Sleep walking

Alternative names:

somnambulism; walking during sleep

Definition:

A sleep disorder characterized by walking or other activity while seemingly still asleep

Causes, incidence, and risk factors:

The normal sleep cycle involves distinct stages from light drowsiness to deep sleep. Rapid eye movement (REM) sleep is a different type of sleep, in which the eyes move rapidly and vivid dreaming is most common. During a night, there will be several cycles of non-REM and REM sleep. Sleep walking (somnambulism) most often occurs during deep non-REM sleep (stage 3 or stage 4 sleep) early in the night. It can occur during REM sleep near morning.

In children, the cause is usually unknown but may also be related to fatigue, prior sleep loss, or anxiety. In adults, sleep walking is usually associated with a disorder of the mind but may also be seen with reactions to drugs and/or medications and alcohol, and medical conditions such as partial complex seizures. In the elderly, sleep walking may be a symptom of an organic brain syndrome or REM behavior disorders.

The sleep walking activity may include simply sitting up and appearing awake while actually asleep, getting up and walking around, or complex activities such as moving furniture, going to the bathroom, dressing and undressing, and similar activities. Some people even drive a car while actually asleep. The episode can be very brief (a few seconds or minutes) or can last for 30 minutes or longer.

One common misconception is that a sleep walker should not be awakened. It is not dangerous to awaken a sleep walker, although it is common for the person to be confused or disoriented for a short time on awakening. Another misconception is that a person cannot be injured when sleep walking. Actually, injuries caused by such things as tripping and loss of balance are common for sleep walkers.

Sleep walking occurs at any age, but it occurs most often in children aged 6 to 12 years old. It may occur in younger children, in adults, or in the elderly, and it appears to run in families.