Sleep and Activity Disorders of Childhood
Sleep problems are common in childhood. A distinction
is made between problems in which polysomnography (PSG)
is abnormal (i.e., the parasomnias, sleep apnoea and narcolepsy)
and problems that are behavioural in origin and have normal
The parasomnias-sleep terrors, somnambulism and enuresis-appear
to be related to central nervous system immaturity and are
often outgrown. Obstructive sleep apnoea syndrome (OSAS)
is frequently missed in children and can often be cured
Behavioural sleep problems may be overcome after parents
Physicians and Therapists can be of great assistance to
these families by recommending techniques to parents that
have been shown to be effective.
The most commonly encountered childhood sleep disorders
For most children dreams are pleasant experiences of everyday
events. Whilst nightmares are infrequent, often very real,
and soon forgotten, for some children they are very disturbing,
particularly if frequent or the child dwells on them for
several days for example by repetitive acting out of the
nightmare with toys; a dread of sleep; struggling to stay
awake. So the impact of nightmares should be weighed up
with the effect these have on the child's life in general.
- Sleep Paralysis
Paralysis can occur in children when they wake up suddenly
out of a nightmare and find that they can not move or
call out for their parents. The motor inhibition of REM
sleep is still active, and may take from seconds to minutes
to lift; all the sufferer can do is to breathe, move the
eyes and possibly, moan. This is alarming and adds to
the child's distress, especially if the dream imagery
continues into this wakefulness, as can happen. Younger
children may have difficulty in explaining these events
and this adds to the parents' concern. Such experiences,
which have a neurological basis, usually remit by early
adolescence. True familial sleep paralysis is much rarer,
and typically happens at sleep onset and/or on awakening,
and may well be a symptom of narcolepsy, although, it
can occur in isolation. However, narcolepsy seldom appears
before adolescence. Both forms of sleep paralysis can
often be terminated prematurely by sustained voluntary
eye-movement or, if possible, by touch from someone else.
- REM Sleep Behaviour Disorder
During REM sleep voluntary muscle are paralysed in order
to stop dreams being enacted. In rare circumstances, the
paralysis is absent, and if a dream is violent, then harm
may come to the sleeper and nearby persons. Although these
behaviours are usually correctly diagnosed by patients
or their parents, as violent nightmares, they are misunderstood.
This disorder has been more frequently reported in adults,
but has been found in children. More careful examination
usually discloses hindbrain lesions of REM sleep control
mechanisms. The most effective treatment is by drugs which
suppress REM sleep and psychotherapy such as Hypnosis
When children are forcibly roused out of stage 2 sleep,
a lighter form of non-REM sleep, "thinking"
is often reported, which contrasts with the gross visual
imagery, unrealism, and more vivid actions of dreaming
usually found (but not wholly) in REM sleep. Such thinking
is less prevalent in SWS. Sometimes, more disturbing mental
events can occur during SWS, with the most notable being
sleepwalking (somnambulism) and night terrors (pavor nocturnes),
with the latter being quite distinct from the nightmares
of dreaming sleep.
These SWS phenomena can be found together. They mainly
occur in childhood and tend have some hereditary basis.
Sleepwalking peaks in adolescence, but declines rapidly
by the late teens. Episodes are often triggered by anxiety;
in susceptible children, the worry can be trivial - the
loss of a favourite toy, or just a frustrating day. Only
in serious cases, when sleepwalking occurs most nights,
might there be severe distress and underlying emotional
conflict, requiring intervention.
Children are particularly difficult to arouse from SWS,
and even very loud sounds of 123 dB can have no effect.
It is difficult to wake up a sleepwalking child, and is
unwise to do so, as distress or a wild and emotional outburst
may set in. It is best to guide or carry them back to
bed. As many sleepwalking episodes occur within the first
two hours of sleep (when SWS is most prolific), parents
are usually still up.
The mind of a sleepwalker is unresponsive to what is going
on around and seems steeped in thought. The sleepwalker
behaves like an automaton with a limited repertoire of
behaviour, but does not walk about with the hands out
in front, as is commonly portrayed. There is no memory
of the nocturnal activities the next day. Episodes can
last up to 30 minutes, but usually average 5-15 minutes.
Sleep EEG recordings of sleep walkers show that they usually
remain in SWS whilst sleepwalking, with few signs of arousal.
Typically, in a sleepwalking episode the child will sit
up quietly, get out of bed and move about in a confused
and clumsy manner. Although behaviour becomes more coordinated,
the sleepwalker tends to remain in the bedroom, often
preoccupied by searching for something in drawers, cupboards
or under the bed. It is almost impossible to attract their
attention; however, if left alone they normally go back
to bed. Navigation is done mostly by memory of the layout
of the room and house; the eyes are unseeing and usually
it is dark. If the sleepwalker is asked to repeat the
act the next day, in wakefulness and blindfolded, then
he or she will soon come to grief as recall of the houshold
layout is now poor, but somehow heightened during sleep.
Difficulties and sometimes injuries occur to sleep-walkers
at night if they think they are somewhere else, when walls,
doors, staircases and windows are not where they should
- Night Terrors
These are another phenomenon of deep sleep (SWS) and are
sometimes associated with sleep-walking. They are quite
distinct from the visually vivid, prolonged nightmare,
and are not just bad dreams, but sudden and horrifying
sensations accompanying fleeting mental images that shock
the sleeper into immediate wakefulness. Night-terrors
are also more common in older children than in adults,
where, in the latter, the problem is more serious. Typically,
the child sits abruptly up in bed, screams and appears
to be staring wide-eyed at some imaginary object - maybe
"a monster". When this part of the episode passes
the child appears to awaken somewhat but is confused and
disoriented. They may well remain like this for many minutes
until sleep returns, having little or no recollection
of the event next morning.
Night terrors can be combined with sleepwalking, particularly
in adolescence, when the terrified child may run around
the house in an inconsolable and incommunicable state
for many minutes; half an hour or more is not uncommon.
Again, morning recollection is fragmentary at best.
Bruxism is a minor disorder usually found in stages 1
and 2 sleep, and has a tendency to be related to anxiety
and/or stressing days. It can occur in children soon after
the first dentition has erupted and may lead to tooth
damage and misalignment. For this reason a night-time
rubber mouthguard is often used. If anxiety is indicated,
then relaxation treatments can be successful.
More recently there has been an increasing interest in
the role of sleep in children diagnosed with Attention
Deficit Hyperactivity Disorder (ADHD). Difficulty
falling asleep, restless sleep, night waking, and early
morning waking are frequently reported in patients with
ADHD. Some professionals now regard sub-groups of these
patients as having a primary sleep disorder. More than
40% of patients with ADHD report significant sleep disturbance
including insomnia and parasomnias. There is also evidence
that inadequate sleep can cause ADHD-like symptoms in
some children. Sleep loss in children results in symptoms
of inattention, irritability, distractibility and impulsiveness
- the core features of ADHD. The evaluation of sleep and
activity through the use of Actigraphy is now recommended
as a part of the diagnostic workup of children with symptoms
of inattention and impulsiveness.
The relationship between ADHD and sleep is complex and
requires further research. It is precisely for this reason
that the Sleep Medicine group of sleep centres is about
to embark on a research project to objectively measure
sleep parameters in patients with ADHD.
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