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.
Tables
| 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 |
| 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 |
