Posttraumatic stress disorder increases the odds of REM sleep behavior disorder and other parasomnias in Veterans with and without comorbid traumatic brain injury

Abstract

Study objectives: To describe the crude prevalence of rapid eye movement (REM) sleep behavior disorder (RBD) following traumatic brain injury (TBI) and posttraumatic stress disorder (PTSD) in Veterans, given potential relationships between TBI, PTSD, RBD, and neurodegeneration.

Methods: Veterans (n = 394; 94% male; 54.4 ± 15.5 years of age) were prospectively/cross-sectionally recruited from the VA Portland Health Care System and completed in-lab video-polysomnography and questionnaires. TBI and PTSD were assessed via diagnostic screening and medical record review. Subjects were categorized into four groups after assessment of REM sleep without atonia (RSWA) and self-reported dream enactment: (1) "Normal," neither RSWA nor dream enactment, (2) "Other Parasomnia," dream enactment without RSWA, (3) "RSWA," isolated-RSWA without dream enactment, and (4) "RBD," RSWA with dream enactment. Crude prevalence, prevalence odds ratio, and prevalence rate for parasomnias across subjects with TBI and/or PTSD were assessed.

Results: Overall prevalence rates were 31%, 7%, and 9% for Other Parasomnia, RSWA, and RBD, respectively. The prevalence rate of RBD increased to 15% in PTSD subjects [age adjusted POR: 2.81 (1.17-4.66)] and to 21% in TBI + PTSD subjects [age adjusted POR: 3.43 (1.20-9.35)]. No subjects met all diagnostic criteria for trauma-associated sleep disorder (TASD), and no overt dream enactment was captured on video.

Conclusions: The prevalence of RBD and related parasomnias is significantly higher in Veterans compared with the general population and is associated with PTSD and TBI + PTSD. Considering the association between idiopathic-RBD and synucleinopathy, it remains unclear whether RBD (and potentially TASD) associated with PTSD or TBI + PTSD similarly increases risk for long-term neurologic sequelae.

Keywords: PTSD; RBD; REM sleep without atonia; TBI; trauma-associated sleep disorder.

Figure 1.

Study overview. Schematic overview of our patient population, exclusion criteria and parasomnia grouping. Of the total n = 595 subjects evaluated with in-lab polysomnography, we excluded n = 76 for having <4 hr of recorded sleep, n = 11 for having <10 epochs of recorded REM sleep, n = 114 for reporting selective serotonin reuptake inhibitor (SSRI), selective norepinephrine reuptake inhibitor (SNRI), or tricyclic antidepressant (TCA) use. Mentalis muscle electromyographic (EMG) activity in the remaining n = 394 subjects was analyzed according to American Academy of Sleep Medicine (AASM) criteria [29] to separate subjects into those with normal (n = 333, 85%) and abnormal (n = 61, 15%) REM sleep EMG activity. Subjects were subsequently further stratified based on their self-reported history of dream enactment [30]. Those with normal REM sleep EMG activity and no history of dream enactment (Normal; n = 211, 53%), those with normal REM sleep EMG activity and a history of dream enactment (Other Parasomnia; n = 122, 31%), those with abnormal REM sleep EMG activity and no history of dream enactment (RSWA; n = 27, 7%), those with abnormal REM sleep EMG activity and a history of dream enactment (RBD; n = 34, 9%). In the analysis of abnormal REM sleep EMG activity, epochs that co-occurred with an apnea or hypopnea were not considered “abnormal.” Thus, only epochs that unambiguously met AASM criteria for abnormal REM sleep EMG activity (i.e. RSWA) contributed to the identification of RSWA and RBD.

Figure 2.

Schematic representation of neuropsychiatric trauma and sleep parasomnia. Subjects with neither a TBI nor PTSD, TBI alone, PTSD alone, and comorbid TBI + PTSD are oriented along the abscissa. For each trauma group, the total percentage of subjects with Normal sleep (clear bar), Other Parasomnia (light fill), RSWA (dark fill), and RBD (totally filled) are shown. Accordingly, the general breakdown between Normal sleep and a parasomnia, within trauma groups, is readily evident. Note the significant percentage of subjects with PTSD or TBI + PTSD that have RBD.