Even more importantly, says study leader Christian Guilleminault, MD, professor of sleep medicine at Stanford, "If you treat the breathing disorder" -- with surgery to remove the tonsils, for example -- "you can eliminate sleepwalking or sleep terrors. It's a cure."
In the study, the researchers found that more than half of the 84 children with recurring sleepwalking and/or sleep terrors also suffered problems that affected sleep-time breathing -- such as habitual snoring, a history of upper respiratory infection, earaches, or mouth breathing. In contrast, virtually none of 36 children without sleep disturbances experienced sleep-related breathing problems.
Guilleminault says that all of the children with sleep-disordered breathing who underwent a tonsillectomy or adenoidectomy, procedures to remove enlarged tonsils and adenoids and help improve airflow, were cured of sleepwalking and night terrors. Meanwhile, the six children whose sleep-time breathing problems were left untreated continued to suffer from their parasomnias.
Guilleminault isn't suggesting that surgery be done to prevent these sleep disturbances in all children. "Most children have an occasional sleepwalking episode or night terror," he says. The children in the study represent a "very small group" that suffers persistent problems -- once or several times a week, on a regular basis.
Though Guilleminault has recently completed a similar study in adults, he is reluctant to share the results, pending acceptance and publication in a scientific journal. But, he hints, in the future, "we will be able to treat the underlying cause of sleepwalking."
Mark W. Mahowald, MD, director of the Minnesota Regional Sleep Disorders Center at Hennepin County Medical Center and professor of neurology at the University of Minnesota in Minneapolis, agrees that parents shouldn't worry if their kids occasionally sleepwalk or suffer night terrors. Even in adults, about 5% to 10% of whom sleepwalk and 1% of whom have sleep terrors, the condition is generally harmless, he says.
Acting Out Dreams
Mahowald says that sleepwalking and night terrors result from an abnormal and abrupt arousal out of a deep stage of sleep known as slow wave sleep. The normal transition from deep sleep to a lighter sleep stage having been bypassed, "the brain is not fully conscious; it's almost as if it's half awake and half asleep," he says. "You can perform a complex behavior such as driving a car, but you're not aware enough to know what you are doing."