Parasomnias

The most common of the parasomnias are “disorders of arousal,” which include confusional arousals, sleepwalking (somnambulism), and sleep terrors. Experts believe that the various arousal disorders are related and share some characteristics. Essentially, these occur when a person is in a mixed state, both asleep and awake, and often emerging from the deepest stage of non-dreaming sleep. The sleeper is awake enough to act out complex behaviors, but is still asleep and not aware of or able to remember these activities.

Parasomnias are very common in young children and do not usually indicate significant psychiatric or psychological problems. Such disorders tend to run in families, and can be more severe when a child is overly tired, has a fever, or is taking certain medications. They may occur during periods of stress, and may increase or decrease with “good” and “bad” weeks.

Confusional Arousals
Confusional arousals are most common in infants and toddlers, but are also seen in adults. These episodes may begin with crying and thrashing around in bed. The sleeper appears to be awake, and seems to be confused and upset, but resists attempts to comfort or console. It is difficult to awaken a person in the grips of a parasomnias episode. The confusional arousal can last up to half an hour, and usually ends when the agitation subsides and the sleeper awakens briefly, wanting to return to sleep.

Sleepwalking
This disorder is commonly seen in older children, and can range from simply getting out of bed and walking around the bedroom to prolonged and complex actions, such as going to another part of the house or even outdoors. A sleepwalker will sometimes speak, but is unlikely to be clearly understood. Sometimes complicated behaviors take place during a sleepwalking episode (such as rearranging furniture), but these activities are usually not purposeful. While injuries during sleepwalking are uncommon, sleepwalkers may put themselves in harm’s way – such as walking outside in bedclothes during the winter. Simple precautions can enhance safety.

In most cases, no treatment is necessary. The sleepwalker and family can be assured that these events rarely indicate and serious underlying medical or psychiatric problem. In children, the number of events tends to decrease with age, although they can occasionally persist into adulthood or even originate during the adult years.

Sleep-Related Eating
A rare variation of sleepwalking is “sleep-related eating.” This disorder manifests itself as recurrent episodes of eating during sleep, without conscious awareness. Sleep-related eating can occur often enough to result in significant weight gain. Although it can affect both sexes and all ages, it is most common in young women.

Sleep Terrors
These are the most extreme and dramatic of the arousal disorders, and the most distressing to witness. A sleep terror episode often begins with a “blood –curdling” scream or shout, and can produce signs that suggest extreme terror, such as dilated pupils, rapid breathing, racing heart, sweating, and extreme agitation. During a sleep terror episode, the victim may bolt out of bed and run around the room or even out of the house. In the course of the frenzied event, sleepers can hurt themselves or others.

As disturbing and frightening as these episodes are to an observer, the sleeper usually has no conscious awareness of the event, and generally does not remember it upon awakening.

Unlike typical nightmares or bad dreams, sleep terror episodes are not usually associated with vivid dream images that are recalled after awakening.

In typical childhood occurrences of arousal disorders, medical evaluation is not likely to be needed, You should, however, contact a healthcare professional if a child’s disturbed sleep causes: 1) potentially dangerous behavior, such as that which is violent or could cause injury; 2) extreme disturbance of other household members; or 3) excessive sleepiness during the day. In these cases, formal evaluation at a sleep center is warranted.

Because disorders of arousal are relatively uncommon after childhood, adults suffering from these disorders should seek evaluation. In some cases, these disorders can be triggered by other limb movements during sleep. A sleep specialist should evaluate the patient’s behaviors and medical history.

Simple precautions should be taken to ensure safety for people with arousal disorders. Clearing the bedroom of obstructions, securing windows, sleeping on the ground floor, and installing locks or alarms on windows and doors can add a degree of security for the individual and the family.

In cases severe enough that the sleep disorder leads to injury or involves violence, excessive eating, or disturbance to others, treatment may be warranted. Therapy can include medical intervention with prescription drugs, or behavior modification through hypnosis or relaxation/mental imagery.

While the great majority or sleep-related complex behaviors and experiences are due to disorders of arousal, several other conditions can be frightening or disturbing to those who experience them.

Hypnagogic Hallucinations & Sleep Paralysis
Hypnagogic hallucinations are episodes of dreaming while awake, usually just before falling asleep. These dreams can be frightening because the setting reflects reality (for example, the bedroom), and the content of the dream is often threatening.

Sleep Paralysis
Sleep paralysis is the experience of waking up – usually following a dream – with a feeling that the muscles of the body (except for those used to breathe and move the eyes) are paralyzed. Hypnagogic hallucinations and sleep paralysis may occur together. They are common in people with narcolepsy, but can also affect others, particularly individuals who are sleep-deprived. While they can be terrifying, these events are not physically harmful.

Nocturnal Seizures
These seizures, which occur only during sleep, can cause the victim to cry, scream, walk or run about, curse, or fall out of bed, The victim may behave in a manner similar to a person with an arousal parasomnias. Like other seizures, these are usually treated with medication.

Rapid Eye Movement (REM) Sleep Behavior Disorder
All body muscles – except those used in breathing – are normally paralyzed during REM sleep. In some people, commonly older men, this paralysis is incomplete or absent, allowing dreams to be “acted out.” Such dream-related behavior can be violent and can result in injury to the victim or bed partner. In contrast to those who experience sleep terrors, the victim will recall vivid dreams. REM sleep behavior disorder can be controlled with medication.

Sleep Starts
Most people have experienced the common “motor” sleep start – a sudden, often violent jerk of the entire body upon falling asleep. Other forms of sleep starts also occur just as sleep begins. A “visual” sleep start is a sensation of blinding light coming from inside the eyes or head. An “auditory” sleep start is a loud snapping noise that seems to come from inside the head. Such occurrences, while they can be frightening, are harmless.

Teeth Grinding (Bruxism)
Grinding of teeth during sleep is a very common occurrence, and little evidence suggests that teeth grinding is associated with any significant medical or psychological problems. In severe cases, mouth devices can help reduce the risk of dental injury.

Rhythmic-Movement Disorder
This condition, seen most frequently in young children, can also occur in adults. It takes the form or recurrent head banging, head rolling and body rocking. The individual may also moan or hum. These activities can occur just before sleep begins or during sleep. Medical or psychological problems are unlikely to be associated with rhythmic movement disorder. Behavioral treatments may be effective in severe cases.

Sleep Talking (Somniloquy)
Sleep talking is a normal phenomenon and is of no medical or psychological importance.

Since most of these sleep-related behaviors are due to disorders of arousal – which are not medically significant – medical evaluation and treatment is often not necessary. Medical attention should be considered, however, if the parasomnia behaviors: 1) are violent or may cause injury; 2) are disturbing to other household members; or 3) result in excessive daytime sleepiness.

Minor sleep problems can be handled by a primary care professional, often with a telephone consultation with a sleep medicine specialist experienced with these conditions. Due to the complex nature of some parasomnias, however, proper diagnosis requires expert clinical evaluation and sleep laboratory monitoring of many body functions during sleep. These evaluations should be directed by a sleep specialist with experience in such cases. In most cases of bothersome parasomnias, a specific cause can be identified and effectively treated.