Somnambulism

Somnambulism, commonly called sleepwalking, is a parasomnia characterized by complex behaviors that arise during sleep, most often during non-REM sleep in the first part of the night. During an episode, a person may sit up, walk, perform routine activities, or engage in goal-directed actions while having limited awareness of the surroundings. Episodes typically feature partial arousal with limited memory for the event afterward.

Clinical presentation usually includes wandering or performing familiar activities in an automatised state, often with glassy or unfocused gaze, and poor responsiveness to others. Schedules of episodes can be irregular and vary in frequency. Most individuals return to bed and amnesia for the events is common. Episodes can be harmless but may involve dangerous activities or injuries, particularly in unfamiliar environments or when doors and stairs are involved. Somnambulism is more common in children and often decreases with age; triggers include sleep deprivation, fever, stress, alcohol, and certain medications.

Causes and risk factors include a genetic predisposition, family history, and disturbances in sleep architecture such as fragmented sleep or slow-wave sleep predominance. Underlying conditions that may contribute include obstructive sleep apnea, restless legs syndrome, fever, and mood or anxiety disorders. Medications or substances that depress the central nervous system (for example, sedatives or alcohol) can increase risk.

Diagnosis is clinical, based on history and, when necessary, nighttime observation or video polysomnography to exclude seizures or other disorders. It is important to differentiate somnambulism from confusional arousals, night terrors, and nocturnal seizures.

Management focuses on safety and addressing triggers. Recommended steps include regular sleep schedules, a safe sleep environment, avoiding alcohol and sedatives, and treating coexisting sleep disorders. Most cases in children resolve with age; in adults, evaluation for underlying conditions and targeted treatment may reduce episodes. Pharmacologic therapy is considered only in selected cases.