Specialist Approaches to Prognostic Counseling in Isolated REM Sleep Behavior Disorder / iRBD, Library / By Rob Most middle-aged and older adult patients with isolated (idiopathic) REM sleep behavior disorder (RBD) eventually develop parkinsonism, dementia with Lewy bodies, or multiple system atrophy.https://doi.org/10.1016/j.sleep.2020.12.014