Treatment of REM Sleep Behavior Disorder (RBD) With Sodium Oxybate

"Sodium Oxybate will be titrated up weekly by 1.5g nightly dose increments from an initial 4.5g total nightly dose (which could be given in two unequal doses if needed, or one single dose no greater than 4.5g) to an optimal individual dose based on clinical response on RBD symptoms and tolerance, to a maximum nightly dose of 9g (flexible dose period lasting up to 8 weeks). The optimal dose will then be continued for at least 4 weeks (stable dose)."

Placebo will be similar in appearance, smell and flavor to the subjects, so that the investigators and participants will be unable to distinguish it from sodium oxybate.