Evolution of Motor and Nonmotor Characteristics in an Idiopathic/Isolated REM Sleep Behavior Disorder Cohort

New research led by NAPS Co-Principal Investigator Dr. Ronald Postuma, sheds light on the earliest signs of synucleinopathies like Parkinson’s disease, dementia with Lewy bodies, and multiple system atrophy.

In a long-term study of people with iRBD, researchers tracked changes up to 14 years before diagnosis:

🕺 Motor symptoms: slow changes start 10 years prior, with sharp decline ~4 years before diagnosis.

🧠 Cognition & color vision: begin worsening 4–5 years prior.

👃 Smell loss & autonomic symptoms: appear much earlier (up to 14 and 12 years before).

These findings highlight overlapping but distinct trajectories between PD and DLB and underscore how early detection in iRBD may help predict and prepare for disease progression.