Objective: Posttraumatic stress disorder (PTSD) and traumatic brain injury (TBI), which are prevalent conditions among post-9/11 veterans, increase risks of rapid eye movement (REM) sleep behavior disorder (RBD) and degenerative synucleinopathy. Rates and predictors of RBD symptoms were investigated by screening post-9/11 veterans for RBD with a validated questionnaire.
Methods: In this cross-sectional analysis, consecutive patients in the Houston Translational Research Center for TBI and Stress Disorders (TRACTS) were screened with the English translation of the RBD Questionnaire-Hong Kong (RBDQ-HK). In addition to data from the standard TRACTS battery, systematic chart review was used to identify known sleep disorders mimicking or manifesting RBD.
Results: Of the 119 patients with available RBDQ-HK scores, 71 (60%) and 65 (55%) screened positive for RBD, when a total score ≥21 and a factor 2 score ≥8 were used as cutoff scores, respectively. Univariable analyses with both cutoffs showed consistent associations between a positive RBDQ-HK screen and global sleep quality, number of TBI exposures, and PTSD severity. Multivariable logistic regression with total score ≥21 as a cutoff indicated that PTSD severity (odds ratio=1.06, 95% CI=1.02-1.10) and number of TBIs (odds ratio=1.63, 95% CI=1.16-2.41) were independent predictors of a positive screen, whereas global sleep quality was no longer significant. Multivariable logistic regression with factor 2 score ≥8 as a cutoff showed similar results.
Conclusions: Interdisciplinary parasomnia assessment, further validation of RBD screens, and standardized reporting of REM sleep without atonia could provide necessary information on the pathophysiological relationships linking PTSD, TBI, RBD symptoms, and ultimately synucleinopathy risk among post-9/11 veterans.
Keywords: Parasomnias; Posttraumatic Stress Disorder; REM Sleep Behavior Disorder; Rapid Eye Movement Sleep; Traumatic Brain Injury; Veterans.