To report neurodegenerative outcomes of patients with REM Sleep Behavior Disorder (RBD) or isolated REM sleep without atonia (RSWA).

This IRB-approved retrospective cohort study was comprised of patients who underwent in-lab sleep studies at our institution for any indication between 2006-2016.  All patients had a sleep study procedure report completed by a sleep medicine physician, which also detailed comorbidities and medications at the time of testing.  Medical records were queried for diagnoses of neurodegenerative disease made after testing.  Patients under 40 years, with pre-existing diagnosis of a neurodegenerative disorder, or with under one year of follow-up with an institutional provider after sleep testing were excluded.

142 patients (73% male, mean age 62 years) were identified with a diagnosis of RBD (n=102 patients) or isolated RSWA (n=40 patients).    Patients were followed for an average of 55.5 months (SD +/- 25.4 months).  23% of patients had a new diagnosis of any neurodegenerative disease.   Parkinson’s disease was the most common diagnosis (n=15), followed by mild cognitive impairment (n=13), and Lewy body dementia (n=6). When patients were stratified by RBD or isolated RSWA, 29% of RBD patients developed neurodegenerative disease compared with only 5% of isolated RSWA patients (p = 0.005).

To our knowledge, this is one of the largest RBD cohort studies in the United States.  Our findings corroborate with previous studies with respect to neurodegenerative outcomes, indicating our methodology may be viable for detecting patients at high risk of neurodegeneration.  Patients diagnosed with isolated RSWA were at lower risk for conversion to neurodegenerative disease than those diagnosed with RBD.