Sleepwalkers do the strangest things. Many accounts attest to a somnambulist leaving their house clad only in underpants, or rising to cook a meal and returning to bed without so much as tasting it. A stern warning is frequently tacked onto these tales: waking a sleepwalker could kill them. The chances of killing a sleepwalker due to the shock of sudden awakening, however, is about as likely as somebody expiring from a dream about dying.
While it is true that waking a sleepwalker, especially forcefully, may distress them, it is an absolutely false statement that someone would die from shock, says Michael Salemi, general manager at the California Center for Sleep Disorders. "You can startle sleepwalkers, and they can be very disoriented when you wake them up and they can have violent, or confused reactions, but I have not heard of a documented case of someone dying from being woken up." Sleepwalking's hazard is more closely linked to what the sleepwalker may encounter when roaming about in a nocturnal reverie.
Sleepwalking, or "somnambulism," is part of a larger category of sleep-related disorders known as parasomnias, which include night terrors, REM behavior disorder, restless legs syndrome and sleepwalking. For the majority of people, sleepwalking consists of mundane activities such as sitting up in bed, ambling around the house or dressing and undressing. A minority of sleepwalkers, however, perform more complex behaviors, including preparing meals, having intercourse, climbing through windows and driving cars—all while actually asleep. These episodes can be as brief as a few seconds or can continue for 30 minutes or longer.
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"In sleepwalking you are half asleep and half awake," says Carlos Schenck of the Minnesota Regional Sleep Disorders Center at the University of Minnesota Medical School, "The brain produces delta waves and theta waves, which really demonstrates that the person is in a twilight state." Sleepwalking commonly occurs during the third and fourth stage of non-REM sleep—the deepest stage of sleep—characterized by slow-wave, or delta, sleep and little to no dreaming.
"Children developmentally are much more at risk of sleepwalking," Schenck says. "If a child does sleepwalk, waking up the child 45 minutes after going to sleep can interrupt the cycle. In general, soothing and leading them back to bed is the best way to handle the situation." Up to 17 percent of children have at least one sleepwalking episode. They peak between the ages of 11 and 12 and then decline during adolescence. Though rarer in adults (2.5 percent of the population), episodes could be caused by stress, lack of sleep or irregular sleep.
Still, more disconcerting than the occasional nocturnal stroll is the potential peril caused by sleepwalking. "Sleepwalkers can harm themselves and others, and even kill themselves and others, and they can engage in highly complex behaviors such as driving long distances, and hurt others with sleep aggression and violence," Schenck says. "So there are a number of ways that sleepwalkers can be dangerous to themselves and others during their episodes." For example, he notes, Sandy, a slender female in her teens, tore her bedroom door off the hinges one night. She was unable to replicate that strength when awake. And a young man frantically drove to his parent's house 10 miles away. He woke to the sound of his own fists beating on their front door. In dramatic cases like these, doctors will prescribe benzodiazepines to ease a patient's nighttime activity.
Typically, though, sleepwalking is a moderate, infrequent occurrence most easily managed by leading a sleepwalker back to bed by the elbow. One final caveat: if spectators are still chuckling about the episode in the morning, they may be alone. Somnambulist's memories snooze through the whole event.