Night terrors are a common preschool-aged sleep disorder in which a child quickly wakes up from sleep in a terrified state. For the majority of these episodes, the child will not have any recollection of this event ever happening.
A night terror is considered a parasomnia due to its characterization of unusual physical and verbal behaviors. Parasomnias can often occur during any stage of sleep; however, night terrors specifically are associated with non-rapid eye movement (REM) sleep stages in which the person or child is in a transitional state in between sleep and wakefulness.
The act of sleeping can be categorically broken down into several stages and states. There are three primary states of sleep consisting of (1) wake, (2) non-REM sleep, and (3) REM sleep. Within these states, they are further broken down into the separate stages. Sleep stages 1, 2, 3, and 4 are considered non-REM sleep while stage 5 is considered REM sleep. The different sleep stages represent different electrical patterns and frequencies in the brain that can be detected and measured with an electroencephalogram (EEG). These states and stages can overlap each other, and it is during these transition states where parasomnias can occur.
Because there is no clear transition between the primary sleep states and stages, there are multiple time periods in a single duration of sleep in which a person can be in a combination of both wakefulness and sleep. Herein lies the most accepted theory of parasomnia etiology.
Furthermore, there are theories that there is a genetic component however this has never been proven and remains antidotal. The exact etiology is unknown however there are strong correlations with fever and illness, excessive physical activity, excessive caffeine or alcohol intake, lack of sleep and exhaustion, and emotional stress.
Night terrors are most often seen between the ages 3 to 7 years of age, and they often subside by 10 years of age. It appears that there is equal prevalence between boys and girls with a prevalence of approximately 30% in children.
Night terrors can occur in adults however it is rare. This may be indicative of underlying neurologic disorders that require more work up and investigation.
Episodes of night terrors most often occur in the first third of the night during slow wave sleep when the child is in the transitional state of being wakeful and sleeping. This particular period is referred to as the arousal state.
Episodes can appear to be very dramatic in presentation with the child screaming and thrashing without realization of his or her surroundings. Children may show signs of excessive autonomic activity such as tachycardia, tachypnea, mydriasis, and excessive sweating. In some cases, enuresis can also occur.
Unfortunately, children often do not respond to verbal cues, being comforted, or attempts to awaken. It is extremely difficult to wake these children in the middle of an episode. These spells can last approximately 10 to 20 minutes and then the child will abruptly return to sleep. Most do not recall the episodes.
No specific test must be done in an emergent clinical setting to make the diagnosis. A night terror is a clinical diagnosis that can be determined by taking a careful history, especially detailing the actual episode from families and witnesses. The only lab work or imaging that needs to be done is to rule out other differential diagnoses that are listed below.
There is no specific treatment for night terrors other than comforting the child. Reassurance and education for the parents or guardians are strongly encouraged especially to ensure the safety of the child during a night terror.
If there is excessive stress or conflict in the child’s life, a combination of therapy and coping techniques can be recommended to help decrease the frequency of episodes. Medication administration is strongly discouraged and not indicated.
Rarely is a sleep study ever indicated since the prognosis of night terrors is good and self-limiting; however, there is developing research involving scheduled awakenings through the night with a vibration machine to help improve quality of life.
The differential diagnosis for night terrors can include but is not limited to the following:
The prognosis for night terror is good with most children outgrowing these episodes by 10 years of age. In contrast, the excessive movement may become a disturbance that alters a family’s or child’s quality of life during an exacerbation. There are developing therapies to encourage scheduled awakenings to prevent further episodes.