Sleep Terrors 

Updated: Mar 14, 2019
Author: Eve G Spratt, MD, MSc; Chief Editor: Caroly Pataki, MD 

Overview

Practice Essentials

Sleep terrors (also referred to as night terrors) are a specific sleep disruption most remarkable for their intensity and anxiety-inducing nature. Several precipitating factors have been suggested, but no consistent structural or biochemical abnormality has been identified to account for all cases of sleep terrors.

Signs and symptoms

Symptoms of sleep terrors include the following:

  • Sudden arousal from non–rapid eye movement (NREM) sleep, usually occurring in the first third of the night

  • Associated autonomic and behavioral manifestations of fear, including crying, screaming, or thrashing

  • Agitation (more commonly seen in adults)

  • Significant autonomic hyperactivity, including tachycardia, tachypnea, and diaphoresis

  • No or minimal response to external stimuli during the event

  • Upon wakening: Confusion, disorientation, and amnesia regarding the event

There are no specific physical findings or signs found on routine physical examination when the individual is awake.

See Presentation for more detail.

Diagnosis

The diagnosis is made primarily based on a history that identifies the classic symptoms of sleep terror and by excluding other possible etiologies for the sleep disturbance based on the clinical presentation. There have been no identified irregularities in laboratory evaluation, and no additional workup is required in a classic sleep terror presentation. Further evaluation may be useful as follows:

  • Sleep diary to help identify sleep patterns and triggers for sleep terrors

  • Investigation of comorbidities

  • Assessment for significant daytime somnolence, violent behavior during episodes, or severe distress on the part of family members

  • Polysomnography for a suspected respiratory disturbance

  • Routine electroencephalography (EEG) or sleep-deprived EEG if nocturnal seizures are suspected

The American Academy of Sleep Medicine's (AASM) 2014 International Classification of Sleep Disorders (3rd Edition) ciagnostic criteria for sleep terrors are as follows:[1]

  • Recurrent episodes of incomplete awakening from sleep

  • Inappropriate or absent responsiveness to efforts of others to intervene or redirect the person during the episode.

  • Limited or no associated cognition or dream imagery

  • Partial or complete amnesia for the episode

  • The disturbance is not better explained by another sleep disorder, mental disorder, medication, or substance use

  • The arousals are characterized by episodes of abrupt terror, typically beginning with an alarming vocalization such as a frightening scream.

  • There is intense fear and signs of autonomic arousal, including mydriasis, tachycardia, tachypnea, and diaphoresis during an episode.

See Workup for more detail.

Management

Because sleep terrors are typically benign and self-limited, most affected individuals require no specific medical intervention other than reassurance and education.

Measures that may be helpful include the following:

  • Appropriate treatment of associated comorbid conditions

  • Promoting a stable environment with adequate regular sleep habits

  • Routine follow-up and developmental assessment for affected children

  • Continued support and reassurance for affected families

  • Surveillance for deviation from classic sleep terror characteristics or increasing severity of behavior during episodes

  • Efforts to keep affected individuals from harming themselves or others during episodes

  • Scheduled awakenings

See Treatment and Medication for more detail.

Background

Sleep terrors (also known as night terrors) are a sleep disturbance characterized by waking from sleep with a fit of apparent sudden, intense distress (often indicated by a loud cry or scream). This is followed by a state of apparent panic and lack of responsiveness. The eyes are usually open during an episode, sometimes noted to have a glassy stare. Most episodes occur within the first 90 minutes after a person initiates sleep.[2] The sleep terror occurs as the person goes through stages 3 and 4 of non–rapid eye movement (NREM) sleep, though episodes may occur later or during naps. These usually emerge between 4 and 12 years of age.[1]

Diagnostic criteria

Parasomnias are sleep-wake disorders characterized by undesirable motor, verbal, or experiential phenomena occurring in association with sleep, specific stages of sleep, or sleep-awake transition phases. 

There are two main sets of diagnostic criteria for sleep terrors. One from the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5),[3]  and one from the 2014 International Classification of Sleep Disorders, 3rd Edtiion (ICSD-3)[1] , from the American Academy of Sleep Medicine (AASM). The two are described in the table below.

Table 1. Diagnostic criteria for sleep terrors (Open Table in a new window)

Features DSM-5 ICSD-3
Frequency Recurrent episodes Recurrent episodes
Awakening Abrupt arousal from sleep Incomplete awakening from sleep
Responsiveness Relative unresponsiveness Inappropriate or absent responsiveness
Recall Little or no recall of dream imagery Little or no associated cognition or dream imagery
Amnesia Amnesia of the episode Partial or complete amnesia of the episode
Functional Impact Significant distress or impairment in social, occupational, or other areas of functioning  
Differential Symptoms cannot be explained by another mental disorder, medical condition, or the effects of drugs of abuse or medication Symptoms cannot be explained by another mental disorder, medical condition, or the effects of drugs of abuse or medication
Initial Expression of Fear Panicked scream Alarming vocalization, such as a frightened scream
Autonomic Symptoms Autonomic arousal Mydriasis, tachycardia, tachypnea, diaphoresis during an episode

 

Pathophysiology

Several precipitating factors for sleep terrors have been suggested, but no consistent structural or biochemical abnormality has been identified to account for all cases of sleep terrors. A dysfunction in the serotoninergic system has been suggested, owing to an association found between adolescents with migraines and a history of sleep terrors.[4] Additionally, some evidence has suggested that the serotonin precursor L-5-hydroxytryptophan and the serotonin reuptake inhibitor paroxetine can help reduce the frequency of sleep terrors.[5]

Sleep studies demonstrate that sleep terrors occur during stages 3 and 4 of non–REM (NREM) sleep. Data from a single-proton emission computed tomography (SPECT) scan in a patient with parasomnia show there was activation of the thalamocingulate pathway with persistent deactivation in the thalamocortical arousal pathway.[6, 7] In one study, 96% of the patients were found to have positive family history in first- to third degree relatives[8, 7] . In a prospective twin study, correlation was more than 0.6 for monozygotic twins compared with 0.36 and 0.24 for dizygotic twins at 18 and 36 months of age, respectively.[9, 7] A high prevalence in those with parasomnias had HLA DQB1*05 and HLA DQB1*04 alleles[10]

A strong correlation between sleep terrors and sleepwalking is noted, with a high frequency of either process in first-degree family members of individuals who experience sleep terrors.[petit] An association of sleep terrors and sleepwalking in family members of individuals with nocturnal frontal lobe epilepsy has also been reported.[11]

Etiology

No specific cause has been identified for sleep terrors. Suggested triggers have included the following:[8, 12] 11[2, 7]

  • Inadequate or irregular sleep schedule

  • Unfamiliar or disruptive sleep environment (including having a TV set in a child's room)

  • Travel

  • Concurrent fever or illness

  • Certain medications such as lithium, clonidine, risperidone [13, 14, 7] anticholinergics, sedative-hypnotic agents and alcohol, and some stimulants
  • A full bladder during sleep

  • Generalized stress

  • Obstructive sleep disorders

  • Periodic limb movements

These triggers do not appear to cause sleep terrors but may lower the threshold for sleep terror events.

An association of sleep terrors and sleepwalking in family members of individuals with nocturnal frontal lobe epilepsy has also been reported.[11]

Epidemiology

It is estimated that between 1% and 6.5% of children and 2.2% of adults experience sleep terrors although prevalence is difficult to accurately assess.[1] In children younger than 3.5 years, the peak frequency is at least 1 episode per week; among older children, the peak frequency is 1–2 episodes per month.[15] The course in adults is more chronic, with significant variability in both the frequency and the severity of episodes among affected individuals.[3]

Night terrors can occur from infancy through adulthood.[16] The age range of peak frequency is 4–12 years for children and 20–30 years for adults. However, one study found peak prevalence in children at 18 months of age, indicating that previous thoughts on prevalence might be affected by lack of studies in children under two years old.[17]  Most childhood-onset sleep terrors resolve by adolescence. Most sources indicate that the genders experience sleep terrors at an equal frequency; however, the APA (in DSM-5) states that the incidence is increased in male children.[3] Sleep terrors are experienced equally across racial categories. In the geriatric population prevalence of sleep terrors is slightly less than 1%.[18]

Prognosis

Most children with sleep terrors experience resolution before adolescence. No increased occurrence of psychiatric diagnoses is found in children. Adults who experience sleep terrors have an increased occurrence of other psychiatric conditions, particularly posttraumatic stress disorder (PTSD), generalized anxiety, and dependent, schizoid, and borderline personality disorders.[3, 9, 19]

As many as one third of children with sleep terrors will develop sleepwalking later in their childhood.[20]

A strong correlation between sleep terrors and sleepwalking is noted, with a high frequency of either process in first-degree famiy members of individuals who experience sleep terrors.[21]

Sleep terrors are fundamentally benign, but some affected individuals may experience trauma from interactions with their surroundings or may injure others attending them. Attempts to awaken an affected individual during an episode are generally unsuccessful and increase the potential of harm to persons offering support.[22]

Patient Education

Families and individuals must understand that sleep terrors are fundamentally benign, self-limited events. Safety measures including modifying the sleep environment to afford increased patient protection, securing windows, and limiting access to potentially harmful situations. Because the affected individual is generally unresponsive to outside interventions, aggressive attempts to intervene should be discouraged. Improvement of sleep hygiene and avoidance of potential triggers may reduce the frequency or severity of events.[12]

For patient education resources, see the Sleep Disorders Center, as well as Night Terrors, Disorders That Disrupt Sleep (Parasomnias), and REM Sleep Behavior Disorder.

Healthy Sleep

In 2016, the American Academy of Sleep Medicine (AASM) issued consensus recommendations for the amount of sleep needed to promote optimal health in children and teenagers and to avoid the health risks of insufficient sleep.[23]

To promote optimal health, the recommendations advise the following amount of sleep (per 24 hours) on a regular basis:

  • Infants 4 to 12 months: 12 to 16 hours of sleep (including naps);

  • Children 1 to 2 years of age: 11 to 14 hours (including naps);

  • Children 3 to 5 years of age: 10 to 13 hours (including naps);

  • Children 6 to 12 years of age: 9 to 12 hours; and

  • Teenagers 13 to 18 years of age: 8 to 10 hours.

 

Presentation

History

Sleep terror is characterized by a sudden arousal from non–rapid eye movement (NREM) sleep (usually from slow-wave sleep) and associated autonomic and behavioral manifestations of fear. Commonly, patients let out a piercing scream, followed by fear, crying and inconsolability. In adults, agitation is often seen. Significant autonomic hyperactivity is present, with tachycardia, tachypnea, flushing, diaphoresis, and increased muscle tone.

The patient is routinely unresponsive to external stimuli and, if awakened, is confused, disoriented, and amnestic regarding the event. It should be cautioned that confrontation of an individual during an episode may be dangerous, in that the individual may become violent. Incoherent vocalizations or micturition have been reported to accompany the event.

Because sleep terror events are relatively common and many affected individuals have family members with similar experiences, many families may not seek medical attention. When the episodes cause clinically significant distress or impairment in social, occupational, or other important areas of functioning, the diagnosis of sleep terrors advances to the diagnosis of NREM sleep arousal disorder, sleep terror type.[3]

Physical Examination

No specific physical findings or signs are expected during a routine physical examination when the individual is awake. Several conditions that may be associated with sleep terror occurrence may demonstrate distinct physical abnormalities (eg, tonsillar enlargement). These findings are not consistent for all individuals who experience sleep terrors and are frequently noted in individuals with no recognized sleep terror occurrences.

 

DDx

Diagnostic Considerations

In addition to the conditions listed in the differential diagnosis, other medical conditions that interrupt sleep and can distress an individual should be considered, including the following:

  • Acute stress disorder

  • Gastroesophageal reflux

  • Hypnagogic hallucinations

  • Nocturnal frontal lobe epilepsy (NFLE)

  • Noncturnal panic attacks

  • Noncturnal seizures

  • Separation anxiety

  • Sleep breathing disorders

  • Sleep paralysis

It is especially important to distinguish sleep terrors from nightmares. The table below compares features of both.

Table 2. Comparison of sleep terrors and nightmares. (Open Table in a new window)

Feature Sleep Terror Nightmare
Categorization Disorder of arousal REM parasomnia
Timing Usually occurs during the first half of the night and typically out of stage N3 slow-wave sleep Begins out of REM sleep and typically occurs in the last third of the night
Family history Frequently positive May be positive
Behavior semiology Sudden arousal with intense screaming, inconsolable crying, agitation, heightened autonomic discharge Paroxysmal awakenings with anxiety dream recall
Event duration Few seconds to minutes Few seconds to minutes
Age at onset Typically < 10 years old Typically < 10 years old
Triggers Sleep deprivation, febrile illness, anxiety, stress, sleep apnea, motor disorders of sleep Sleep deprivation, febrile illness
Frequency Few times per month/week; very rarely >1 episode in a single night Few times per month/week; very rarely >1 episode in a single night
Post-spell Limited to no recall of the events with confusion Recall is typical at times with vivid detail
PSG changes Abrupt arousal from slow-wave sleep (stage N3) with expression of confusion/ambulation/intense fright in all three arousal types, followed by return to sleep; increased cyclic alternating pattern Dense eye(phasic) movements during REM sleep

 

Differential Diagnoses

 

Workup

Approach Considerations

No consistent irregularities in laboratory evaluation have been identified, and no additional workup is required in a classic sleep terror presentation. No specific imaging is indicated with normal development and no focal neurologic abnormalities. If trauma during an episode has been sustained, appropriate imaging should be sought to evaluate the injury.

A sleep diary may help families identify particular triggers for sleep terror events. Comorbidities should be investigated independently of their association with sleep terrors.

Further evaluation and intervention may be required for individuals with significant daytime somnolence, for those who exhibit violent behavior during the episodes that threatens harm to self or others, or in situations where the sleep terrors generate severe distress to family members. Polysomnography is useful if a respiratory disturbance is suspected. However, note that a normal sleep study does not rule out a diagnosis of sleep terror.[2]

If the individual clearly wakes up at the end of the episode abruptly and at no point in time sits up, stands, or walks, the individual may have nocturnal frontal lobe epilepsy. Also, if the individual is seen to undergo head turning to one direction and dystonic posturing during the event, it suggests epilepsy.[18]

When nocturnal seizures are a possibility, routine electroencephalography (EEG) or sleep-deprived EEG may be helpful.[24, 13] EEG findings are often similar with sleep terrors and nocturnal seizures, especially nocturnal frontal lobe epilepsy (NFLE), making diagnosis difficult. Additionally, a normal awake EEG or interictal sleep EEG may not rule out a seizure disorder.[14] Findings on EEG that suggest parasomnias rather than NFLE include the presence of vertex waves, sleep spindles, non-rhythmic theta activity, or evidence of EEG state dissociation with a posterior dominant alpha rhythm. Additionally, NFLE most often presents in stages 1 and 2 of sleep as opposed to parasomnias, which most often present in stages 3 and 4.[25]

 

Treatment

Approach Considerations

In view of the benign and self-limited nature of sleep terrors, most affected individuals require no specific medical intervention other than reassurance, establishing environmental safety, and education.

The use of scheduled awakenings has been suggested as a possible means of reducing sleep terror occurrences.[26] This involves noting what time the episodes usually occur for five nights in a row, then waking the child up 10 to 15 minutes before that time, keeping the child awake for 4 to 5 minutes, then allowing the child to resume sleep.[27]

During episodes, efforts should be made to keep affected individuals from harming themselves or others. These efforts can be supported by removing hazardous objects from the sleep area, securing windows, and impeding exit from the sleep area. Affected children are typically resistant to interference in the midst of a sleep terror event, but patient surveillance to avert injury as permitted may be all that is required.

When the episode has terminated, parents should assist the child back to bed. Discussion of the event immediately or the following day is usually not helpful, because the experience either is not remembered or is only vaguely recalled.Associated comorbid conditions, particularly sleep breathing disorders, should be appropriately treated; this may or may not affect the frequency of sleep terrors.[8] General efforts to promote a stable environment with adequate regular sleep habits are encouraged but may not alter the occurrence of sleep terrors.

Hypnosis has proven to be effective in some children.[2, 7]

Long-Term Monitoring

Routine follow-up and developmental assessment are indicated for all children, including those affected by sleep terrors.

Continued support and reassurance can be helpful for affected families. Surveillance for deviation from classic sleep terror characteristics or increasing severity of behavior during episodes may prompt reconsideration of the diagnosis or increased protective interventions.

 

Guidelines

Guidelines Summary

Healthy sleep

In 2016, the American Academy of Sleep Medicine (AASM) issued consensus recommendations for the amount of sleep needed to promote optimal health in children and teenagers and to avoid the health risks of insufficient sleep.[23]

To promote optimal health, the recommendations advise the following amount of sleep (per 24 hours) on a regular basis:

  • Infants 4 to 12 months of age: 12 to 16 hours of sleep (including naps)
  • Children 1 to 2 years of age: 11 to 14 hours (including naps)
  • Children 3 to 5 years of age: 10 to 13 hours (including naps)
  • Children 6 to 12 years of age: 9 to 12 hours
  • Teenagers 13 to 18 years of age: 8 to 10 hours
 

Medication

Medication Summary

Medications rarely are indicated for sleep terrors and usually provide no long-term help to patients. They should be prescribed only for severe symptoms that affect waking behavior (eg, school performance and peer or family relations) and only after behavioral interventions have failed. Pharmacologic therapy should be administered only as a temporary measure.

Tricyclic Antidepressants

Class Summary

Tricyclic antidepressants decrease deep delta sleep and arousal between sleep stages.

Imipramine (Tofranil, Tofranil-PM)

Imipramine hydrochloride inhibits reuptake of norepinephrine or serotonin at the presynaptic neuron. This agent is an antagonist at histamine H1 and alpha1 adrenoceptors, as well as at M2 muscarinic acetylcholine receptors. In limited studies, imipramine has stopped the disorder when administered at bedtime for 8 weeks.

Amitriptyline

Amitriptyline is a tricyclic antidepressant (TCA) with sedative effects. It inhibits reuptake of serotonin and/or norepinephrine at the presynaptic neuronal membrane, which increases concentration in the central nervous system (CNS). Amitriptyline has been effective in the treatment of REM sleep disorder behaviors.

Benzodiazepines

Class Summary

Some studies suggest that long-term management with low dose clonazepam is effective for adults with severe sleep terrors involving violence or self-injurious behaviors.[28, 6]

Clonazepam (Klonopin)

Long-acting benzodiazepine that increases the presynaptic GABA inhibition and reduces the monosynaptic and polysynaptic reflexes. It has been used off-label for REM and nonREM sleep behavior disorders.

Antidepressants, selective serotonin reuptake inhibitors (SSRIs)

Class Summary

SSRIs are antidepressant agents that inhibit the central nervous system (CNS) neuronal uptake of serotonin and may also have a weak effect on norepinephrine and dopamine neuronal reuptake. SSRIs are used effectively to treat panic attacks. The overlap in symptoms between nocturnal panic attacks and night terrors could suggest a role for SSRIs in the treatment of night terrors.

Paroxetine (Pexeva, Paxil, Paxil CR)

Paroxetine is a potent selective inhibitor of neuronal serotonin reuptake, but it has a weak effect on norepinephrine and dopamine neuronal reuptake. This agent is a low-affinity antagonist at some subtypes of muscarinic acetylcholine receptors and is a nitric oxide synthase inhibitor. The anticholinergic effects of paroxetine may result in sedation or cardiovascular effects. Patients suffering from night terrors have been shown to respond to paroxetine therapy.

 

Questions & Answers

Overview

What are sleep (night) terrors?

What are the signs and symptoms of sleep (night) terrors?

How are sleep (night) terrors diagnosed?

What are the AASM diagnostic criteria for sleep (night) terrors?

Which supportive measures may be helpful in alleviating sleep (night) terrors?

How are sleep (night) terrors characterized?

How do the DSM-5 and ICSD-3 diagnostic criteria for sleep (night) terrors compare?

What is the pathophysiology of sleep (night) terrors?

What causes sleep (night) terrors?

What is the prevalence of sleep terrors?

Which age groups have the highest prevalence of sleep terrors?

What is the prognosis of sleep (night) terrors?

What is included in patient education about sleep (night) terrors?

What are the AASM recommendations for the amount of sleep needed to promote optimal health?

Presentation

Which clinical history findings are characteristic of sleep (night) terrors?

Which physical findings are characteristic of sleep (night) terrors?

DDX

Which conditions are included in the differential diagnoses of sleep (night) terrors?

How are sleep (night) terrors differentiated from nightmares?

What are the differential diagnoses for Sleep Terrors?

Workup

What is the role of lab tests and imaging in the workup of sleep (night) terrors?

What is the role of a sleep diary in the workup of sleep (night) terrors?

What is the role of polysomnography in the workup of sleep (night) terrors?

What is the role of EEG in the workup of sleep (night) terrors?

Treatment

How are sleep (night) terrors treated?

What is included in the long-term monitoring of sleep (night) terrors?

Guidelines

What are the AASM healthy sleep guidelines?

Medications

What is the role of medications in the treatment of sleep (night) terrors?

Which medications in the drug class Antidepressants, selective serotonin reuptake inhibitors (SSRIs) are used in the treatment of Sleep Terrors?

Which medications in the drug class Benzodiazepines are used in the treatment of Sleep Terrors?

Which medications in the drug class Tricyclic Antidepressants are used in the treatment of Sleep Terrors?