Consciousness 149Parkinson’s disorders (Peever et al., 2014). This has positive implications for early detec-
tion and treatment of these disorders.
NIGHT TERRORS Often seen as a rare disorder, night terrors have been found to occur
in up to 56 percent of children between the ages of 1½ to 13 years old, with greatest
prevalence around 1½ years of age (34.4%) and rapidly decreasing as the child grows
older (13.4% at 5 years; 5.3% at 13 years; Petit et al., 2015). A night terror is essen-
tially a state of panic experienced while sound asleep. People may sit up, scream, run
around the room, or flail at some unseen attacker. It is also not uncommon for people
to feel unable to breathe while they are in this state. Considering that people suffering
a night-terror episode are in a deep stage of sleep and breathing shallowly, one can
understand why breathing would seem difficult when they are suddenly active. Most
people do not remember what happened during a night-terror episode, although a few
people can remember vividly the images and terror they experienced.
But that sounds like the description of a nightmare—what’s the
difference?Some very real differences exist between night terrors and nightmares. Nightmares
are usually vividly remembered immediately upon waking. A person who has had a
nightmare, unlike a person experiencing a night terror, will actually be able to awaken
and immediately talk about the bad dream. Perhaps the most telling difference is that
nightmares occur during REM sleep rather than deep NREM, slow wave sleep, which is
the domain of night terrors, which means that people don’t move around in a nightmare
as they do in a night-terror experience.
SLEEPWALKING Real sleepwalking, or somnambulism, occurs in approximately
29 percent of children overall between the ages of 2½ to 13 years and is most likely
between the ages of 10 and 13 years, at about 13 percent (Petit, et al., 2015). Sleep-
walking is at least partially due to heredity, with greatest risk for children of parents
who are or were sleepwalkers (Kales et al., 1980; Petit et al., 2015). The prevalence for
children without parents having a history of sleepwalking is 22.5 percent, increasing
to 47.4 percent where one parent did, and reaches 61.5 percent for children where
both parents were sleepwalkers. In other words, children with one or both parents
having a history of sleepwalking are three to seven times more likely to be sleep-
walkers themselves (Petit, et al., 2015). A person who is sleepwalking may do nothing
more than sit up in bed. But other episodes may involve walking around the house,
looking in the refrigerator or even eating, and getting into the car. Most people typ-
ically do not remember the episode the next day. One student said that her brother
walked in his sleep, and one morning his family found him sound asleep behind the
wheel of the family car in the garage. Fortunately, he had not been able to find the
keys in his sleep.
Many people with this disorder grow out of their sleepwalking by the time they
become adolescents. Many parents have found that preventing sleep loss makes sleep-
walking a rare occurrence. This is most likely due to the deeper stage N3 sleep becom-
ing even deeper during sleep loss, which would make fully waking even more difficult
(Pilon et al., 2008; Zadra et al., 2008, 2013). The only real precaution that the families of
people who sleepwalk should take is to clear their floors of obstacles and to put not-easy-
to-reach locks on the doors. And although it is typically not dangerous to wake sleep-
walkers, they may strike out before awakening.
There have been incidents in which people who claimed to be in a state of sleep-
walking (or more likely RBD) have committed acts of violence, even murder (Mahowald
et al., 2005; Martin, 2004; Morris, 2009). In some cases the sleepwalking defense led to the
acquittal of the accused person.
“Wait! Don’t! It can be dangerous to wake
them.”
©The New Yorker Collection J. Dator from
cartoonbank.com. All Rights Reserved.night terrors
relatively rare disorder in which the
person experiences extreme fear and
screams or runs around during deep
sleep without waking fully.sleepwalking (somnambulism)
occurring during deep sleep, an
episode of moving around or walking
around in one’s sleep.