What Is the Prognostic Significance of Rapid Eye Movement Sleep Without Atonia in a Polysomnogram?

Freud said we are lucky to be paralyzed during sleep, so we cannot act out our dreams. Atonia of skeletal muscles normally present during rapid eye movement sleep prevents us from acting out our dreams. Observing rapid eye movement sleep without atonia in a polysomnogram in older adults first and foremost warrants consideration of rapid eye movement behavior disorder. Seventy-five to 90% of older adults with isolated rapid eye movement behavior disorder will develop a neurodegenerative disease within 15 years, most often a synucleinopathy. Rapid eye movement sleep without atonia in those younger than 50 years is commonly found in individuals with narcolepsy and those taking antidepressant medications.