Scientists really do not know properly the actual cause of RBD apart from the animal studies. But Nerve pathways in the brain that prevent muscles from moving are active during normal REM or dreaming sleep, resulting in temporary paralysis of your body. In REM sleep behavior disorder, these pathways no longer work and you may physically act out your dreams. There is a successful treatment effective of 90% of patients without tolerance and abuse by using Clonazepam. Usually results are shown after a few nights.