During normal REM sleep, we experience a state of muscle paralysis which does not allow us to physically act out our dreams. This is because our voluntary muscles exhibit a generalized atonia (Latin for without tone). Generally this is a good thing, because we have our most vivid dreams during REM sleep.
People with Rapid Eye Movement Sleep Behavior Disorder, or RBD, lack this muscle paralysis. They are able to react physically to the content of their dreams, often kicking, screaming, punching, jabbing or jumping out of bed and injuring themselves or others when faced with dreams that are action-filled or unpleasant.
Upon awakening, a person with RBD is usually quickly alert and can recall the content of their dreams, but they will not be aware that they were moving.
RBD is a male-predominant disorder that usually emerges after age 50. It has come to be closely associated with the development of neurodegenerative disorders such Parkinsons Disease. RBD may occur in younger individuals but, in such cases, other factors should be considered such as medication-induced RBD (from the likes of Serotonin-Reuptake Inhibitors, or SSRIs) or untreated Obstructive Sleep Apnea.
Potential forensic implications:
- fall risk