Assessment and Management of Sleep Disorders in Children

More frequent sleep problems were seen in children with chronic medical, neurodevelopmental, or psychiatric disorders. Sleep problems were reported in 30% to 80% of children with mental retardation and in 50% to 70% of children with pervasive developmental disorder and autism.^5,6 Up to 75% of children with psychiatric disorders such as major depression, anxiety disorders, attention-deficit/ hyperactivity disorder (ADHD), or posttraumatic stress disorder have reported symptoms of insomnia, bedtime resistance, bedtime refusal, nocturnal fears, and nightmares.⁷

Sleep disorders are very common and are often underrecognized and underreported in children. If left untreated, these disorders can cause serious developmental and physiologic problems.

Behavioral sleep disorders are most commonly observed in infants, toddlers, and preschoolers. The International Classification of Diseases, 9th revision, Clinical Modification⁸ defines 2 subtypes of pediatric behavioral insomnia: (1) limit-setting, and (2) sleep-onset association. Limit-setting sleep disorder refers to parental difficulties in establishing behavioral limits and enforcing bedtimes, which commonly result in stalling by the child and refusal to go to bed. Nocturnal wakings are typically related to inappropriate sleep-onset associations such as rocking, feeding, and parental presence. Once children wake up at night they are unable to go back to sleep without recreating the same sleep association. Behavioral insomnia results in delayed sleep onset, fragmented nocturnal sleep, insufficient sleep, and daytime sleepiness.

Parasomnias are much more frequently seen in the pediatric population and usually represent the normal neurophysiology of sleep development. These phenomena are partial CNS arousals that are characterized by autonomic and motor activity. They almost always occur in slow-wave sleep and may include sleepwalking, sleeptalking, night terrors, confusional arousals, and nocturnal enuresis. Para- somnias are strongly associated with genetics and usually present in many family members. They appear around the second year of life and continue in preschool-aged or school-aged children. Most parasomnias resolve by adolescence. Although they represent a rather benign developmental condition, they can be associated with severe sleep disruption and may cause significant family distress. Parasomnias are much more prevalent in children with psychiatric or neurologic disorders and can be exacerbated or induced by psychopharmacologic agents.

Circadian rhythm disorders are disruptions of the internal body rhythms that regulate the sleep-wake cycle. Delayed sleep-phase syndrome is normally associated with changes in the regulation of sleep homeostasis and the circadian clock seen during the pubertal stage of development and results in the delay of sleep phase in relation to dark and light cycles. Because of the necessity of rising early on school days, adolescents with delayed sleep-phase syndrome may become significantly sleep deprived and present with excessive daytime sleepiness that results in academic decline, mood problems, and attentional deficits.

Sleep apnea is defined as episodes of complete or partial cessation of the airflow during a respiratory cycle, and it is associated with oxygen desaturations or arousals. Breathing-related sleep disorder in children has been associated with daytime somnolence and symptoms of inattentiveness and hyperactivity.⁹ Obstructive sleep apnea (OSA) has been estimated to affect about 2% of children in the general population¹⁰ with much higher rates found in children with neuromuscular and craniofacial problems; in children with genetic syndromes, the prevalence may be as high as 85%.¹¹ Because OSA in children may increase the risk for serious neurocognitive impairment, it is imperative to recognize and treat this syndrome early to prevent negative consequences.

Narcolepsy is a rare chronic neurologic disorder that presents with daytime sleepiness, cataplexy (sudden loss of muscle tone triggered by emotional arousal such as laughter), hypnagogic hallucinations, and sleep paralysis. The prevalence in adults is about 2 to 5 cases per 10,000, and in children it is presumably half that. In children, the classic presentation of narcolepsy with all of the above symptoms is rare. Many pediatric patients present with excessive daytime sleepiness that is often masked by behavioral and emotional symptoms, such as irritability, hyperactivity, inattentiveness, and, in younger children, an increased need for sleep.

Restless legs syndrome (RLS) is a common sensorimotor disorder defined as an urge to move the legs, which is often accompanied by uncomfortable and unpleasant sensations in the legs. Periodic limb movement disorder (PLMD) is characterized by episodes of repetitive stereotypical limb movements. Insomnia or excessive sleepiness is required to establish a diagnosis of PLMD. Several studies have documented the occurrence of RLS and PLMD in children and adolescents.^12-15 Similar to adults, children with RLS manifest their symptoms by moving their legs, fidgeting, running, walking, and stretching; however, because they frequently report symptoms of RLS differently from adults, diagnosing RLS in children is more challenging. As RLS and PLMD have been more extensively studied, the association between these disorders and ADHD in children has become evident: many children with ADHD were found to have RLS/PLMD and vice versa.¹⁶