Through an analysis of literature of data from over 15 years of sleep studies, Antonio Zadra and his colleagues have uncovered new findings on sleepwalking and made clear diagnostic criteria for doctors and researchers.
Their results were published in the Lancet Neurology and touch upon a possibility that people who are sleepwalking are half awake and half asleep, as well as several myths related to sleepwalking (Somnambulism).
Sleepwalking - Less Common As You AgeSleepwalking is genetic. Close to 80 percent of sleepwalkers have a family history of the condition. An identical twin is five times more likely to sleepwalk if the other twin does too.
The current study reveals that stress and tiredness can cause sleepwalking as well. In predisposed people, any situation that interrupts sleep could result in sleepwalking.
Generally, sleepwalking is harmless. Even though the deep slow-wave sleep of sleepwalkers is broken, most events are short and not dangerous, and if they are the danger is small.
Rarely, dangerous longer episodes may occur with sleepwalkers who injure themselves or put themselves or others at risk. For example, driving a car while sleeping.
Sleepwalking is prevalent in children between the ages of six and twelve years. The authors point out that transitioning from sleep to wakefulness necessitates some maturation of the brain, which is sometimes difficult in kids of this age. After puberty the problem normally goes away.
Sleepwalking may continue into adulthood in 25 percent of adolescent cases. If this happens it will always decrease with age, because as a person gets older they get fewer hours of deep slow-wave sleep - the stage in which sleepwalking happens.
Antonio Zadra explained:
"Both children and adults are in a state of so-called dissociated arousal during wandering episodes: parts of the brain are asleep while others are awake. There are elements of wakefulness since sleepwalkers can perform actions such as washing, opening and closing doors, or going down stairs. Their eyes are open and they can recognize people. But there are also elements specific to sleep: sleepwalkers' judgment and their ability for self-thought are altered, and their behavioural reactions are nonsensical."
Sleepwalking is Not AutomaticWhen conceptualizing sleepwalking the authors point out that people can be partially awake and partially asleep. This means that the brain does not fall asleep all at at once - it may happen part by part - certain areas of the brain falling asleep before others.
This could explain why some people remember sleepwalking and others don't. Amnesia is more common in children and teens because of neurophysiological reasons. In adults, it is more common to remember some or all of a sleepwalking episode.
Another popular myth is that sleepwalking is automatic. However, a large number of sleepwalkers remember what they did and why. They are able to admit their actions were illogical, but see that for each episode there is a hidden rationale. A motivation normally accompanies and accounts for the action.
Nearly 45 percent of sleepwalkers are sleepy during the day. Adolescent sleepwalkers are able to mask their sleepiness more easily. Although, when compared with control subjects, they performed worse in vigilance tests. Also, if they were given the chance to take a nap, they went to sleep faster than individuals who had not been sleepwalking.
"Over the last few years, we have shown that the deep slow-wave sleep of sleepwalkers is atypical. Fragmented by numerous micro-arousals of 3 to 10 seconds, their sleep is less restorative. Sleepwalking is therefore not only a problem of transitioning between deep sleep and wakefulness. There is something more fundamental in their sleep every night, whether or not they have sleepwalking episodes."
A separate study carried out recently suggests that sleepwalking is a serious condition that can trigger violent behaviors and affect overall health.
The authors found that sleepwalkers experienced the following more often: