Disruptive Sleep Disorders (Parasomnias)

  • Medical Author: Sat Sharma, MD, FRCPC, FCCP
  • Medical Editor: Anthony M Murro, MD
  • Medical Editor: Mary L Windle, PharmD
  • Medical Editor: Stephen Berman, MD, PhD
Reviewed on 12/3/2021

What Are the Disorders That Disrupt Sleep (Parasomnias)?

Sleep disorder
The Most Common Types of sleep disorders are nightmare disorder, sleep terror disorder, sleepwalking disorder, and REM sleep behavior disorder.

What Is the Medical Definition of Parasomnia?

Parasomnias are disruptive sleep-related disorders. They are characterized by undesirable physical or verbal behaviors or experiences. Parasomnias occur in association with sleep, specific stages of sleep (see Sleep: Understanding the Basics), or sleep-wake transition phases.

Parasomnias may be divided into the following categories:

  • Primary parasomnias are the disorders of sleep states. They are further classified according to the stage of sleep in which they originate: rapid eye movement (REM) (a stage of sleep in which the eyes move rapidly and dreaming occurs) or non-rapid eye movement (NREM) (stage of sleep in which the eye movement does not take place. For details of stages of sleep, see Sleep: Understanding the Basics).
  • Secondary parasomnias are disorders of other organ systems that may manifest during sleep, for example, seizures (convulsions), respiratory dyskinesias (difficulty in performing respiratory movements), arrhythmias (abnormal heart rhythms), and gastroesophageal reflux (food or liquid regurgitating from the stomach into the food pipe).

The 4 parasomnia sleep disorders that are discussed in this article are nightmare disorder, sleep terror disorder, sleepwalking disorder (somnambulism), and REM sleep behavior disorder. Two additional disorders classified as Sleep-Related Movement Disorders are restless legs syndrome (RLS), and periodic limb movement disorder (PLMD).

What Are the Most Common Types of Sleep Disorder?

Nightmare disorder

Nightmare disorder is also called a dream anxiety attack. Most patients with nightmare disorder are children although some adults may manifest them after trauma-related events. Nightmares are frightening dreams that occur during REM sleep and are associated with an increase in heart rate (tachycardia), an increase in the rate of breathing (tachypnea), profuse sweating, and arousal. Most of the time, the patient remembers the scary dream in detail and responds to soothing and comforting by a parent or caregiver.

Sleep terror disorder

Sleep terror disorder is characterized by extreme panic and a sudden, loud, terrifying scream during sleep, which may be followed by physical activities such as hitting objects or moving in and out of the bedroom. Persons with this disorder can injure themselves. Sleep terror is a disorder of arousal that primarily occurs during stage III of NREM sleep. Subsequent recollection of the episodes either does not occur or is partial. The event is often more stressful for the parent or bystander since the individual is technically still asleep.

Sleepwalking disorder

Patients with the sleepwalking disorder show complex automatic behaviors, such as wandering, carrying objects without any purpose, going outdoors, and performing other activities of varying complexity and duration (even driving). Persons affected with the disorder usually have their eyes wide open in a stare. They may mumble; however, communication with a person who is sleepwalking is usually poor or impossible. This disorder occurs in the slow-wave stages of NREM sleep. Safety proofing the sleep environment is an important consideration. Alarms on doors and windows and gates on stairs can be placed if appropriate.

REM sleep behavior disorder

Patients with REM sleep behavior disorder (RBD) act out distinctly altered dreams that are vivid, intense, action-packed, and violent. Dream-enacting behaviors include talking, yelling, punching, kicking, sitting, jumping out of bed, arm flailing, and grabbing. An acute form may occur during withdrawal from ethanol or sedative-hypnotic drugs. See REM Sleep Behavior Disorder.

Restless legs syndrome and periodic limb movement disorder

Restless legs syndrome and periodic limb movement disorder are classified as Sleep-Related Movement Disorders. They are common disorders that often may coexist. The primary symptom of restless legs syndrome is insomnia (inability to sleep), whereas periodic leg movement disorder is a well-recognized cause of excessive daytime sleepiness. There is a high correlation between patients having restless legs syndrome and have a periodic limb movement disorder, but they are not the same.

What Causes Sleep Disorders?

Few, if any, specific causes exist for parasomnias, but each type of parasomnia has a number of predisposing factors. They are as follows:

Nightmare disorder

  • Personality disorders
  • Relationship difficulties
  • Other stressors
  • Drugs, for example, levodopa, beta-adrenergic drugs, and withdrawal of REM-suppressing medications

Sleep terror disorder

  • Fever
  • Sleep deprivation (lack of sleep)
  • CNS depressant medications

Sleepwalking disorder

  • Possible hereditary/familial trend
  • Drugs, for example, thioridazine, fluphenazine, perphenazine, desipramine, chloral hydrate, and lithium
  • Fever
  • Sleep deprivation and obstructive sleep apnea (a condition in which breathing stops temporarily while sleeping)
  • Other disorders that disrupt slow-wave sleep
  • Internal stimuli, such as a full urinary bladder
  • External stimuli, such as noises

REM sleep behavior disorder

  • Mostly no known cause
  • More commonly found in males over 50 years old with other neurologic conditions
  • Has been associated with some neurodegenerative disorders including Parkinson's disease, narcolepsy, and other neurologic conditions including dementia (progressive loss of intellectual functions), subarachnoid hemorrhage (leakage of blood into the space surrounding the brain), ischemic cerebrovascular disease (brain dysfunction due to reduced blood supply), olivopontocerebellar degeneration (brain disease), multiple sclerosis (disease of the central nervous system), and brain stem neoplasms (tumor)

Restless legs syndrome and periodic limb movement disorder

What Are Sleep Disorder Symptoms?

The symptoms associated with each subtype of the parasomnias are as follows:

Nightmare disorder

  • The person complains of a frightening dream.
  • Arousal during the dream is common.
  • The presence of a dream is the essential feature that differentiates nightmare disorder from sleep terror disorder.

Sleep terror disorder

  • Asleep terror is characterized by sudden arousal.
  • Commonly, the person cries out or screams as he or she is aroused.
  • The person has an increased heart rate, an increase in respiratory rate, flushing, sweating, and increased muscle tone.
  • The person is routinely unresponsive to external stimuli and, when awakened, is confused, disoriented, and does not remember the event.
  • Incoherent speech or passing of urine has been reported to accompany the event.

Sleepwalking disorder

  • Episodes of sleepwalking are associated with behaviors that range from simply sitting up in bed to walking, possibly with associated complex behaviors such as eating. Talking behavior has also been noted during episodes of sleepwalking.
  • Upon awakening, the person most often is confused and does not remember the event.
  • The event may spontaneously terminate, or the person may return to bed or lie down somewhere else and go off to sleep without waking up from sleep.

REM sleep behavior disorder

  • The main feature of this disorder is the acting out of dreams. The behavior can include punching, kicking, leaping, and running from the bed. The most common reason for a medical consultation is an injury to the bed partner, although the effects of sleep disruption can also precipitate such consultation. The event occurs during REM sleep.
  • In persons with REM sleep behavior disorder, arousals from sleep to alertness and orientation occur rapidly, and they usually vividly recall their dreams.
  • After awakening, the person’s behavior and interactions are normal.
  • Acute (short-term) and chronic (long-term) forms exist. The acute form can emerge during withdrawal from ethanol or sedative-hypnotic abuse and with anticholinergic and other drug intoxication states. The chronic form presents for evaluation following observations of bed partners.
  • Despite nighttime behavior, few persons develop excessive daytime sleepiness or fatigue.

Restless legs syndrome and periodic limb movement disorder

  • Persons with restless legs syndrome describe discomfort in the legs, using terms, such as “pulling, searing, crawling, creeping, and boring” to describe these sensations. The symptoms usually occur at bedtime or during other periods of inactivity. These distressing symptoms are relieved by moving the legs, walking about, rubbing the legs, squeezing or stroking the legs, and by taking hot showers or baths. The symptoms may wax and wane over the person’s lifetime.
  • Persons with restless legs syndrome commonly present with complaints of insomnia (inability to initiate or return to sleep), and, in severe cases, the disorder may cause depression and suicidal thoughts.
  • Periodic limb movement disorder primarily occurs during sleep. This disorder is described as a rhythmic extension of the great toe, associated with dorsiflexion (upward movement) of the ankle and light flexion (bending) of the knee and hip. Because periodic limb movement disorder occurs during sleep, the symptoms are often not noticed by the person. Affected persons often complain of excessive daytime sleepiness, initially during passive activities, such as watching TV, being a passenger in a car, or reading. In later stages, one may have excessive daytime sleepiness during activities requiring alertness, such as driving, operating machinery, or talking with people.
  • Restless legs syndrome and periodic limb movement disorder may occur even during childhood and may present clinically as attention deficit disorder with hyperactivity or as growing pains.
  • Restless legs syndrome and periodic limb movement disorder are present in a significant percentage of pregnant women, and exacerbations are observed during menstruation and menopause.
  • These disorders are associated with numerous neurological conditions, such as peripheral neuropathy, postpolio syndrome, and spinal cord pathology (disease).
  • Restless legs syndrome and periodic limb movement disorder affect 20-40% of persons with chronic renal (kidney) failure who are on dialysis.
  • History of iron deficiency anemia is also common in persons with restless legs syndrome and periodic limb movement disorder.

What Are the Exams and Tests for Sleep Disorders?

These are the most important items for parasomnia evaluation:

  • Interview the person and his or her bed partner
  • Review of medical records
  • Elicit details about sleep-wake patterns
  • Medical history
  • Psychiatric history
  • Alcohol and drug-use history
  • Family history
  • Past or current history of physical, sexual, and emotional abuse
  • Psychiatric and neurologic interviews and examinations

Polysomnography (sleep test)

This test is usually conducted in a sleep study center. The patient sleeps at the center, and the following parameters are monitored:

  • Electrical activity of the brain (electroencephalogram)
  • Electrical activity of the heart (electrocardiogram)
  • Movements of the muscles (electromyogram)
  • Eye movements (electrooculogram)

These parameters are monitored as the person passes through the various sleep stages. Characteristic patterns from the electrodes are recorded while the person is awake with eyes closed and during sleep. Continuous audiovisual recording monitors physical activity during sleep.


Sleep Quiz IQ

What Is the Treatment Sleep Disorders?

These sleep hygiene measures are important for all parasomnias:

  • Go to bed at the same time each night.
  • Use the bed only for sleeping and intimacy.
  • Avoid napping.
  • Avoid stress, fatigue, and sleep deprivation.
  • Avoid vigorous activity prior to bedtime, though a brief period of aerobic activity 4 hours before bedtime may be helpful.
  • Avoid cigarettes, alcohol, and excessive caffeine.

In general, when a person has been diagnosed with sleepwalking, the following precautions need to be taken:

  • Remove potentially dangerous items.
  • Have the person sleep in a bedroom on the ground floor if possible.
  • Lock the doors and windows.
  • Cover glass windows with heavy drapes.
  • Place an alarm or bell on the bedroom door.

Benzodiazepines, which are used for insomnia situations where an individual awakens after falling asleep, such as estazolam (ProSom), have been found to be safe and remarkably effective in adults with sleepwalking and sleep, terrors.

REM sleep behavior disorder

Treatment for REM sleep behavior disorder is initiated with clonazepam (Klonopin) at 0.5-1.5 mg taken at bedtime. Clonazepam is remarkably effective in controlling both the behavioral and the dream-disordered components of REM sleep behavior disorder. This drug has been shown to be beneficial in the long term. Drug discontinuation often results in prompt relapse.

Tricyclic antidepressants are occasionally used in the treatment of REM sleep behavior disorder. Imipramine has been used, but the effects are unpredictable.

Several reports of levodopa/carbidopa, gabapentin, pramipexole, and clonidine have been published, but the benefit of these drugs has not been systemically evaluated.

Restless legs syndrome and periodic limb movement disorder

Restless legs syndrome and periodic limb movement disorder are treated with 3 classes of medications. Treatment guidelines are as follows:

  • Anti-parkinsonian drugs, such as levodopa/carbidopa, bromocriptine, ropinirole (Requip), pergolide (Permax), and pramipexole (Mirapex), have been used.
  • Benzodiazepines, especially clonazepam have been effective. Other benzodiazepines used have included diazepam, temazepam, and lorazepam.
  • Opiates, such as codeine, oxycodone, methadone, and propoxyphene, are other drugs that have been used.
  • Dopamine agonists, such as levodopa or pergolide, may be effective, but the effectiveness may not last, and some individuals are unable to tolerate side effects.
  • Other drugs that have shown effectiveness include clonidine or anticonvulsants, such as carbamazepine, valproate, and gabapentin.
  • Several studies have reported the efficacy of different medications belonging to the aforementioned groups, but comparative studies between various classes of drugs or even individual drugs do not exist. Therefore, persons should receive one drug, and, if no response is noted, they should be placed on another drug of the same class or a different class.
  • A combination of drugs may be required in more severe cases. Some persons who do not respond to benzodiazepines alone, levodopa alone or a combination of both may be treated with opiates.
  • One should receive the smallest possible dose and should be closely observed for the development of dependency. Experience reveals that the incidence of abuse, tolerance, or addiction to opiates or benzodiazepines in persons with severe restless legs syndrome appears to be insignificant. The disabling condition of severe restless legs syndrome must be treated aggressively.
  • Restless legs syndrome and periodic limb movement disorder are chronic conditions that require long-term drug therapy. Some persons may develop symptoms of restless legs during the daytime, and this may be treated with controlled release of levodopa/carbidopa administered in the evening and morning.
  • Avoidance of certain drugs, such as tricyclic antidepressants, fluoxetine, or lithium, may be helpful because these drugs generally worsen the symptoms of restless legs syndrome and periodic limb movement disorder.
  • A decrease in body iron stores, as indicated by serum ferritin (an iron-protein complex) levels less than 75 mcg/L, should be corrected with iron supplementation. Oral iron is preferred but takes a long time to provide improvement because gastrointestinal absorption is low. However, replenishment is an effective treatment strategy for iron deficiency anemia and may also relieve symptoms of restless legs syndrome and periodic limb movement disorder (if present).

What Are the Medications for Sleep Disorders?

The common classes of drugs used for the treatment of parasomnias are benzodiazepines and anticonvulsants. The general aim of drug treatment is to prevent arousal out of sleep or to suppress REM sleep.


Benzodiazepines help suppress REM sleep and limit arousal. They include the following drugs:

  • Diazepam (Valium) is most frequently used in children, especially children with night terrors.
  • Alprazolam (Xanax) is the second choice in this category for parasomnias. It has a brief duration of action; therefore, the likelihood of morning effects, such as grogginess, is decreased. However, it has a potential for exacerbating symptoms at lower doses when effects attenuate, owing to possible rebound.
  • Clonazepam (Klonopin) is similar to alprazolam; it is a good alternative option to diazepam.


Anticonvulsants inhibit arousal. They include the following drugs:

  • Carbamazepine (Tegretol, Carbatrol) is the most commonly used drug for parasomnias.
  • Valproate (Depakene, Depakote) has been reported to be effective in treating parasomnias, in both a once nightly dosage schedule and a standard dosage schedule.
  • Gabapentin (Neurontin) has not been used as frequently as the other 2 anticonvulsants. As with carbamazepine and valproate, no information is available and no consensus has been reached regarding the use of a once nightly dosage versus a standard antiepileptic dosage.


Antiparkinsonian drugs are very effective for the treatment of persons with restless legs syndrome and periodic limb movement disorder.

  • Levodopa is the most commonly used drug for the treatment of restless legs syndrome and periodic limb movement disorder. An oral dose of 50-100 mg, controlled-release formulation, is prescribed as initial therapy for restless legs syndrome.
  • For periodic limb movement disorder, a controlled-release preparation of levodopa combined with a decarboxylase inhibitor (carbidopa) at a dose of 50-100 mg is started.
  • A dose increase not to exceed 200 mg may be required to completely suppress restless legs syndrome and periodic limb movement disorder.
  • The major adverse effects of levodopa therapy are (1) rebound of symptoms during the daytime and (2) tardive dyskinesia (difficulty in performing voluntary movements), which is extremely uncommon.
  • Ropinirole (Requip), pergolide (Permax), and pramipexole (Mirapex) cause fewer side effects compared with levodopa and have become first-line drugs in the treatment of restless legs syndrome and periodic limb movement disorder. Pramipexole is started at the lowest dose of the one-half tablet of 0.25 mg once a day for 5 days and then increased to 0.25 mg per day. The dose may be increased to a maximum of 0.5 mg per day. Ropinirole is started at 0.25 mg at bedtime for individuals with primarily nighttime symptoms. For those with symptoms throughout the day, it may be given 2 times per day. The dose may be gradually increased each week. Average doses are 2.5 mg per day.


Opiates, such as codeine, propoxyphene, and dihydromorphine, have been used in persons who have severe restless legs syndrome and who do not benefit from other therapy. One should be closely observed for the development of tolerance and dependency.

What Is the Other Therapy for Sleep Disorders?

Behavioral treatments, such as relaxation therapy, biofeedback, hypnosis, and stress reduction, may be helpful, although they are not universally effective.

What Is the Prognosis for Sleep Disorders?

Nightmare disorder

  • Most children outgrow this disorder.
  • A small number of children report this disorder persisting into adulthood and becoming a lifelong problem.
  • Some persons may experience a reduction of the symptoms later in life.

Sleep terror disorder

  • If the onset is in childhood, the outlook is excellent.
  • If the onset is in adulthood, the outlook is poor because the disorder tends to be chronic (lasting a long time), with a waxing and waning course.

Sleepwalking disorder

  • If the onset is in childhood, the outlook is excellent.
  • If the onset is in adulthood and no evidence of an underlying neurological or substance abuse problem is present, the outlook is poor because the disorder tends to be chronic, following a waxing and waning course.

Restless legs syndrome and periodic limb movement disorder

  • The outlook of these disorders is variable.
  • Many persons develop long-term remissions, whereas others continue to experience the symptoms throughout life.
  • Generally, the severity increases as one become older.
Reviewed on 12/3/2021
Medically reviewed by Jon Glass, MD; American board of Psychiatry and Neurology


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