Sleepwalking and night terrors: psychopathological and psychophysiological correlates

Sleepwalking and night terrors are considered to be manifestations of the same nosologic continuum. It has been proposed that a sudden arousal from non-rapid eye movement (NREM) sleep is the cause of these disorders. Benign forms of NREM arousal parasomnias occur frequently in childhood and attenuate in teen years; however, they can persist into or begin in adulthood. The available literature documents high levels of psychopathology in adult patients. Sleepwalking and night terrors are most likely to manifest during the first episode of slow wave sleep, but may also appear any time during NREM sleep. The hypersynchronous delta activity, previously considered to be a hallmark of somnambulism, has proven to be unspecific. Post-arousal EEG activity reveals altered consciousness during sleepwalking and sleep terror episodes. Pathophysiology of NREM arousal parasomnias consists of predisposing factors, which may be a genetically determined tendency for deep sleep, facilitating factors which deepen sleep and increase slow wave sleep, and triggering factors which increase sleep fragmentation, such as stress, environmental or endogenous stimuli, and stimulants. Recently published data on low delta power in the first sleep cycle and slow decline of delta power in successive sleep cycles suggest a chronic inability to sustain slow wave sleep.