168 Chapter 20
Night terrorsaffect about 3% of children, mainly in the 6–12 year age
range but they can start at any age including adulthood. Parents are
woken by a sudden scream and find their child looking terrified: sweaty,
with a rapid pulse, eyes wide open, calling out or crying. The child may
get out of bed and rush around in an agitated state (perhaps sustaining
injuries). After just a few minutes, the child resumes peaceful sleep, and
often doesn’t remember anything of the episode in the morning. If they
happen to wake after an episode, they may describe an intense but non-
specific sense of danger or impending doom, but they don’t describe
the sort of elaborate plot of a typical nightmare. The main differential
diagnoses are nightmares (vividly remembered and mostly happening
in the second half of the night) and some types of nocturnal seizures.
When night terrors (or sleepwalking or confusional arousals) are
happening frequently and at a regular time, they can sometimes be
prevented by ‘scheduled awakenings’. These involve gently waking the
child up 15–30 minutes before the episode is due and then letting
the child go rapidly back to sleep. If the arousals have failed to respond
to scheduled awakenings, and if they are exposing the child to danger,
medication should be considered. Benzodiazepines can be effective, but
should only be given short term under specialist supervision.Nightmares
These are very common and arise from REM sleep. The individual wakes
up, frightened and alert, and remembers all too clearly what was going on
in the dream. The fear takes a while to subside enough for the individual to
go back to sleep. Parental reassurance and comforting usually help. Night-
mares are more likely to occur when the child or adolescent is stressed or
ill. Post-traumatic stress disorder often results in prominent nightmares
related to the trauma. REM sleep is suppressed by alcohol and many
medications (most antidepressants, benzodiazepines, stimulants). Sudden
withdrawal of any REM-suppressing substance can lead to nightmares as
part of the REM rebound.
Rhythmic movement disorder
This involves head banging, head rolling or body rocking at the onset of
sleep (and sometimes during nocturnal awakenings or at the end of sleep).
Episodes can last up to 15 minutes or more. It is common in infancy, nearly
always ending by the age of 3 or 4. Whereas head banging while awake is
often associated with severe intellectual disability or major psychiatric dif-
ficulties, head banging while asleep is generally benign. All that is needed
in most cases is reassurance for the parents and padding for the cot sides.
Narcolepsy and related symptoms
About 1 in every 3,000 individuals has narcolepsy, with males and females
equally affected and with most having had their first symptoms in adoles-
cence or even childhood (around 5% before 5 years old). The symptoms
involve elements of REM sleep intruding into wakefulness: