What are parasomnias?
Parasomnias are disruptive
sleep-related disorders that can occur during arousals from REM
sleep or partial arousals from NREM sleep. Parasomnias:
- Are characterized by undesirable physical or verbal behaviors,
such as walking or talking during sleep
- Occur in association with sleep, specific stages of sleep, or
sleep-wake transitions
- Can be divided into two groups--primary parasomnias and
secondary parasomnias
Primary parasomnias are disorders of sleep states, while
secondary parasomnias are disorders of other organ systems that
arise during sleep.
Primary parasomnias are marked by a simultaneous occurrence of
elements of both wakefulness and sleep. Primary parasomnias are
classified according to the stage of sleep during which they occur:
rapid eye movement (REM) or non-rapid eye movement
(NREM).
Secondary parasomnias are disorders of other organ systems that
might take place during sleep. Secondary parasomnias might be quite
common, but can be unrecognized, misdiagnosed, or ignored in
clinical practice.
Types of parasomnias
Nightmares
Nightmares are vivid nocturnal events
that can cause feelings of fear, terror, and/or anxiety. Usually,
the person having a nightmare is abruptly awakened from REM sleep
and is able to describe detailed dream content. Usually, the person
having a nightmare has difficulty returning to sleep. Nightmares
can be caused by many factors including illness, anxiety, the loss
of a loved one, or negative reactions to a medicine. Call your
doctor if nightmares occur more often than once a week or if
nightmares prevent you from getting a good nights rest for a
prolonged period of time.
Sleep terrors/night terrors
A person experiencing a
night terror or sleep terror abruptly awakens from sleep in a
terrified state. The person might appear to be awake, but acts
confused and is not able to communicate. Night terrors last about
15 minutes, after which time the person usually lies down and
appears to fall back asleep. People who have sleep terrors usually
don't remember the events the next morning. Night terrors are
similar to nightmares, but night terrors usually occur during
stages 3 and 4 sleep (deep sleep). People experiencing sleep
terrors might pose dangers to themselves or others because of limb
movements. Night terrors are fairly common in children aged 3 to 5.
This sleep disorder, which might run in families, also can occur in
adults. Strong emotional tension and/or the use of alcohol can
increase the incidence of night terrors among adults.
Sleepwalking (somnambulism)
Sleepwalking occurs
when a person appears to be awake and moving around is actually
asleep. Sleepwalkers have no memory of their actions. Sleepwalking
most often occurs during deep non-REM sleep (stages 3 and 4 sleep)
early in the night. It can occur during REM sleep in the early
morning. This disorder is most commonly seen in children aged 6 to
12; however, sleepwalking can occur among younger children, the
elderly, and adults. Sleepwalking appears to run in families.
Contrary to what many people believe, it is not dangerous to wake a
person who is sleepwalking. The sleepwalker simply might be
confused or disoriented for a short time upon awakening. Although
waking a sleepwalker is not dangerous, sleepwalking itself can be
dangerous because the sleepwalker is unaware of his or her
surroundings and can bump into objects or can fall down.