Nightmares, Sleepwalking, and Night Terrors Haunt Many

No one knows the true purpose of dreaming. Most researchers think that when we dream, we process what we've learned during the day, store some of it, and throw the rest out. Another theory is that dreaming helps us deal with emotions that we might have been putting aside during the day. But nightmares, night terrors, and sleepwalking are not a normal part of our dreaming sleep.

Rose Franco, MD, Fellowship Director of the Medical College of Wisconsin's Sleep Medicine Program, says that children and adults have nightmares for mainly the same reasons. "Something disturbing becomes distorted in your dream and it becomes scary," she explains.

There are some cultural differences in dreaming, whereby people in a particular culture have nightmares about similar subjects, but there are several subjects that are common across all cultures. "Everybody has the nightmare about falling and the dream about running too slow," notes Dr. Franco.

When nightmares, night terrors, and sleepwalking are recurrent, they are called parasomnias - which means "arising from sleep." Dr. Franco says that while dreaming is normal, recurrent nightmares, night terrors, and sleepwalking are considered disorders and often indicate more serious sleep health issues.

Nightmares
"Sometimes nightmares occur because of disturbing things that happen during the day, as in the case of someone who's going through a depression or an anxious period in their lives, or because of social or work-related situations," says Dr. Franco. Very vivid recurring nightmares can also be an indication of post-traumatic stress disorder.

"While stress and anxiety are recognized triggers, even food that brings on heartburn or indigestion, a new medication or supplement, medical diseases, fever, or pain can lead to nightmares," says Dr. Franco.

If dreams or nightmares have very distressing content and occur frequently, Dr. Franco recommends seeking a physician's attention. "When nightmares happen on a recurrent basis, to the point where they distress the individual, then we consider it a sleep disorder that should be evaluated."

Nightmares that awaken the sleeper should also be examined because they could signal a sleep disorder. "When we dream, normally we don't remember it; we go into our dream and we come out of it and go on sleeping," says Dr. Franco. "But when there's something wrong with your sleep, where you're waking up out of the dreams or nightmares, you'll remember what you were dreaming about."

In a situation where there is not a clearly related triggering event or medication, Dr. Franco checks for a causative sleep disorder - such as sleep apnea or restless legs syndrome - to see what's causing the patient to wake up in the midst of a dream.

Night Terrors
Night terrors are sleep disorders in which the individual awakens abruptly in a terrified state, sometimes screaming or yelling. While nightmares occur in REM sleep, says Dr. Franco, "night terrors are a Delta phenomenon, like sleepwalking - and adults do have them." Subjects have no recall of the event and it is very difficult to console them during the episode. Their focus is clearly directed inward. Attempts to soothe them may be met with resistance.

Night terrors can occur as part of normal development in early childhood, but when they are recurrent or occur outside of the normal age range, they are considered sleep disorders.

About half of the patients who have recurrent night terrors have family members who also suffer with night terrors or sleepwalking. If an individual has recurring night terrors or sleepwalking, they should see a physician.

"Often there's not only a genetic predisposition, but a factor that triggers it," says Dr. Franco. "The trigger could be something such as sleep apnea. When breathing is disturbed, that triggers an arousal and the sleeper has night terrors or starts sleepwalking." When the sleep apnea is treated, it will often end the night terrors and sleepwalking as well.

REM Behavior Disorder
In some cases, self-injury during sleep is associated with dreams or nightmares. When this occurs, it could be a sign of Rapid Eye Movement Behavior Disorder. During Rapid Eye Movement, or REM, sleep, "Our bodies are paralyzed to protect us from acting out the dream," explains Dr. Franco. "The only parts of our body that can move are the diaphragm and the eye muscles."

But in people who have REM Behavior Disorder, "They don't have the paralysis, so whatever they dream about, they act out." REM Behavior Disorder tends to occur in middle-aged men, and the dreams are very physical or emotion-filled.

"There's a lot of vigorous activity, and they can hurt themselves or their bed partner because of it," Dr. Franco says. For instance, she explains, "If they're dreaming that they're running, they can literally get up out of bed and start running across the room and right out the window."

Less than 1% of the population has REM Behavior Disorder, but it requires medical attention because it can be extremely dangerous. In addition, it is sometimes associated with or precedes the diagnosis of other neurological disorders such as Parkinson's disease or olivopontine degenerative disorder, which leads to dementia.

"REM Behavior Disorder can also be associated with certain medications," says Dr. Franco. "You can start on a new medication for depression and suddenly begin to have this disorder." The vigorous dreaming activity is often preceded by symptoms that should not be ignored, such as moaning, talking, and small jerks, before the individual actually gets up out of bed. "People say, 'I wish I would have known, so I could have helped avoid this injury,'" says Dr. Franco.

Sleepwalking
Sleepwalkers should also seek medical treatment, says Dr. Franco. Depending upon the age group, between 0.5% and 5% of people in the US sleepwalk. While it is considered normal during early childhood to occasionally sleepwalk, when it occurs repeatedly and outside of the normal age range, sleepwalking is considered a sleep disorder. Sleepwalking occurs in Delta sleep, or non-REM sleep, in which the brain is very quiet and metabolic activity is lowered.

Unlike REM Behavior Disorder, in which sleepers will wake up and tell you exactly what was going on in their dream, sleepwalkers are hard to wake up, notes Dr. Franco. "They're focused inward instead of outward. They can hurt themselves simply because they don't recognize their environment - they can sleepwalk out of the house and into the road. They can sleepwalk down the steps and fall and hurt themselves. One-third of adult sleepwalkers come to the doctor's attention because of injury."

Sleepwalkers can even sleepwalk into the kitchen and cook themselves a meal. "We refer to that as Sleep-Related Eating Disorder. It occurs in about 5% of patients who go to a sleep doctor," says Dr. Franco. This disorder is characterized by bizarre food combinations - such as frozen fish and peanut butter - which are often high-calorie and high-fat; they are usually not foods the subject would eat during wakefulness. The sleeper has partial to total amnesia of the sleep-eating episodes.

It might be difficult to distinguish sleepwalking from REM Behavior Disorder, but that's where the sleep doctor comes in: in order to provide the appropriate treatment, it's important to know if the patient is in REM sleep or Delta sleep.

In each of the sleep disorders discussed, recurrent events trigger an evaluation that includes a sleep study. In a sleep study the sleeper's brain activity, breathing, heart rhythm, and oxygen levels are monitored and recorded along with videotaping of the sleep and sleeper's behaviors.

The sleep study allows doctors to uncover the sources (such as sleep apnea or limb movements) of the unusual behaviors as well as fully define the type of sleep from which the parasomnia develops. The sleep study results are then incorporated into the treatment plan.

The parasomnias are a challenging group of sleep disorders, says Dr. Franco, but there are treatments available. Once the correct diagnosis is made, a treatment plan can be implemented so everyone can get a good night's rest.

P.J. Early
HealthLink Contributing Writer

Rose A. Franco, MD, Medical College of Wisconsin Assistant Professor of Pulmonary/Critical Care Medicine, practices at the Froedtert & The Medical College of Wisconsin Pulmonary Medicine Clinic.

For more information on this topic, see the second part of Dr. Franco's article, Sleep Detective: Dr. Franco Seeks Causes of Parasomnias.