Written by Anthony Degani and Kevin Morton with contributions from the Stanford Sleep Book, Winter 2010

Why Do They Occur? | In Children | In Adults | Awake or Not? | Treatment | Your Stories

What’s In A Name?

Pavor nocturnus, sleep terror, night terror, incubus attack? Why so many names??

Well, “pavor nocturnus” is literally Latin for “sleep terror”–so those phrases are just saying the exact same thing in two separate languages. In addition, “pavor nocturnus” is used most commonly to refer to sleep terrors in children.

On the other hand, the phrase “incubus attacks” is commonly used to refer to sleep terrors in adults. The word “incubus” (from the Latin in: upon, & cubare: to press) reflects the medieval belief that sleep terrors are caused by a devil pressing on the chest of the sleeper, although this cause is scientifically yet to be proven 😉

Since pavor nocturnus episodes also occur during naps, the term “sleep terror” is preferred over “night terror” to be technically correct.

Sleep terrors have also been referred to as nightmares, but don’t confuse this with the REM nightmare that you usually think of with this word!

In a characteristic pavor nocturnus (or sleep terror) episode, the sleeper sits up suddenly in bed and screams out in fear. Eyes wide open, pupils dilated, and breathing fast, he or she appears to be in a state of great terror, autonomically awake but clearly distanced. Throughout the episode, communication is difficult (and sometimes downright impossible), and the victim can typically neither be consoled nor comforted.

A sleep terror is a common sleep complication that affects both children and adults. (Do you experience sleep terrors? Let us know and share your experiences.)

Sleep terrors are a sleep disorder, though often just a temporary one. Since they involve abnormal physical behaviors during sleep they are classified as a parasomnia (learn about the different types of sleep disorders). Episodes typically last several minutes and end rather spontaneously.

Dr. D’s Sleep Book Says…

Dr. D’s Sleep Book Says…

Also known as incubus attacks or pavor nocturna, sleep terrors often involve individuals screaming in the middle of the night, ostensibly in a state of panic. Sleep terrors typically last several minutes and resolve themselves. Attacks are more frequent in children and can occur throughout the lifespan, although they occur less frequently with age.

What is Dr. D’s sleep book?

When and Why Do Sleep Terrors Occur?

Polysomnographic sleep recordings that have captured pavor nocturnus episodes have shown that they mainly occur during arousals from slow wave sleep (SWS, or NREM stages 3 & 4), which occurs predominantly during the first third of the night. When several sleep terror episodes occur during the course of the same night, they may also occur in NREM stage 2, or even stage 1.

Creating A Sleep Terror

In subjects who are predisposed to episodes, attacks can be elicited experimentally by forced arousal during SWS, suggesting that the transition out of this deep slumber is an important component (albeit not a standalone one) of a sleep terror.

It is not likely for someone to have multiple sleep terrors in one night, as frequent attacks occur in only 3 percent of children and less than 1 percent of adults, but some have reported as much as 40! The majority of people who experience the sleep terror disorder have, on average, one to four episodes per month.

Sleep terrors sometimes run in the family and are associated with increased incidence of sleepwalking and confusional arousals in the person affected and/or other family members.

Some factors like sleep deprivation (sleep debt), sickness or fevers, and stress can contribute to the triggering of a sleep terror episode, but no one factor acts independently and it is as of now at least a leap of faith to name a specific mechanism that causes sleep terrors.

Dr. D’s Sleep Book Says…

Dr. D’s Sleep Book Says…

In making a correct identification, sleep terrors must be distinguished from nightmares. The latter typically occur in the last (rather than the first) third of the night; they do not have the same intensity of terror, autonomic arousal, or motor activity; and they are not followed by such intense mental confusion. Moreover, a person who has had a nightmare typically recalls an organized dream in which evolving events became frightening and personally threatening.

What is Dr. D’s sleep book?

Sleep Terrors in Children

Childhood Sleep Disorders

Many sleep disorders tend to present themselves predominantly in childhood, before the patiend grows out of them later in life. Sleep terrors is typically one of them, and you can explore more about the other sleep disorders in children here.

As mentioned above, sleep terrors in children are sometimes referred to as pavor nocturna, or pavor nocturnus in the singular (which is just Latin for sleep terror).

The attacks can occur from early childhood on, are more common in males than in females, and many children experience the occasional episode. Frequent attacks occur in only about 3 percent of children (as mentioned above) and tend to disappear before adolescense.

A good way to tell if your child has pavor nocturnus is if you ever notice him or her wake up with expressions of extreme fear with symptoms like rapid heartbeat, sweating, or quick breathing. Often the person experiencing the sleep terror will be jolted into motion and sit up suddenly in bed, scream, cry, or have a very frightened facial expression.

Does your child experience this? Share your thoughts, questions, or concerns with us and we will respond back.

Sleep Terrors In Adults

While psychopathology (mental conditions) in children experiencing pavor nocturnus is very rare, it is commonly associated with sleep terrors in adults. Common associated conditions include anxiety and post-traumatic disorders. That said, sleep terrors themselves are much less common in adults, and this is not to say that having sleep terrors as an adult necessitates any kind of mental condition. (Browsing our visitor-submitted stories of adult sleep terrors is testament to that.

If present in adulthood, incubus attacks typically are most frequent in the 20- to 30-year-old range and less frequent in old age. Due to the link with psychopathology, it would seem that one would not have to have experienced pavor nocturna as a child in order to have sleep terrors as an adult.

Sleep terrors in adults are not normal, and if they are occurring on a frequent basis (more than a few times a week) and/or resulting in injuries to the individual or another, or significant stress, the individual should consult a sleep specialist.

Are you an adult who experiences sleep terrors? Share your thoughts, questions, and concerns with us.

Are You Awake During A Sleep Terror Episode?

While it has been mentioned above that sleep terrors occur mostly during arousals from slow wave sleep, these arousals are quite autonomic, meaning that an individual is not fully awake by any means. This, despite the fact that he or she will often have eyes wide open with pupils dilated and will be screaming or talking in a fearful flurry.

In fact, while an episode is going on victims can be almost impossible to wake up to a coherent state or even to comfort, and this can be very hard on most parents. While parents should know that many individuals in a pavor nocturnus episode may respond violently to attempts to help or restrain them, it is understandable of course to console them. Parents may also take solace in the fact that many children will have no recollection at all of their episode when they wake up in the morning.

For some subjects though, once awake they will often remember having difficulty breathing but will very rarely recall detailed mental activity at the time of the episode. Instead, if memory is present of what happened it will often just consist of a static scene like a single photograph, rather than the progressive storyline of images that accompanies a dream.

Treatment for Sleep Terrors

Treatment is often unneccessary when episodes of pavor nocturnus are rare, whether in children or adults. For children, Dr. Dement’s words below should calm the minds of most parents:

Dr. D’s Sleep Book Says…

Dr. D’s Sleep Book Says…

Parents of young patients must be reassured that these dramatic episodes have no psychopathological implications, that they seldom cause injury, and are almost always outgrown.

What is Dr. D’s sleep book?

However, for frequently occuring episodes of sleep terrors, especially those occuring in adults, or for episodes that cause injury or significant anxiety, a sleep specialist should definitely be consulted.