The review found that violent behaviors associated with provocations and/or close proximity were found to be present in 100 percent of confusional arousal patients and 81 percent of sleep terror patients. Violent behaviors were associated with provocation or close proximity in 40-90 percent of sleepwalking cases. The provocation was often quite minor, and the response exaggerated greatly.

According to the review, violent behavior occurs in slightly different ways in sleepwalking, confusional arousals and sleep terrors. In the case of sleepwalking, the violence occurs only after the sleepwalking episode has been triggered and is underway. During the sleepwalking episode, while moving about the environment, the sleepwalking individual encounters someone else – most likely a family member. This person may approach or make physical contact with the sleepwalker, triggering a violent reaction.

With confusional arousals, violence may be precipitated in one of two ways. An individual may have a confusional arousal associated with complex behaviors but never leave the bed. The bed partner or parent may try to calm or restrain the individual by grabbing or holding them. More often, a confusional arousal occurs when someone attempts to awaken a sleeping individual in bed.

Sleep terrors differ from sleepwalking and confusional arousals in that the individual appears to react to some type of frightening image. The individual may act in an improper or agitated manner without regard to reality. If another individual is encountered or is in close proximity, violent behavior may occur.

Dr. Pressman noted that, despite the findings made in the review, the overwhelming majority of sleepwalking, confusional arousal and sleep terror episodes do not involve aggression or violence.

“There is no evidence that individuals with these disorders are inherently violent or predetermined to seek out victims,” said Pressman. “Episodes of sleepwalking related violence against other individuals almost never occur more than once. At least among the cases reported here, the majority describe close proximity or direct provocation before violent behaviors. It is possible that the absence of physical contact or proximity to other individuals is the only factor that distinguishes violent sleepwalkers from nonviolent sleepwalkers. This suggests under the right circumstances that any sleepwalker might respond to a perceived threat or close proximity with violence. Families are frequently advised to not touch or grab sleepwalkers during episodes as they may resist physically.”

Sleepwalking occurs when you get up from bed and walk around even though you are still asleep. It can also involve a series of other complex actions. Sleepwalking is more common in children and affects both boys and girls. It can begin as soon as a child is able to walk. The rate of it in children is as high as 17 percent. It peaks by the time they are eight to 12 years old. Most children with it also had confusional arousals at a younger age.

Rarely, sleepwalking may begin at any time in the adult life, even when someone is in their seventies. Up to four percent of adults sleepwalk. In adults, men are much more likely to display aggressive behavior when they sleepwalk. Your chance of sleepwalking can increase if one or both parents had sleepwalking episodes as a child or adult.

Confusional arousals take place when you are waking up, or just after waking up. You act in a way that is very strange and confused. It appears that you don’t know where you are or what you are doing. Your behavior may consist of slow speech, confused thinking, poor memory or blunt responses to questions or requests. Confusional arousals occur at the same rate among both men and women. Rates are high among children and adults under the age of 35. It may occur in as many as 17 percent of children. About three to four percent of adults have confusional arousals. You are more likely to have this disorder if a relative also has it.

Sleep terrors is also called “night terrors”. In a typical episode, you will sit up in bed and pierce the night with a "blood-curdling" scream or shout. This scream can include kicking and thrashing. You may say or shout things that others are unable to understand. You will also have a look of intense fear with eyes wide open and heart racing. You may also sweat, breathe heavily and be very tense. At times, you may even bolt out of bed and run around the house. This response is more common in adults. It may also lead to violent actions. Sleep terrors are more common in children, and affects males and females equally. It may affect as many as 6.5 percent of all children. It tends to begin when a child is four to 12 years old. Children with sleep terrors will often talk in their sleep and sleepwalk. In rare cases, it can begin in adulthood. Overall, only about 2.2 percent of adults have it. Very few people over the age of 65 have sleep terrors. There is a strong genetic and family link. It can occur in several members of the same family.

Those who suspect they might be suffering from a sleep disorder are urged to consult with their primary care doctor or a sleep specialist.

SLEEP is the official journal of the Associated Professional Sleep Societies, LLC, a joint venture of the American Academy of Sleep Medicine (AASM) and the Sleep Research Society.

SleepEducation.com, a Web site maintained by the AASM, provides information about the various sleep disorders that exist, the forms of treatment available, recent news on the topic of sleep, sleep studies that have been conducted and a listing of sleep facilities.

For a copy of this article, entitled, “Disorders of Arousal From Sleep and Violent Behavior: The Role of Physical Contact and Proximity”, or to arrange an interview with an AASM spokesperson regarding this study, please contact Jim Arcuri, public relations coordinator, at (708)492-0930, ext. 9317, or jarcuri@aasmnet.org.