This study will enroll participants with idiopathic REM sleep behavior disorder (RBD) and healthy controls for the purpose of preparing for a clinical trial of neuroprotective treatments against synucleinopathies.

REM sleep behavior disorder (RBD) is a disorder where people act out their dreams. People with RBD often, but not always, develop Parkinson's Disease, dementia with Lewy bodies, multiple system atrophy, or other neurodegenerative diseases of the synucleinopathy type.

The North American Prodromal Synucleinopathy Consortium Stage 2 (NAPS2) was formed with the purpose of enrolling participants with RBD, in anticipation of a future clinical trial of a neuroprotective trreatment against synucleinopathies. The NAPS Consortium will collect standardized clinical assessments, biofluids, and neuroimaging data. The RBD group will also undergo two overnight sleep studies. Some of this data will be used to develop biomarkers for synucleinopathies in the prodromal (presymptomatic) stage as well as a trial-ready registry of participants.

RBD group procedures include a clinical assessment, questionnaires, blood draw, neuroimaging (MRI and DaTscan), polysomnogram (sleep study), and optional lumbar puncture.

Control group procedures include a clinical assessment, questionnaires, blood draw, neuroimaging (MRI), and lumbar puncture.

Inclusion Criteria for RBD Group

1. Polysomnogram-confirmed RBD by ICSD-3 criteria
2. Capable of providing informed consent at time of study enrollment
3. Age > 18 years

Exclusion Criteria for RBD Group

1. Diagnosis of PD, dementia of any type, or MSA unless previous participant in NAPS1.
2. Narcolepsy-associated RBD
3. RBD secondary to any known cause except prodromal synucleinopathy.
4. Participation in a clinical trial, except by specific permission by the Executive Committee
5. In the opinion of the investigator, the individual has a clinically significant uncontrolled medical condition that would impede safe completion of the study protocol

Inclusion Criteria for Control Group

1. Ability to provide written consent
2. Age > 18 years
3. Must meet age, sex, and race matching criteria per the Data Management and Statistical core recommendations for the site
4. Must be willing to undergo all testing procedures, including neuroimaging and lumbar puncture.
5. Normal capacity to perform complex activities of daily living independently based on informant or physician report

Exclusion Criteria for Control Group

1. History of dream enactment behavior to suggest RBD
2. Parkinsonism, MSA, dementia, or mild cognitive impairment
3. Active central nervous system, systemic, psychiatric condition or use of psychoactive medication that would adversely affect cognitive, neuropsychiatric, motor, or autonomic functioning.
4. Contraindications to complete MRI.
5. Contraindications to lumbar puncture.
6. Participation in a clinical trial, except by specific permission by the Executive Committee
7. In the opinion of the investigator, the individual has a clinically significant uncontrolled medical condition that would impede safe completion of the study protocol

Idiopathic REM sleep behavior disorder, adults.

De-identified subject level data will be shared upon approved data request. This project will develop a large database of potential neurocognitive, neuroimaging, genetic, and polysomnographic biomarkers in rapid eye movement sleep behavior disorder (RBD), as well as a biobank of blood, DNA, RNA, and cerebrospinal fluid. A large part of the clinical battery is the Uniform Dataset version 3, will be uploaded to the National Alzheimer's Coordinating Center (NACC). Biofluid samples will be banked at the National Cell Repository for Alzheimer's Disease (NCRAD). Genetic data will be submitted to the National Institute on Aging Genetics of Alzheimer's Disease Data Storage (NIAGADS). Brain MRI and DaTscan imaging data will be uploaded to the Laboratory of NeuroImaging (LONI). Polysomnogram data will be uploaded to the National Sleep Research Resource (NSRR).

Updated datasets will be made available after completion of each semiannual data cleaning and data freeze. De-identified data will be available for at least the duration of the NAPS2 study.

The NAPS2 Administrative Core will receive, process, and track all requests for data/biospecimens. All requests will be reviewed and tracked per the current NAPS Data Access Policy (https://www.naps-rbd.org/resources at the bottom of the webpage) at the time of request. Approved requests will be filled using data that has been de-identified.