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A night terror, sleep terror or ''pavor nocturnus'' is a sleep disorder, causing feelings of terror or dread, and typically occurs during the first hours of stage 3-4 non-rapid eye movement (NREM) sleep. Night terrors tend to happen during periods of arousal from delta sleep, also known as slow-wave sleep. During the first half of a sleep cycle, delta sleep occurs most often, which indicates that people with more delta sleep activity are more prone to night terrors.〔 However, they can also occur during daytime naps. Night terrors have been known since ancient times, although it was impossible to differentiate them from nightmares until rapid eye movement was discovered.〔 While nightmares (bad dreams that cause feelings of horror or fear) are relatively common during childhood, night terrors occur less frequently according to the American Academy of Child and Adolescent Psychiatry. The prevalence of sleep terror episodes has been estimated at 1%–6% among children, and at less than 1% of adults. Night terrors can often be mistaken for confusional arousal.〔 Sleep terrors begin between ages 3 and 12 years and then usually dissipate during adolescence. In adults, they most commonly occur between the ages of 20 to 30. Though the frequency and severity vary between individuals, the episodes can occur in intervals of days or weeks, but can also occur over consecutive nights or multiple times in one night.〔〔 Night terrors are a largely unknown phenomenon. This has created a situation in which any type of nocturnal attack or nightmare may be confused with and reported as a night terror.〔 ==Signs and symptoms== The universal feature of night terrors is inconsolability. During night terror bouts, patients are usually described as "bolting upright" with their eyes wide open and a look of fear and panic on their faces. They will often scream. Furthermore, they will usually sweat, exhibit rapid breathing, and have a rapid heart rate (''autonomic signs''). In some cases, individuals are likely to have even more elaborate motor activity, such as a thrashing of limbs—which may include punching, swinging, or fleeing motions. There is a sense that the individuals are trying to protect themselves and/or escape from a possible threat of bodily injury.〔 Although people may seem to be awake during a night terror, they will appear confused, be inconsolable and/or unresponsive to attempts to communicate with them, and may not recognize others familiar to them. Occasionally, when a person with a night terror is awakened, they will lash out at the one awakening them, which can be dangerous to that individual.〔 Most people who experience this do not remember the incident the next day.〔 Sleepwalking is also common during night terror bouts,〔 as sleepwalking and night terrors are different manifestations of the same parasomnia.〔 During lab tests, subjects are known to have very high voltages of electroencephalography (EEG) delta activity, an increase in muscle tone, and a doubled increase in heart rate, if not more. Brain activities during a typical episode show theta and alpha activity when using an EEG. It is also common to see abrupt arousal from NREM sleep that does not progress into a full episode of a night terror. These episodes can include tachycardia. Night terrors are also associated with intense autonomic discharge of tachypnea, flushing, diaphoresis, and mydriasis.〔 That is, unconscious or involuntary rapid breathing, reddening of the skin, profuse sweating, and dilation of the pupils. In children with night terrors, there is no increased occurrence of psychiatric diagnoses.〔 However, in adults who suffer from night terrors there is a close association with psychopathology or mental disorders. There may be an increased occurrence of night terrors—particularly among those suffering or having suffered from post-traumatic stress disorder (PTSD) and generalized anxiety disorder (GAD). It is also likely that some personality disorders may occur in individuals with night terrors, such as dependent, schizoid, and borderline personality disorders.〔(【引用サイトリンク】 title=Night Terrors Follow-up - Prognosis )〕 There have been some symptoms of depression and anxiety that have increased in individuals that have suffered from frequent night terrors. Low blood sugar is associated with both pediatric and adult night terrors.〔〔Blog from Fountia, "Things You Didn’t Know About Night Terrors"〕 A study of adults with thalamic lesions of the brain and brainstem have been occasionally associated with night terrors. Night terrors are closely linked to sleepwalking and frontal lobe epilepsy.〔(【引用サイトリンク】 title=Night Terrors - Pathophysiology )〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Night terror」の詳細全文を読む スポンサード リンク
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