Parasomnia Dreams: The Other Forms of Sleep-associated Consciousness  James Pagel (Family Medicine - Pueblo, University of Colorado School of Medicine, Pueblo, CO )   C21

Dreaming is reported from all of the polysomnographically described states of sleep. The sleep states are considered to be states of consciousness because of reports of mentation occurring in sleep (dreaming). Parasomnias, classified based on the sleep stage in which they occur, are undesired and disruptive sleep disorders inducing arousal, sometimes associated with strange and unusual behaviors. Nightmares disorder, sleep paralysis, and REM behaviour disorder are rapid-eye movement sleep (REMS) parasomnias that include dream reports. These parasomnias describe the psychological and physiological extremes of the REMS dream experience. Much of what we know of sleep consciousness outside REMS comes from the dream reports obtained on awakening after individual experiences of a non-REMS parasomnia. Sleep starts, sleep paralysis, and hypnagogic hallucinations are associated with sleep onset (stage 1). Sleep talking and panic attacks occur most often in light sleep (stage 2). Somnambulism (sleep walking), night terrors and confusional arousals are associated with dream reports and strange/unusual behaviors on awakening from deep sleep (stage 3). Parasomnia associated dream mentation is commonly experienced, most often not reflective of underlying medical or psychiatric disease, and quite different from the mentation associated with alternative forms of consciousness induced by drugs in waking. Dreams are manifestations of underlying central nervous system (CNS) activity. The dream mentation reported from each defined sleep state reflects the well-described electrophysiology, neuroanatomy, neurochemistry, and neurophysiology that underlies each sleep stage. The parasomnias occurring in association with a particular stage of sleep share stage-associated characteristics. These sleep state specific reports have consistent formal characteristics, bizarreness, and types of thought processing that can be used to develop and describe the typical phenomenology of dream mentation reported from each state of consciousness. The typical dreams of each state differ markedly. Parasomnia dream reports can include intense visual hallucinations, extreme emotions, apparently real dream worlds, as well as confusion, autonomic discharge, and strange automatic behaviors on awakening. The dreaming reported from each sleep state has a characteristic phenomenology. Such sleep state associated dream phenomenology can be used in the attempt to determine whether a reported dream was most likely to have originated in REM sleep, sleep onset (Stage 1), Stage 2, or in deep sleep (Stage 3). Aspects of phenomenological consciousness reported from each sleep stage can be correlated with what is known of that sleep state physiology. Further study of parasomnia associated cognition offers the possibility for extending our understanding of the different forms of sleep consciousness described by their associated dreams.