What causes sleepwalking

What is Sleepwalking?

Sleepwalking, medically termed somnambulism, is a sleep disorder that causes people to walk or perform other behaviors while they are not fully awake. These actions can range from simple tasks like sitting up in bed and looking around to more complex activities such as walking, talking, dressing, preparing and eating food, or even leaving the house. Despite these actions, the individual remains asleep and has no memory of the event upon waking. It falls under the category of parasomnias, which are disruptive sleep-related disorders that occur during the transition from one sleep stage to another or during arousal from sleep.

Understanding Sleep Stages

Sleep is divided into two main types: Rapid Eye Movement (REM) sleep and Non-Rapid Eye Movement (NREM) sleep. NREM sleep is further divided into three stages: N1 (lightest sleep), N2 (deeper sleep), and N3 (deepest sleep, also known as slow-wave sleep). Sleepwalking primarily occurs during stage N3 sleep, the restorative phase where the body and brain repair themselves. This deep sleep stage typically happens in the first half of the night, usually 1-2 hours after falling asleep.

Causes of Sleepwalking

The exact cause of sleepwalking is not fully understood, but it is believed to be related to an incomplete awakening from deep NREM sleep. During this stage, the brain is mostly asleep, but parts of the motor cortex (responsible for movement) may become active, allowing for physical actions. Several factors can increase the likelihood of sleepwalking:

1. Genetics

There is a strong genetic component to sleepwalking. If one parent has a history of sleepwalking, their child has about a 50% chance of developing it. If both parents have a history, the risk increases to over 50%.

2. Age

Sleepwalking is most common in children, particularly between the ages of 3 and 12. This is likely because children spend more time in deep sleep (stage N3) compared to adults. Most children outgrow sleepwalking by adolescence, although it can persist into adulthood for some.

3. Sleep Deprivation

Insufficient sleep is a major trigger for sleepwalking. When the body is sleep-deprived, it tends to spend more time in deep sleep stages upon finally resting. This increased time in deep sleep can make episodes of sleepwalking more likely to occur.

4. Fever and Illness

High fevers, particularly in children, can disrupt normal sleep patterns and trigger sleepwalking episodes. Illnesses that cause discomfort or fever can lead to a more fragmented sleep, increasing the chance of arousal disturbances that manifest as sleepwalking.

5. Stress and Anxiety

Emotional stress, anxiety, and significant life changes can also contribute to sleepwalking. The brain's response to stress can affect sleep architecture and increase the likelihood of parasomnias.

6. Medications

Certain medications, especially those affecting the central nervous system such as sedatives, hypnotics, or certain psychiatric medications, can sometimes trigger sleepwalking as a side effect.

7. Other Sleep Disorders

The presence of other sleep disorders can also be a contributing factor. Conditions like obstructive sleep apnea (OSA), restless legs syndrome (RLS), or periodic limb movement disorder (PLMD) can lead to disrupted sleep and increased arousals, potentially triggering sleepwalking.

8. Environmental Factors

Disruptions in the sleep environment, such as loud noises, sudden light changes, or being touched while in deep sleep, can sometimes trigger an episode.

When to Seek Medical Advice

While sleepwalking is usually harmless and often resolves on its own, it's advisable to consult a doctor if:

• Episodes are frequent or dangerous (e.g., involving self-harm or property destruction).
• Sleepwalking persists into adulthood.
• The person has injuries from sleepwalking episodes.
• Sleepwalking is accompanied by other concerning symptoms like confusion, hallucinations, or daytime sleepiness.

A healthcare professional can help identify potential triggers and rule out underlying medical conditions. Treatment, if necessary, often focuses on managing triggers, ensuring sleep safety, and sometimes medication or cognitive behavioral therapy for insomnia (CBT-I).