Sleep terrors are characterized by a sudden arousal from slow wave sleep with a piercing scream or cry, accompanied by autonomic (controlled by the part of the nervous system that regulates motor functions of the heart, lungs, etc.) and behavioral manifestations of intense fear.
Sleep terror are also referred to as Pavor Nocturnus, incubus, severe autonomic discharge and night terrors.
Sleep terrors are indicated by a sudden episode of intense terror during sleep. The episodes usually occur within the 1st third of the night. Partial or total amnesia occurs for the events during the episode.
Polysomnographic monitoring demonstrates the onset of episodes during stage 3 or 4 sleep. Tachycardia usually occurs in association with the episodes. Other medical disorders are not the cause of the episode, e.g., epilepsy. Other sleep disorders can be present, e.g., nightmares.
Some people have episodes of sleep terrors that may occur less than once per week or once per month, and these episodes do not result in harm to the patient or others. In its severest form, the episodes occur almost nightly, or are associated with physical injury to the patient or others. Consult a sleep specialist if you are concerned.