++
A survey from the National Sleep Foundation (NSF) shows that
69% of children under 10 years of age experience some type
of sleep disturbance.1 Significant sleep problems
affect 25% to 40% of children and adolescents.2 These
sleep problems tend to persist to adulthood if left untreated. Despite
the high prevalence of sleep problems, most pediatricians do not
ask question about children’s sleep. The survey from community practice
shows that pediatricians acknowledge the importance of sleep problems,
but they fail to screen adequately for them, especially in older
children and adolescents.3 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
the signs and symptoms of sleep disorders and integrate sleep issues
as part of the routine health maintenance. In this chapter, normal
sleep development and the common sleep problems encountered in general pediatric
practices are discussed. Obstructive sleep apnea is reviewed in Chapter 508.
++
Knowledge of sleep regulation, normal sleep, and its change during
development is essential to understand and recognize sleep disorders
in children and adolescents. Certain features of sleep help in the
diagnosis of sleep disorders. For example, night terror, a phenomenon
that occurs in nonrapid eye movement (NREM) sleep, is more likely
to occur during the first part of the night when NREM predominates,
while nightmares, a rapid eye movement (REM) phenomenon, are common
during the latter part of the night. Sleep is the result of complex
interaction between sleep- and wake-promoting neurons. The sleep-promoting
neurons are located in the ventrolateral preoptic nucleus, which
contains GABA-ergic (Gamma-amino-butyric acid) and galaninergic
neurons. The awake-promoting neurons are located in the posterior lateral
hypothalamus, which contains orexin/hypocretin neurons.
A model is proposed in which wake- and sleep-promoting neurons inhibit
each other, which results in stable wakefulness and sleep.4 Sleep
and alertness are regulated by 2 important factors: the homeostatic
factor, which depends on prior sleep duration and quality and awakening
time and the circadian rhythm or intrinsic biological clock. These
2 forces interact and allow the diurnal pattern of sleep with consolidated
sleep at night and wakefulness during daytime. Two “sleepiness” periods
occur in humans. The first occurs at night between midnight and
6.00 am and the second in the early afternoon.5 The
circadian rhythm is affected by several environmental cues (zeitgebers),
such as social interaction and timing of meals, but 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 the characteristic of the electroencephalogram, electromyogram,
and electrooculogram.6 NREM sleep is subdivided
into 4 stages. Stage 1 is defined by an attenuation of high-frequency
alpha wave (8–13 Hz); the presence of low-amplitude, mixed-frequency electroencephalogram
(theta wave, 4–7 Hz); a slight decrease in chin electromyogram
from awake; vertex sharp waves; ...