Sleep Detective: Dr. Franco Seeks Causes of Parasomnias

While dreaming is normal, people who regularly experience nightmares, night terrors, and sleepwalking have sleep disorders that often indicate more serious health issues, says Rose Franco, MD, Medical College of Wisconsin Assistant Professor of Pulmonary/Critical Care Medicine.

Recurrent nightmares, night terrors, and sleepwalking are called parasomnias, which means "arising from sleep". Dr. Franco, who practices at the Froedtert & The Medical College of Wisconsin Pulmonary Medicine Clinic, serves as Associate Director of the Medical College's Sleep Disorders Program.

In diagnosing parasomnias, Dr. Franco says, "A good history will help. We look at family history, as well as that of the individual. We do a physical exam, looking for any evidence of neurological disease." A thorough sleep history for each patient includes questions about snoring, kicking, restless legs, and other sleep movements. "It's helpful to have someone who has witnessed the events," she says, "because they can give insight into what's really happening."

The history includes an investigation of exactly when the sleep disturbances occur. "The timing of the event gives us a better idea of whether it's an REM phenomena or a Delta phenomena," says Dr. Franco. "We spend the first couple hours of sleep getting our Delta sleep, and the last couple hours are more REM sleep." In Delta sleep, the brain is very quiet and metabolic activity is lowered. Sleepwalking takes place during Delta sleep.

During Rapid Eye Movement, or REM, sleep, explains Dr. Franco, there is a jump in both blood pressure and heart rate, and brain activity is the same as when we're wide awake. REM behavior, like nightmares and REM Behavior Disorder, usually occurs in the early morning hours." People who have REM Behavior Disorder act out their dreams and can hurt themselves or their bed partner.

The Next Step: Sleep Study
The sleep history will be followed by a sleep study at the Froedtert Hospital Center for Sleep. "Sleep disorder triggers cannot be diagnosed any other way than by doing a sleep study," says Dr. Franco.

During the study, physicians monitor the sleeper with electroencephalography (EEG) to examine the pattern of sleep. They check breathing with airflow oxygen monitors and watch for any abnormal movements by using video monitoring and attaching electromyography (EMG) leads on the limbs. This comprehensive study allows the doctors to check to observe there is kicking or other movement, breathing problems such as sleep apnea, or early warning signs of REM Behavioral Disorder, such as thrashing, talking, or moaning.

"Be a Detective"
Treatment for sleep disorders varies according to the specific condition the sleeper experiences. For nightmares, Dr. Franco recommends looking at lifestyle issues first. "Be a detective. Are you eating too close to bedtime, having untreated heartburn, taking a new medication or dietary supplement? Are you under stress?" If it is a stress issue, she advises, "Reflect on it, talk to a spouse or a friend, or even a counselor if it's very distressing."

In cases of sleepwalking, it's important to find out what triggers the walking. The most common cause of recurrent sleepwalking is chaotic sleep patterns. "If you're working rotating shifts, for instance, and you begin sleepwalking, and then you have a week off and don't sleepwalk, that tells you what the problem is," Says Dr. Franco. "Your brain just can't adjust, and you're never fully rested. It might be that simple - you need to recognize that you aren't as flexible as some of your co-workers. Some people don't mind the irregularity, but if you're a sleepwalker, it can bring on problems."

During sleep studies, says Dr. Franco, patients who have apparent sleep disorders often turn out to have either sleep apnea or limb movements that cause the behavior. Once those problems are treated, the erratic sleep behaviors resolve.

It's important to keep a regular sleep schedule and not skip out on sleep time, says Dr. Franco. "When we are sleep-restricted and then have an opportunity to sleep, there is a rebound in lost Delta sleep to recover from staying awake." This actually makes sleepwalking more likely.

If lifestyle causes can't be found for sleep disturbances, it might be necessary to seek professional help. "Treat these sleep disorders only under the advice of a doctor," emphasizes Dr. Franco. "There's no evidence that over-the-counter sleep aids reduce sleepwalking, nightmares, or night terrors. And they're not a very good sleep aid in general, because the brain finds a way around them; the effects are very temporary."

Dreaming and Memory
While researchers don't know the purpose of dreams or what specific dreams mean, there is evidence that shows that dreaming is important for short-term memory.

Studies have shown the importance of spending an adequate amount of time dreaming. "When we look at people who stay up and study, missing out on some of their dream time, and we look at the people who study until their usual bedtime, and test them both the next day, the subjects who went to bed at the usual time have much better retention of what they studied than the person who stays up all night," Dr. Franco says.

These studies were not about sleep restriction, she says, but designed to examine the effects of not getting enough dream time. "Even if people catch up on their sleep later, they don't have the same retention." Dreaming is also important in retaining small motor skills. "People who are learning new activities like intricate hand-eye coordination movements really need an adequate amount of dream time to learn properly."

P.J. Early
HealthLink Contributing Writer

For more information on this topic, see the first part of Dr. Franco's article, Nightmares, Sleepwalking, and Night Terrors Haunt Many.

MCW Health News presents up-to-date information on patient care and medical research by the physicians of the Medical College of Wisconsin.