Sleepwalking: Purposeful moving, usually but not always including walking, while in a deep stage of sleep. Sleepwalking occurs most frequently in children, particularly boys. Sedatives tend to exacerbate rather than cure sleepwalking. The best measures are preventative: ensure that the sleepwalker is in a safe room for walking, and cannot accidentally fall through an open window or down stairs. Some types of sleepwalking are related to seizure disorders , bipolar disorder, or other neurological conditions, but most cases are transitory and due to unknown causes. Also called somnambulism.