A survey from the National Sleep Foundation (NSF) has shown that 69% of children younger than 10 years of age experience some type of sleep disturbance. Significant sleep problems affect 25% to 40% of children and adolescents. These sleep problems tend to persist into adulthood if left untreated. Despite the high prevalence of sleep problems, most pediatricians do not ask questions about their patients’ sleep. A survey of community practices has shown that pediatricians acknowledge the importance of sleep problems, but they fail to adequately screen for them, especially in older children and adolescents. Untreated sleep disorders can lead to long-term consequences. Several studies have demonstrated the association between sleep disorders and cardiovascular and neurocognitive complications. Therefore, it is crucial that pediatricians recognize signs and symptoms of sleep disorders and integrate sleep issues into routine health maintenance visits. In this chapter, normal sleep development and common sleep problems encountered in general pediatric practices are discussed. Obstructive sleep apnea is reviewed in Chapter 508.
NORMAL SLEEP AND SLEEP MATURATION
Knowledge of sleep regulation, normal sleep, and its change during development is essential to understanding and recognizing sleep disorders in children and adolescents. Certain characteristics of sleep will also help in the diagnosis of sleep disorders. For example, night terrors, phenomena that occur in non-rapid eye movement (NREM) sleep, are more likely to occur during the first part of the night, whereas nightmares, rapid eye movement (REM) sleep phenomena, are common during the latter part of the night when REM sleep is predominate. Sleep is the result of a complex interaction between sleep- and wake-promoting neurons. The sleep-promoting neurons are located in the ventrolateral preoptic nucleus, which contains GABAergic and galaninergic neurons. The wake-promoting neurons are located in several areas of the brain including the lateral hypothalamus (orexin/hypocretin neurons), the posterior hypothalamus (histaminergic neurons), the pons and midbrain (cholinergic neurons), the raphe nuclei (serotonergic neurons), and the locus coeruleus (adrenergic neurons). A model is proposed in which wake- and sleep-promoting neurons inhibit each other, which results in stable wakefulness and sleep. Sleep and alertness are regulated by 2 important factors: the homeostatic factor, which depends on prior sleep duration and sleep quality and awakening time, and the circadian rhythm or intrinsic biological clock. These 2 forces interact and allow humans to have a diurnal pattern of sleep with consolidated sleep at night and wakefulness during the day. Two “sleepiness” periods occur in human. The first occurs at night between midnight and 6:00 AM, and the second occurs in the early afternoon. The circadian rhythm is affected by several environmental cues (zeitgebers) such as social interaction and timing of meals. However, the most important environmental cue is light exposure, which has different effects on the biological clock depending on the time of exposure.
Normal human sleep comprises 2 major stages, NREM and REM sleep, based on characteristic appearances of the electroencephalogram (EEG), electromyogram ...