Physiology, REM Sleep

Excerpt

Sleep is a reversible state of disconnection from the environment, characterized by reduced consciousness, skeletal muscle immobility, and metabolic slowdown. All forms of sensory responses are markedly decreased to varying degrees, depending on the stage of the sleep cycle. Although this phenomenon is observed in all species studied and occupies a significant portion of the human lifespan, the purpose and function of sleep remain poorly understood.

Sleep is measured primarily by polysomnography (PSG) which is considered the gold standard for diagnosing sleep disorders.. PSG reveals that sleep architecture comprises several distinct stages that alternate between non-rapid eye movement (NREM) stages and rapid eye movement (REM) stages. The REM stage is of particular interest due to its association with various pathological, psychological, and physiological phenomena. The wide variety of medical and psychiatric pathologies, as well as common pharmacotherapies that can disrupt normal sleep, are summarized in this topic. With more than 50 million Americans affected by sleep loss, the treatment of sleep disorders is becoming an increasingly more specialized and interprofessional field with a significant impact on patient health in both acute and chronic settings.