A woman wakes up to find she has eaten all the butter out of the refrigerator. Across the country, the family of a middle-aged man is startled to find a pile of black coal on their white living room rug in the morning. A sleeping child jerks up in bed and lets out a piercing scream, a look of sheer terror on his face. A wife says "there is no stopping" her husband when he initiates sex in his sleep at least once a month -- during which, she says, he is both more aggressive and more amorous than when he is awake.
Their stories may differ radically, but all these people have one thing in common: They suffer from often misunderstood and under-recognized sleep-related disorders known collectively as parasomnias, their doctors tell WebMD. From sleep eating and sleepwalking to night terrors and sleep sex, "parasomnias are things that go bump in the night -- unusual, out-of-the-ordinary events that occur during sleep or arousal from sleep," says Colin M. Shapiro, MD, PhD, a professor of psychiatry at the University of Toronto who recently published an article describing 11 patients with sexsomnia in the Canadian Journal of Psychiatry.
Knowledge of parasomnias has exploded in recent years, with new disorders recognized and known disorders reported to occur more frequently than previously thought, says Carlos H. Schenck, MD, senior staff psychiatrist at the Minnesota Regional Sleep Disorders Center at Hennepin County Medical Center and associate professor of psychiatry at the University of Minnesota in Minneapolis.
Left untreated, or misdiagnosed as psychiatric problems, parasomnias can have dire consequences: The sleepwalker may hurl himself out the window; the sexsomniac may actually rape his or her spouse. The good news, sleep specialists tell WebMD, is that a better understanding of parasomnias' roots has led to new treatments -- and in some cases, even cures.
The Sleepwalking Cure
For years, doctors had no idea what causes even the most common and well-known of the parasomnias, sleepwalking and night terrors. But recently, researchers at the Stanford University Sleep Disorders Clinic found that at least in some children, mild sleep-time breathing problems caused by allergies or swollen tonsils are to blame.
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."
Mahowald and Schenck have been studying a parasomnia that strikes during a different stage of sleep -- REM (rapid eye movement) sleep, when most dreaming occurs. What they found, Mahowald says, is a fascinating link to neurological illnesses such as Parkinson's disease.
Normally during REM sleep, the muscles are completely paralyzed, "so if you dream you are killing your mother-in-law, you're not actually going to do it," Guilleminault says. But people with the parasomnia dubbed REM sleep behavior disorder have an abnormality that causes the normal paralysis of REM sleep to fail.
The result: Victims act out their dreams -- thrashing, swearing, punching, kicking, running out of bed, even pummeling their bed partners, Mahowald says.
Of the dozens of otherwise healthy people with REM sleep behavior disorder that Mahowald and Schenk have followed since the 1980s, two-thirds have gone on to develop Parkinson's disease or other related neurodegenerative disorders, Mahowald says. Most are men, over 50 years old, with the average time between the development of the sleep problem and the neurological disorder being 13 years.
Taking the research a step further, other scientists have implicated the same faulty brain chemistry in both disorders. In a recent study of 13 people with the condition and 27 healthy individuals, Mayo Clinic researchers found REM sleep behavior disorder is associated with low stores of dopamine -- the same neurotransmitter known to be deficient in Parkinson disease. The greater the loss of dopamine in the brain, the more severe the symptoms, the researchers reported in the journal Neurology.
Other researchers have done brain imaging scans of people with REM sleep behavior disorder. They found abnormalities in the region of the midbrain where Parkinson's originates -- even in patients who did not yet have signs of neurological problems.
Though the work is still early, it suggests that REM sleep behavior disorder can be the first symptom of Parkinson's disease, Mahowald says. "If we can develop a drug that protects against Parkinson's, this will be very important."
Sleep Sex, Sleep Eating
Less well known and more recently recognized are sleep sex and sleep eating disorder. "They have some characteristics of each of the other [parasomnias], but don't quite fit the mold," Shapiro says.
Shapiro and Guilleminault have each published research describing 11 patients with symptoms of sexsomnia that ranged from loud, disruptive moaning to sexual assault. Regardless of how unusual or violent the behavior, Guilleminault says his patients had no memory of the events the next morning.
He notes that often, people who engage in sleep sex have a history of sleepwalking, REM behavior disorders, apnea, bed-wetting, or other sleep-related problems, to name a few. Some even have seizure disorders.
"That's a big find," Guilleminault says. "It suggests we can treat the seizures and eliminate the problem."
Shapiro urges people to have an open dialogue about any abnormal sexual behavior during sleep with their doctors. "Just recognizing that sexsomnia is a sleep disorder is a step in the right direction," he says. "Now that we know it is possible and doctors start to ask the right questions, we will start to learn more about it."
The medical community has also been slow to recognize sleep eating as a medical condition, says Lea Montgomery, RN, MS, an instructor at Texas Christian University Harris School of Nursing in Fort Worth, who has written review articles on the disorder. "I had one woman frantic to get help; she had been sleep eating for 13 years. She tried to get help but wasn't taken seriously."
Sleep eaters get up to nosh as many as 12 times a night, Montgomery tells WebMD. "It's messy, primitive eating -- butter right out of the butter dish, salt out of the saltshaker -- not what they would normally eat during the day," she says.
A Good Night's Sleep
Doctors still don't know the cause of sleep sex or sleep eating. But, experts agree, the best way to combat any sleep woe is to practice good sleep habits:
- Eat right
- Exercise regularly
- Avoid stress
- Avoid or at least limit alcohol and caffeine
- Don't eat or drink too close to bedtime
- Go the bed at the same time each night
If symptoms of parasomnia persist, you may want to seek help at an accredited sleep center, the specialists say. The American Academy of Sleep Medicine maintains a list of accredited sleep centers around the country.