(Medical Xpress)—A troubling sleep disorder that causes sleepers to physically act out their dreams by kicking, screaming or falling out of bed may be more common than reported, according to Loyola University Medical Center sleep specialist Dr. Nabeela Nasir.

The condition is called REM behavior disorder. The sleeper, usually a man, will kick, punch, scream, thrash about or fall out of bed, potentially injuring himself or his partner.

"I don't think we have a clear idea of how prevalent it is," Dr. Nasir said. "Patients don't report it and doctors don't ask about it."

Dr. Nasir would like to raise awareness of the disorder because sufferers often can be treated successfully with medications. And even when medications don't work, patients can prevent injuries to themselves and their partners by safe-proofing their bedrooms, Dr. Nasir said.

REM behavior disorder occurs during rapid-eye movement (REM) sleep, when dreams occur. Normally, a sleeper's muscles don't move during dreams. But this temporary paralysis doesn't occur in patients with REM behavior disorder. They physically act out vivid dreams in which they are, for example, running, fighting, hunting, warding off attackers, etc.

REM behavior disorder belongs to a class of sleeping disorders called parasomnias, which also includes sleep walking and eating while sleeping.
REM behavior disorder occurs most often in men, typically after age 60. Many patients eventually develop Parkinson's disease or other neurodegenerative disorders - but this does not happen to everyone.

Many patients can be successfully treated with a class of medications called benzodiazepines. One such drug is clonazepam, which works by decreasing in the brain. (Side effects may include daytime drowsiness and dependence.) , a hormone that helps to regulate the sleep-wake cycle, also is being studied as a treatment.

Dr. Nasir recommends safe-proofing the bedroom. For example: Sleep on a mattress on the floor; clear the room of furniture and objects that could cause injury, such as glass lamps; and sleep alone, if necessary.

Not all dream enactments are caused by REM . In some people, alcohol or antidepressants can trigger dream enactments, Dr. Nasir said. Patients who act out their dreams, or experience other , should see a specialist, Dr. Nasir said.