attacks and catalepsy: 70%
• Sleep paralysis: 50%
• Hallucinations: 25%
• All four: 10%

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Etiology of Narcolepsy

Narcolepsy is a genetically complex disorder. The close association between narcolepsy–cataplexy and the human leukocyte antigen (HLA) allele DQB1*0602 suggests an autoimmune etiology. Recent studies have identified abnormalities in hypothalamic hypocretin (orexin) neurotransmission (important in regulating the sleep–wake cycle) and in the pathophysiology of narcolepsy (Chabas et al., 2003).

Diagnosis of Narcolepsy

Narcolepsy is diagnosed by history and documentation of objective findings using both overnight polysomnography and daytime multiple sleep latency test (MSLT). The overnight polysomnography will exclude other sleep disorders, such as sleep apnea. The MSLT is the most specific test for narcolepsy. It will show a shortened time to sleep onset (sleep latency) and early onset of REM sleep.

Parasomnias

Sleepwalking and Night Terrors (Disorders of Partial Arousal)

Sleepwalking (somnambulism) and night terrors (sleep terrors, pavor nocturnus) are both disorders of impaired and partial arousal from deep slow-wave sleep.

• Both conditions occur in the first one third of the sleep episode, during the rapid transition from deep NREM sleep to light NREM sleep.
• Both conditions usually begin in childhood or early adolescence and disappear by older adolescence.
• Approximately 40% of 6- to 16-year-old children have at least one episode of sleepwalking and 1% to 3% experience night terrors.
• A positive family history is found in one or both parents in >60% of cases.
• Characteristics

Sleepwalking (somnambulism):

• –Usually lasts from 1 to 30 minutes.
• –The person usually has a low level of awareness manifested by clumsiness.
• –The individual usually has a blank expression with indifference to the environment.
• –There is usually no recall of the experience.

Night terrors (sleep terrors, pavor nocturnus):

• –Intense anxiety, fear, and sensation of doom that starts suddenly.
• –Autonomic discharge (tachycardia, tachypnea, and sweating).
• –Vocalizations in the form of screams, moans, or gasps.
• –There is usually no recall of the experience.
• Psychological disturbances are thought to be a more likely cause of night terrors or sleepwalking if the onset is after age 12 years, the condition has persisted for several years, there is a negative family history, and there is maladaptive daytime behavior.
• Hysterical phenomena such as fugue states are suggested by a more alert state, more purposeful movements, and longer duration.

Rapid Eye Movement–Related Parasomnia

1. Nightmares(dream anxiety attacks): This is the most common type of REM–related parasomnia (Table 24.2).
2. Frequent nightmares affect approximately 5% of the population and are more common in children than adults. There is an increased incidence with insomnia.
3. Onset is usually before age 10 years. Onset after this age is more suggestive of psychological cause.
4. Often associated with fear of attack, falling, or death.
5. Nightmares occur in the last one third to one half of the sleep episode.
6. Drug withdrawal, particularly from benzodiazepines, barbiturates, or alcohol can lead to nightmares.
7. Sleep paralysis, hypnagogic and hypnopompic hallucinations.

TABLE 24.2 Characteristics of Night Terrors (Arousal Disorder) versus Nightmares (Rapid Eye Movement–Related Parasomnia)

Characteristic Night Terrors Nightmares NREM, nonrapid eye movement; REM, rapid eye movement. Vocalization Intense Limited Autonomic activity Marked increase Slight increase Arousal Difficult Easy Motility Marked Limited Recall Minimal Vivid Sleep stage NREM sleep REM sleep

Although frequently seen in narcolepsy, they can occur in nonnarcoleptics.

Nocturnal Enuresis

1. Approximately 2% to 3% of 12-year-old children and 1% to 3% of older adolescents are enuretic (enuresis is discussed in Chapter 26).
2. Enuresis is independent of stage of sleep.
3. Enuresis may be primary or secondary.
4. Etiology of primary enuresis. The cause is likely mutifactorial:

• There is probably a genetic component as a positive family history is often found in most young people with this condition.
• Maturational delay in neuromuscular control of the bladder.

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• Blunting of the diurnal antidiuretic hormone secretion, resulting in an increased nocturnal urine production that exceeds the functional bladder capacity.

1. Sleep apnea has also been associated with enuresis.

Treatment of Sleep Disorders

Prevention

Preventive counseling can preclude the development of certain sleep disorders that are secondary to poor sleep habits. The sleep-smart tips for teens from the National Sleep Foundation (www.sleepfoundation.org) are useful for adolescents with and without complaints of sleep difficulties.

Sleep-Smart Tips for Teens

1. Sleep is food for the brain: Get enough of it, and get it when you need it. Even mild sleepiness can hurt your performance—from taking school exams to playing sports or video games. Lack of sleep can make you look tired and feel depressed, irritable, and angry.
2. Keep consistency in mind: Establish a regular bedtime and wake-time schedule, and maintain it during weekends and school (or work) vacations. Don't stray from your schedule frequently, and never do so for two or more consecutive nights. If you must go off schedule, avoid delaying your bedtime by more than 1 hour, awaken the next day within 2 hours of your regular schedule, and, if you are sleepy during the day, take an early afternoon nap.
3. Learn how much sleep you need to function at your best. You should awaken refreshed, not tired. Most adolescents need between 8.5 and 9.25 hours of sleep each night. Know when you need to get up in the morning, then calculate when you need to go to sleep to get at least 8.5 hours of sleep a night.
4. Get into bright light as soon as possible in the morning, but avoid it in the evening. The light helps to signal to the brain when it should wake up and when it should prepare to sleep.
5. Understand your circadian rhythm. Then, you can try to maximize your schedule throughout the day according to your internal clock. For example, to compensate for your “slump (sleepy) times,” participate in stimulating activities or classes that are interactive, and avoid lecture classes or potentially unsafe activities, including driving.
6. After lunch (or after noon), stay away from coffee, colas with caffeine, and nicotine, which are all stimulants. Also avoid alcohol, which disrupts sleep.
7. Relax before going to bed. Avoid heavy reading, studying, and computer games within 1 hour of going to bed. Don't fall asleep with the television on—flickering light and stimulating content can inhibit restful sleep. If you work during the week, try to avoid working night hours. If you work until 9:30 p.m., for example, you will still need to plan time to unwind before going to sleep.
8. Say no to all-nighters. Staying up late can cause chaos to your sleep patterns and your ability to be alert the next day … and beyond. Remember, the best thing you can do to prepare for a test is to get plenty of sleep. All-nighters or late-night study sessions might seem to give you more time to cram for your exam, but they are also likely to drain your brainpower.

Insomnia/Excessive Daytime Sleepiness due to Inadequate Sleep

The treatment of insomnia/excessive daytime sleepiness will differ depending on the cause. Some general management strategies include:

1. Counseling regarding any existing situational stresses.
2. Regularize bedtime and awakening hours. Try to have the adolescent wake up at a similar hour each day. Avoid excessive sleep on weekends. Avoid trying to force sleep when the adolescent is not tired.
3. Encourage regular mealtimes, especially breakfast in the morning. Avoid heavy late-night meals. A light carbohydrate snack may help induce sleep at bedtime.
4. Teach relaxation techniques.
5. Daily exercise, but not close to bedtime.
6. Curtail nicotine, alcohol, food, or beverages that contain caffeine and other stimulants.
7. Bedroom environment should be for sleep only (i.e., no television or computer in the bedroom).
8. Keep bedroom dark and as quiet as possible. Morning exposure to bright light is also helpful.
9. Avoid daytime naps.
10. Medications. Behavioral techniques should be used to treat adolescents with insomnia unless there are specific medical, psychiatric, or other sleep disorders (e.g., restless leg syndrome) that require medications. There has been a paucity of research on the use of medications for sleep disorders in adolescents. There remains a significant lack of knowledge concerning the efficacy, tolerability, and safety profiles of these medications in adolescents. As such, there are no formal guidelines for the use of these medications alone or as an adjunct in the treatment of adolescent sleep disorders (Owens et al., 2005).

Insomnia due to Delayed Sleep Phase Syndrome

1. Review all of the above suggestions for the treatment of insomnia.
2. Another treatment for delayed sleep phase syndrome is chronotherapy which involves advancing bedtime by 15-minute intervals or by delaying the bedtime by 2- to 4-hour adjustments every few days, forcing the adolescent to sleep around the clock until reaching an appropriate bedtime with 8.5 to 9.5 hours of sleep. An expert in sleep disorders usually performs this adjustment of sleep-waking schedule. There has been limited research on the efficacy of this treatment either alone or in combination with other treatments.
3. Referral to psychologist or psychiatrist may be required for evaluation of underlying psychological issues contributing to the development and perpetuation of the delayed sleep phase syndrome.
4. Referral to a sleep specialist may be needed for adolescents who do not respond to treatment.

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Insomnia due to Obstructive Sleep Apnea Syndrome

The treatment of OSAS requires a team effort. Weight loss, tonsillectomy and adenoidectomy, constant positive airway pressure, and bi-level pressure ventilation are all modalities used to treat SDB. Consultation with pulmonology, a sleep laboratory or center, and head and neck surgery is suggested. A cardiac echocardiogram, looking for pulmonary artery hypertension or right ventricular hypertrophy, and a lateral x-ray of the soft tissues of the neck are useful studies.

Narcolepsy

1. Arrange life (school, extracurricular activities, time with friends, work, long-term career planning) to accommodate the condition.
2. Ensure regular nocturnal sleep habits, with attention to sleep hygiene.
3. Short scheduled naps during the day may prevent sleep attacks.
4. Avoid dangerous activities (driving or participating in sports when sleepy).
5. Medication for sleepiness—modafinil (a nonamphetamine central nervous system [CNS] stimulant) is effective for treating excessive daytime sleepiness. Amphetamine-like stimulants can also be used but the new treatments (modafinil and sodium oxybate) are decreasing the need for these medications (Mignot, 2004). Any of these medications should be titrated to the lowest effective dose, avoiding late afternoon or evening doses.
6. Medication for cataplexy—tricyclic antidepressants such as protriptyline, imipramine, desipramine, and clomipramine are known to suppress REM sleep. SSRIs are also effective. Sodium oxybate (also known as γ-hydroxybutyrate[GHB]) has efficacy for cataplexy and daytime sleepiness. It is a known drug of abuse associated with CNS adverse events, including death.

Parasomnias

1. Arousal disorders (sleepwalking and night terrors)
2. Take precautions to prevent injury (e.g., limiting access to staircases, open doors and windows, harmful objects).
3. Reassure, educate, and explain the phenomena (night terrors in preschool children should resolve with time).
4. Evaluate precipitating factors (e.g., sleep deprivation, irregular sleep–wake schedule, medications).
5. There is some evidence to suggest that scheduled awakenings may be helpful (fully waking an adolescent 15 to 30 minutes before expected time of arousal).
6. Encourage stress reduction/relaxation.
7. Refer for psychological evaluation and treatment when there is evidence of psychopathology.
8. Pharmacotherapy is rarely needed. Some medications (e.g., benzodiazepine, tricyclic antidepressant) have been reported to have efficacy when used for a short term to “break the cycle” or to decrease arousals.
9. Nightmares (Sleep Anxiety Attacks)
10. Evaluate and treat any underlying psychological stresses or fears.
11. Evaluate and treat any associated alcohol or other drug abuse problems.
12. Nocturnal Enuresis The treatment of primary enuresis (with no organic etiology) is reviewed in Chapter 26.

Sleep Disorder Clinics

For severe sleep disorders or diagnostic dilemmas, referral to a sleep disorder clinic can help. Appendix II contains a partial list of institutions specializing in the treatment of sleep disorders.

The National Sleep Foundation keeps an updated state-wise list of accredited sleep disorder centers (www.sleepfoundation.org). In addition, clinics in the United States accredited by the American Academy of Sleep Medicine (listed by state) are available at www.aasmnet.org and clinics in Canada (listed by province) are available at www.css.to/sleep/centers.htm.

Resources

Organizations

American Academy of Sleep Medicine
6301 Bandel Road, Suite 101
Rochester, MN 55901; www.asda.org
Canadian Sleep Society
www.css.to

National Center on Sleep Disorders Research
National Heart, Lung, and Blood Institute
National Institutes of Health (NIH)
9000 Rockville Pike, Bldg 31
Bethesda, MD 20892; www.nhlbi.nih.gov/about/ncsdr/index/htm

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

Web Sites

For Teenagers and Parents

http://www.sleephomepages.org. Sleep Home Pages.

http://www.nhlbi.nih.gov/about/ncsdr/. NIH site about sleep disorders.

http://www.sleepnet.com/disorder.htm. Information about various sleep disorders.

For Health Professionals

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

http://www.css.to. Canadian Sleep Society.

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