Sleepwalking is in fact a brain disorder as well as a sleep disorder, but it is a brain disorder of the nervous system which usually corrects itself as the sufferer gets older. By way of explanation, normally, as people wake up, the whole body and whole brain wake up together, whereas with sleepwalkers, the mobility part of the brain and the body wakes up, but the cognitive/awareness part of the brain stays asleep, at least for a while.
The most prevalent time for an bout of sleepwalking to take place is within the first two hours of sleep. The periods of somnambulance typically last from fifteen minutes to two hours and the sleepwalker might get dressed and venture outside.
Despite its name, sleepwalking (also called somnambulism) actually involves more than just walking. Sleepwalking behaviors can range from harmless (sitting up), to potentially dangerous (wandering outside), to just inappropriate (kids may even open a closet door and urinate inside). No matter what kids do during sleepwalking episodes, though, it's unlikely that they'll remember ever having done it!
The normal sleep cycle has distinct stages, from light drowsiness to deep sleep. During rapid eye movement (REM) sleep, the eyes move quickly and vivid dreaming is most common.
When people sleepwalk, they may sit up and look as though they are awake when they are actually asleep. They may get up and walk around, or do complex activities such as moving furniture, going to the bathroom, and dressing or undressing. Some people even drive a car while they are asleep.
Some people mistakenly believe that a sleepwalker should not be awakened. It is not dangerous to awaken a sleepwalker, although it is common for the person to be confused or disoriented for a short time when they wake up.
Safety measures may be needed to prevent injury. This may include moving objects such as electrical cords or furniture to reduce the chances of tripping and falling. You may need to block off stairways with a gate.
Sleepwalking is characterized by complex behavior (walking) accomplished while asleep. Occasionally nonsensical talking may occur while sleepwalking. The person's eyes are commonly open but have a characteristic glassy "look right through you" character. This activity most commonly occurs during middle childhood and young adolescence. Approximately 15% of children between 4-12 years of age will experience sleepwalking. Generally sleepwalking behaviors are resolved by late adolescence; however, approximately 10% of all sleepwalkers begin their behavior as teens. A genetic tendency has been noted.
Normal children can sleep walk and they generally outgrow the problem by age 15. The old literature suggested that when the few children who persisted in having sleep walking episodes as adults, that there may be strong psychological problems that may make the problem worse. My anecdote, my impression is that this is often overstated. Nevertheless, in an adult with sleepwalking, I routinely have my group of neuropsychologists who specialize in insomnia (sleep disorders) perform a Minnesota Multiphasic Personality Inventory (MMPI) to look for underlying psychological personality and social factors which might be contributing to the disorder.