Even in the deepest of non-dreaming sleep, our thought processes continue. Our ruminations are often dull, sometimes funny, maybe sad. But occasionally they get out of hand, or to be more precise, get out of bed and sleepwalk. Sleepwalking, or somnambulism, is not the enactment of dreams, but the confused and sometimes anxious thoughts of a deep sleep, which predominates in the first three hours.
Sleepwalking is common in children and seems to run in families. It peaks in adolescence, but declines in the late teens. Episodes are usually triggered by anxiety. The worry can be trivial — the loss of a favorite toy, or just a frustrating day. Only when sleepwalking occurs almost every night is there likely to be more severe underlying distress, requiring specific treatment.
Sleepwalkers are unresponsive to their environment. They are preoccupied with their own thoughts and, the next day, have no memory of their nocturnal activities. Episodes can last for up to 30 minutes but usually average five to 15 minutes. Although sleepwalkers behave like automatons, with vacant eyes and a limited repertoire of behavior, they don’t walk about with their hands in front of them. The child will typically sit up quietly, get out of bed, and move about in a confused and clumsy manner.
Although behavior becomes more coordinated, the sleepwalker tends to remain in the bedroom, often preoccupied with searching for something in drawers, cupboards, or under the bed. It is almost impossible to attract his or her attention. But if left alone the child will normally go back to bed.
The sleepwalker’s eyes are unseeing and it is usually dark. So how does the child avoid walking into things? Successful navigation is achieved mostly by memory. Ask the sleepwalker to repeat the act the next day, blindfolded, and he or she will come to grief.
Difficulties only occur if sleepwalkers think they are somewhere else, and walls, doors, and staircases are not where they should be. For this reason, some doors — but not the bed room’s —may need to be locked.
More adventurous activities such as dressing, going to the fridge for food, or walking outdoors can occur. The last is more common in the elderly and may be associated with daytime confusion. If the behavior is more complex, with the individual seemingly alert and organized, and able to get out the lawnmower, connect it up, and mow the lawn, for instance, or drive off in a car, then this is likely to be a state of dissociation. The individual is actually awake but in another world.
It is difficult and unwise to wake a sleepwalker, particularly a child. It may cause distress or even hysteria. It is best simply to guide them gently back to bed. Sleepwalking is seldom anything to worry about. The most important thing is to reassure parents. The child can sense parental anxiety, and become more anxious, and so be more likely to sleepwalk.
Another phenomenon of a deep sleep, sometimes associated with sleepwalking, is the more frightening night terror (distinct from a nightmare). A sudden, horrifying sensation and a fleeting mental image shock the sleeper into immediate wakefulness. Night terrors are more common in children than in adults.
Usually, the child sits bolt upright and screams, staring wide-eyed at an imaginary being. The child is awake but confused and may require an hour’s consolation before settling down.
But night terrors are rarely a matter for concern. One approach recommended by Dr. Bryan Lask, at the Hospital for Sick Children in Great Ormond Street, is to pre-empt night terrors.
Over a week or so, their occurrence is timed (often around two hours into sleep). For the next few nights, the child is gently awoken about 15 minutes beforehand and kept awake for five minutes before being allowed to return to sleep.
Night terrors in adults are more serious. There is an overwhelming sensation of doom, disaster, or death, often the re-experience of some genuinely terrify ing event, such as a car crash, drowning. Helping the sufferer come to terms with the trauma helps resolve the terrors.
The most minor of the peculiar mental events of sleep is sleeptalking, a muttering of jumbled words or phrases, with no real content. It occurs in light sleep, and has little, like sleepwalking, to do with dreaming. Sleeptalking is common in adults and children.
If two or more children share a bedroom and one begins sleeptalking, then the curtain goes up on the bizarre theatre of the mind. Other sleepers will join in. But none of the participants will be listening to the ramblings of the others. Each will be in a world of its own.