Sleep is critical for proper sensory and social development in young prairie voles, an affiliative and monogamous rodent species.

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.

Clearance of perivascular wastes in the brain may be critical to the pathogenesis of amyloidopathies. Enlarged perivascular spaces (ePVS) on MRI have also been associated with amyloidopathies, suggesting that there may be a mechanistic link between ePVS and impaired clearance. Sleep and traumatic brain injury (TBI) both modulate clearance of amyloid-beta through glymphatic function. Therefore, we sought to evaluate the relationship between sleep, TBI, and ePVS on brain MRI. A retrospective study was performed in individuals with overnight polysomnography and 3T brain MRI consented from a single site ( n = 38). Thirteen of these individuals had a medically confirmed history of TBI. ePVS were visually assessed by blinded experimenters and analyzed in conjunction with sleep metrics and TBI status. Overall, individuals with shorter total sleep time had significantly higher ePVS burden. Furthermore, individuals with TBI showed a stronger relationship between sleep and ePVS compared to the non-TBI group. These results support the hypothesis that ePVS may be modulated by sleep and TBI, and may have implications for the role of the glymphatic system in ePVS.

Study Objectives: Veterans are at an increased risk for traumatic brain injury (TBI) and posttraumatic stress disorder (PTSD), both of which are associated with sleep disturbances and increased pain. Furthermore, sleep disturbances and pain are reciprocally related such that each can exacerbate the other. Although both TBI and PTSD are independently linked to sleep disturbances and pain, it remains unclear whether Veterans with comorbid TBI+PTSD show worse sleep disturbances and pain compared to those with only TBI or PTSD. We hypothesized that sleep and pain would be worse in Veterans with comorbid TBI+PTSD compared to Veterans with only TBI or PTSD. Methods: Veterans (n = 639) from the VA Portland Health Care System completed overnight polysomnography and self-report questionnaires. Primary outcome variables were self-reported sleep disturbances and current pain intensity. Participants were categorized into four trauma-exposure groups: (1) neither: without TBI or PTSD (n = 383); (2) TBI: only TBI (n = 67); (3) PTSD: only PTSD (n = 126); and (4) TBI+PTSD: TBI and PTSD (n = 63). Results: The PTSD and TBI+PTSD groups reported worse sleep compared to the TBI and neither groups. The TBI+PTSD group reported the greatest pain intensity compared to the other groups. Conclusions: These data suggest sleep and pain are worst in Veterans with TBI and PTSD, and that sleep is similarly impaired in Veterans with PTSD despite not having as much pain. Thus, although this is a complex relationship, these data suggest PTSD may be driving sleep disturbances, and the added effect of TBI in the comorbid group may be driving pain in this population. stress disorder (PTSD). Among the most prevalent, persistent, and debilitating sequelae in both TBI and PTSD are sleep disturbances and increased pain. Importantly, sleep disturbances and pain also share a reciprocal relationship such that increases in either can independently exacerbate the other. [4][5][6][7] It has been estimated that > 50% of people with TBI experience sleep disturbances, 8-10 including insomnia, 11 hypersomnia, 8 obstructive sleep apnea (OSA), 9 and circadian rhythm sleep disorders. 9,12 Furthermore, current evidence suggests these sleep disturbances can persist for several years postinjury. 13 Sleep disturbances are also a hallmark feature of PTSD BRIEF SUMMARY Current Knowledge/Study Rationale: Traumatic brain injury (TBI) and posttraumatic stress disorder (PTSD) are common in Veterans and are independently associated with sleep disturbances and pain, both of which can exacerbate the other and impede rehabilitation. Understanding the relationship between TBI, PTSD, sleep, and pain will help improve treatment and rehabilitation in this vulnerable population. Study Impact: This study demonstrates that Veterans with PTSD and with both PTSD and TBI experience more sleep disturbances, but those with TBI and PTSD report significantly greater current pain intensity. These data help in the limited understanding of how Veterans with comorbid TBI and PTSD differ from Veteran...

These data are the first to report the prevalence and association between sensory sensitivity and sleep disturbances in Veterans with TBI. These data also suggest that the underlying mechanism of the sleep-sensory relationship could be due in part to comorbid PTSD and autonomic nervous system hyperarousal.