Pediatric Sleep Problems



Pediatric Sleep Problems


Elizabeth Super MD

Kyle P. Johnson MD



Introduction and Background

While pediatric sleep disorders have long been recognized by parents and pediatricians, systematic study has only recently been applied. Nineteenth and early twentieth century clinicians were primarily interested in sleep-related breathing problems. Some of the earliest descriptions of pediatric sleep disorders are in the literary works of Charles Dickens, most famously the depiction of Joe in the Pickwick Papers published in 1836. Joe was an obese boy who was always excessively sleepy. He snored loudly and likely had right-sided heart failure as a result of severe obstructive sleep apnea (OSA). In 1892, William Osler described childhood OSA in his classic textbook, The Principles and Practice of Medicine. Over 60 years passed before there was further study, linking OSA to adenotonsillar hypertrophy and cardiac failure.

In the second half of the twentieth century, as adult sleep medicine was developing into a medical science, systematic study of children and adolescents started at Stanford University under the direction of Dr. Mary Carskadon. For 10 years beginning from 1976, Dr. Carskadon and her colleagues ran the Stanford Summer Sleep Camp. Basically, the same cohort of preadolescents and adolescents returned each summer allowing for the systematic collection of data. This information provided the first objective description of pediatric sleep and how it changes with development. During the same time span, other pioneers in the field such as Dr. Richard Ferber and Dr. Thomas Anders concentrated on sleep in infants, toddlers, and school children.

More recently, studies have documented the deleterious effect of persistent sleep disturbance on various areas of functioning in children and adolescents. Sleep loss in adolescents is associated with excessive daytime sleepiness, depressed mood, and poor school performance. OSA can result in serious sequelae such as failure to thrive and cor pulmonale as well as neurocognitive deficits such as learning problems and disruptive behavior. In young children who are at particular risk for adenotonsillar hypertrophy, these neurocognitive deficits present similarly to attention-deficit/hyperactivity disorder (ADHD). Treatment for OSA often improves daytime functioning and school performance.

Increasingly, sleep is being investigated in special pediatric populations. For example, it has been discovered that the majority of children with autism spectrum disorders experience insomnia. Patients with Down Syndrome, Prader Willi, and those with cleft palates are at increased risk for OSA. Treatment can improve their daytime functioning and ability to learn.


Review of Normal Sleep in Children and Adolescents

In simple behavioral terms, sleep is a reversible state of perceptual disengagement from and unresponsiveness to the environment, typically occurring while lying down, quiet with closed eyes. Although the exact purpose of sleep still eludes investigation, we do know that it is necessary for healthy functioning as persistent disturbance causes psychological and sometimes physical impairments.









TABLE 20-1 Average Sleep Needs Over Development



























Age


Duration of Sleep Over 24 Hours


Newborn


16-20


Infant (0-1 year)


14


Toddler (1-3 years)


12


Preschooler (3-5 years)


11-12


School Age (6-12 years)


10-11


Adolescent (>12 years)


9


Young Adult (19-22 years)


8-8.5


There are two states within sleep, nonrapid eye movement sleep (NREM) and rapid eye movement sleep (REM), which are distinct from one another as well as from wakefulness based on a myriad of physiological parameters. According to the American Academy of Sleep Medicine Manual for the Scoring of Sleep and Associated Events, NREM sleep is divided into three stages (N1, N2, and N3) which correspond to the depth of sleep. Stage N3 is also referred to as slow-wave sleep or delta sleep. Fragmented mental activity occurs in NREM and bodily movement is possible. REM sleep is defined by electroencephalogram (EEG) activation, muscle atonia, and periodic bursts of REMs. Mental activity is more continuous in REM sleep and is associated with dreaming. In adults, approximately 20% of sleep is REM sleep and 80% is NREM, and these stages alternate in 90—120 minute cycles. Sleep changes over the course of development with the most pronounced changes occurring in the first 5 years of life, as outlined in Table 20-1.

At birth, normal full-term newborns spend 16 to 20 hours out of 24 hours asleep. As any new parent knows, sleep in the first month of life is not consolidated at night, instead occurs in 3 to 4 hour cycles throughout a 24-hour period of time. After the first month, the infant starts adapting to the light—dark cycle and regularly recurring time cues. By 6 months of age, most infants have a continuous sleep period of 6 hours during the night. At 1 year, the infant is sleeping 14 to 15 hours per day with the majority of sleep occurring at night and two naps during the day. In the second year, sleep decreases to about 12 hours and the morning nap usually ceases. The afternoon nap tends to drop out by 4 to 5 years of age. Infants spend more time in REM sleep compared with adults and actually enter sleep through REM, a phenomenon considered pathologic in adults. REM and NREM cycles are of 50 to 60 minutes in infants and young children and progressively increase until adult cycle lengths are reached in adolescence.

School-aged children demonstrate excellent sleep as evidenced by high sleep efficiencies and considerable daytime alertness compared to other age groups. Sleep efficiency is the ratio of total sleep time to time in bed expressed as a percentage. Problems with sleep or daytime alertness at this age is reason for concern. School-aged children need 9.5 to 11 hours of sleep typically, usually consolidated at night. Adolescents’ sleep requirements do not decrease significantly, if at all, compared with school-aged children. However, they tend to delay preferred sleep times, going to bed on school nights an average of an hour later than school-aged children. Teenagers tend to have lower levels of alertness during the day, particularly during the morning and early afternoon hours. This appears to be a normal part of development since the level of daytime sleepiness correlates more with pubertal development (Tanner Stages) than age when adequate amounts of sleep are ensured. Adolescents also have more irregular sleep patterns than the school-aged child, delaying sleep onset even longer on weekend nights and then sleeping later the next morning.



Epidemiology

Sleep problems in children and adolescents are very common. Population studies of toddlers demonstrate bedtime settling or frequent-awakening problems occurring at most nights or every night at rates of 20% to 25%. Once these sleep problems are established in toddlers, they tend to persist into early childhood at rates ranging from 25% to 84% over a 3-year period. The prevalence of parent-reported sleep problems in school-aged children is 11% to 37%. OSA occurs in approximately 2% of the pediatric population. Narcolepsy, which occurs in 1/2000 people, usually onsets during adolescence. Many patients with restless legs syndrome (RLS) experience the onset of symptoms in childhood, with an estimated prevalence of 2%. Delayed sleep phase syndrome (DSPS) affects approximately 5% to 10% of adolescents.

Insufficient sleep and irregular sleep patterns are particularly common in adolescents with the majority of students getting inadequate sleep during school nights. Children with developmental and neurological disabilities are at high risk for severe sleep disturbances. Up to 80% of children with mental retardation, Down syndrome, brain damage, and blindness suffer with clinically significant sleep disorders. The prevalence rates of sleep problems in children who have autism range from 44% to 83%. Sleep disturbance is often comorbid with psychiatric disorders including depression, anxiety, trauma-related pathology, and disruptive behavior disorders. Thus, sleep problems are common, but probably inadequately considered or evaluated, in clinical practice.


Sleep Disorder Syndromes


Overview and General Issues

Sleep disorders in children and adolescents differ from those occurring in adults. Some sleep disorders are specific to childhood while others occur across the developmental spectrum but may have different presentations and etiologies in children and adolescents. In pediatric sleep medicine, the parents are often the ones to complain, not the child, making parental perception an important part of the picture. Often the complaint is more consistent with a problem rather than a true disorder. What is defined as a sleep problem will vary from family to family and culture to culture. Therefore, pediatric sleep disturbances need to be considered within the specific psychosocial context of the child being assessed. In fact, pediatric insomnia has recently been defined with family considerations in mind. A consensus paper on the subject in 2006 by Mindell and colleagues defined pediatric insomnia as follows: “Repeated difficulty with sleep initiation, duration, consolidation, or quality that occurs despite age-appropriate time and opportunity for sleep and results in daytime functional impairment for the child and/or family.”

Sleep problems have a bidirectional relationship with many child and adolescent psychiatric disorders, particularly ADHD, anxiety disorders, and depression. Insomnia is a criterion symptom for depression and many of the anxiety disorders experienced in childhood. Conversely, chronic insomnia and sleep deprivation place children at increased risk to suffer with these conditions. Although insomnia is not a criterion symptom of ADHD, a large percentage of children with ADHD have sleep problems including initial insomnia, RLS, and OSA. Clinical and experimental research shows that sleep deprivation can result in ADHD-type symptoms and behaviors.

Sleep disorders are classified into four major categories in the Diagnostic and Statistical Manual, Fourth Edition (DSM-IV) : Primary Sleep Disorders; Sleep Disorder Due to a Medical Condition; Sleep Disorder Due to Another Mental Disorder; and Substance-Induced Sleep Disorder. These DSM-IV categories appropriately describe sleep disorders in adults, but are inadequate for categorizing sleep disorders in children. Instead, it is easier to conceptualize pediatric sleep problems in three broad categories: sleeplessness; excessive daytime sleepiness; and disturbed behavior during sleep. Some of the more common pediatric sleep disorders are summarized in Table 20-2 and discussed below.










TABLE 20-2 Common Pediatric Sleep Disorders





































































Category



Typical Age


Prevalence


Symptoms/Signs


Evaluation


Interventions


Excessive daytime sleepiness


OSA


3-to 8-year olds and adolescents


1-2% of children


Habitual snoring, noisy breathing, pauses in breathing, nocturnal sweating, mouth breathing


Full PSG is gold standard; limited channel cardiopulmonary study; home oximetry


Adenotonsillectomy; CPAP/BIPAP


Excessive daytime sleepiness


DSPS


Adolescents


5-10% of adolescents


Delayed sleep onset (usually after midnight) with difficulty awakening in a.m.; sleep very late on weekends; normal sleep quality


Detailed sleep history; sleep diaries; actigraphy


Chronotherapy; behavioral interventions; light therapy; motivational counseling; potentially melatonin


Excessive daytime sleepiness


Narcolepsy


Adolescents


1/2000


Cataplexy, hypnogogic hallucinations, sleep paralysis, sleep attacks


PSG and MSLT


Modafinil or stimulants for EDS; SSRI’s or TCA’s for cataplexy; scheduled naps


Disturbed sleep behaviors


Sleep terrors


Toddlers and school-aged children


3%


Occur in first third of the night; autonomic arousal with tachycardia, tachypnea, sweating; inconsolable screaming; amnesia for event


Detailed sleep history with attention to timing of episodes; family history of parasomia; video taping


Reassurance of parents; avoid sleep deprivation; benzodiazepines for severe cases


Disturbed sleep behaviors


Sleep walking


4-to 8-yearolds


15-40% have one episode; 3-4% have weekly/monthly episodes


Usually occur 1-2 hours after sleep onset; walks for a few minutes up to one-half hour; confusion; incoherence; difficult to awaken; amnesia for event


Detailed sleep history; video taping; family history


Reassurance of parents; safety measures (lock outside doors and windows; alarm on bedroom door); benzodiazepines for severe cases


Sleeplessness


Sleep-onset association disorder


Infants and toddlers


25-50% of 6-to 12-month-olds; 15-20% of 1-to 3-year-olds


Frequent signaling of parents after nightwakings; initiation of sleep requires parental involvement; inappropriate sleep associations (falls asleep in parent’s arms)


Detailed sleep history with attention to reinforcing behaviors of parents; charting of sleep associations; sleep diaries; video taping


Behavioral interventions (put to bed awake but sleepy); parental guidance regarding bedtime routines and sleep scheduling, education on graduated extinction.


Sleeplessness


Restless legs syndrome


School age and adolescents


2%


Uncomfortable sensation in legs; urge to move legas at time of rest, relieved with movement


Clinical history, family history, at times PSG appropriate to evaluate for overlapping periodic limb movement disorder


Avoidance of caffeine Iron replacement if low Dopamine agonists


OSA, obstructive sleep apnea; CPAP, continuous positive airway pressure; DSPS, delayed sleep phase syndrome; PSG, polysomnogram; MSLT, multiple sleep latency test; EDS, excessive daytime sleepiness; SSRI, selective serotonin reuptake inhibitor; TCA, tricyclic antidepressant.




Sleeplessness

Sleeplessness is a broad category which can be broken down into three basic types: problems settling and initiating sleep; frequent awakenings during the night; and awakening too early in the morning. These particular forms can occur in isolation or combination. It is important to determine the specific type of sleeplessness as etiologies will differ and, subsequently, so will treatment. In addition, potential causes of sleeplessness change according to the age of the child or adolescent.

Infants and toddlers often experience problems with settling and frequent awakenings. Potential medical causes (such as colic, middle ear disease or gastroesophageal reflux) need to be considered, although are rarely the problem for persistent nightly awakenings. In addition, it is quite uncommon for pain to be the cause of frequent awakenings in children. If pain were the cause of the awakenings, the child would not be able to return to sleep after being held or fed. Difficult temperaments can also manifest as sleeplessness. Behavioral issues are often the cause, specifically inappropriate sleep associations, clinically described as “sleep-onset association disorder.” Sleep-onset is a learned behavior and, therefore, is assisted or inhibited by certain environmental stimuli. If a child learns to fall asleep at bedtime in the mother’s arms, it will be difficult for the child to initiate sleep independently during a nighttime awakening. These children will signal care providers to aid in the transition back to sleep.

Family expectations can play a part in “sleeplessness” in toddlers. Often, parents expect a child to sleep more than is biologically necessary. When total sleep time is added up, including daytime naps, expected sleep is excessive leading to a decrease in homeostatic sleep drive. A sleep diary can help determine this cause.

According to the 2007 International Classification of Sleep Disorders, behavioral insomnia of childhood is divided into sleep-onset association type or limit-setting type. Inadequate limit-setting and sleep routines are often the culprits especially in overwhelmed or chaotic families. Sleep-onset association insomnia is characterized by an extended process of falling asleep that requires special conditions which are highly problematic or demanding for caregivers. In the absence of the associated conditions, sleep onset is significantly delayed or sleep is otherwise disrupted. Nighttime awakenings required caregiver intervention to return to sleep. In limit-setting insomnia, the child has difficulty initiating or maintaining sleep, refuses to go to bed at an appropriate time or refuses to return to bed after a nighttime awakening. The caregiver demonstrates insufficient and/or inappropriate limit setting to establish appropriate sleeping behavior in the child.

School-aged children (5 to 12 years) have the best sleep efficiency of any age group, so sleeplessness is concerning when it happens. Psychiatric disorders such as anxiety and depression become more common at these ages as well as circadian rhythm disturbances. Children can develop into either “larks” or “owls” based on their tendency to advance or delay their sleep schedules. The intrinsic, biologically driven sleep/wake rhythms may be in conflict with parental and societal expectations leading to a perception of sleeplessness, particularly problems falling asleep or arising either too late or early in the morning. If these children are allowed to sleep their own schedule, they sleep soundly and are rested during waking hours. Behavioral sleep disorders continue to be prevalent in this age group.

More recently, RLS has been described in children. Manifestations of RLS include uncomfortable sensations in the legs associated with urges to move the legs and motor restlessness. Patients may describe the sensation as “crazy legs, creepy-crawlies” or “growing pains.” These symptoms are experienced during times of rest and relaxation particularly in the evening and night when one is recumbent. The uncomfortable feeling is relieved when the legs are moved. RLS tends to cause sleep-onset problems as the behaviors that relieve symptoms (movement) are likely to interfere with sleep onset. In a large population-based survey, criteria for definite RLS were met by approximately 2% of 8- to 17-year-olds. RLS is thought to be an autosomal
dominant condition and, therefore, shows strong familial trends. Reduced iron stores appear to play a role in children and adults with RLS. Synthesis of iron is the rate-limiting step of dopamine synthesis and metabolism. Thus, it is compelling to consider that iron deficiency plays a role in other central nervous system dopamine-related conditions like ADHD. In this population-based study, there was approximately 35% comorbidity of self-reported ADHD and RLS. Further work has found that children with RLS and ADHD tend to have lower ferritin levels than children with ADHD alone, and tend to be more severely affected by ADHD.

Adolescents experience sleeplessness for reasons similar to those described for school-aged children. In addition, substances such as caffeine and illicit drugs can disrupt sleep. Social and academic pressures may cause worry and anxiety and, subsequently, sleep disturbance. Other psychiatric disorders to consider in teens are bipolar disorder and psychotic illnesses such as schizophrenia, both of which can cause sleeplessness. DSPS is a circadian rhythm disturbance often manifesting at puberty. Adolescents with this problem have sleep-onset insomnia and excessive daytime sleepiness during the first half of the day.


Excessive Daytime Sleepiness (EDS)

Sleepiness differs from tiredness. Tiredness is similar in nature to fatigue, lethargy, or exhaustion and typically has a medical cause such as depression or endocrine dysfunction. Sleepiness describes an actual urge to fall asleep which tiredness does not entail, although the two conditions can simultaneously exist. Daytime sleepiness in children and adolescents has long been ignored, only recently supported by systematic research. Sleepiness can range from mild to severe and can present differently depending on age. Preschoolers and school-aged children usually do not manifest the behavioral signs seen in adolescents and adults, that is, difficulty in initiating or sustaining motor activity, droopy eyelids, or head nodding. Instead, they often present paradoxically with hyperactivity, increased impulsivity and aggressiveness, as well as impaired concentration and irritability.

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Jul 5, 2016 | Posted by in PSYCHIATRY | Comments Off on Pediatric Sleep Problems

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