Sleepwalking episodes can include a wide variety of behaviors. Episodes may begin with confusion: the individual may simply sit up in bed, look about, or pick at the blanket or sheet. This behavior then becomes progressively complex. The individual may actually leave the bed and walk into closets, out of the room, and even out of buildings. Individuals may use the bathroom, eat, talk, or engage in more complex behaviors. Running and fran- tic attempts to escape some apparent threat can also occur. Most behaviors during sleep- walking episodes are routine and of low complexity. However, cases of unlocking doors and even operating machinery (driving an automobile) have been reported. Sleepwalking can also include inappropriate behavior (e.g., commonly, urinating in a closet or waste- basket). Most episodes last for several minutes to a half hour but may be more protracted.
Inasmuch as sleep is a state of relative analgesia, painful injuries sustained during sleep- walking may not be appreciated until awakening after the fact.
There are two ”specialized” forms of Sleepwalking: sleep-related eating behavior and sleep-related sexual behavior (sexsomnia or sleep sex). Individuals with sleep-reluted eating experience unwanted recurrent episodes of eating with varying degrees of amnesia, rang- ing from no awareness to full awareness without the ability to not eat. During these epi- sodes, inappropriate foods may be ingested. Individuals with sleep-related eating disorder may find evidence of their eating only the next morning. In sexsomnia, varying degrees of sexual activity (e.g., masturbation, fondling, groping, sexual intercourse) occur as complex behaviors arisin from sleep without conscious awareness. This condition is more common consequences.
During a typical episode of sleep terrors, there is often a sense of overwhelming dread, with a compulsion to escape. Although fragmentary vivid dream images may occur, a story- like dream sequence (as in nightmares) is not reported. Most commonly, the individual does not awaken fully, but returns to sleep and has amnesia for the episode on awakening the next morning. Usually only one episode will occur on any one night. Occasionally several episodes may occur at intervals throughout the night. These events rarely arise during daytime naps.
Isolated or infrequent NREM sleep arousal disorders are very common in the general pop- ulation. From 10% to 30% of children have had at least one episode of sleepwalking, and 2%—3% sleepwalk often. The prevalence of sleepwalking disorder, marked by repeated ep- isodes and impairment or distress, is much lower, probably in the range of 1%—5%. The prevalence of sleepwalking episodes (not sleepwalking disorder) is 10%—7.0% among adults, with weekly to monthly episodes occurring in 0.5%—0.7%. The lifetime prevalence of sleepwalking in adults is 29.2%, with a past-year prevalence of sleepwalking of 3.6%.
The prevalence of sleep terrors in the general population is unknown. The prevalence of sleep terror episodes (as opposed to sleep terror disorder, in which there is recurrence and distress or impairment) is approximately 36.9% at 18 months of age, 19.7% at 30 months of age, and 2.2% in adults.
quency with increasing age. The onset of sleepwalking in adults with no prior history of sleepwalking as children should prompt a search for specific etiologies, such as obstruc- tive sleep apnea, nocturnal seizures, or effect of medication.
Environmental. Sedative use, sleep deprivation, sleep-wake schedule disruptions, fa- tigue, and physical or emotional stress increase the likelihood of episodes. Fever and sleep deprivation can produce an increased frequency of NREM sleep arousal disorders.
Genetic and physiological. A family history for sleepwalking or sleep terrors may oc- cur in up to 80% of individuals who sleepwalk. The risk for sleepwalking is further in- creased (to as much as 60% of offspring) when both parents have a history of the disorder.