SLEEPWALKING (307.46) Sleepwalking or somnambulism is combined sleep and wakefulness during slow-wave, or nonREM sleep. The patient will often do things they would during full consciousness but will be in a low-consciousness state that they don’t remember. Complex behaviors like driving, cooking, and homicide have happened when the patient was in a state of sleepwalking. The memory of the events during sleepwalking is poor to absent and, while the eyes are open, the expression is glazed over. It can last for up to 30 minutes. NREM sleep happens in the first third of sleep and this is when the activity happens. It happens usually once a night or less often. Features of the disorder include the following: •
Partial arousal during NREM sleep, usually in the first third of the night
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Dream content that may or may not be remembered
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Behavior consistent with the dream content that can be simple or complex
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Impairment in environmental perception
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Impaired judgment, problem-solving, and planning
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Blank expression with dilated pupils
The individual is often confused after awakening but soon recovers normal functioning. While in a sleepwalking state, the individual may talk but does not make any sense. Children have less memory of their episodes than adults. The lifetime prevalence is 5-10 percent, being more common in children than adults, who have a prevalence of about 1.5 percent. Sleepwalking has an unknown cause but it may be genetic. Sixty percent of children who have two parents that sleepwalk will have the disorder themselves. It is believed to be autosomal dominant with incomplete penetrance. Sleepwalking can be due to medications, including benzodiazepines, other GABA agonists, antidepressants, antipsychotics, beta blockers, and sedative/hypnotics (like zolpidem) have an increased risk of causing sleepwalking. Parkinson’s disease will trigger sleepwalking in people 186
