Related concepts:

Confusional arousal; Partial arousal state; Sleep terrors

Introduction to night terrors:

Your little angel wakes up screaming in the middle of the night, calling for his mommy – but his mommy is right there, unrecognized. You try to comfort him, but he shrieks even louder, eyes bulging. He might be having a night terror.

What are night terrors?

Within fifteen minutes of your child’s falling asleep, he will probably enter his deepest sleep of the night. This period of slow wave sleep, or deep non-REM sleep, will typically last from forty-five to seventy-five minutes. At this time, most children will transition to a lighter sleep stage or will wake briefly before returning to sleep. Some children, however, become stuck and are unable to completely emerge from slow wave sleep. Caught between stages, these children experience a period of partial arousal.

Partial arousal states are classified in three categories: 1) sleep walking, 2) confusional arousal, and 3) true sleep terrors. These closely related phenomena are all part of the same spectrum of behavior.

When most people (including the popular press and popular parenting literature) speak of night terrors they are generally referring to what are called confusional arousals by most pediatric sleep experts.

During these frightening episodes, the child is not dreaming and typically will have no memory of the event afterwards (unlike a nightmare). If any memory persists, it will be a vague feeling of being chased or of being trapped. The event itself seems to be a storm of neural emissions in which the child experiences an intense flight or fight sensation. Once it is finally over, the child usually settles back to quiet sleep without difficulty.

These are very different from nightmares.

True sleep terrors are a more intense form of partial arousal. They are considerably less common than confusional arousals and are seldom described in popular parenting literature. True sleep terrors are primarily a phenomenon of adolescence.

Who gets night terrors?

The tendency toward sleepwalking, confusional arousals, and true sleep terrors often runs in families. They tend to be more common in boys, and are much less common after age 7.

The events are often triggered by sleep deprivation or by the sleep schedule's shifting irregularly over the preceding few days. A coincidentally timed external stimulus, such as moving a blanket or making a loud noise, can also trigger a partial arousal (which again shows that the event is a sudden neural storm rather than a result of a complicated dream).

What are the symptoms of night terrors?

Typically, a confusional arousal begins with the child moaning and moving about. It progresses quickly to the child crying out and thrashing wildly. The eyes may be open or closed, and perspiration is common. The child will look confused, upset, or even "possessed" (a description volunteered by many parents). Even if the child does call out his parents' names, he will not recognize them. He will appear to look right through them, unable to see them.