Abstract

Introduction
Excessive daytime sleepiness (EDS), a common presenting symptom among children and adolescents, is caused by a wide range of sleep disorders and other conditions, and it may impair health, development, and daily function.1-3 Studies have reported rates of EDS due to various etiologies ranging from 10% to 20% in prepubertal children4-8 and 16% to 47% in adolescents.7,9,10 Sleep problems that can cause EDS are present in an estimated 25% to 40% of children and adolescents, 11 encompassing behavioral, neurologic, and respiratory disorders. Other conditions affecting sleep (eg, chronic pain, nocturnal seizures, and prescription and/or illicit drugs) are important contributors in some children, as reviewed elsewhere.2,12-17
Untreated pediatric sleep problems and associated EDS may lead to behavioral problems, mood disturbances, depression, dysregulation of affect/emotion, impairments in neurocognitive function, increased risk for alcohol and drug use in teenagers, declining academic performance, and safety concerns.18-20 Long-term chronic sleep loss, which results in EDS, adversely affects physiologic systems such as carbohydrate metabolism and endocrine function, potentially increasing risk for type 2 diabetes and cardiovascular dysfunction, with associated hypertension/risk of atherosclerosis and proinflammatory response. 18 Epidemiologic data also suggest that short sleep duration is associated with an increased risk of obesity (a significant health problem itself) in children and adolescents. 21 Other risks associated with chronic sleep loss in children and adolescents include increased unintentional injuries, 22 sports-related injuries, 23 and automobile crashes.22,24 Specific sleep disorders frequently accompanied by EDS have also been associated with health-related adverse effects; for example, obstructive sleep apnea (OSA) in children and adolescents has been correlated in multiple studies with growth failure and insulin resistance, as well as hypertension and inflammatory changes in systemic and central nervous system vasculature.25,26 Children and adolescents with EDS are also more prone to being bullied, to being regarded as “lazy,” “inattentive,” or “unmotivated,” and to having low self-esteem.2,12
Excessive daytime sleepiness in children and adolescents is underreported by parents and underdiagnosed by physicians, possibly due to lack of recognition.3,27 Externalizing symptoms such as hyperactivity and oppositional behavior in children may be attributable to EDS, and children may not recognize or be able to verbalize the internal state of “sleepiness.” 3 Thus, children and adolescents with EDS often present to primary care pediatricians when parents become concerned about behavioral, mood, and academic issues that they may not attribute to underlying sleep problems. Given the high prevalence and potential health implications, prompt detection, diagnosis, and management of EDS is an essential component of primary pediatric care.
Presentation and Screening
Excessive daytime sleepiness has classically been defined as a subjective sense of sleepiness, or increased tendency to fall asleep, occurring at times and in situations when the individual would be expected to be awake and alert.28,29 However, a presenting complaint that may be related to EDS must first be assessed in the context of common developmental manifestations of daytime sleepiness, as well as age-related/developmentally appropriate nocturnal sleep and daytime napping. 3 Recommended ranges of optimal sleep amounts according to standards from the American Academy of Sleep Medicine vary with age and include daytime sleep periods (naps) in young children (Table 1). 30
American Academy of Sleep Medicine Recommendations for Amounts of Sleep to Promote Optimal Health by Pediatric Age Group. 30
Furthermore, daytime sleepiness may be considered excessive when it involves a pattern of increased nocturnal sleep and/or more daytime napping compared with the normal range for children of the same age group (ie, not just a self-limited response to acute sleep curtailment/disruption by illness, change in routine, etc). Difficulty waking in the morning and frequently falling asleep during the day in inappropriate circumstances (short car rides, watching television, playing) may also be considered excessive sleepiness. The propensity to sleep longer than usual when given the opportunity (ie, on weekends, during school vacation) is also an important but underrecognized sign of chronic insufficient sleep and EDS. 31
Manifestations of EDS in children and adolescents can be nuanced, deceptive, and apparently paradoxical.3,32 In prepubertal children, manifestations of EDS may include restlessness, hyperactivity, emotional lability, irritability, aggression, and behavior problems in school, which can be similar to, and possibly attributed to, attention deficit hyperactivity disorder.3,33 Prepubertal children with EDS may also present as quiet, listless, inattentive and unfocused, or withdrawn and isolated because they have missed social events due to their sleepiness.3,33 Considering that alertness in school-aged children is normally high, practitioners should have a very low threshold for investigating complaints of overt sleepiness in this age group.
Adolescents as a group have high levels of sleepiness for various reasons, including developmental puberty-related changes in circadian rhythms, chronic sleep curtailment, and use of electronic media before bed and during the night with resultant sleep disruption. Adolescents with EDS may appear to be lethargic or moody, disinterested, lacking in motivation, bored, and depressed.29,31,32,34 They may fall asleep in class or while completing homework and perform poorly in academics or sports. Given that EDS is nearly ubiquitous in adolescents, the distinction between “normal” sleepiness related to environmental and lifestyle factors and “pathologic” sleepiness that might be a manifestation of an underlying primary central nervous system hypersomnia is important but not always easy to determine. Nonetheless, the consequences of environmentally induced sleepiness (often called “behaviorally induced insufficient sleep syndrome”) can be highly significant 35 ; manifestations of behaviorally induced insufficient sleep syndrome in adolescents include car crashes and other unintentional injuries, depression, and risk-taking behavior. 31
Another challenge in screening for EDS is the need to distinguish it from fatigue. Fatigue, while related and often a co-complaint with EDS, does not by strict definition involve increased sleep propensity, decreased alertness during waking hours, and/or a short time to fall asleep at night (sleep latency). Rather, fatigue is a subjective sense of lack of energy and an abnormal level of exhaustion following normal activities.29,32 Fatigue is more likely to be associated with psychiatric and mood-related conditions, such as depression and anxiety, and chronic medical conditions, such as chronic infection, hypothyroidism, chronic fatigue syndrome, and personality disorders.28,29 However, the distinction between “sleepiness” and “fatigue” in clinical situations may be unclear, and use of both subjective and objective methods to quantify increased sleep propensity may assist in identifying these overlapping conditions.
Screening instruments can help confirm the presence of EDS by probing for sleepiness in specific situations relevant to children and adolescents (Table 2).13,36
Instruments to Screen for and Measure Subjective EDS and Sleep Problems in Children and Adolescents.
Abbreviations: BEARS, B = Bedtime Issues, E = Excessive Daytime Sleepiness, A = Night Awakenings, R = Regularity and Duration of Sleep, S = Snoring; CSHQ, Children’s Sleep Habits Questionnaire; CRSP-S, Children’s Report of Sleep Patterns–Sleepiness Scale; EDS, excessive daytime sleepiness; ESS-CHAD, Epworth Sleepiness Scale–Child Adolescent; PDSS, Pediatric Daytime Sleepiness Scale; PSG, polysomnography; PSQ, Pediatric Sleep Questionnaire; SRBDs, sleep-related breathing disorders.
Widely used and well-validated screening instruments for pediatric sleep problems include the BEARS (B = Bedtime Issues, E = Excessive Daytime Sleepiness, A = Night Awakenings, R = Regularity and Duration of Sleep, S = Snoring) 5-item questionnaire, 37 Children’s Sleep Habits Questionnaire,36,38 Children’s Report of Sleep Patterns–Sleepiness Scale, 39 and Pediatric Sleep Questionnaire. 40 Instruments used specifically to screen for EDS in the pediatric population include the Pediatric Daytime Sleepiness Scale 41 and Modified Epworth Sleepiness Scale for Children and Adolescents.42,43 Another screening tool that is useful in identifying potential causes of EDS is a 24-hour, 2-week, parent-recorded (or self-recorded for adolescents) sleep diary. 13 Sleep diaries allow detailed documentation of variations in sleep patterns and sleep-wake cycles in real time compared with descriptive histories recalled in the clinic. 13
Diagnosing Causes of EDS
Once the presence of EDS has been confirmed, its diagnosis requires a systematic approach, given the many conditions that may result in daytime sleepiness in children and adolescents.2,3,12 Sleep-related causes of EDS may be conceptualized under 4 broad categories: insufficient sleep duration, fragmented/disturbed sleep, circadian misalignment, and primary disorders that increase sleep needs (Table 3).
Abbreviations: CPAP, continuous positive airway pressure; EDS, excessive daytime sleepiness; OSA, obstructive sleep apnea; OTC, over the counter; PLMD, periodic limb movement disorder; RLS, restless legs syndrome; SRBDs, sleep-related breathing disorders.
Estimated prevalence in adolescents.
See Xyrem (sodium oxybate) prescribing information 51 for pediatric dosing schedule by weight.
Table 4 summarizes characteristics and causes of some of the more common and/or representative conditions.
Descriptions of and Factors Contributing to Conditions That May Cause EDS in Children or Adolescents.
Abbreviations: ADHD, attention deficit hyperactivity disorder; CPAP, continuous positive airway pressure; CSF, cerebrospinal fluid; DSPS, delayed sleep-wake phase syndrome; EDS, excessive daytime sleepiness; HLA, human leukocyte antigen; ICSD-3, The International Classification of Sleep Disorders, 3rd edition; MSLT, Multiple Sleep Latency Test; MSOL, mean sleep-onset latency; OSA, obstructive sleep apnea; PCO2, partial pressure of carbon dioxide; PLMD, periodic limb movement disorder; PSG, polysomnography; REM, rapid eye movement; RLS, restless legs syndrome; SOREMP, sleep-onset rapid eye movement period; SRBDs, sleep-related breathing disorders.
Cataplexy is defined as a sudden, brief, and transient partial or complete loss of muscle tone, often precipitated by strong positive emotions. Patients are fully conscious during episodes and aware of their surroundings. Cataplexy may manifest as weakness of the head and facial muscles, leading to head drop, jaw slackening, tongue protrusion, slurred speech, or head nodding, or weakness of the knees.32,64
Figure 1 provides a diagnostic algorithm.

Evaluation and diagnosis of excessive daytime sleepiness in school-aged children and adolescents. Bold, italic text = diagnostic tests; bold, not italic text = diagnoses; shaded boxes = testing/diagnostic endpoints.
Sleep disorders vary somewhat in prevalence by age category. 8 Specific forms of behavioral insomnia, such as settling problems and night waking due to inappropriate sleep-onset associations and/or inadequate caregiver limit setting, for example, are most common in children younger than 3 years; and delayed sleep-wake phase disorder and restless legs syndrome are more typically associated with adolescents.13,32 OSA and sleep-related breathing disorders, although prevalent in the pediatric population as a whole, are most commonly reported between ages 2 and 6 years in association with development of adenoidal and tonsillar hypertrophy; however, additional risk factors occurring in older children and adolescents, such as obesity, have emerged as important contributors in recent decades.4,44
History and Physical Examination
A comprehensive and detailed history and physical examination are essential for diagnosing causes of EDS in children and adolescents and may include input from classroom teachers, as well as patients and parents/caregivers.2,13,29 Suggested points for the workup are summarized in Table 5.
Considerations in EDS Workup.
Abbreviations: ADHD, attention deficit hyperactivity disorder; BMI, body mass index; EDS, excessive daytime sleepiness; OSA, obstructive sleep apnea; PLMD, periodic limb movement disorder; RLS, restless legs syndrome.
If medical problems are identified, the child should be referred to the relevant specialist for further evaluation and treatment. After appropriate therapy, the presence of EDS should be reevaluated.
Objective Measures
Objective measurement of sleep may be considered if subjective screening instruments, history, and physical examination fail to produce adequate clinical information for diagnosis. 2 Such measures include actigraphy, polysomnography (PSG), and the Multiple Sleep Latency Test (MSLT); the Maintenance of Wakefulness Test may be used in the context of treatment (Table 6).
Abbreviations: CPAP, continuous positive airway pressure; EDS, excessive daytime sleepiness; EEG, electro-encephalography; EMG, electromyography; EOG, electro-oculography; MSLT, Multiple Sleep Latency Test; MWT, Maintenance of Wakefulness Test; OSA, obstructive sleep apnea; PLMD, periodic limb movement disorder; PSG, polysomnography; REM, rapid eye movement; RLS, restless legs syndrome.
Cannot differentiate movement during sleep such as RLS from wakefulness, or wakefulness from sleep while the patient is lying awake but motionless.
The need for in-laboratory assessment using multiple wires connecting the patient to monitors may undermine the ability to replicate normal sleep at home.
Normative values for sleep latency in children <8 years of age are unclear; mean values are particularly long in prepubertal children (up to 26 minutes) and shorter in adolescents.
Normative values for this test are not available for children/adolescents.
Actigraphy, which uses small, validated portable devices similar to wristwatches to record the presence or absence of limb movement (indicating wakefulness or sleep), is useful primarily to evaluate insomnia and circadian rhythm disorders.45,46 Actigraphy is also used to confirm sufficient nighttime sleep before the PSG and MSLT (insufficient sleep can skew MSLT results). Overnight, in-laboratory PSG is particularly helpful for diagnosing OSA, periodic limb movement disorder, and narcolepsy in children and adults,45,47 but it is not useful or indicated for evaluation of behavioral sleep disorders, including insomnia. 13 The MSLT assesses the propensity to fall asleep and is the standard test for quantifying EDS.45,48 In addition to the presence of EDS, a mean sleep-onset latency ≤8 minutes and ≥2 sleep-onset rapid eye movement periods as assessed by the MSLT are diagnostic for narcolepsy. 49 However, the applicability of the MSLT for children is unclear, because normative values have not been established for children younger than 8 years, and mean values appear to vary across pediatric age categories. 45 The Maintenance of Wakefulness Test is a test of wakefulness used primarily to measure response to therapy for narcolepsy and hypersomnia (ie, effects on EDS), and it may also help judge the risk of vehicle crashes or other injury in patients with EDS.2,48
Treatment
Treatments for the various causes of EDS are shown in Table 3. Therapy for insomnia and other causes of insufficient sleep often begins with behavioral and nonpharmacologic approaches, with pharmacotherapy used as an adjunct, based on the common nature of the problems (eg, behavioral and habitual). The first step in treating EDS is always the optimization and maintenance of good sleep hygiene. Specific treatment options for patients with OSA include adenotonsillectomy, weight reduction, and continuous positive airway pressure. For children with movement disorders resulting in insufficient and/or disrupted sleep, such as restless legs syndrome and periodic limb movement disorder, iron supplementation in those with ferritin levels <50 ng/mL is advised; pharmacotherapy with agents such as gabapentin or clonazepam may be recommended in cases unresponsive to iron supplementation.
Treatment plans for children with narcolepsy and idiopathic hypersomnia include education, behavioral changes, and medication, with the goal of improving their quality of life. Children’s families, other caregivers, and friends require education about the disorder. The school should be notified of the child’s need for specific accommodations (eg, planned naps, extended time on examinations), commonly included in an Individualized Education Program/504 plan. Behavioral changes are essential and include regular sleep-wake schedules, short planned naps 1 to 3 times daily, increased physical activity, and weight management. As there is no cure for narcolepsy and idiopathic hypersomnia, a number of medications are prescribed off-label to control EDS (eg, modafinil, methylphenidate) or cataplexy (eg, antidepressants). 50 Notably, sodium oxybate is Food and Drug Administration approved for the treatment of EDS or cataplexy in patients ≥7 years of age with narcolepsy 51 based, in part, on a recent phase 3, randomized, placebo-controlled study in children and adolescents. 52
Conclusions
Excessive daytime sleepiness is common in children and can have serious adverse effects when undiagnosed and untreated. Improper diagnosis can lead to inappropriate use of medications that could worsen sleepiness and associated disruptive behaviors. Although EDS has many potential causes in children, the correct diagnosis may be identified through a systematic and thorough approach. Behavioral and educational interventions are preferred for treatment of most sleep disorders in children; and drug therapies may be effective adjuncts.
Author Contributions
All authors drafted the manuscript and have contributed equally to this work. All the authors have seen and approved the submission of this version of the manuscript and take full responsibility of the manuscript.
Footnotes
Declaration of Conflicting Interests
The author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: Judith A. Owens has received consultancy fees from Jazz Pharmaceuticals, TouchPoint, and Sleep Number, and receives royalties from WebMD, Wolters Kluwer, and Taylor and Francis. Debra Babcock has received consultancy fees from Jazz Pharmaceuticals and Johnson and Johnson. Miriam Weiss has no conflicts of interest to report.
Funding
The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: Under the direction of the authors, Larry Deblinger (employee of The Curry Rockefeller Group, LLC) and Peloton Advantage, LLC, an OPEN Health company, provided medical writing and editorial support for this article, which was funded by Jazz Pharmaceuticals.
