0685 Preliminary Data from the REM Sleep Behavior Disorder Associations with Parkinson’s Disease Study (RAPiDS)

Abstract

Introduction: Rapid eye movement (REM) sleep behavior disorder (RBD) is accepted as a significant risk factor for development of alpha-synucleinopathies, comprising neurodegenerative disorders such as Parkinson's disease (PD). However, there are as yet no means of predicting prognosis in RBD patients. We have initiated the REM Behavior Disorder Associations with Parkinson's Disease Study (RAPiDS) database and biorepository, to enroll and track 100 patients with RBD and REM sleep without atonia (RSWA), with the initial goal of examining association of specific clinical, neurophysiological, and laboratory tests that may be predictive of prognosis. Here we report baseline data on our initial enrollees. Methods: Participants with RBD and/or RSWA were prospectively recruited from the Weill Cornell Center for Sleep Medicine. Those with a diagnosed neurodegenerative disorder were excluded. Evaluations comprised polysomnography, medical and neurological history, and standardized rating scales and examination focused on neurologic, neuropsychiatric, and autonomic function. Results: Participants evaluated included 12 with RBD and 1 with RSWA, with mean 3.15 ± 3.1 years since diagnosis. Mean age was 58.1 ± 16.6 years, and 4/13 were women. Total sleep time was 398 ± 107.1 minutes with sleep efficiency 80.3 ± 14%. Respiratory disturbance index was 5.5 ± 4.9 events/hour and periodic limb movement index was 28.9 ± 37.5 events/hour. Depression was reported in 69%; antidepressant medications were used in 46%; 69% had tremor; 38% had subtle signs of parkinsonism; 31% had cognitive dysfunction; 38% had constipation; and 10% had urinary dysfunction. None had orthostasis. Conclusion: We report initial baseline data from the longitudinal observational RAPiDS study, recruiting a well-characterized cohort with RBD/RSWA. Despite excluding patients with a known neurodegenerative disorder, we detected an unexpectedly high incidence of subtle neuropsychiatric and neurological symptoms and signs. We propose the term “RBD-plus” to describe such patients, and will track for phenoconversion in the longitudinal phase of the RAPiDS study. While it is too early to detect what factors may be implicated in the conversion to alpha-synucleinopathy, our cohort will allow for improved understanding and characterization of which patients are at risk.