Because REM sleep is characterized by paralysis, the person does not move around while they are asleep. With Rapid Eye Movement Sleep Behavior Disorder (RBD), however, that paralysis is weakened. As a result, sleepers with RBD can act out their dreams, and risk injuring themselves and/or their bed partners.
RBD-related behaviors range in severity from loud talking, swearing, laughing and shouting to reaching, grabbing, leaping out of bed, and crawling. Walking is uncommon, however.
The person usually remembers dreams that are associated with RBD episodes, including nightmares in which the patient tries to defend himself from an attacker1.
The International Classification of Sleep Disorders (ICSD) lists RBD as a REM-Related Parasomnia2.
- Boeve, B., REM sleep behavior disorder: updated review of the core features, the RBD-neurodegenerative disease association, evolving concepts, controversies, and future directions, Ann N Y Acad Sci;1184:15-54, 2010.
- American Academy of Sleep Medicine, International Classification of Sleep Disorders (Third Edition), Darien, IL: American Academy of Sleep Medicine, 2014.