Sleepwalking (somnambulism) is a type of parasomnia, an abnormal disruptive behavior that occurs during sleep. Most commonly seen in children ages 3-8 years old, sleepwalking is hereditary and typically resolves spontaneously during adolescence.
Sleepwalkers may jump out of bed, walk around or even act out different activities, ranging from eating and rearranging furniture to leaving the house and driving a car. Individuals who sleepwalk usually have no memory of the event.
The cause of sleepwalking is not well understood and rarely involves any serious underlying medical or psychiatric problems. Treatment of sleepwalking is centered on improving sleep hygiene, identifying and managing potential triggers and keeping the sleepwalking individual safe from harm.
Contents of this article:
Fast facts on sleepwalking
Here are some key points about sleepwalking. More detail and supporting information is in the main article.
- Parasomnias, common in the general population, arise as the brain transitions between rapid eye movement sleep (REM), non-rapid eye movement sleep (NREM) and wakefulness
- Sleepwalking is an incomplete disconnection of wakefulness from sleep that occurs during NREM sleep
- Sleepwalking occurs in about 15% of children, peaking between age 8 and 12 years and typically resolving during adolescence
- Children who sleepwalk will often talk in their sleep and have night terrors
- For most children, treatment is unnecessary; the child is usually unaware of the event at the time of occurrence and does not recall the event in the morning
- Childhood-onset sleepwalking continues into adulthood in 20% of cases
- Adult sleepwalking affects 2.5% of the general population
- Around 1 out of every 3 people will sleepwalk at some point in their lives
- Individuals have a 10-fold or higher increased risk of developing sleepwalking if one or both parents were sleepwalkers
- Stress can play a significant role in triggering sleepwalking
- Drug and alcohol consumption has been linked to sleepwalking activity
- Sleepwalkers should be kept safe and gently guided back to bed without being fully woken.
What is sleepwalking?
Sleepwalking is a parasomnia - an unwanted event that occurs during sleep. Other parasomnias include sleep paralysis, confusion arousals and night terrors.
Sleepwalking occurs during the first third of the night in non-rapid eye movement sleep.
Sleepwalking is a disorder of arousal that occurs while the brain is in deep non-rapid eye movement sleep (NREM stages 3 and 4). This period of sleep happens during the first third of the night.
In a sense, sleepwalking is an error in timing and balance, where something triggers the brain out of deep sleep and into a transitional state between sleeping and waking. As dreaming only occurs during REM (rapid eye movement) sleep, sleepwalkers are not acting out their dreams.
A sleepwalking event may last from several minutes to up to an hour.
Individuals with this type of parasomnia who are awakened during sleep are typically disoriented and confused. The sleepwalking individual's mind is asleep but their body is awake, allowing the individual to perform complex behaviors such as eating, walking around and engaging in conversations.
During episodes of sleepwalking, the individual exhibits decreased awareness and responsiveness to their surroundings. The sleepwalker appears clumsy and may trip over furniture, walk into mirrors, walk through a window or fall down stairs, potentially resulting in injury.
The frequency of sleepwalking episodes varies from person to person. Some have only isolated, rare occurrences, while others may have multiple events per night.
The majority of sleepwalking episodes do not result in any harm or accidental injury. Individuals will likely return to bed without incident, or may find themselves waking up in a different location in the house.
Causes of sleepwalking
N-REM is the deepest part of the sleep cycle, when the brain is most resistant to awakening. This period of sleep is when the brain repairs itself and balances necessary chemicals and hormones.
The exact cause of sleepwalking is not well understood, although research suggests children are most vulnerable because a child's brain is still maturing.
Known triggers of sleepwalking include:
- Comorbid sleep disorders, particularly obstructive sleep apnea (OSA)
- Sleep deprivation
- Fever or illness
- Menstrual cycle or pregnancy
- Extreme exercise or fatigue
- Environmental stimuli
- Bladder fullness
- Sleeping in strange surroundings
- Emotional or situational stress
- Childhood separation anxiety
- Medications including phenothiazines, chloral hydrate, zolpidem and lithium.
On the next page, we look at the signs and symptoms of sleepwalking, how sleepwalking is diagnosed and the available treatment options for the condition.