A patient has asked me to write about night terrors. While night terrors can be seen in adults, they are much more common in children. It's hypothesized that this is due to their developing brains.

Night terrors are a subclass of sleep disorders termed "parasomnias." Rather than focus specifically on adults, I'll also cover kids. People who exhibit parasomnias often have family members who suffer from them as well. Virtually all of these conditions go away with time.

Parasomnias are a category of sleep disorders defined by abnormal and unnatural movements, behaviors, emotions, perception, and dreams. They occur while falling asleep, sleeping, between sleep stages, or arousal from sleep. They are further classified by when they occur in the sleep cycle - during REM (Rapid Eye Movement) sleep or non-REM sleep.

REM sleep is very light sleep characterized by rapid eye movements and muscle relaxation. This is the stage of sleep where dreaming occurs. Babies spend about 50 percent of their sleep time in REM while adults spend about 20 percent in this stage. Non-REM sleep is comprised of three or four stages, with stage 3 or 4 being the deepest sleep.

There are many parasomnias, but I want to focus on two of the most common, nightmares and sleep walking. Since my patient had an interest in night terrors, I'll go into a little more detail about them.

Nightmares occur during REM sleep. People who suffer from nightmares often are under some type of stress during their waking hours. They typically will awaken abruptly and appear frightened. The key component of nightmares is that the person typically has vivid recall of what the nightmare was about. They also have trouble returning to sleep.

Children and adults who suffer night terrors (pavor nocturnus) on the other hand, have no recall of their events. Night terrors are found in about five percent of kids 3 to 12 years old and in about three percent of adults, usually prior to age 65.

These people typically sit bolt upright in their beds and usually scream or yell. They tend to be inconsolable for around 15 minutes. They show physical signs of fright such as elevated heart rate and breathing. Adults may jump out of bed and run around the house and sometimes commit violent acts.

In contrast to nightmares, night terrors occur during deep sleep (stage 3 or 4), usually in the first third of the night. The depth of sleep accounts for the lack of memory of the events. These people also typically have no problem falling back to sleep after the terror passes.

The best thing to do for these people is to stay with them during the attack to ensure they don't endanger themselves. You can try to wake them up, but they are typically very difficult to arouse and are usually very confused. Children who have very severe episodes may benefit from medications like Valium®.

Sleepwalking (somnambulism) and sleep talking (somniloquy) are usually found in children between the ages of six and twelve and are more common in boys. They also manifest in the deeper stages of the sleep cycle. These kids usually sit up or get out of bed with their eyes open, but appear "unseeing."

Most children outgrow these conditions by adolescence, but they can persist into adulthood. Similarly to night terrors, the main concern with these people is the possibility of injury. Their bedrooms should be on the first floor if possible and doors and windows should be safely secured (with devices that can easily be opened by an awake person in case of fire or other emergency).

Again, children usually outgrow this problem. Some people recommend keeping a log of when the sleepwalking occurs and then waking the person 15 minutes before that time each night. This has been shown to be about 80 percent effective in terminating the condition.

One other interesting parasomnia is nocturnal enuresis or bedwetting. This is also considered a parasomnia since it occurs only during the deeper stages of sleep.

There are also a number of conditions that can be associated with parasomnias, particularly in adults. The most common are sleep deprivation, hyperthyroidism, migraine headaches, head injury, stroke, physical or emotional stress, travel, sleeping in unfamiliar surroundings, certain medications, and alcohol or substance abuse.

Dr. John Roberts is a Crawfordsville physician and one of the owners of The Paper. In addition to his weekly column, he writes a daily health tip that can be found on page A1.