Traumatic Brain Injury and Incidence Risk of Sleep Disorders in Nearly 200,000 US Veterans

Traumatic brain injury persistently increases the incidence of both ischemic and hemorrhagic strokes: Potential mechanisms

Traumatic brain injuries (TBI) significantly increase the risk of both ischemic and hemorrhagic strokes, with effects persisting for years after the initial injury. The mechanisms underlying this increased stroke risk are complex, multifactorial, and incompletely understood but likely include chronic cerebrovascular dysfunction, blood-brain barrier disruption, and inflammatory responses. Epidemiological studies consistently show that TBI is an independent risk factor for stroke, with more severe injuries associated with greater risk, especially for hemorrhagic strokes. Traditional risk factors for stroke, such as hypertension, poor diet, and sedentary lifestyle, further elevate the risk in TBI survivors. Modifiable lifestyle factors, such as improving sleep, increasing physical activity, and adopting heart-healthy diets, offer potential intervention points to mitigate stroke risk. Pharmacological considerations, including the use of antidepressants, anticoagulants, and statins, also influence stroke risk, particularly with regard to hemorrhagic complications. This review explores the pathophysiological mechanisms linking TBI and stroke, emphasizing the need for future research to identify specific biomarkers and imaging techniques to predict stroke vulnerability in TBI patients. Addressing the gaps in understanding, particularly regarding small vessel pathology, will be essential to developing targeted therapies for reducing stroke incidence in TBI survivors.

Traumatic Brain Injury in US Veterans: Prevalence and Associations With Physical, Mental, and Cognitive Health

OBJECTIVE

To examine the prevalence of traumatic brain injury (TBI) in the US veteran population, and physical, mental, and cognitive health conditions associated with TBI.

DESIGN

Retrospective cohort study.

SETTING

A nationally representative sample of US military veterans surveyed in 2019-2020.

PARTICIPANTS

Veterans with probable TBI (n=943; M=58.8 years, SD=16.4; 75.9% non-Hispanic White) and without probable TBI (n=3,033; M=63.3 years, SD=15.3; 78.6% non-Hispanic White) were categorized based on a 2-item modified Veterans Health Administration TBI screen or self-reported health professional diagnoses of concussion/TBI.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE(S)

Self-reported health professional-diagnosed physical and cognitive health conditions, disability with basic and instrumental activities of daily living (ADLs), positive screens for posttraumatic stress disorder (PTSD), major depressive disorder, anxiety disorder, alcohol use disorder, or drug use disorder, and current suicidal ideation or prior suicide attempts.

RESULTS

Among the full sample, 24.5% (95% confidence interval: 22.7, 26.3) had probable TBI. In adjusted analyses, probable TBI was independently associated with greater odds of rheumatoid arthritis (odds ratio [OR]=2.06), chronic pain (OR=1.87), kidney disease (OR=1.81), pulmonary disease (OR=1.74), arthritis (OR=1.65), migraine (OR=1.59), sleep disorders (OR=1.57), and osteoporosis or osteopenia (OR=1.51). Veterans with probable TBI also had higher odds of mild cognitive impairment (OR=4.53) and disability with ADLs (OR=2.18) and instrumental ADLs (OR=1.98), although ADL disability was explained by other physical health conditions. Probable TBI was associated with higher odds of probable current anxiety disorder (OR=2.82), major depressive disorder (OR=2.17), suicidal ideation (OR=1.78), PTSD (OR=1.72), drug use disorder (OR=1.54), and alcohol use disorder (OR=1.47).

CONCLUSIONS

Nearly 1-in-4 US veterans screen positive for probable TBI, which was associated with several physical and mental health conditions that adversely affect health and functioning. Results underscore the importance of multidisciplinary interventions that concurrently target the unique physical, mental, cognitive, and functional health needs of this population.

Decisional Needs of Veterans With Mild Traumatic Brain Injury Initiating Treatment for Insomnia Disorder and Obstructive Sleep Apnea

OBJECTIVE

We sought to elicit key informant (KI) perspectives regarding decisional needs of Veterans with mild traumatic brain injury (mTBI) who are initiating insomnia disorder and obstructive sleep apnea (OSA) treatment within the Veterans Health Administration (VHA) Polytrauma/TBI System of Care (PSC). Specifically, we sought to understand: (1) information regarding treatment options that Veterans with mTBI require in order to make an informed decision; and (2) values used to guide decision-making (ie, personally meaningful aspects of the decision used to compare treatment options).

SETTING

Nationwide VHA PSC sites.

PARTICIPANTS

Clinicians included VHA providers and policymakers involved in the management of mTBI and/or sleep disorders in the VHA PSC ( n = 29). Veterans included those with a clinician-confirmed mTBI who received care for insomnia disorder and/or OSA within the past year ( n = 20).

DESIGN

Semi-structured interviews with the 49 KIs were recorded and transcribed verbatim. Themes were identified using a descriptive and interpretive approach to qualitative analysis.

MAIN MEASURES

Not applicable.

RESULTS

Informational needs identified by both KI groups included information regarding outcomes and downsides of treatment, accessible delivery, treatment candidates, description of diagnosis, and level of commitment. Values used to guide decision-making for both insomnia disorder and OSA treatment included benefits, downsides, and availability of treatments. Values used to decide on insomnia treatments alone included time commitment, intrinsic management of sleep, beliefs regarding mental health treatment, and time course of benefit. Values used to decide on OSA treatment alone included intrusiveness of the treatment, appearance, and impact on bed partners.

CONCLUSIONS

The current study revealed the decisional needs of Veterans with mTBI who are initiating sleep disorder treatment. Findings can inform the development of decision aids and other efforts aimed at promoting patient-centered management of comorbid mTBI and sleep disorders, thereby improving care quality and clinical outcomes.

Characterizing supplement use and dietary behaviors in adults with acquired brain injury

BACKGROUND

Acquired brain injury (ABI) can result in persistent symptoms and lasting disability. Supplements are becoming more popular in patients with chronic symptoms; however, little is known about supplementation and dietary behaviors after ABI.

METHODS

In this cross-sectional observational study, questionnaires were collected from 211 adults with ABI presenting to outpatient brain injury clinics. The temporality of 54 unique supplements and 15 dietary behaviors were surveyed. Sources of information, reasons for use, side effects, and perceived safety were obtained.

RESULTS

After ABI, 55% of the participants increased supplement utilization by ≥1 supplement, resulting in 74% consuming supplements (3.8±4.1 unique supplements daily); Vitamin D, multivitamins, magnesium, and omega 3- and/or -6 were most commonly consumed. Healthcare professionals were the main source of information, as reported by 69% of the respondents. The primary reason for supplementation was following a recommendation by a healthcare professional (63%). Supplementation was widely considered safe (83%), and most participants (76%) did not experience side effects. The majority of participants (70%) did not adhere to specific dietary behaviors.

Insomnia and sleep apnea in the entire population of US Army soldiers: Associations with deployment and combat exposure 2010-2019, a retrospective cohort investigation

OBJECTIVES

This retrospective cohort study examined clinically diagnosed insomnia and sleep apnea and analyzed associations with deployment and combat exposure in active-duty soldiers (n=1,228,346) from 2010 to 2019.

METHODS

Retrospective data were obtained from the Soldier Performance, Health, and Readiness database.

RESULTS

Overseas soldier deployments peaked in 2010, decreasing thereafter as soldiers were withdrawn from Iraq and Afghanistan. From 2010 to 2012 insomnia incidence increased at a rate of 6.7 cases/1000 soldier-years, then decreased after 2012 at 5.3 cases/1000 soldier-years. Sleep apnea increased 2010-2016 at 1.9 cases/1000 soldier-years and generally declined thereafter. Risk of insomnia increased with deployment (hazard ratio=1.51; 95% confidence interval=1.49-1.52) and combat exposure (hazard ratio=1.15; 95% confidence interval=1.13-1.17). Risk of sleep apnea was increased by deployment (hazard ratio=1.89; 95% confidence interval, 1.86-1.92) and combat exposure (hazard ratio=1.09; 95% confidence interval, 1.07-1.11). Most relationships remained after accounting for other factors in multivariable analyses, except that the association between sleep apnea and combat exposure was reduced (hazard ratio=0.94; 95% confidence interval=0.92-0.97).

CONCLUSIONS

Insomnia risk decreased in the period nearly in parallel with a reduction in the number of deployments; nonetheless deployment and combat exposure increased insomnia risk in the period examined. Risk of sleep apnea increased in the period and was related to deployment but not combat exposure after accounting for demographics and comorbid conditions. Despite reductions in insomnia incidence and a slowing in sleep apnea incidence, sleep disorders remain highly prevalent, warranting continued emphasis on sleep-disorder screening and improving the soldier sleep habits.

Sleep and circadian rhythms after traumatic brain injury

Traumatic brain injury (TBI) is a serious public health concern and is one of the major causes of death and chronic disability in young individuals. Sleep-wake disturbances are among the most persistent and debilitating consequences of TBI and are reported by 50%-70% of TBI patients regardless of TBI severity. Excessive daytime sleepiness, fatigue, hypersomnia, and insomnia are the most common sleep disturbances in TBI patients. Post-TBI sleep-wake disturbances are often associated with pain, anxiety, depression, and posttraumatic stress disorder. They may exacerbate cognitive impairment following TBI, reduce community integration, and delay recovery and return to normal life. Changes in sleep architecture following TBI have been reported in the literature but cannot fully explain the extent and intensity of the sleep-wake disturbances reported by TBI patients. The alteration in the circadian timing system is another factor that may partially account for the presence of post-TBI sleep-wake disturbances. Current literature supports cognitive behavioral therapy and sleep hygiene education, light therapy, and certain pharmacologic interventions for treating sleep disturbances in TBI patients. Due to heterogeneous consequences of TBI, early screening and individualized approaches to treatment must be prioritized to improve sleep in TBI patients and consequently speed up recovery.

Insomnia and Chronic Pain Mediate the Relationship Between Traumatic Brain Injury and Reduced Positive Airway Pressure Adherence Among Veterans

OBJECTIVE

To examine whether co-morbid insomnia, post-traumatic stress disorder (PTSD), depression, and chronic pain mediate the relationship between traumatic brain injury (TBI) and positive airway pressure (PAP) treatment adherence.

SETTING

One Veterans Health Administration (VHA) sleep medicine site.

PARTICIPANTS

Veterans (n = 8836) who were prescribed a modem-enabled PAP device.

DESIGN

Secondary analysis of clinical data. We used path analysis to examine: (1) whether Veterans with a history of TBI were more likely to experience insomnia, PTSD, depression, and chronic pain; (2) in turn, whether Veterans with these co-morbid conditions exhibited lesser PAP adherence; and (3) whether Veterans with a history of TBI will exhibit lesser PAP adherence, even while accounting for such co-morbid conditions. Model estimates were adjusted for sociodemographic (eg, race/ethnicity) and clinical characteristics (eg, mask leakage).

MAIN MEASURES

Health conditions were abstracted from the VHA medical record. PAP adherence was measured using average nightly use (hours).

RESULTS

Among 8836 Veterans, 12% had a history of TBI. TBI history was not associated with PAP adherence when accounting for the presence of insomnia, PTSD, depression, and chronic pain. Indirect effect estimates indicated that a history of mild, moderate-severe, or unclassified TBI was associated with lesser PAP adherence, as mediated by the presence of co-morbid insomnia and chronic pain. Generally, TBI was associated with an increased likelihood of co-morbid insomnia, PTSD, depression, and chronic pain. In turn, insomnia and chronic pain, but not PTSD or depression, were associated with lesser PAP adherence.

CONCLUSIONS

Our study offers empirical support for insomnia and chronic pain as potential explanatory mechanisms underlying the relationship between TBI history and suboptimal PAP adherence. While additional research is needed to confirm causality, findings offer preliminary evidence that can inform the development of tailored PAP adherence interventions for Veterans with TBI and obstructive sleep apnea.

Increased Risk for Clinically Significant Sleep Disturbances in Mild Traumatic Brain Injury: An Approach to Leveraging the Federal Interagency Traumatic Brain Injury Research Database

STUDY OBJECTIVES

The Federal Interagency Traumatic Brain Injury Research (FITBIR) Informatics System contains individual-patient-level traumatic brain injury (TBI) data, which when combined, allows for the examination of rates and outcomes for key subpopulations at risk for developing sleep disturbance.

METHODS

This proof-of-concept study creates a model system for harmonizing data (i.e., combining and standardizing data) across FITBIR studies for participants with and without a history of TBI to estimate rates of sleep disturbance and identify risk factors.

RESULTS

Three studies were eligible for harmonization (N = 1753). Sleep disturbance was common among those with a history of mild TBI (63%). Individuals with mild TBI were two to four times more likely to have sleep disturbance compared to those with no history of TBI.

CONCLUSIONS

This study established methods, harmonization code, and meta-databases that are publicly available on the FITBIR website. We demonstrated how the harmonization of FITBIR studies can answer TBI research questions, showing that associations between TBI and sleep disturbance may be influenced by demographic factors.

Associations between Chronic Medical Conditions and Persistent Dietary Supplement Use: The US Military Dietary Supplement Use Study

This longitudinal study examined associations between chronic medical conditions (CMCs) and persistent dietary supplement (DS) use. On two separate occasions, 1.3 ± 0.2 years apart, military service members (SMs) (n = 5778) completed identical questionnaires concerning their DS use in the past 6 months and their demographic and lifestyle characteristics. Medical conditions were obtained from a medical surveillance system six months before the first questionnaire and during the period between questionnaires. Diagnoses were grouped into 19 major (largely systemic) and 9 specific CMCs. Conditions diagnosed in both periods (CMCs) were examined in relation to DS use reported on both questionnaires (persistent DS use). After adjustment for demographic and lifestyle factors, higher odds of persistent DS use were found in 7 of the 19 major CMCs and 5 of the 9 specific CMCs. SMs with a CMC had 1.25 (95% confidence interval [95%CI] = 1.10-1.41) higher adjusted odds of persistent DS use. The three specific CMCs with the highest adjusted odds of persistent DS use were anxiety (odds ratio [OR] = 2.30, 95%CI = 1.36-3.89), depression (OR = 2.12, 95%CI = 1.20-3.73), and gastroesophageal reflux disease (OR = 2.02, 95%CI = 1.02-4.04). Among DS categories, participants with a CMC had higher adjusted odds of persistent vitamins or mineral use (OR = 1.31, 95% CI = 1.12-1.53). Participants with CMCs had a higher prevalence of persistent DS use, especially individual vitamin and mineral use.

Assessment of sleep parameters in adults with persistent post-concussive symptoms

OBJECTIVES

The primary aim of this study was to characterize sleep in adults with persistent post-concussive symptoms (PPCS). Secondary aims explored relationships between sleep parameters, injury characteristics, and symptom questionnaires.

METHODS

This case-controlled, cross-sectional study recruited adults (18-65yrs) diagnosed with PPCS and age and sex-matched controls. Participants wore a wrist-worn actigraph for 3-7 nights and completed daily sleep diaries. Participants completed questionnaires examining daytime sleepiness, fatigue, anxiety/depressive symptoms, and sedentariness. Sleep parameters were compared between groups using Mann-Whitney U tests. Secondary analyses used two-way ANOVA and Spearman's rank correlations.

RESULTS

Fifty adults with PPCS (43.7 ± 10.6yrs, 78 % female) and 50 controls (43.6 ± 11.0yrs) were included in this study. Adults with PPCS had significantly longer sleep onset latency (PPCS 16.99 ± 14.51min, Controls 8.87 ± 6.44min, p < 0.001) and total sleep time (PPCS 8.3 ± 1.0hrs, Control 7.6 ± 0.9hrs, p = 0.030) compared to controls, but woke up later (PPCS 7:57:27 ± 1:36:40, Control 7:17:16 ± 0:50:08, p = 0.026) and had poorer sleep efficiency (PPCS 77.9 ± 7.5 %, Control 80.8 ± 6.0 %, p = 0.019) than controls. Adults with PPCS reported more daytime sleepiness (Epworth Sleepiness Scale: PPCS 8.70 ± 4.61, Control 4.28 ± 2.79, p < 0.001) and fatigue (Fatigue Severity Scale: PPCS 56.54 ± 12.92, Control 21.90 ± 10.38, p < 0.001). Injury characteristics did not significantly affect sleep parameters in adults with PPCS. Actigraphy parameters were not significantly correlated to questionnaire measures.

CONCLUSION

Several actigraphy sleep parameters were significantly altered in adults with PPCS compared to controls, but did not correlate with sleep questionnaires, suggesting both are useful tools in characterizing sleep in PPCS. Further, this study provides potential treatment targets to improve sleep difficulties in adults with PPCS.

Factors Influencing Adherence to Insomnia and Obstructive Sleep Apnea Treatments among Veterans with Mild Traumatic Brain Injury

OBJECTIVE

To understand factors influencing adherence to recommended treatment for insomnia and obstructive sleep apnea (OSA) among Veterans with mild traumatic brain injury (mTBI).

METHOD

Semi-structured interviews (n = 49) with 29 clinical stakeholders and 20 Veterans were conducted. Clinical stakeholders included Veterans Health Administration providers and policymakers involved in the management of mTBI and/or sleep disorders. Veterans included those with a clinician-confirmed mTBI with a recent history of insomnia disorder and/or OSA treatment. Themes were identified using a Descriptive and Interpretive approach.

RESULTS

Barriers to sleep disorder treatment adherence included factors associated with the patient (e.g., negative appraisal of treatment benefit), intervention (e.g., side effects), health conditions (e.g., cognitive challenges), health care system (e.g., limited availability of care), and socioeconomic status (e.g., economic instability). Similarly, facilitators of adherence included patient- (e.g., positive appraisal of treatment benefit), intervention- (e.g., flexible delivery format), condition- (e.g., accommodating cognitive impairments), health care system- (e.g., access to adherence support), and socioeconomic-related factors (e.g., social support).

CONCLUSIONS

Interviews revealed the multi-faceted nature of factors influencing adherence to sleep disorder treatment among Veterans with mTBI. Findings can inform the development of novel interventions and care delivery models that meet the complex needs of this population.

Factors influencing shared decision-making for insomnia and obstructive sleep apnea treatment among Veterans with mild traumatic brain injury

STUDY OBJECTIVES

We elicited perspectives of clinical stakeholders and Veterans regarding barriers and facilitators to implementing shared decision-making (SDM) for comorbid mild traumatic brain injury (mTBI) and sleep disorders in the Veterans Health Administration. We also compared the perspectives of clinical stakeholders and Veterans regarding determinants of SDM.

METHODS

Semistructured interviews were conducted with 29 clinical stakeholders and 20 Veterans (n = 49). Clinical stakeholders included Veterans Health Administration providers and policymakers involved in the management of mTBI and/or sleep disorders (insomnia disorder, obstructive sleep apnea). Veterans included those with a clinician-confirmed mTBI who received care for insomnia disorder and/or obstructive sleep apnea within the past year. Themes were identified using a descriptive and interpretive approach to qualitative analysis. We compared results across clinical stakeholders and Veterans.

RESULTS

Barriers to implementing SDM were identified by both groups at the patient (eg, mTBI sequalae), provider (eg, deprioritization of Veteran preferences), encounter (eg, time constraints), and facility levels (eg, reduced care access). Similarly, both groups identified facilitators at the patient (eg, enhanced trust), provider (eg, effective communication), encounter (eg, decision support), and facility levels (eg, mitigating access barriers). Integrated services and provider discontinuity were factors identified by clinical stakeholders and Veterans alone, respectively.

CONCLUSIONS

Our study revealed factors shaping the implementation of SDM at the levels of the patient, provider, encounter, and facility. Findings can inform the development of strategies aimed at implementing SDM for comorbid mTBI and sleep disorders, promoting patient-centered care and enhancing clinical outcomes.

CITATION

Kinney AR, Brenner LA, Nance M, et al. Factors influencing shared decision-making for insomnia and obstructive sleep apnea treatment among Veterans with mild traumatic brain injury. J Clin Sleep Med. 2024;20(5):801-812.

The Frequency of Neuropsychiatric Sequelae After Traumatic Brain Injury in the Global South: A systematic review and meta-analysis

This study aimed to assess the prevalence of neuropsychiatric sequelae following traumatic brain injury (TBI) among the Western Asian, South Asian and African regions of the global south. All studies on psychiatric disturbances or cognitive impairment following TBI conducted (until August 2021) in the 83 countries that constitute the aforementioned regions were reviewed; 6 databases were selected for the literature search. After evaluating the articles using the Joanna Briggs Institute guidelines, the random effects model was used to estimate the prevalence of depression, anxiety, post-traumatic stress disorder (PTSD), TBI-related sleep disturbance (TBI-SD), obsessive-compulsive disorder (OCD) and cognitive impairment. Of 56 non-duplicated studies identified in the initial search, 27 were eligible for systematic review and 23 for meta-analysis. The pooled prevalence of depression in 1,882 samples was 35.35%, that of anxiety in 1,211 samples was 28.64%, that of PTSD in 426 samples was 19.94%, that of OCD in 313 samples was 19.48%, that of TBI-SD in 562 samples was 26.67% and that of cognitive impairment in 941 samples was 49.10%. To date, this is the first critical review to examine the spectrum of post-TBI neuropsychiatric sequelae in the specified regions. Although existing studies lack homogeneous data due to variability in the diagnostic tools and outcome measures utilised, the reported prevalence rates are significant and comparable to statistics from the global north.

Reactive gliosis in traumatic brain injury: a comprehensive review

Traumatic brain injury (TBI) is one of the most common pathological conditions impacting the central nervous system (CNS). A neurological deficit associated with TBI results from a complex of pathogenetic mechanisms including glutamate excitotoxicity, inflammation, demyelination, programmed cell death, or the development of edema. The critical components contributing to CNS response, damage control, and regeneration after TBI are glial cells-in reaction to tissue damage, their activation, hypertrophy, and proliferation occur, followed by the formation of a glial scar. The glial scar creates a barrier in damaged tissue and helps protect the CNS in the acute phase post-injury. However, this process prevents complete tissue recovery in the late/chronic phase by producing permanent scarring, which significantly impacts brain function. Various glial cell types participate in the scar formation, but this process is mostly attributed to reactive astrocytes and microglia, which play important roles in several brain pathologies. Novel technologies including whole-genome transcriptomic and epigenomic analyses, and unbiased proteomics, show that both astrocytes and microglia represent groups of heterogenic cell subpopulations with different genomic and functional characteristics, that are responsible for their role in neurodegeneration, neuroprotection and regeneration. Depending on the representation of distinct glia subpopulations, the tissue damage as well as the regenerative processes or delayed neurodegeneration after TBI may thus differ in nearby or remote areas or in different brain structures. This review summarizes TBI as a complex process, where the resultant effect is severity-, region- and time-dependent and determined by the model of the CNS injury and the distance of the explored area from the lesion site. Here, we also discuss findings concerning intercellular signaling, long-term impacts of TBI and the possibilities of novel therapeutical approaches. We believe that a comprehensive study with an emphasis on glial cells, involved in tissue post-injury processes, may be helpful for further research of TBI and be the decisive factor when choosing a TBI model.

The Effect of Concussion Mechanism of Injury on Sleep Problems in Active Duty Service Members Following Deployment

INTRODUCTION

Sleep disruption is pervasive in the military and is generally exacerbated during deployment, partially due to increases in operational tempo and exposure to stressors and/or trauma. In particular, sleep disruption is a commonly reported symptom following deployment-related traumatic brain injury (TBI), though less is known about the prevalence of sleep disturbance as a function of whether the TBI was induced by high-level blast (HLB) or direct impact to the head. TBI assessment, treatment, and prognosis are further complicated by comorbidity with posttraumatic stress disorder (PTSD), depression, and alcohol misuse. Here, we examine whether concussion mechanism of injury is associated with differences in the prevalence of self-reported sleep disturbance following deployment in a large sample of U.S. Marines while accounting for probable PTSD, depression, and alcohol misuse.

MATERIALS AND METHODS

This was a retrospective cohort study of active duty enlisted Marines with a probable concussion (N = 5757) who completed the Post-Deployment Health Assessment between 2008 and 2012. Probable concussion was defined as endorsement of a potentially concussive event with corresponding loss or alteration of consciousness. The presence of concussion-related sleep problems was assessed with a dichotomous item. Probable PTSD, depression, and alcohol misuse were assessed using the Primary Care PTSD Screen, the Patient Health Questionnaire-2, and the Alcohol Use Identification Test-Concise, respectively. Logistic regression models investigated the effects of mechanism of injury (HLB vs. impact), PTSD, depression, and alcohol misuse on the presence of sleep problems, adjusting for sex and pay grade. The study was approved by the Naval Health Research Center Institutional Review Board.

RESULTS

Approximately 41% of individuals with a probable deployment-related concussion reported sleep problems following the event; 79% of concussed individuals reporting both HLB and probable PTSD reported sleep problems. All main effects were significantly associated with sleep disturbance in adjusted models. PTSD showed the strongest association with sleep disturbance (adjusted odds ratio [AOR] = 2.84), followed by depression (AOR = 2.43), HLB exposure (AOR = 2.00), female sex (AOR = 1.63), alcohol misuse (AOR = 1.14), and pay grade (AOR = 1.10). A significant HLB × PTSD interaction emerged (AOR = 1.58), which suggests that sleep disturbance was elevated among those with both HLB-induced (vs. impact-induced) concussions and presence (vs. absence) of PTSD. No other significant interactions emerged.

CONCLUSION

To our knowledge, this is the first study to examine the prevalence of concussion-related sleep complaints following deployment as a function of the mechanism of injury in individuals with and without probable PTSD and depression. Individuals with HLB-induced concussion were twice as likely to report sleep problems as those with an impact-induced concussion. Future work should examine these effects longitudinally with validated measures that assess greater precision of exposure and outcome assessment (e.g., blast intensity and type of sleep disturbance).

Economic Burden of Trauma-Related Injuries in Iran in 2019

Objective

Trauma-related injuries are the leading cause of death and disability in the active population, with devastating economic, health, and social consequences for nations. TThis study aimed to assess the economic burden of injuries in Iran.

Methods

In this study, the economic impact of trauma in Iran in 2019 was estimated using a prevalence-based approach. The prevalence was estimated based on available statistics in Iran and the GBD website. Direct medical expenditures were calculated using a top-down approach. The cost of lost production due to injuries and premature death was also estimated using the DALY value. Microsoft Excel 2019 and Stata software version 13.0 were used for the analysis.

Results

In Iran, approximately 16,500,000 individuals were estimated to have sustained injuries in a single year. The average direct medical expenses for each trauma patient were around $226. Fractures contributed to 39% of the financial impact of trauma. The overall economic burden of trauma in Iran was calculated to be $10,214,403,423. Approximately 66% of this economic burden was attributed to lost productivity and premature death resulting from trauma, while direct medical costs made up 34%.

Conclusion

The economic burden of trauma in Iran is expected to significantly rise in the future. It may be necessary to enhance awareness of injury-related mortality and disability, improve therapies, and expand evidence-based interventions to reduce the economic impact of injuries.

Traumatic brain injury and sleep in military and veteran populations: A literature review

BACKGROUND

Traumatic brain injury (TBI) is a hallmark of wartime injury and is related to numerous sleep wake disorders (SWD), which persist long term in veterans. Current knowledge gaps in pathophysiology have hindered advances in diagnosis and treatment.

OBJECTIVE

We reviewed TBI SWD pathophysiology, comorbidities, diagnosis and treatment that have emerged over the past two decades.

METHODS

We conducted a literature review of English language publications evaluating sleep disorders (obstructive sleep apnea, insomnia, hypersomnia, parasomnias, restless legs syndrome and periodic limb movement disorder) and TBI published since 2000. We excluded studies that were not specifically evaluating TBI populations.

RESULTS

Highlighted areas of interest and knowledge gaps were identified in TBI pathophysiology and mechanisms of sleep disruption, a comparison of TBI SWD and post-traumatic stress disorder SWD. The role of TBI and glymphatic biomarkers and management strategies for TBI SWD will also be discussed.

CONCLUSION

Our understanding of the pathophysiologic underpinnings of TBI and sleep health, particularly at the basic science level, is limited. Developing an understanding of biomarkers, neuroimaging, and mixed-methods research in comorbid TBI SWD holds the greatest promise to advance our ability to diagnose and monitor response to therapy in this vulnerable population.

TBICoE approach to concussion rehabilitation in service members and veterans

BACKGROUND

Concussion, also known as mild traumatic brain injury (mTBI), is a condition with unique ties to military service. Service members (SMs) are inherently at a higher risk for concussive injuries due to the intense physical training environment and combat operational tempo required to serve. The Traumatic Brain Injury Center of Excellence (TBICoE) is the US Department of Defense authority on this condition and provides a thorough approach to management of concussion and associated symptom sequela.

OBJECTIVES

This article seeks to review the TBICoE approach to the management and rehabilitation of military SMs with mTBI, and highlight resources available to military medical providers.

METHODS

The authors reviewed evidence and TBICoE resources to provide this comprehensive overview of the TBICoE approach to management and rehabilitation of concussion in military SMs.

RESULTS

A progressive return to activity protocol in conjunction with symptom-guided management of common post-concussive sequelae, including headache, vestibular and oculomotor issues, sleep dysfunction, cognitive rehabilitation, and behavioral health comorbidities are essential for concussion management in the acute, post-acute and chronic phases of injury.

CONCLUSION

The TBICoE approach to the rehabilitation of military SMs is comprehensive, and includes initial management with a stepwise return to duty protocol and an objective return to duty screening. The mainstays of treatment for SMs with post-acute and chronic post-concussion symptoms are headache management, vestibular and oculomotor rehabilitation, sleep interventions, cognitive rehabilitation, and early intervention for behavioral health comorbidities. These evidence-based strategies may be applied in the treatment of SMs in the US and internationally.

Exploring the relationship between sleep apnea and vestibular symptoms following traumatic brain injury

BACKGROUND

Traumatic brain injury (TBI) is a complex health problem in military veterans and service members (V/SM) that often involves comorbid vestibular impairment. Sleep apnea is another comorbidity that may exacerbate, and/or be exacerbated by, vestibular dysfunction.

OBJECTIVE

To examine the relationship between sleep apnea and vestibular symptoms in V/SM diagnosed with TBI of any severity.

DESIGN

Multicenter cohort study; cross-sectional sample.

SETTING

In-patient TBI rehabilitation units within five Veterans Affairs (VA) Polytrauma Rehabilitation Centers.

PARTICIPANTS

V/SM with a diagnosis of TBI (N = 630) enrolled in the VA TBI Model Systems study.

INTERVENTION

Not applicable.

METHODS

A multivariable regression model was used to evaluate the association between sleep apnea and vestibular symptom severity while controlling for relevant covariates, for example, posttraumatic stress disorder (PTSD).

MAIN OUTCOME MEASURES

Lifetime history of sleep apnea was determined via best source reporting. Vestibular disturbances were measured with the 3-item Vestibular subscale of the Neurobehavioral Symptom Inventory (NSI).

RESULTS

One third (30.6%) of the sample had a self-reported sleep apnea diagnosis. Initial analysis showed that participants who had sleep apnea had more severe vestibular symptoms (M = 3.84, SD = 2.86) than those without sleep apnea (M = 2.88, SD = 2.67, p < .001). However, when the data was analyzed via a multiple regression model, sleep apnea no longer reached the threshold of significance as a factor associated with vestibular symptoms. PTSD severity was shown to be significantly associated with vestibular symptoms within this sample (p < .001).

CONCLUSION

Analysis of these data revealed a relationship between sleep apnea and vestibular symptoms in V/SM with TBI. The significance of this relationship was affected when PTSD symptoms were factored into a multivariable regression model. However, given that the mechanisms and directionality of these relationships are not yet well understood, we assert that in terms of clinical relevance, providers should emphasize screening for each of the three studied comorbidities (sleep apnea, vestibular symptoms, and PTSD).

The prevalence of persistent post-traumatic headache in adult civilian traumatic brain injury: a systematic review and meta-analysis on the past 14 years

ABSTRACT

The most recent prevalence estimate of post-traumatic headache (PTH) after traumatic brain injury (TBI) in veterans and civilians dates back to 2008. The prevalence was found to be 57.8%, with surprising higher rates (75.3%) in mild TBI when compared with those with moderate/severe TBI (32.1%). However, the revision of mild TBI diagnostic criteria and an historic peak of TBI in the elderly individuals attributed to the ageing population may lead to different results. Thus, we conducted a systematic review and meta-analysis to assess the updated prevalence of PTH during the past 14 years only in civilians. A literature search was conducted following PRISMA guidelines guided by a librarian. Screening, full-text assessment, data extraction, and risk of bias assessment were performed blindly by 2 raters. Meta-analysis of proportions using the Freeman and Tukey double arcsine method of transformation was conducted. Heterogeneity, sensitivity analysis, and meta-regressions were performed with the predictors: year of publication, mean age, sex, TBI severity, and study design. Sixteen studies were selected for the qualitative analysis and 10 for the meta-analysis. The overall prevalence estimate of PTH was 47.1%, (confidence interval = 34.6, 59.8, prediction intervals = 10.8, 85.4), being similar at different time points (3, 6, 12, and 36+ months). Heterogeneity was high, and none of the meta-regressions were significant. The overall prevalence of PTH after TBI over the past 14 years remains high even if assessed only in civilians. However, the prevalence rates attributed to mild and moderate/severe TBI were similar, differing significantly from previous reports. Efforts are needed to improve TBI outcomes.

Long-term risk of cardiovascular disease after traumatic brain injury: screening and prevention

Traumatic brain injury (TBI) is highly prevalent among individuals participating in contact sports, military personnel, and in the general population. Although it is well known that brain injury can cause neurological and psychiatric complications, evidence from studies on individuals exposed to a single or repetitive brain injuries suggests an understudied association between TBI and the risk of developing chronic cardiovascular diseases and risk factors for cardiovascular disease. Several studies have shown that people without pre-existing comorbidities who sustain a TBI have a significantly higher risk of developing chronic cardiovascular disease, than people without TBI. Similar observations made in military and professional American-style football cohorts suggest causal pathways through which modifiable cardiovascular risk factors might mediate the relationship between brain injury and chronic neurological diseases. A better understanding of cardiovascular disease risk after TBI combined with a proactive, targeted screening programme might mitigate long-term morbidity and mortality in individuals with TBI, and improve their quality of life.

Nanowired delivery of antibodies to tau and neuronal nitric oxide synthase together with cerebrolysin attenuates traumatic brain injury induced exacerbation of brain pathology in Parkinson's disease

Concussive head injury (CHI) is one of the major risk factors for developing Parkinson's disease in later life of military personnel affecting lifetime functional and cognitive disturbances. Till date no suitable therapies are available to attenuate CHI or PD induced brain pathology. Thus, further exploration of novel therapeutic agents are highly warranted using nanomedicine in enhancing the quality of life of veterans or service members of US military. Since PD or CHI induces oxidative stress and perturbs neurotrophic factors regulation associated with phosphorylated tau (p-tau) deposition, a possibility exists that nanodelivery of agents that could enhance neurotrophic factors balance and attenuate oxidative stress could be neuroprotective in nature. In this review, nanowired delivery of cerebrolysin-a balanced composition of several neurotrophic factors and active peptide fragments together with monoclonal antibodies to neuronal nitric oxide synthase (nNOS) with p-tau antibodies was examined in PD following CHI in model experiments. Our results suggest that combined administration of nanowired antibodies to nNOS and p-tau together with cerebrolysin significantly attenuated CHI induced exacerbation of PD brain pathology. This combined treatment also has beneficial effects in CHI or PD alone, not reported earlier.

A2AR and traumatic brain injury

Accumulating evidence has revealed the adenosine 2A receptor is a key tuner for neuropathological and neurobehavioral changes following traumatic brain injury by experimental animal models and a few clinical trials. Here, we highlight recent data involving acute/sub-acute and chronic alterations of adenosine and adenosine 2A receptor-associated signaling in pathological conditions after trauma, with an emphasis of traumatic brain injury, including neuroinflammation, cognitive and psychiatric disorders, and other severe consequences. We expect this would lead to the development of therapeutic strategies for trauma-related disorders with novel mechanisms of action.

Temporal Trend and Research Focus of Injury Burden from 1998 to 2022: A Bibliometric Analysis

Background

Injury is one of the leading causes of mortality and disability worldwide. It is a major contributor to the overall burden of disease. This study aimed to analyze the temporal trend, research focus and future direction of research related to injury burden.

Methods

Publications on injury burden published between January 1998 and September 2022 were extracted from the Web of Science Core Collection (WoSCC) through topic advanced search strategy. Microsoft Excel, RStudio, VOSviewer, and CiteSpace were used to extract, integrate, and visualize bibliometric information.

Results

A total of 2916 articles and 783 reviews were identified. The number of publications on injury burden showed a steady upward trend. The United States of America (USA) (n=1628) and the University of Washington (n=1036) were the most productive country and institution. High-income countries started research in this domain earlier, while research in low- and middle-income countries began in recent years. Lancet was the most influential journal. Public, environmental occupational health, general medicine and neurology were the predominant research domains. Based on keyword co-occurrence analysis, the research focus was divided into five clusters: injury epidemiology and prevention, studies related to the global burden of disease (GBD), risk factors for injury, clinical management of injury, and injury outcome assessment and economic burden.

Conclusion

The burden of injury has drawn increasing attention from various perspectives over the years. The research field on injury burden is also becoming more and more extensive. However, there are some gaps among different countries or regions, and more attention needs to be paid to low and middle-income countries.

Traumatic Brain Injury, Sleep, and Melatonin-Intrinsic Changes with Therapeutic Potential

Traumatic brain injury (TBI) is one of the most prevalent causes of morbidity in the United States and is associated with numerous chronic sequelae long after the point of injury. One of the most common long-term complaints in patients with TBI is sleep dysfunction. It is reported that alterations in melatonin follow TBI and may be linked with various sleep and circadian disorders directly (via cellular signaling) or indirectly (via free radicals and inflammatory signaling). Work over the past two decades has contributed to our understanding of the role of melatonin as a sleep regulator and neuroprotective anti-inflammatory agent. Although there is increasing interest in the treatment of insomnia following TBI, a lack of standardization and rigor in melatonin research has left behind a trail of non-generalizable data and ambiguous treatment recommendations. This narrative review describes the underlying biochemical properties of melatonin as they are relevant to TBI. We also discuss potential benefits and a path forward regarding the therapeutic management of TBI with melatonin treatment, including its role as a neuroprotectant, a somnogen, and a modulator of the circadian rhythm.

The Putative Role of Neuroinflammation in the Interaction between Traumatic Brain Injuries, Sleep, Pain and Other Neuropsychiatric Outcomes: A State-of-the-Art Review

Sleep disturbances are widely prevalent following a traumatic brain injury (TBI) and have the potential to contribute to numerous post-traumatic physiological, psychological, and cognitive difficulties developing chronically, including chronic pain. An important pathophysiological mechanism involved in the recovery of TBI is neuroinflammation, which leads to many downstream consequences. While neuroinflammation is a process that can be both beneficial and detrimental to individuals' recovery after sustaining a TBI, recent evidence suggests that neuroinflammation may worsen outcomes in traumatically injured patients, as well as exacerbate the deleterious consequences of sleep disturbances. Additionally, a bidirectional relationship between neuroinflammation and sleep has been described, where neuroinflammation plays a role in sleep regulation and, in turn, poor sleep promotes neuroinflammation. Given the complexity of this interplay, this review aims to clarify the role of neuroinflammation in the relationship between sleep and TBI, with an emphasis on long-term outcomes such as pain, mood disorders, cognitive dysfunctions, and elevated risk of Alzheimer's disease and dementia. In addition, some management strategies and novel treatment targeting sleep and neuroinflammation will be discussed in order to establish an effective approach to mitigate long-term outcomes after TBI.

Persistent hypersomnia following repetitive mild experimental traumatic brain injury: Roles of chronic stress and sex differences

Traumatic brain injury (TBI) is often more complicated than a single head injury. An extreme example of this point may be military service members who experience a spectrum of exposures over a prolonged period under stressful conditions. Understanding the effects of complex exposures can inform evaluation and care to prevent persistent symptoms. We designed a longitudinal series of non-invasive procedures in adult mice to evaluate the effects of prolonged mild stress and head injury exposures. We assessed anxiety, depression, and sleep-wake dysfunction as symptoms that impact long-term outcomes after mild TBI. Unpredictable chronic mild stress (UCMS) was generated from a varied sequence of environmental stressors distributed within each of 21 days. Subsequently, mice received a mild blast combined with closed-head mild TBI on 5 days at 24-h intervals. In males and females, UCMS induced anxiety without depressive behavior. A major finding was reproducible sleep-wake dysfunction through 6- to 12-month time points in male mice that received UCMS with repetitive blast plus TBI events, or surprisingly after just UCMS alone. Specifically, male mice exhibited hypersomnia with increased sleep during the active/dark phase and fragmentation of longer wake bouts. Sleep-wake dysfunction was not found with TBI events alone, and hypersomnia was not found in females under any conditions. These results identify prolonged stress and sex differences as important considerations for sleep-wake dysfunction. Furthermore, this reproducible hypersomnia with impaired wakefulness is similar to the excessive daytime sleepiness reported in patients, including patients with TBI, which warrants further clinical screening, care, and treatment development.

Post-concussive symptoms mediate the relationship between sleep problems and participation restrictions among veterans with mild traumatic brain injury

Background

Sleep problems are common among Veterans with mild traumatic brain injury (mTBI) and may contribute to participation restrictions. However, explanatory mechanisms underlying this relationship are poorly understood. Sleep problems are associated with post-concussive symptoms (e.g., headaches). In turn, post-concussive symptoms contribute to participation restrictions. We hypothesized that post-concussive symptom severity mediates the purported relationship between sleep problems and participation restrictions among Veterans with mTBI.

Materials and Methods

This study was a retrospective analysis of clinical data among 8,733 Veterans with mTBI receiving Veterans Health Administration outpatient care. Sleep problems (yes/no) were identified using the sleep-related item from the Neurobehavioral Symptom Inventory (NSI). Post-concussive symptoms were measured using remaining NSI items. Participation restrictions were measured using the Mayo-Portland Adaptability Inventory Participation Index. We specified a latent variable path model to estimate relationships between: (1) sleep problems and three latent indicators of post-concussive symptoms [vestibular-sensory (e.g., headache)]; mood-behavioral [e.g., anxiety]; cognitive [e.g., forgetfulness]); and, (2) the three latent indicators of post-concussive symptoms and two latent indicators of participation restrictions (social and community participation [e.g., leisure activities]; productivity [e.g., financial management]). We examined the indirect effects of sleep problems upon participation restrictions, as mediated by post-concussive symptoms. Estimates were adjusted for sociodemographic factors (e.g., age), injury characteristics (e.g., blast), and co-morbid conditions (e.g., depression).

Results

87% of Veterans reported sleep problems. Sleep problems were associated with greater social and community participation restrictions, as mediated by mood-behavioral (β = 0.41, p < 0.001) and cognitive symptoms (β = 0.13, p < 0.001). There was no evidence that vestibular-sensory symptoms mediated this relationship (β = -0.01, p = 0.48). Sleep problems were associated with greater productivity restrictions, as mediated by vestibular-sensory (β = 0.16, p < 0.001) and cognitive symptoms (β = 0.14, p < 0.001). There was no evidence that mood-behavioral symptoms mediated this relationship (β = 0.02, p = 0.37).

Discussion

Findings suggest that evidence-based sleep treatment should occupy a prominent role in the rehabilitation of Veterans with mTBI. Indirect effects of sleep problems differed when considering impact on social and community participation vs. productivity, informing individualized rehabilitative care for Veterans with mTBI.

Regulation of sleep disorders in patients with traumatic brain injury by intestinal flora based on the background of brain-gut axis

OBJECTIVE

This study investigates whether people with sleep disorders following traumatic brain injury exhibit altered intestinal flora. The changes may allow us to gain a better understanding of the role of intestinal flora in patients with sleep disorders after traumatic brain injury, which may give us insights into curing the sleep disorder after traumatic brain injury (TBI).

METHOD

We analyzed the intestinal microbial colony structure in the feces of the 28 patients in the normal sleep group and the sleep disorder group by 16SrDNAsequencing technology. The bioinformatics method was used to analyze the intestinal flora change in the v3-v4 region of patients with biorhythm disorder and to observe the difference between the two groups.

RESULTS

Group grouping comparison and analysis of the evolutionary cladistic map showed the intestinal flora of patients with normal sleep after TBI was mainly Bacilli and Lactobacillales, while that of patients with sleep disorders was mainly Lachnospiraceae and Bacteroidales. The histogram of group value distribution by grouping comparison and analysis showed that Lachnospiraceae, Bacteroidales, Bacteroidia, and Bacteroidetes were dominant in the sleep disorder group. A relative abundance map of species with significant differences by group grouping comparison showed the main manifestations of intestinal flora are Firmicutes, Bacilli, Lactobacillales, Streptococcaceae, and Bacteroidetes. The normal sleep group was dominated by Bacilli, Lactobacillales, Streptococcus, and Veillonella, while in the sleep disorder group, Lachnospiraceae, Bacteroidales, Bacteroidia, and Bacteroidetes were the main species. It was found that there were also significant differences in intestinal flora abundance between the two groups after TBI. After statistics processing, it was compared with the normal sleep group, Lactobacillus, Streptococcus, Oribacterium and Rothia, Actinomyces, Streptophyta, TM7-3 bacteria, and Serratia, showing a significant reduction in the sleep disorder group (P < 0.05). However, Odoribacter, Lachnospiraceae, and Bilophila increased significantly (P < 0.05).

CONCLUSION

The sleep disorders of patients after TBI can be closely related to intestinal flora disturbance, and its internal mechanism needs further study. Intestinal flora has the potential to be a new therapeutic target.

Mild-to-Moderate Traumatic Brain Injury: A Review with Focus on the Visual System

Traumatic Brain Injury (TBI) is a major global public health problem. Neurological damage from TBI may be mild, moderate, or severe and occurs both immediately at the time of impact (primary injury) and continues to evolve afterwards (secondary injury). In mild (m)TBI, common symptoms are headaches, dizziness and fatigue. Visual impairment is especially prevalent. Insomnia, attentional deficits and memory problems often occur. Neuroimaging methods for the management of TBI include computed tomography and magnetic resonance imaging. The location and the extent of injuries determine the motor and/or sensory deficits that result. Parietal lobe damage can lead to deficits in sensorimotor function, memory, and attention span. The processing of visual information may be disrupted, with consequences such as poor hand-eye coordination and balance. TBI may cause lesions in the occipital or parietal lobe that leave the TBI patient with incomplete homonymous hemianopia. Overall, TBI can interfere with everyday life by compromising the ability to work, sleep, drive, read, communicate and perform numerous activities previously taken for granted. Treatment and rehabilitation options available to TBI sufferers are inadequate and there is a pressing need for new ways to help these patients to optimize their functioning and maintain productivity and participation in life activities, family and community.

Seizure Susceptibility and Sleep Disturbance as Biomarkers of Epileptogenesis after Experimental TBI

Objectives: We investigated whether seizure susceptibility increases over weeks−months after experimental traumatic brain injury (TBI), and whether seizure susceptibility in rats predicts the development of post-traumatic epilepsy (PTE) or epileptiform activity. We further investigated whether rats develop chronic sleep disturbance after TBI, and whether sleep disturbance parameters—alone or in combination with pentylenetetrazol (PTZ) test parameters—could serve as novel biomarkers for the development of post-traumatic epileptogenesis. Methods: TBI was induced in adult male Sprague-Dawley rats with lateral fluid-percussion injury. Sham-operated experimental controls underwent craniectomy without exposure to an impact force. Seizure susceptibility was tested with a PTZ test (30 mg/kg, intraperitoneally) on day (D) 30, D60, D90, and D180 after TBI (n = 28) or sham operation (n = 16) under video electroencephalogram (vEEG). In the 7th post-injury month, rats underwent continuous vEEG monitoring to detect spontaneous seizures and assess sleep disturbances. At the end of the experiments, rats were perfused for brain histology. Results: In the TBI group, the percentage of rats with PTZ-induced seizures increased over time (adjusted p < 0.05 compared with D30). Combinations of three PTZ test parameters (latency to the first epileptiform discharge (ED), number of EDs, and number of PTZ-induced seizures) survived the leave-one-out validation for differentiating rats with or without epileptiform activity, indicating an area under the receiver operating curve (AUC) of 0.743 (95% CI 0.472−0.992, p = 0.05) with a misclassification rate of 36% on D90, and an AUC of 0.752 (95% CI 0.483−0.929, p < 0.05) with a misclassification rate of 32% on D180. Sleep analysis revealed that the number of transitions to N3 or rapid eye movement (REM) sleep, along with the total number of transitions, was increased in the TBI group during the lights-on period (all p < 0.05). The sleep fragmentation index during the lights-on period was greater in the TBI rats than in sham-operated rats (p < 0.05). A combination of sleep parameters showed promise as diagnostic biomarkers of prior TBI, with an AUC of 0.792 (95% CI 0.549−0.934, p < 0.01) and a misclassification rate of 28%. Rats with epilepsy or any epileptiform activity had more transitions from N3 to the awake stage (p < 0.05), and the number of N3−awake transitions differentiated rats with or without epileptiform activity, with an AUC of 0.857 (95% CI 0.651−1.063, p < 0.01). Combining sleep parameters with PTZ parameters did not improve the biomarker performance. Significance: This is the first attempt to monitor the evolution of seizure susceptibility over months in a well-described rat model of PTE. Our data suggest that assessment of seizure susceptibility and sleep disturbance can provide diagnostic biomarkers of prior TBI and prognostic biomarkers of post-traumatic epileptogenesis.

Differential diagnosis and theories of pathophysiology of post-traumatic photophobia: A review

BACKGROUND: Photophobia is a common sensory symptom after traumatic brain injury (TBI) that may have a grave impact on a patient’s functional independence, neurorehabilitation, and activities of daily living. Post-TBI photophobia can be difficult to treat and the majority of patients can suffer chronically up to and beyond one year after their injury. OBJECTIVES: This review evaluates the current theories of the pathophysiology of photophobia and the most-common co-morbid etiologies of light sensitivity in TBI to help guide the differential diagnosis and individualized management of post-TBI photophobia. METHODS: Primary articles were found via PubMed and Google Scholar search of key terms including “photophobia” “light sensitivity” “photosensitivity” “photo-oculodynia” “intrinsically photosensitive retinal ganglion cells” “ipRGC” and “concussion” “brain injury” “dry eye”. Due to paucity of literature papers were reviewed from 1900 to present in English. RESULTS: Recent advances in understanding the pathophysiology of photophobia in dry eye and migraine and their connection to intrinsically photosensitive retinal ganglion cells (ipRGC) have revealed complex and multifaceted trigeminovascular and trigeminoautonomic pathways underlying photophobia. Patients who suffer a TBI often have co-morbidities like dry eye and migraine that may influence the patient’s photophobia. CONCLUSION: Post-traumatic photophobia is a complex multi-disciplinary complaint that can severely impact a patient’s quality of life. Exploration of underlying etiology may allow for improved treatment and symptomatic relief for these patients beyond tinted lenses alone.

Translational Approaches to Influence Sleep and Arousal

Sleep disorders are widespread in society and are prevalent in military personnel and in Veterans. Disturbances of sleep and arousal mechanisms are common in neuropsychiatric disorders such as schizophrenia, post-traumatic stress disorder, anxiety and affective disorders, traumatic brain injury, dementia, and substance use disorders. Sleep disturbances exacerbate suicidal ideation, a major concern for Veterans and in the general population. These disturbances impair quality of life, affect interpersonal relationships, reduce work productivity, exacerbate clinical features of other disorders, and impair recovery. Thus, approaches to improve sleep and modulate arousal are needed. Basic science research on the brain circuitry controlling sleep and arousal led to the recent approval of new drugs targeting the orexin/hypocretin and histamine systems, complementing existing drugs which affect GABA_A receptors and monoaminergic systems. Non-invasive brain stimulation techniques to modulate sleep and arousal are safe and show potential but require further development to be widely applicable. Invasive viral vector and deep brain stimulation approaches are also in their infancy but may be used to modulate sleep and arousal in severe neurological and psychiatric conditions. Behavioral, pharmacological, non-invasive brain stimulation and cell-specific invasive approaches covered here suggest the potential to selectively influence arousal, sleep initiation, sleep maintenance or sleep-stage specific phenomena such as sleep spindles or slow wave activity. These manipulations can positively impact the treatment of a wide range of neurological and psychiatric disorders by promoting the restorative effects of sleep on memory consolidation, clearance of toxic metabolites, metabolism, and immune function and by decreasing hyperarousal.

Traumatic brain injury and the development of parkinsonism: Understanding pathophysiology, animal models, and therapeutic targets

The clinical translation of therapeutic approaches to combat debilitating neurodegenerative conditions, such as Parkinson's disease (PD), remains as an urgent unmet challenge. The strong molecular association between the pathogenesis of traumatic brain injury (TBI) and the development of parkinsonism in humans has been well established. Therefore, a lot of ongoing research aims to investigate this pathology overlap in-depth, to exploit the common targets of TBI and PD for development of more effective and long-term treatment strategies. This review article intends to provide a detailed background on TBI pathophysiology and its established overlap with PD with an additional emphasis on the recent findings about their effect on perivascular clearance. Although, the traditional animal models of TBI and PD are still being considered, there is a huge focus on the development of combinatory hybrid animal models coupling concussion with the pre-established PD models for a better recapitulation of the human context of PD pathogenesis. Lastly, the therapeutic targets for TBI and PD, and the contemporary research involving exosomes, DNA vaccines, miRNA, gene therapy and gene editing for the development of potential candidates are discussed, along with the recent development of lesser invasive and promising central nervous system (CNS) drug delivery strategies.

Characterizing Sleep and Wakefulness in the Acute Phase of Concussion in the General Population: A Naturalistic Cohort from the Toronto Concussion Study

Growing literature links concussion to changes in sleep and wakefulness in humans and in rodent models. Sleep has been linked with synaptic reorganization under other conditions; however, the characterization and role of sleep after acute concussion remains poorly understood. While much research has focused on insomnia among patients with chronic or persistent concussion symptoms, there is limited understanding of sleep and acute concussion, its potential role in recovery, and associated risk factors for the development of chronic sleep disturbance. Studies to date are limited by small sample sizes of primarily athlete or military populations. Additional studies among the general population are critical to inform best practice guidelines. We examined the sleep and daytime wakefulness of 472 adults from a naturalistic general population cohort (mean age, 33.3 years, females = 60.8%) within seven days of diagnosed concussion, using a validated, condition-specific measure, the Sleep and Concussion Questionnaire. Participants identified immediate changes in sleep characterized by hypersomnia and difficulty maintaining daytime wakefulness; 35% considered these changes as moderate to severe and 79% required monitoring or follow-up. Females experienced significantly greater severity of changes in sleep compared with males. Positive correlations between severity of sleep and pain and headache were identified. Differences by sex are an important consideration for early intervention and long-term monitoring. Because sleep was compromised by pain, pain management is also an integral part of early intervention. Our findings suggest that assessment of sleep beginning in the acute stage is a critical component of concussion management in the general population.