Sleepwalking, also known as somnambulism, tends to occur during arousals from slow-wave sleep. It most often emerges in the first third or first half of the sleep period when slow-wave sleep is more common. Sleepwalking consists of a series of complex behaviors that culminate in walking around with an altered state of consciousness and impaired judgment. Before walking the person often sits up in bed and looks about in a confused manner with eyes wide open. Sometimes the person immediately gets up and walks or even bolts from the bed running. The sleepwalker can be hard to awaken. Once he or she is awake, the person often is confused and has little recall of the event. The sleepwalking may end suddenly, sometimes in unusual or inappropriate places. In other cases the person may return to bed and continue sleeping without ever becoming alert. Sleepwalking can involve strange, inappropriate and even violent behaviors. The person may walk out of the house or even climb out of a window. On rare occasions the sleepwalker may get in a car and drive. A sleepwalking child may walk quietly toward a light or to the parents’ bedroom. Sleepwalking can be dangerous if the child walks toward a window or goes outside.
Sleep talking is a common sleep disorder that is classified as an isolated symptom. It can arise during any stage of sleep and can occur with varying levels of comprehensibility. The sleep talker tends to be unaware of the problem, but loud and frequent talking can disturb the sleep of the bed partner. At times the content of the talking can be objectionable and offensive to others.
Sleepwalking occurs in as many as 17 percent of children and four percent of adults. Sleep talking occurs in half of young children and in about five percent of adults.