context: Night terrors typically occur in children ages 3-12, with a peak onset at age 3 1/2. There are two main types of sleep: rapid eye movement ( REM) and non-rapid eye movement (non- REM). Non- REM sleep has stages, and night terrors happen during the transition from stage 3 to stage 4. They typically occur approximately 90 minutes after the child falls asleep. Night terrors are distinctly different from the common nightmares, which occur during REM sleep. Night terrors are characterized by frequent recurrent episodes of intense crying and fear during sleep, with difficulty arousing the child. Unlike nightmares, most children do not recall a dream after a night terror episode, and they usually do not remember the episode the next morning. Night terrors are frightening episodes that can disrupt family life. An estimated 1%-6% of children experience night terrors. Boys and girls are equally affected. Children of all races also seem to be affected equally. It is a disorder that is usually outgrown by adolescence. Night terrors tend to run in families. While most of the time they have no specific cause, night terrors can sometimes result from: Stressful life events Fever Sleep deprivation Medications that affect the central nervous system (the brain) Recent anesthesia given for surgery In addition to frequent recurrent episodes of intense crying and fear during sleep, with difficulty arousing the child, children with night terrors may also experience the following: Tachycardia (increased heart rate) Tachypnea (increased breathing rate) Sweating during episodes The typical night terror episode usually begins approximately 90 minutes after falling asleep. The child sits up in bed and screams, appearing awake but is confused, disoriented, and unresponsive to stimuli. Although the child seems to be awake, the child does not seem to be aware of the parents' presence and usually does not talk. The child may thrash around in bed and does not respond to comforting by the parents. Most episodes last 1-2 minutes, but they may last up to 30 minutes before the child relaxes and returns to normal sleep. If the child does awake during a night terror, only small pieces of the episode may be recalled. Usually, the child does not remember the episode upon waking in the morning. Sleep disruption is a parent's most frequent concern during the first years of a child's life. Half of all children develop a disrupted sleep pattern serious enough to warrant a visit to the pediatrician. During his or her evaluation, the doctor may also be able to exclude other possible disorders that might cause night terrors. Usually, a complete history and a physical exam are sufficient to diagnose night terrors. If other disorders are suspected, additional tests may be useful to exclude them: An electroencephalogram ( EEG), which measures brain activity, may be performed if a seizure disorder is suspected. Polysomnography (a combination of tests used to check for adequate breathing while asleep) may be done if a breathing disorder is suspected. CT scans and MRIs are usually not necessary. Parents might take the following precautions at home: Make the child's room safe to try to prevent the child from being injured during an episode. Eliminate all sources of sleep disturbance. Maintain a consistent bedtime routine and wake-up time. Unfortunately, no adequate treatment exists for night terrors. Management primarily consists of educating family members about the disorder and reassuring them that the episodes are not harmful. In severe cases in which daily activities (for example, school performance or peer or family relations) are affected, low-dose benzodiazepines (such as clonazepam) or tricyclic antidepressants (such as imipramine) may be used as a temporary treatment. If it helps to alleviate your child's anxiety - or yours - make an appointment to talk to his doctor. If your child has night terrors, you can try to interrupt her sleep in order to prevent one. Here is how to do it: First, note how many minutes the night terror occurs from your child's bedtime. Then, awaken your child 15 minutes before the expected night terror, and keep her awake and out of bed for five minutes. You may want to take your child to the bathroom to see if she will urinate. Continue this routine for a week. Night terror episodes are short-lived and usually occur over several weeks. Nearly all children outgrow night terrors by adolescence.