Use dream enactment behavior, circadian timing, and nocturnal cramps to separate REM sleep behavior disorder from circadian phase advance and leg cramp syndromes. Document the dominant clinical clue and the next bedside decision.

REM sleep behavior disorder is linked to alpha-synucleinopathies and narcolepsy; Clonazepam is the standard treatment for violent dream enactment; Advanced phase sleep disorder causes very early sleep and very early awakening; Nocturnal leg cramps should prompt a neurologic review when frequent or severe; Quinine is no longer a preferred leg cramp treatment because of safety concerns