Probable rapid eye movement (REM) sleep behavior disorder (pRBD) is a synucleinopathy-associated parasomnia in which loss of REM sleep muscle atonia results in motor behavior during REM sleep, including dream enactment. Traumatic brain injury is independently associated with increased risk of pRBD and Lewy body disease, and both pRBD and Lewy body disease are often observed in chronic traumatic encephalopathy (CTE). However, the frequency and pathological substrate of pRBD in CTE have not been formally studied and remain unknown. Of the total sample of 247 men, age at death of 63.1 ± 18.8 years (mean ± SD), 80 [32%] were determined by informant report to have symptoms of pRBD. These participants had played more years of contact sports (18.3 ± 11.4) than those without pRBD (15.1 ± 6.5; P = 0.02) and had an increased frequency of Lewy body disease (26/80 [33%] vs 28/167 [17%], P = 0.005). Of the 80 participants with pRBD, 54 [68%] did not have Lewy body disease; these participants were more likely to have neurofibrillary tangles and pretangles in the dorsal and median raphe (41 of 49 [84%] non-LBD participants with pRBD symptoms vs 90 of 136 [66%] non-LBD participants without pRBD symptoms, P = 0.02), brainstem nuclei with sleep regulatory function. Binary logistic regression modeling in the total study sample showed that pRBD in CTE was associated with dorsal and median raphe nuclei neurofibrillary tangles (OR = 3.96, 95% CI [1.43, 10.96], P = 0.008), Lewy body pathology (OR = 2.36, 95% CI [1.18, 4.72], P = 0.02), and years of contact sports participation (OR = 1.04, 95% CI [1.00, 1.08], P = 0.04). Overall, pRBD in CTE is associated with increased years of contact sports participation and may be attributable to Lewy body and brainstem tau pathologies.
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We gratefully acknowledge the use of resources and facilities at the Edith Nourse Rogers Memorial Veterans Hospital (Bedford, MA) as well as all the individuals whose participation and contributions made this work possible.
This work was supported by the Department of Veterans Affairs, Veterans Health Administration, Clinical Sciences Research and Development Merit Award (I01-CX001038); Veterans Affairs Biorepository (BX002466); Alzheimer’s Association (NIRG-305779, NIRG-362697); National Institute of General Medical Sciences (5T32GM007198); National Institute of Aging (RF1AG054156, R56AG057768, RF1AG057768, K23AG046377); National Institute of Neurological Disorders and Stroke (U54NS115266, U01NS086659, K23NS102399); National Institute of Aging Boston University AD Center (P30AG13846; supplement 0572063345-5); Department of Defense Peer Reviewed Alzheimer’s Research Program (PRARP #13267017); and the Concussion Legacy Foundation. This work was also supported by unrestricted gifts from the Andlinger Foundation and WWE.
Conflict of interest
Michael L. Alosco has received honorarium as a Scientific Advisor for Corino Therapeutics, Inc. Dr Goldstein is a paid consultant to Johnson & Johnson, Janssen Research & Development LLC, and Rebiscan Inc, and has received funding from the WWE (World Wrestling Entertainment) and Ivivi Health Sciences. Dr Stern has received research funding from Avid Radiopharmaceuticals Inc, is a member of the Mackey-White Committee of the National Football League Players Association, is a paid consultant to Biogen and Eli Lilly, receives royalties for published neuropsychological tests from Psychological Assessment Resources Inc, and is a member of the Board of Directors of King-Devick Technologies. Dr Cantu is a paid consultant to the National Football League Head Neck and Spine Committee, a vice president and chair of the scientific advisory committee of the National Operating Committee on Standards for Athletic Equipment, and a consultant to the Concussion Legacy Foundation; he also receives royalties from Houghton Mifflin Harcourt and compensation for expert legal opinion to the National Collegiate Athletic Association and National Hockey League and is a member of the Mackey-White Committee of the National Football League Players Association. Dr McKee is a member of the Mackey-White Committee of the National Football League Players Association and reports receiving grants from the National Institutes of Health and Department of Veteran Affairs. Dr Alosco reported grants from National Institutes of Health/National Institute of Neurological Disorders and Stroke during the conduct of the study. Dr Katz reported grants from Boston University School of Medicine Department of Neurology during the conduct of the study. Dr Stern reported grants from the National Institutes of Health during the conduct of the study; personal fees from Biogen and Eli Lilly outside the submitted work; membership on the board of directors for King-Devick Technologies, with stock options; and royalties for published neuropsychological tests from Psychological Assessment Resources Inc. Dr Mez reported grants from the National Institutes of Health, Department of Defense, Alzheimer’s Association, and Concussion Legacy Foundation during the conduct of the study. No other disclosures were reported.
The study was performed in accordance with the ethical standards established by the 1964 Declaration of Helsinki and its later amendments or comparable ethical standards. Institutional review board approval was granted from the Boston University Medical Center (BUMC) and the Edith Nourse Rogers Memorial Veterans Hospital, Bedford, MA. The BUMC IRB also granted approval for postmortem clinical record review, neuropathological evaluation, and clinical interviews with donor family members.
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Adams, J.W., Alosco, M.L., Mez, J. et al. Association of probable REM sleep behavior disorder with pathology and years of contact sports play in chronic traumatic encephalopathy. Acta Neuropathol (2020). https://doi.org/10.1007/s00401-020-02206-x
- Chronic traumatic encephalopathy
- REM sleep behavior disorder
- Lewy body disease
- Repetitive head impacts
- Contact sports