Outcome from mild traumatic brain injury

Effects of Age, Sex, and Postconcussive Symptoms on Domain-Specific Quality of Life a Year After Mild Traumatic Brain Injury

OBJECTIVE

To identify the factors influencing longitudinal changes in patients' scores across 6 domains of the Quality of Life after Brain Injury (QOLIBRI) instrument 1 year after mild traumatic brain injury (mTBI).

DESIGN

This was a longitudinal cohort study.

PARTICIPANTS AND SETTING

Eligible patients with a new diagnosis of mTBI were recruited from the outpatient clinics of the neurosurgery departments of 3 teaching hospitals in Taipei City, Taiwan. In total, 672 patients participated in the baseline assessment. Postinjury follow-up was conducted at 6 and 12 months.

MAIN OUTCOME MEASURE

Six domains of the 37-item QOLIBRI: Cognition, Self, Daily Life and Autonomy, Social Relationships, Emotions, and Physical Problems.

RESULTS

Linear mixed-effects analyses revealed that, among patients younger than 60 years, the scores of the Cognition, Self, Daily Life and Autonomy, and Social Relationships domains significantly increased 6 months after injury; furthermore, their scores of the Cognition, Self, and Daily Life and Autonomy significantly increased 12 months after injury. By contrast, among patients 60 years and older, the scores of these domains reduced from baseline to 6 and 12 months. No significant sex-based difference was observed in the changes in scores of any QOLIBRI domain. At 6 and 12 months post-injury, the scores of the Cognition, Emotions, and Physical Problems domains were significantly higher for patients with postconcussive symptoms than for those without these symptoms.

CONCLUSIONS

Although multiple characteristics of patients significantly affected their baseline scores on the 6 domains of the QOLIBRI, only age and postconcussive symptoms were significantly associated with longitudinal changes in their scores 6 and 12 months after mTBI.

Meta-analysis of Cognitive Rehabilitation Interventions in Veterans and Service Members With Traumatic Brain Injuries

MAIN OBJECTIVE

Cognitive difficulties are some of the most frequently experienced symptoms following mild-to-moderate traumatic brain injuries (TBIs). There is meta-analytic evidence that cognitive rehabilitation improves cognitive functioning after TBI in nonveteran populations but not specifically within the veteran and service member (V/SM) population. The purpose of the current meta-analysis was to examine the effect of cognitive rehabilitation interventions for V/SMs with a history of mild-to-moderate TBI.

DESIGN AND MAIN MEASURES

This meta-analysis was preregistered with PROSPERO (CRD42021262902) and used the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) checklist for reporting guidelines. Inclusion criteria required studies to have (1) randomized controlled trials; (2) used adult participants (aged 18 years or older) who were US veterans or active-duty service members who had a history of mild-to-moderate TBI; (3) cognitive rehabilitation treatments designed to improve cognition and/or everyday functioning; (4) used objective neuropsychological testing as a primary outcome measure; and (5) been published in English. At least 2 reviewers independently screened all identified abstracts and full-text articles and coded demographic and effect size data. The final search was run on February 24, 2023, using 4 databases (PubMed, PsycINFO, Web of Science, and Google Scholar). Study quality and bias were examined using the revised Cochrane Risk-of-Bias Tool for Randomized Trials.

RESULTS

We identified 8 articles meeting full criteria (total participants = 564; 97% of whom had a history of mild TBI). Compared with control groups, participants showed a small, but significant, improvement in overall objective neuropsychological functioning after cognitive rehabilitation interventions. Interventions focusing on teaching strategies had a larger effect size than did those focusing on drill-and-practice approaches for both objective neuropsychological test performance and performance-based measures of functional capacity.

CONCLUSION

There is evidence of cognitive improvement in V/SMs with TBI histories after participation in cognitive rehabilitation. Clinician-administered interventions focusing on teaching strategies may yield the greatest cognitive improvement in this population.

Forced choice test score of p ≤ .20 and failures on ≥ six performance validity tests results in similar Overall Test Battery Means

Objective: To determine if similar levels of performance on the Overall Test Battery Mean (OTBM) occur at different forced choice test (FCT) p-value score failures. Second, to determine the OTBM levels that are associated with failures at above chance on various performance validity (PVT) tests. Method: OTBMs were computed from archival data obtained from four practices. We calculated each examinee's Estimated Premorbid Global Ability (EPGA) and OTBM. The sample size was 5,103 examinees with 282 (5.5%) of these scoring below chance at p ≤ .20 on at least one FCT. Results: The OTBM associated with a failure at p ≤ .20 was equivalent to the OTBM that was associated with failing 6 or more PVTs at above-chance cutoffs. The mean OTBMs relative to increasingly strict FCT p cutoffs were similar (T scores in the 30s). As expected, there was an inverse relationship between the number of PVTs failed and examinees' OTBMs. Conclusions: The data support the use of p ≤ .20 as the probability level for testing the significance of below chance performance on FCTs. The OTBM can be used to index the influence of invalid performance on outcomes, especially when an examinee scores below chance.

Association of Premorbid Anxiety and Depression Symptoms in Concussion Recovery in Collegiate Student-Athletes

BACKGROUND

Mental health disorders are linked to prolonged concussion symptoms. However, the association of premorbid anxiety/depression symptoms with postconcussion return-to-play timelines and total symptom burden is unclear.

OBJECTIVE

To examine the association of self-reported premorbid anxiety/depression symptoms in collegiate student-athletes with (1) recovery times until asymptomatic, (2) return-to-play, and (3) postconcussion symptom burden.

STUDY DESIGN

Athletes in the Concussion Assessment, Research and Education Consortium completed baseline concussion assessments (Sport Concussion Assessment Tool [SCAT3] and Brief Symptom Inventory-18 [BSI-18]). Athletes were tested postinjury at <6 hours, 24 to 48 hours, time of asymptomatic and start of return-to-play protocol, unrestricted return-to-play, and 6 months after injury. Injured athletes were categorized into 4 groups based on BSI-18 scores: (1) B-ANX, elevated anxiety symptoms only; (2) B-DEP, elevated depression symptoms only; (3) B-ANX&DEP, elevated anxiety and depression symptoms; and (4) B-NEITHER, no elevated anxiety or depression symptoms. Relationship between age, sex, BSI-18 group, SCAT3 total symptom and severity scores, and time to asymptomatic status and return-to-play was assessed with Pearson's chi-squared test and robust analysis of variance.

LEVEL OF EVIDENCE

Level 3.

RESULTS

Among 1329 athletes with 1352 concussions, no respondents had a self-reported premorbid diagnosis of anxiety/depression. There was no difference in time until asymptomatic or time until return-to-play between BSI-18 groups (P = 0.15 and P = 0.11, respectively). B-ANX, B-DEP, and B-ANX&DEP groups did not have higher total symptom or severity scores postinjury compared with the B-NEITHER group.

CONCLUSION

Baseline anxiety/depression symptoms in collegiate student-athletes without a mental health diagnosis are not associated with longer recovery times until asymptomatic, longer time to return-to-play, or higher postconcussion total symptom and severity scores compared with athletes without baseline symptoms.

CLINICAL RELEVANCE

Anxiety and depression symptoms without a clear mental health diagnosis should be considered differently from other comorbidities when discussing prolonged recovery in collegiate student-athletes.

STEP-Home transdiagnostic group reintegration workshop to improve mental health outcomes for post-9/11 Veterans: Design, methods, and rationale for a randomized controlled behavioral trial

BACKGROUND

Many post-9/11 U.S. combat Veterans experience difficulty readjusting to civilian life after military service, including relationship problems, reduced work productivity, substance misuse, and increased anger control problems. Mental health problems are frequently cited as causing these difficulties, driven by unparalleled rates of mild traumatic brain injury, posttraumatic stress, and other co-occurring emotional and physical conditions. Given the high prevalence of multimorbidity in this cohort, acceptable, non-stigmatizing, transdiagnostic interventions targeting reintegration are needed. The STEP-Home reintegration workshop has the potential to significantly improve skills to foster civilian reintegration, increase engagement in VA services, and improve mental health outcomes in Veterans with and without diagnosed clinical conditions.

METHODS/DESIGN

Ongoing from 2019, a prospective, two-site, randomized trial of 206 post-9/11 U.S. military Veterans randomized to receive either 12 sessions of the STEP-Home transdiagnostic reintegration workshop (SH; Active Intervention) or Present Centered Reintegration Group Therapy (PCRGT; Active Control Intervention). Primary outcomes are reintegration, anger, and emotional regulation post-intervention and at 3-months post-intervention. Secondary outcomes include measures of mental health, functional and vocational status, and cognition.

CONCLUSION

This study addresses an important gap in transdiagnostic interventions to improve civilian reintegration in post-9/11 Veterans. STEP-Home is designed to promote treatment engagement and retention, opening the door to critically needed VA care, and ultimately reducing long-term healthcare burden of untreated mental health illness in U.S. Veterans.

TRIAL REGISTRATION

Clinicaltrials.gov: D2907-R.

Cause of Concussion With Persisting Symptoms Is Associated With Long-Term Recovery and Symptom Type, Duration, and Number in a Longitudinal Cohort of 600 Patients

It is important for patients and clinicians to know the potential for recovery from concussion as soon as possible after injury, especially in patients who do not recover completely in the first month and have concussion with persisting concussion symptoms (C+PCS). We assessed the association between the causes of concussion and recovery from C+PCS in a consecutive retrospective and prospective cohort of 600 patients referred to the Canadian Concussion Center (CCC) at Toronto Western Hospital. Data were obtained from clinical records and follow-up questionnaires and not from a standardized database. A novel method was used to assess long-term recovery, and multi-variable Cox proportional hazards models were used to assess relationships between cause of concussion and time to recovery. We examined the subsequent recovery of patients who had not recovered after at least one month from the time of concussion. Patients were grouped into the following four causes: sports and recreation (S&R, n = 312, 52%); motor vehicle collisions (MVC, n = 103, 17%); falls (n = 100, 17%); and being struck by an object including violence (SBOV, n = 85, 14%). The MVC group had the highest percentage of females (75.7%), the oldest participants (median: 40.0 [interquartile range (IQR):30.5-49.0] years), the most symptoms (median:11.0 [IQR:8.5-15.0]), and the longest symptom duration (median: 28.0 [IQR:12.0-56.00] months). In contrast, the S&R group had the highest percentage of males (58.1%), the youngest participants (median:20.0 [IQR:17.0-30.0] years), the best recovery outcome, and shortest symptom duration (median:22.0 [IQR:8.0-49.5] months). Significant differences among the four causes included age (p < 0.001), sex (p < 0.001), number of previous concussions (p < 0.001), history of psychiatric disorders (p = 0.002), and migraine (p = 0.001). Recovery from concussion was categorized into three groups: (1) Complete Recovery occurred in only 60 (10%) patients with median time 8.0 (IQR:3.5-18.0) months and included 42 S&R, 7 MVC, 8 falls, and 3 SBOV; (2) Incomplete Recovery occurred in 408 (68.0%) patients with persisting median symptom time of 5.0 (IQR:2.0-12.0) months; and (3) Unknown Recovery occurred in 132 (22.0%) patients and was because of lack of follow-up. In summary, the cause of C+PCS was associated with the type, number, and duration of symptoms and time required for recovery, although all causes of C+PCS produced prolonged symptoms in a large percentage of patients, which emphasizes the importance of concussions as a public health concern necessitating improved prevention and treatment strategies.

Emotional functioning in long COVID: Comparison to post-concussion syndrome using the Personality Assessment Inventory

Objective: Recent studies on Long COVID found that patients report prominent emotional distress and significant correlations between distress and cognitive performance have been identified, raising the question of how to manage or treat these issues. To understand psychological functioning in Long COVID further, this study examined personality responses on the Personality Assessment Inventory (PAI) to compare psychological functioning in a Long COVID group with a post-concussion syndrome (PCS) group, a syndrome with a significant psychological component. Participants and methods: Participants included 201 consecutive Long COVID outpatients (Mean age = 48.87 years, mean education = 14.82, 71.6% Female, 82.6% White) and a comparison group of 102 consecutively referred PCS outpatients (Mean age = 46.08, mean education = 14.17, 63.7% Female, 88.2% White). Effect sizes and t-tests were calculated using the PAI validity, clinical, interpersonal, and treatment consideration scales as well as clinical subscales. Results: The results replicated earlier findings on the PAI in Long COVID by demonstrating that both Long COVID and PCS groups had the highest mean elevations on SOM and DEP scales but no statistically significant between group differences in mean scale elevations. Results support similarities in psychological functioning between Long COVID and PCS patients emphasizing the importance of evaluating psychological functioning in neuropsychological evaluations for these populations. Further, results suggest that psychological treatment strategies for PCS patients may be helpful for Long COVID patients, but more research is needed.

Cross validation of the response bias scale and the response bias scale-19 in active-duty personnel: use on the MMPI-2-RF and MMPI-3

The Response Bias Scale (RBS) is the central measure of cognitive over-reporting in the MMPI-family of instruments. Relative to other clinical populations, the research evaluating the detection of over-reporting is more limited in Veteran and Active-Duty personnel, which has produced some psychometric variability across studies. Some have suggested that the original scale construction methods resulted in items which negatively impact classification accuracy and in response crafted an abbreviated version of the RBS (RBS-19; Ratcliffe et al., 2022; Spencer et al., 2022). In addition, the most recent edition of the MMPI is based on new normative data, which impacts the ability to use existing literature to determine effective cut-scores for the RBS (despite all items having been retained across MMPI versions). To date, no published research exists for the MMPI-3 RBS. The current study examined the utility of the RBS and the RBS-19 in a sample of Active-Duty personnel (n = 186) referred for neuropsychological evaluation. Using performance validity tests as the study criterion, we found that the RBS-19 was generally equitably to RBS in classification. Correlations with other MMPI-2-RF over- and under-reporting symptom validity tests were slightly stronger for RBS-19. Implications and directions for research and practice with RBS/RBS-19 are discussed, along with implications for neuropsychological assessment and response validity theory.

Whole-brain traumatic controlled cortical impact to the left frontal lobe: Magnetic resonance image-based texture analysis

This research assesses the capability of texture analysis (TA) derived from high-resolution (HR) T2-weighted magnetic resonance imaging to identify primary sequelae following 1-5 hours of controlled cortical impact mild or severe traumatic brain injury (TBI) to the left frontal cortex (focal impact) and secondary (diffuse) sequelae in the right frontal cortex, bilateral corpus callosum, and hippocampus in rats. The TA technique comprised first-order (histogram-based) and second-order statistics (including gray-level co-occurrence matrix, gray-level run length matrix, and neighborhood gray-level difference matrix). Edema in the left frontal impact region developed within 1 hour and continued throughout the 5-hour assessments. The TA features from HR images confirmed the focal injury. There was no significant difference among radiomics features between the left and right corpus callosum or hippocampus from 1 to 5 hours following a mild or severe impact. The adjacent corpus callosum region and the distal hippocampus region (s), showed no diffuse injury 1-5 hours after mild or severe TBI. These results suggest that combining HR images with TA may enhance detection of early primary and secondary sequelae following TBI.

Personality traits beyond Neuroticism predict post-concussive symptomatology in the post-acute period after mild traumatic brain injury in premorbidly healthy adults

There is growing evidence that an individual's personality traits are related to post-concussion symptomatology beyond the acute period after mild traumatic brain injury (mTBI). Few studies, however, have analyzed this impact beyond the personality trait of Neuroticism. We examined the impact of personality traits on post-concussion symptoms (PCS) by measuring the Big Five personality domains and their lower-order aspects in 87 pre-morbidly healthy participants assessed 6-12 weeks post-mTBI (n = 53) or physical trauma (n = 34). As expected, Neuroticism predicted PCS endorsement in both groups. Conscientiousness and Openness/intellect were predictive of lower PCS endorsement, but only in the mTBI group. Withdrawal, one aspect within the Neuroticism domain, independently predicted PCS endorsement in the mTBI group; the remaining Neuroticism aspect, Volatility, did not predict PCS endorsement in either group. These findings suggest that individuals high in Neuroticism are more likely to report PCS following mTBI and that this relationship is driven by susceptibility to depression/anxiety symptoms (Withdrawal aspect) rather than irritability (Volatility aspect). Further, they suggest that the current focus on the relationship between Neuroticism and PCS reporting in individuals with mTBI should be broadened to include other personality domains, such as Conscientiousness and Openness/intellect.

The relationship between cognition and white matter tract damage after mild traumatic brain injury in a premorbidly healthy, hospitalised adult cohort during the post-acute period

Introduction

Recent developments in neuroimaging techniques enable increasingly sensitive consideration of the cognitive impact of damage to white matter tract (WMT) microstructural organisation after mild traumatic brain injury (mTBI).

Objective

This study investigated the relationship between WMT microstructural properties and cognitive performance.

Participants setting and design

Using an observational design, a group of 26 premorbidly healthy adults with mTBI and a group of 20 premorbidly healthy trauma control (TC) participants who were well-matched on age, sex, premorbid functioning and a range of physical, psychological and trauma-related variables, were recruited following hospital admission for traumatic injury.

Main measures

All participants underwent comprehensive unblinded neuropsychological examination and structural neuroimaging as outpatients 6-10 weeks after injury. Neuropsychological examination included measures of speed of processing, attention, memory, executive function, affective state, pain, fatigue and self-reported outcome. The WMT microstructural properties were estimated using both diffusion tensor imaging (DTI) and neurite orientation dispersion and density imaging (NODDI) modelling techniques. Tract properties were compared between the corpus callosum, inferior longitudinal fasciculus, uncinate fasciculus, anterior corona radiata and three segmented sections of the superior longitudinal fasciculus.

Results

For the TC group, in all investigated tracts, with the exception of the uncinate fasciculus, two DTI metrics (fractional anisotropy and apparent diffusion coefficient) and one NODDI metric (intra-cellular volume fraction) revealed expected predictive linear relationships between extent of WMT microstructural organisation and processing speed, memory and executive function. The mTBI group showed a strikingly different pattern relative to the TC group, with no relationships evident between WMT microstructural organisation and cognition on most tracts.

Conclusion

These findings indicate that the predictive relationship that normally exists in adults between WMT microstructural organisation and cognition, is significantly disrupted 6-10 weeks after mTBI and suggests that WMT microstructural organisation and cognitive function have disparate recovery trajectories.

Preliminary efficacy and predictors of response to a remotely-delivered symptom self-management program for persistent symptoms after concussion

BACKGROUND

More than a quarter of adults with concussion endure prolonged symptoms of >3 months. We developed the Concussion Education Self-Management program to help people manage persisting symptoms. Here, we assess feasibility, preliminary efficacy, and correlates of response.

METHODS

N = 80 adults participated in the program; ages ranged from 18 to 65 years and time post-injury ranged from 6 months to 18 years. Weekly sessions, delivered remotely and in groups, comprised education and strategies for management of cognitive, emotional, and physical symptoms. Primary outcome: Confidence to self-manage symptoms. Secondary outcomes: Quality of life; mood/anxiety/stress. Predictors of response: Self-reported cognitive, emotional and physical symptoms at intake.

RESULTS

Pre- to post-program improvements were observed in confidence to self-manage, p < 0.03; quality of life, p < 0.001; depression, p < 0.001; anxiety, p < 0.001; and stress, p < 0.001. Considering confidence to self-manage, those with fewer cognitive and physical symptoms benefitted more (p's < 0.0005 and p < 0.01, respectively).

DISCUSSION

This program shows promise for improving self-management of prolonged symptoms. Those with high symptom burden may need extra sessions to benefit. This is a cost-effective and scalable program that can reach people regardless of geographic location or impediments to travel.

Military-related mild traumatic brain injury: clinical characteristics, advanced neuroimaging, and molecular mechanisms

Mild traumatic brain injury (mTBI) is a significant health burden among military service members. Although mTBI was once considered relatively benign compared to more severe TBIs, a growing body of evidence has demonstrated the devastating neurological consequences of mTBI, including chronic post-concussion symptoms and deficits in cognition, memory, sleep, vision, and hearing. The discovery of reliable biomarkers for mTBI has been challenging due to under-reporting and heterogeneity of military-related mTBI, unpredictability of pathological changes, and delay of post-injury clinical evaluations. Moreover, compared to more severe TBI, mTBI is especially difficult to diagnose due to the lack of overt clinical neuroimaging findings. Yet, advanced neuroimaging techniques using magnetic resonance imaging (MRI) hold promise in detecting microstructural aberrations following mTBI. Using different pulse sequences, MRI enables the evaluation of different tissue characteristics without risks associated with ionizing radiation inherent to other imaging modalities, such as X-ray-based studies or computerized tomography (CT). Accordingly, considering the high morbidity of mTBI in military populations, debilitating post-injury symptoms, and lack of robust neuroimaging biomarkers, this review (1) summarizes the nature and mechanisms of mTBI in military settings, (2) describes clinical characteristics of military-related mTBI and associated comorbidities, such as post-traumatic stress disorder (PTSD), (3) highlights advanced neuroimaging techniques used to study mTBI and the molecular mechanisms that can be inferred, and (4) discusses emerging frontiers in advanced neuroimaging for mTBI. We encourage multi-modal approaches combining neuropsychiatric, blood-based, and genetic data as well as the discovery and employment of new imaging techniques with big data analytics that enable accurate detection of post-injury pathologic aberrations related to tissue microstructure, glymphatic function, and neurodegeneration. Ultimately, this review provides a foundational overview of military-related mTBI and advanced neuroimaging techniques that merit further study for mTBI diagnosis, prognosis, and treatment monitoring.

Functional Overlay Model of Persistent Post-Concussion Syndrome

Persistent post-concussion syndrome (PPCS) is a complex and debilitating condition that can develop after head concussions or mild traumatic brain injury (mTBI). PPCS is characterized by a wide range of symptoms, including headaches, dizziness, fatigue, cognitive deficits, and emotional changes, that can persist for months or even years after the initial injury. Despite extensive research, the underlying mechanisms of PPCS are still poorly understood; furthermore, there are limited resources to predict PPCS development in mTBI patients and no established treatment. Similar to PPCS, the etiology and pathogenesis of functional neurological disorders (FNDs) are not clear neither fully described. Nonspecific multifactorial interactions that were also seen in PPCS have been identified as possible predispositions for FND onset and progression. Thus, we aimed to describe a functional overlay model of PPCS that emphasizes the interplay between functional and structural factors in the development and perpetuation of PPCS symptoms. Our model suggests that the initial brain injury triggers a cascade of physiological and psychological processes that disrupt the normal functioning of the brain leading to persistent symptoms. This disruption can be compounded by pre-existing factors, such as genetics, prior injury, and psychological distress, which can increase the vulnerability to PPCS. Moreover, specific interventions, such as cognitive behavioral therapy, neurofeedback, and physical exercise can target the PPCS treatment approach. Thus, the functional overlay model of PPCS provides a new framework for understanding the complex nature of this condition and for developing more effective treatments. By identifying and targeting specific functional factors that contribute to PPCS symptoms, clinicians and researchers can improve the diagnosis, management, and ultimately, outcomes of patients with this condition.

Impact of depression and post-traumatic stress on manual and oculomotor performance in service members with a history of mild TBI

OBJECTIVE

To determine the impact of depression and post-traumatic stress on an automated oculomotor and manual measure of visual attention, compared to conventional neuropsychological assessment. Setting: Military traumatic brain injury (TBI) rehabilitation program.

PARTICIPANTS

188 Active Duty Service Members (ADSM) with a history of mild TBI.

DESIGN

A cross-sectional and correlational study with data obtained through an IRB-approved data registry study. Main measures: Bethesda Eye & Attention Measure (BEAM); brief neuropsychological battery; self-reported symptom surveys including Neurobehavioral Symptom Inventory (NSI), Patient Health Questionnaire-8 (PHQ-8), and PTSD Checklist-5 (PCL-5).

RESULTS

Small effect sizes were found for partial correlations between both depression and post-traumatic stress and key BEAM metrics. In contrast, small-to-medium effects sizes were found across all traditional neuropsychological test measures.

CONCLUSION

This study illustrates the profile of impairments associated with depression and post-traumatic stress on saccadic eye movements and manual responses to BEAM relative to conventional neuropsychological tests. Results demonstrated that among ADSM seen for mTBI, depression and PTS exert a significant negative impact on measures of processing speed, attention, executive function, and memory across saccadic, manual, and conventional neuropsychological tests. However, the unique psychometric features of each of these assessment approaches may assist in distinguishing the effects of psychiatric comorbidities within this population.

Life After Mild Traumatic Brain Injury: Widespread Structural Brain Changes Associated With Psychological Distress Revealed With Multimodal Magnetic Resonance Imaging

Background

Traumatic brain injury (TBI) can alter brain structure and lead to onset of persistent neuropsychological symptoms. This study investigates the relationship between brain injury and psychological distress after mild TBI using multimodal magnetic resonance imaging.

Methods

A total of 89 patients with mild TBI from the TRACK-TBI (Transforming Research and Clinical Knowledge in Traumatic Brain Injury) pilot study were included. Subscales of the Brief Symptoms Inventory 18 for depression, anxiety, and somatization were used as outcome measures of psychological distress approximately 6 months after the traumatic event. Glasgow Coma Scale scores were used to evaluate recovery. Magnetic resonance imaging data were acquired within 2 weeks after injury. Perivascular spaces (PVSs) were segmented using an enhanced PVS segmentation method, and the volume fraction was calculated for the whole brain and white matter regions. Cortical thickness and gray matter structures volumes were calculated in FreeSurfer; diffusion imaging indices and multifiber tracts were extracted using the Quantitative Imaging Toolkit. The analysis was performed considering age, sex, intracranial volume, educational attainment, and improvement level upon discharge as covariates.

Results

PVS fractions in the posterior cingulate, fusiform, and postcentral areas were found to be associated with somatization symptoms. Depression, anxiety, and somatization symptoms were associated with the cortical thickness of the frontal-opercularis and occipital pole, putamen and amygdala volumes, and corticospinal tract and superior thalamic radiation. Analyses were also performed on the two hemispheres separately to explore lateralization.

Conclusions

This study shows how PVS, cortical, and microstructural changes can predict the onset of depression, anxiety, and somatization symptoms in patients with mild TBI.

Inflammatory cytokines associated with mild traumatic brain injury and clinical outcomes: a systematic review and meta-analysis

Mild traumatic brain injuries (mTBIs) trigger a neuroinflammatory response, which leads to perturbations in the levels of inflammatory cytokines, resulting in a distinctive profile. A systematic review and meta-analysis were conducted to synthesize data related to levels of inflammatory cytokines in patients with mTBI. The electronic databases EMBASE, MEDLINE, and PUBMED were searched from January 2014 to December 12, 2021. A total of 5,138 articles were screened using a systematic approach based on the PRISMA and R-AMSTAR guidelines. Of these articles, 174 were selected for full-text review and 26 were included in the final analysis. The results of this study demonstrate that within 24 hours, patients with mTBI have significantly higher levels of Interleukin-6 (IL-6), Interleukin-1 Receptor Antagonist (IL-1RA), and Interferon-γ (IFN-γ) in blood, compared to healthy controls in majority of the included studies. Similarly one week following the injury, patients with mTBI have higher circulatory levels of Monocyte Chemoattractant Protein-1/C-C Motif Chemokine Ligand 2 (MCP-1/CCL2), compared to healthy controls in majority of the included studies. The results of the meta-analysis also confirmed these findings by demonstrating significantly elevated blood levels of IL-6, MCP-1/CCL2, and Interleukin-1 beta (IL-1β) in the mTBI population compared to healthy controls (p < 0.0001), particularly in the acute stages (<7 days). Furthermore, it was found that IL-6, Tumor Necrosis Factor-alpha (TNF-α), IL-1RA, IL-10, and MCP-1/CCL2 were associated with poor clinical outcomes following the mTBI. Finally, this research highlights the lack of consensus in the methodology of mTBI studies that measure inflammatory cytokines in the blood, and also provides direction for future mTBI research.

NDRG2 regulates the formation of reactive astrocyte-derived progenitor cells via Notch signaling pathway after brain traumatic injury in rats

In response to traumatic brain injury, a subpopulation of cortical astrocytes is activated, resulting in acquisition of stem cell properties, known as reactive astrocytes-derived progenitor cells (Rad-PCs). However, the underlying mechanisms remain largely unknown during this process. In this study, we examined the role of N-myc downstream-regulated gene 2 (NDRG2), a differentiation- and stress-associated molecule, in Rad-PCs after cortical stab injury in adult rats. Immunohistochemical analysis showed that in the cerebral cortex of normal adult rats, NDRG2 was exclusively expressed in astrocytes. After liu cortical injury, the expression of NDRG2 was significantly elevated around the wound and most cells expressing NDRG2 also expressed GFAP, a reactive astrocyte marker. Importantly, NDRG2-expressing cells were co-labeled with Nestin, a marker for neural stem cells, some of which also expressed cell proliferation marker Ki67. Overexpression of NDRG2 further increased the number of NDRG2/Nestin double-labeling cells around the lesion. In contrast, shRNA knockdown of NDRG2 decreased the number of NDRG2+/Nestin+ cells. Intracerebroventricular administration of stab-injured rats with a Notch antagonist, DAPT, led to a significant decrease in Nestin+/NDRG2+ cells around the injured boundary, but did not affect NDRG2+ cells. Moreover, overexpression or knockdown of NDRG2 led to up- and down-regulation of the expression of Notch intracellular domain NICD and Notch target gene Hes1, respectively. Taken together, these results suggest that NDRG2 may play a role in controlling the formation of Rad-PCs in the cerebral cortex of adult rats following traumatic injury, and that Notch signaling pathway plays a key role in this process.

Hierarchical clustering of prolonged post-concussive symptoms after 12 months: symptom-centric analysis and association with functional impairments

BACKGROUND

Following a concussion, approximately 15% of individuals experience persistent symptoms that can lead to functional deficits. However, underlying symptom-clusters that persist beyond 12 months have not been adequately characterized, and their relevance to functional deficits are unclear. The aim of this study was to characterize the underlying clusters of prolonged post-concussive symptoms lasting more than 12 months, and to investigate their association with functional impairments.

METHODS

Although hierarchical clustering is ideally suited in evaluating subjective symptom severities, it has not been applied to the Rivermead Post-Concussion Questionnaire (RPQ). The RPQ and functional impairments questions were administered via a smartphone application to 445 individuals who self-reported prolonged post-concussive symptoms. Symptom-clusters were obtained using agglomerative hierarchical clustering, and their association with functional deficits were investigated with sensitivity analyses, and corrected for multiple comparisons.

RESULTS

Five symptom-clusters were identified: headache-related, sensitivity to light and sound, cognitive, mood-related, and sleep-fatigue. Individuals with more severe RPQ symptoms were more likely to report functional deficits (p < 0.0001). Whereas the headache and sensitivity clusters were associated with at most one impairment, at-least-mild sleeping difficulties and fatigue were associated with four, and moderate-to-severe cognitive difficulties with five (all p < 0.01).

CONCLUSIONS

Symptom-clusters may be clinically useful for functional outcome stratification for targeted rehabilitation therapies. Further studies are required to replicate these findings in other cohorts and questionnaires, and to ascertain the effects of symptomatic intervention on functional outcomes.

Return to work following mild traumatic brain injury: Psychological and cognitive factors in a litigating sample in the post acute stage of recovery

The purpose of this study was to investigate return to work (RTW) rates following a single uncomplicated mild Traumatic Brain Injury (mTBI) in the post-acute stage in the context of active litigation. More specifically, we sought to determine what psychological and/or cognitive factors predict a RTW after mTBI. Archival data were obtained from a random sample of litigating patients (n = 125; 54% female; mean age: 42.96 (SD = 12.74) who were referred to a private practice for a neuropsychological examination regarding their disability status following a single uncomplicated mTBI. A hierarchical regression analysis was used to assess the predictive value of emotional symptoms and cognition with respect to RTW status. Approximately 50% of the sample did not RTW. Attentional deficits (rs = -0.248) and depressive symptoms (rs = 0.248) were significantly associated with RTW. A hierarchical regression analysis found that depressive symptoms (p < .05) were associated with RTW outcomes. These findings suggest that individuals with increased depressive symptoms are more likely to demonstrate poor RTW outcomes in the post-acute stages of mTBI. These results are of interest to clinicians as they underscore the importance of screening and early intervention for depressive symptoms following a single uncomplicated mTBI in the post-acute stages in litigating samples.

Efficacy of aerobic exercise following concussion: a narrative review

Concussion is a type of mild traumatic brain injury which results in symptoms within the physical, cognitive, emotional, and sleep domains. Historically, guidelines established by expert opinion have recommended rest during the initial stages of recovery following a concussion until symptom resolution. However, recent recommendations have shifted to advise an initial period of 24-48 h of rest immediately following concussion with the gradual introduction of light-to-moderate intensity aerobic exercise thereafter. Given the relatively recent transition in recommendations, the aim of this review is to provide an overview of the current literature on the efficacy of aerobic exercise following concussion. The current literature is limited to studies assessing the impact of standardized aerobic exercise following concussion. Upon review, literature suggests participating in aerobic exercise below the point of symptom exacerbation is safe in both the acute and chronic post-concussion symptom stages of recovery and does not delay time to medical clearance. Future large-scale randomized controlled trials assessing the impact of aerobic exercise and differences between males and females would help support the current evidence suggesting aerobic exercise could improve time to recovery following concussion and identify any sex differences in response. As well, future studies with the purpose of identifying optimal aerobic exercise volume and intensity in the treatment of concussion could improve the specificity of the current guidelines.

Prevalence of post-concussion syndrome and associated factors among patients with traumatic brain injury at Debre Tabor Comprehensive Hospital, North Central Ethiopia

Introduction

The occurrence of three or more of the following signs and symptoms, such as headache, dizziness, exhaustion, irritability, sleeplessness, difficulties in concentrating, or memory problems, following a head injury is referred to as post-concussion syndrome (PCS). Even though post-concussion syndrome has not been studied in Ethiopia, the productive age group is frequently affected by health issues related to head trauma, which either directly or indirectly affect the growth of the nation.

Objective

To assess the prevalence and associated factors of post-concussion syndrome among patients with traumatic brain injury at Debre Tabor Comprehensive Hospital, Debre Tabor, North Central Ethiopia.

Methods

A successive sampling technique was used to conduct a hospital-based cross-sectional study on 405 traumatic brain injury patients at Debre Tabor Comprehensive Hospital from January 1, 2022, to May 30, 2022. SPSS version 25 was used to analyze the data. The factors connected to post-concussion syndrome were found using bivariate and multivariable logistic regression analysis. Statistical significance was determined by a P-value of ≤ 0.05.

Results

During the data collection period, 405 cases in total were interviewed, with a 98% response rate. More than half (60.7%) of patients were married, with the majority of patients (39.8%) falling between the ages of 18 and 29. At least three post-concussion syndrome symptoms were present in 42.8% of subjects. A history of comorbidities, GCS levels of 8 or below, 9 to 12 at the time of presentation, brain neuroimaging findings, and having fair or poor social support were found to be substantially linked with PCS in multivariate logistic regression.

Conclusion

About 41.5% of study participants had at least three symptoms of PCS. The Glasgow coma scale level at the time of presentation, the reason for the injury, social support, and the site of the injury were all significantly associated with the occurrence of PCS.

American Speech-Language-Hearing Association Clinical Practice Guideline: Cognitive Rehabilitation for the Management of Cognitive Dysfunction Associated With Acquired Brain Injury

BACKGROUND

Cognitive-communication impairments following acquired brain injury (ABI) can have devastating effects on a person's ability to participate in community, social, vocational, and academic preinjury roles and responsibilities. Guidelines for evidence-based practices are needed to assist speech-language pathologists (SLPs) and other rehabilitation specialists in the delivery of cognitive rehabilitation for the adult population.

PURPOSE

The American Speech-Language-Hearing Association, in conjunction with a multidisciplinary panel of subject matter experts, developed this guideline to identify best practice recommendations for the delivery of cognitive rehabilitation to adults with cognitive dysfunction associated with ABI.

METHOD

A multidisciplinary panel identified 19 critical questions to be addressed in the guideline. Literature published between 1980 and 2020 was identified based on a set of a priori inclusion/exclusion criteria, and main findings were pooled and organized into summary of findings tables. Following the principles of the Grading of Recommendations Assessment, Development and Evaluation Evidence to Decision Framework, the panel drafted recommendations, when appropriate, based on the findings, overall quality of the evidence, balance of benefits and harms, patient preferences, resource implications, and the feasibility and acceptability of cognitive rehabilitation.

RECOMMENDATIONS

This guideline includes one overarching evidence-based recommendation that addresses the management of cognitive dysfunction following ABI and 11 subsequent recommendations focusing on cognitive rehabilitation treatment approaches, methods, and manner of delivery. In addition, this guideline includes an overarching consensus-based recommendation and seven additional consensus recommendations highlighting the role of the SLP in the screening, assessment, and treatment of adults with cognitive dysfunction associated with ABI. Future research considerations are also discussed.

Relationship Between Self-Reported Concomitant Depressive and Anxiety Symptoms and the Post-Concussion Symptoms Scale (PCSS)

OBJECTIVES

The current study explored how affective disturbances, particularly concomitant anxiety and depressive symptoms, impact baseline symptom self-reporting on the Post-Concussion Symptoms Scale (PCSS) in college athletes.

METHODS

Athletes were separated into four groups (Healthy Control (HC) (n = 581), Depression Only (n = 136), Anxiety Only (n = 54), Concomitant Depression/Anxiety (n = 62)) based on their anxiety and depression scores. Groups were compared on Total PCSS Score as well as 5 PCSS Symptom Cluster scores (Cognitive, Physical, Affective, Sleep, and Headache).

RESULTS

The three affective groups reported significantly greater symptomatology than HCs, with the Concomitant group showing the highest symptomatology scores across all clusters. The depressive symptoms only group also reported significantly elevated symptomatology, compared to HCs, on every symptom cluster except headache. The anxiety symptoms only group differed from HCs on only the cognitive symptoms cluster. Additionally, the Concomitant group reported significantly increased PCSS symptomatology, in terms of total scores and all 5 symptom clusters, compared to the depressive symptoms only and anxiety symptoms only groups.

CONCLUSIONS

Our findings suggest that athletes experiencing concomitant depressive/anxiety symptoms report significantly greater levels of symptomatology across all 5 PCSS symptom clusters compared to HCs. Further, results suggest that athletes experiencing concomitant affective disturbance tend to report greater symptomatology than those with only one affective disturbance. These findings are important because, despite the absence of concussion, the concomitant group demonstrated significantly elevated symptomatology at baseline. Thus, future comparisons with post-concussion data should account for this increased symptomatology, as test results may be skewed by affective disturbances at baseline.

Close proximity to blast: No long-term or lasting effect on cognitive performance in service members with and without TBI during blast exposure

OBJECTIVE

Blast related characteristics may contribute to the diversity of findings on whether mild traumatic brain injury sustained during war zone deployment has lasting cognitive effects. This study aims to evaluate whether a history of blast exposure at close proximity, defined as exposure within 30 feet, has long-term or lasting influences on cognitive outcomes among current and former military personnel.

METHOD

One hundred participants were assigned to one of three groups based on a self-report history of blast exposure during combat deployments: 47 close blast, 14 non-close blast, and 39 comparison participants without blast exposure. Working memory, processing speed, verbal learning/memory, and cognitive flexibility were evaluated using standard neuropsychological tests. In addition, assessment of combat exposure and current post-concussive, posttraumatic stress, and depressive symptoms, and headache was performed via self-report measures. Variables that differed between groups were controlled as covariates.

RESULTS

No group differences survived Bonferroni correction for family-wise error rate; the close blast group did not differ from non-close blast and comparison groups on measures of working memory, processing speed, verbal learning/memory, or cognitive flexibility. Controlling for covariates did not alter these results.

CONCLUSION

No evidence emerged to suggest that a history of close blast exposure was associated with decreased cognitive performance when comparisons were made with the other groups. Limited characterization of blast contexts experienced, self-report of blast distance, and heterogeneity of injury severity within the groups are the main limitations of this study.

Efficacy of several statistical methods in differentiating TBI and co-occurring conditions: A replication study

OBJECTIVES

(1) Cross-validation of neuropsychological test data sets of moderate-severe TBI (N = 30) with test data from moderate-severe (N = 74); somatization (N = 24) and PCS (N = 22) cases in a database, (2) Determine if cognitive test data sets alone differentiated TBI from other groups, and (3) Evaluate the efficacy of measures in comparisons: Kullback-Leibler, Correlation, Patterns, Cohen's d, and MNB.

MATERIALS AND METHODS

Meyer's Neuropsychological System; Comparison groups -TBI sample with structural evidence of brain injury (CT/MRI); comparison of 5 statistical measures' efficacy in test data analysis comparing a community sample of moderate TBI (N=30) with a data base containing moderate-severe TBI (N = 74) + co-occurring groups (PCS N = 22) + Somatization (N = 24). Measures utilized: Correlation, Kullbeck-Leibler divergence, Cohen's d, MNB code, Configuration.

RESULTS

Combining the five measures most accurately matched the TBI sample (30/30 cases) with MNB comparison groups of similar TBI severity while differentiating those cases from PCS and Somatoform cognitive testdata. Both Kullback Leibler & Cohens' d reduced false positive errors in comparison with the other measures.

Disentangling subjective symptom complaints and objective cognitive performance in veterans: Impact of posttraumatic stress disorder and lifetime traumatic brain injury burden

Self-reported histories of mild traumatic brain injury (mTBI) and posttraumatic stress disorder (PTSD) symptoms are prevalent among post-9/11 veterans. Both are associated with subjective and often overlapping symptom complaints, but variably with objective neuropsychological test performances. These outcomes are seldom explored in relation to lifetime mTBI burden. This cross-sectional study examined associations of PTSD and lifetime mTBI with subjective (persistent symptoms after concussion and cognitive complaints) and objective (performances across five cognitive domains) measures among 46 veterans. Within this sample, 20 veterans had Clinician-Administered PTSD Scale for DSM-5 (CAPS-5) confirmed PTSD (PTSD+), whereas 26 demographically-similar participants did not meet criteria (PTSD-). The Boston Assessment of Traumatic Brain Injury-Lifetime (BAT-L) yielded total mTBI scores ranging from 0 to 8. Regressions showed PTSD was associated with increased subjective symptoms/cognitive complaints, along with reduced verbal fluency, visuospatial memory, and processing speed performances. Lifetime mTBI burden was associated with subjective symptoms, but not with objective cognitive test performance, after controlling for PTSD. No significant interactions were observed. Exploratory correlations suggested that all PTSD symptom clusters were generally associated with the subjective and objective measures. However, fewer significant associations emerged within the PTSD+/- groups separately, with each group yielding somewhat different patterns of relationships. PTSD and increasing mTBI burden are consistently associated with negative subjective symptoms, including cognitive complaints. Each condition likely explains some degree of unique variance in symptom reporting. PTSD is associated with poorer objective cognition on some tasks, including processing speed, executive functioning, and learning/memory. Implications are explored.

Towards defining biomarkers to evaluate concussions using virtual reality and a moving platform (BioVRSea)

Current diagnosis of concussion relies on self-reported symptoms and medical records rather than objective biomarkers. This work uses a novel measurement setup called BioVRSea to quantify concussion status. The paradigm is based on brain and muscle signals (EEG, EMG), heart rate and center of pressure (CoP) measurements during a postural control task triggered by a moving platform and a virtual reality environment. Measurements were performed on 54 professional athletes who self-reported their history of concussion or non-concussion. Both groups completed a concussion symptom scale (SCAT5) before the measurement. We analyzed biosignals and CoP parameters before and after the platform movements, to compare the net response of individual postural control. The results showed that BioVRSea discriminated between the concussion and non-concussion groups. Particularly, EEG power spectral density in delta and theta bands showed significant changes in the concussion group and right soleus median frequency from the EMG signal differentiated concussed individuals with balance problems from the other groups. Anterior–posterior CoP frequency-based parameters discriminated concussed individuals with balance problems. Finally, we used machine learning to classify concussion and non-concussion, demonstrating that combining SCAT5 and BioVRSea parameters gives an accuracy up to 95.5%. This study is a step towards quantitative assessment of concussion.

Vestibulo-ocular dysfunction in mTBI: Utility of the VOMS for evaluation and management – A review

BACKGROUND: Individuals who have suffered a concussion/mild traumatic brain injury (mTBI) frequently report symptoms associated with vestibular and/or oculomotor dysfunction (VOD) like dizziness, nausea, fatigue, brain fog, headache, gait and neurocognitive impairments which are associated with the development of chronic symptoms. The Vestibular/Ocular Motor Screening (VOMS) tool has been established as a reliable and clinically relevant complement to use alongside a battery of post-concussion tests to improve screening and referral for further evaluation and treatment of VOD. OBJECTIVES: This paper will review the pathoanatomy and symptomatology of common vestibular and oculomotor disorders after concussion, as well as the utility of the VOMS to assist in diagnosis, referral, and management. METHODS: Primary articles were identified using a search via PubMed, Google Scholar, OneSearch, and CINAHL. Search key terms were combinations of “mild traumatic brain injury” or “concussion” or “pursuit” or “accommodation” or “vergence” or “convergence insufficiency” or “saccades” or “vestibulo-ocular reflex” or “vestibular ocular motor screen” or “vestibular rehabilitation”, or “vision rehabilitation” including adult and pediatric populations that were published in print or electronically from 1989 to 2021 in English. Classic papers on anatomy of eye movements, vestibular system and pathological changes in mTBI were also included, regardless of publication date. RESULTS: Objective impairments are commonly found during testing of smooth pursuit, saccades, vergence, accommodation, vestibular ocular reflex, and visual motion sensitivity after mTBI. These deficits can be actively treated with vestibular physical therapy and oculomotor/neuro-optometric vision therapy. VOMS is an efficient and reliable tool that can be used by all healthcare and rehabilitation providers to aid in diagnosis of post-concussion VOD, to help facilitate the decision to refer for further evaluation and treatment to expedite symptomatic post-concussion recovery. CONCLUSIONS: VOD is common after concussion in acute, post-acute, and chronic phases. Once areas of impairments are identified through proper assessment, clinicians can maximize recovery by referring to vestibular physical therapy and/or neuro-optometry to design a targeted treatment program to address individual deficits.

Head and Neck Characteristics as Risk Factors For and Protective Factors Against Mild Traumatic Brain Injury in Military and Sporting Populations: A Systematic Review

BACKGROUND

Investigators have proposed that various physical head and neck characteristics, such as neck strength and head and neck size, are associated with protection from mild traumatic brain injury (mTBI/concussion).

OBJECTIVES

To systematically review the literature and investigate potential relationships between physical head and neck characteristics and mTBI risk in athletic and military populations.

METHODS

A comprehensive search of seven databases was conducted: MEDLINE, EMBASE, CINAHL, Scopus, SPORTDiscus, Cochrane Library, and Web of Science. Potential studies were systematically screened and reviewed. Studies on military and athletic cohorts were included if they assessed the relationship between physical head-neck characteristics and mTBI risk or proxy risk measures such as head impact kinematics.

RESULTS

The systematic search yielded a total of 11,723 original records. From these, 22 studies met our inclusion criteria (10 longitudinal, 12 cross-sectional). Relevant to our PECO (Population, Exposure, Comparator, and Outcomes) question, exposures included mTBI incidence and head impact kinematics (acceleration, velocity, displacement) for impacts during sport play and training and in controlled laboratory conditions. Outcome characteristics included head and neck size (circumference, mass, length, ratios between these measures), neck strength and endurance, and rate of force development of neck muscles.

DISCUSSION

We found mixed evidence for head and neck characteristics acting as risk factors for and protective factors against mTBI and increased susceptibility to head impacts. Head-neck strength and size variables were at times associated with protection against mTBI incidence and reduced impact kinematics (14/22 studies found one or more head-neck variable to be associated with protection); however, some studies did not find these relationships (8/22 studies found no significant associations or relationships). Interestingly, two studies found stronger and larger athletes were more at risk of sustaining high impacts during sport. Strength and size metrics may have some predictive power, but impact mitigation seems to be influenced by many other variables, such as behaviour, sex, and impact anticipation. A meta-analysis could not be performed due to heterogeneity in study design and reporting.

CONCLUSION

There is mixed evidence in the literature for the protective capacity of head and neck characteristics. We suggest field-based mTBI research in the future should include more dynamic anthropometric metrics, such as neck stiffness and response to perturbation. In addition, laboratory-based mTBI studies should aim to standardise design and reporting to help further uncover these complicated relationships.

Randomised, double-blind, placebo-controlled study investigating Safety and efficAcy of MLC901 in post-traUmatic bRAin Injury: the SAMURAI study protocol

INTRODUCTION

Traumatic brain injury (TBI) is a leading cause of death in young adults globally and 90% of cases are mild TBI. Treatment to facilitate recovery after TBI is needed. Traditional medicine MLC901 (NeuroAiD II) with neuroprotective and neuroproliferative properties in cellular and animal models of brain injury showed TBI-associated cognitive improvement in mild or moderate TBI.

METHODS AND ANALYSIS

This is a randomised placebo-controlled trial, with 6-month treatment and 9-month follow-up, to determine the safety and efficacy of MLC901 in improving cognitive function in patients with cognitive impairment following mild TBI. This multicentre trial is conducted at the research centres of six hospitals/institutions in Russia. The primary outcome is to determine the effect of MLC901 on complex attention using the CNS Vital Signs (CNS-VS) online neurological test after 6-month treatment in patients receiving MLC901 compared with placebo. Secondary outcomes include other cognitive domains of CNS-VS and Rivermead Post Concussion Symptoms Questionnaire. The exploratory endpoints include Quality of Life after Brain Injury, Hospital Anxiety and Depression Scale and evaluation of improved neurological parameters 3 months after treatment completion. In addition, treatment compliance, concomitant therapies and adverse events will be collected. Investigators will use a secured online system for data entry.

ETHICS AND DISSEMINATION

The study has been approved by the ethic committee of Ministry of Health of the Russian Federation (No: 58074). The results of this study will be published in a peer-review journal and presented at international conferences as poster presentations.

TRIAL REGISTRATION NUMBER

NCT04861688.

Persistent post-concussive syndrome in children after mild traumatic brain injury is prevalent and vastly underdiagnosed

Data on epidemiology and prognosticators of persistent post-concussion syndrome (PPCS) after mild traumatic brain injury (mTBI) in the pediatric population is scarce. The aim of this study was to evaluate the prevalence of PPCS in children after mTBI and to identify clinical variables in children who are at high risk for developing PPCS. A multicenter, retrospective matched cohort in which PPCS symptoms were evaluated in children 8–15-year-old, 6–60 months after being admitted to the emergency department because of mTBI. The control group included children admitted to the emergency department because of uncomplicated distal radius fractures. The children's guardians were interviewed for the presence of PPCS symptoms using the "Rivermead Post-Concussion Questionnaire". A multivariable logistic regression model was used to identify predictors of PPCS. Two-hundred and five children were included in the mTBI group and 205 in the control. The median time from the injury was 33.5 months in the mTBI group and 33.8 in the control. The prevalence of PPCS in the mTBI group was 25.3% and PPCS like symptoms in the control was 2.4%, p < 0.001. Within the 6–60 months period, the PPCS prevalence was not influenced by the time that elapsed from the injury. In the mTBI group, motor vehicle accidents and adolescence were found to be risk factors for PPCS. PPCS is underdiagnosed in the pediatric population and 25% of children admitted to the ED due to mTBI may suffer from PPCS. Screening guidelines should be implemented to identify and properly treat these children.

"Manoeuvring in uncharted waters - a balancing act": A qualitative exploration of treatment and improvement after mild traumatic brain injury

Background: Individuals who have sustained mild traumatic brain injury (mTBI) with a protracted course of recovery may experience long-lasting somatic, cognitive, and emotional symptoms affecting activities of daily living. There is limited knowledge regarding individuals' lived experiences with treatments and advice provided.Purpose: To explore how individuals with mTBI describe and make sense of their injury, recovery process, and their experiences with various treatment approaches.Methods: Eight participants with mTBI were recruited from the intervention group in an ongoing randomized controlled trial regarding return-to-work. They were interviewed once after treatment delivery using a qualitative hermeneutical approach. Thematic analysis was applied, and findings are discussed in light of a salutogenic theory.Results: Participants expressed uncertainty regarding conflicting advice they received in the early phase of recovery. Three main themes were developed: (1) "Ambiguity and hope"; (2) "Uncertainty concerning activity and rest"; and (3) "To become the person I used to be vs. to become a new version of myself."Conclusion: The findings showed that the participants experienced both uncertainty and hope for further recovery. The recovery process is challenged by the variability of TBI symptoms that affects participation in everyday life, as well as the conflicting advice received by the participants.

Two Symptoms to Triage Acute Concussions: Using Decision Tree Modeling to Predict Prolonged Recovery After a Concussion

OBJECTIVE

The objective was to examine the 22 variables from the Sport Concussion Assessment Tool's 5th Edition Symptom Evaluation using a decision tree analysis to identify those most likely to predict prolonged recovery after a sport-related concussion.

DESIGN

A cross-sectional design was used in this study. A total of 273 patients (52% men; mean age, 21 ± 7.6 yrs) initially assessed by either an emergency medicine or sport medicine physician within 14 days of concussion (mean, 6 ± 4 days) were included. The 22 symptoms from the Sport Concussion Assessment Tool's 5th Edition were included in a decision tree analysis performed using RStudio and the R package rpart. The decision tree was generated using a complexity parameter of 0.045, post hoc pruning was conducted with rpart, and the package carat was used to assess the final decision tree's accuracy, sensitivity and specificity.

RESULTS

Of the 22 variables, only 2 contributed toward the predictive splits: Feeling like "in a fog" and Sadness. The confusion matrix yielded a statistically significant accuracy of 0.7636 (P [accuracy > no information rate] = 0.00009678), sensitivity of 0.6429, specificity of 0.8889, positive predictive value of 0.8571, and negative predictive value of 0.7059.

CONCLUSIONS

Decision tree analysis yielded a statistically significant decision tree model that can be used clinically to identify patients at initial presentation who are at a higher risk of having prolonged symptoms lasting 28 days or more postconcussion.

Discourse Performance in Adults With Mild Traumatic Brain Injury, Orthopedic Injuries, and Moderate to Severe Traumatic Brain Injury, and Healthy Controls

INTRODUCTION

Adults with mild traumatic brain injury (mTBI) are at risk for communication disorders, yet studies exploring cognitive-communication performance are currently lacking.

AIMS

This aim of this study was to characterize discourse-level performance by adults with mTBI on a standardized elicitation task and compare it to (a) healthy adults, (b) adults with orthopedic injuries (OIs), and (c) adults with moderate to severe TBI.

METHOD

This study used a cross-sectional design. The participants included mTBI and OI groups recruited prospectively from an emergency medicine department. Moderate to severe TBI and healthy data were acquired from TalkBank. One-way analyses of variance were used to compare mean linguistic scores.

RESULTS

Seventy participants across all groups were recruited. Groups did not differ on demographic variables. The study found significant differences in both content and productivity measures among the groups. Variables did not appear sensitive to differentiate between mTBI and OI groups.

DISCUSSION

Cognitive and language performance of adults with mTBI is a pressing clinical issue. Studies exploring language with carefully selected control groups can influence the development of sensitive measures to identify individuals with cognitive-communication deficits.

Clinical testing of mild traumatic brain injury using computerised eye-tracking tests

Traumatic brain injury (TBI) refers to the alteration of typical brain function that occurs following a blow to the head. Even a mild case of traumatic brain injury (mTBI) can lead to long-term impairment, so accurate and timely detection is vital. Visual symptoms are common following mTBI, so while it may seem to fall outside their typical scope of practice, optometrists are ideally qualified to assess the visual impacts and help with the diagnosis of mTBI. Given that mTBI is challenging to objectively diagnose and has no universally accepted diagnostic criteria, clinicians can lack confidence in diagnosing mTBI, and be hesitant in becoming involved in the management of such patients. The development of easily quantifiable techniques using eye tracking as an objective diagnostic tool provides practitioners with an easier pathway into the field, assigning numerical values to parameters which are difficult to assess using conventional optometric tests. As this evolving technology becomes increasingly integrated into optometric clinical settings, the potential for it to identify deficits accurately and reliably in patients following mTBI, and to monitor both their recovery and the effectiveness of potential treatments will increase. This paper provides an overview of clinical tests, relevant to optometrists, that can uncover oculomotor, attentional, and exteroceptive deficits following a mTBI, so that an optometrist with an interest in eye tracking can play a role in the detection and monitoring of mTBI symptoms.

Examining the Association Between Childhood Trauma, Brain Injury, and Neurobehavioral Symptoms Among Survivors of Intimate Partner Violence: A Cross-Sectional Analysis

OBJECTIVE

Understanding factors contributing to neurobehavioral symptom burden among intimate partner violence (IPV) survivors has important implications for prevention, screening, and intervention in this vulnerable population. This study aimed to (1) identify the relationship between childhood trauma and neurobehavioral symptoms among a shelter- and community-based sample of IPV survivors, including investigating the mediating role of posttraumatic stress symptoms and alexithymia in this relationship; (2) assess the association between IPV-related brain injury (BI) severity and neurobehavioral symptoms; and (3) assesses whether physical, emotional, or cognitive domains of neurobehavioral symptom burden show differential associations with childhood trauma or IPV-related BI.

SETTING

Community sites serving women who had experienced IPV such as domestic violence shelters and transitional housing sites.

PARTICIPANTS

Women survivors of IPV with and without BI (n = 99), aged 18 to 54 years.

DESIGN

Retrospective, cross-sectional study design.

MEASURES

The following self-reported questionnaires were used: Rivermead Post Concussion Questionnaire (RPQ); Childhood Trauma Questionnaire (CTQ); a modified version of the Conflict Tactics Scale; Brain Injury Severity Assessment (BISA); Clinician-Administered PTSD Scale for DSM IV; and Toronto Alexithymia Scale. The final multivariate regression model assessed the association between childhood abuse, BI severity, and neurobehavioral symptoms (as measured by the RPQ) adjusting for age, educational attainment, and abuse in the past year. We created separate models with total neurobehavioral symptom score as an outcome, as well as somatic, emotional, and cognitive symptom scores. We used structural equation modeling to assess whether posttraumatic stress and alexithymia mediated the effect of childhood trauma and neurobehavioral symptoms.

RESULTS

Childhood trauma was associated with higher levels (P < .01) of overall neurobehavioral symptom burden in women independent of BI and specifically associated with RPQ Emotional and Somatic subscale symptoms (P ≤ .05). BI was positively associated with somatic symptoms in the full sample and cognitive neurobehavioral symptoms in the sample of women with IPV-related BI (P < .05) independent of childhood trauma. Posttraumatic stress symptoms, but not alexithymia, partially mediated the effect of childhood trauma effect on neurobehavioral symptoms.

CONCLUSION

Childhood trauma and BI should not be overlooked as part of efforts to meet the needs of IPV survivors who may experience a range of emotional, somatic, and cognitive symptoms.

Relationship between mild traumatic brain injury and the gut microbiome: A scoping review

There is increasing evidence for the important role of gut microbiota (GMB) in the development and progression of neurologic pathologies. Some studies have shown that modifying the microbiome profile can confer benefits to patients. Mild traumatic brain injury (mTBI) is a common occurrence in the general population. Although most patients recover, in a minority, disabling symptoms can persist for several months. We carried out a review of the literature to assess the effect of mTBI on GMB and to determine whether alleviating dysbiosis can improve clinical outcomes in mTBI patients. We performed searches in Medline/PubMed and Embase using the keywords "MTBI" AND "microbiome" OR "microbiota". Additional articles were identified by manual searches and using the Google search engine. In animal models, a clear perturbation of GMB was reported following TBI and probiotic supplementation (Lactobacillus acidophilus or Clostridium butyricum) improved neurologic function. There were no studies on changes in GMB after mTBI in humans; however, pre- or probiotic supplementation reduced the infection rate in patients with severe TBI and shortened the time spent in the intensive care unit without conferring any neurologic benefits. Thus, although the findings from animal models are promising, clinical studies are needed to determine whether therapeutic strategies that restore gut microbiome profile can improve long-term outcomes of patients with mTBI.

Self-Reported Complaints as Prognostic Markers for Outcome After Mild Traumatic Brain Injury in Elderly: A Machine Learning Approach

Self-reported complaints are common after mild traumatic brain injury (mTBI). Particularly in the elderly with mTBI, the pre-injury status might play a relevant role in the recovery process. In most mTBI studies, however, pre-injury complaints are neither analyzed nor are the elderly included. Here, we aimed to identify which individual pre- and post-injury complaints are potential prognostic markers for incomplete recovery (IR) in elderly patients who sustained an mTBI. Since patients report many complaints across several domains that are strongly related, we used an interpretable machine learning (ML) approach to robustly deal with correlated predictors and boost classification performance. Pre- and post-injury levels of 20 individual complaints, as self-reported in the acute phase, were analyzed. We used data from two independent studies separately: UPFRONT study was used for training and validation and ReCONNECT study for independent testing. Functional outcome was assessed with the Glasgow Outcome Scale Extended (GOSE). We dichotomized functional outcome into complete recovery (CR; GOSE = 8) and IR (GOSE ≤ 7). In total 148 elderly with mTBI (median age: 67 years, interquartile range [IQR]: 9 years; UPFRONT: N = 115; ReCONNECT: N = 33) were included in this study. IR was observed in 74 (50%) patients. The classification model (IR vs. CR) achieved a good performance (the area under the receiver operating characteristic curve [ROC-AUC] = 0.80; 95% CI: 0.74-0.86) based on a subset of only 8 out of 40 pre- and post-injury complaints. We identified increased neck pain (p = 0.001) from pre- to post-injury as the strongest predictor of IR, followed by increased irritability (p = 0.011) and increased forgetfulness (p = 0.035) from pre- to post-injury. Our findings indicate that a subset of pre- and post-injury physical, emotional, and cognitive complaints has predictive value for determining long-term functional outcomes in elderly patients with mTBI. Particularly, post-injury neck pain, irritability, and forgetfulness scores were associated with IR and should be assessed early. The application of an ML approach holds promise for application in self-reported questionnaires to predict outcomes after mTBI.

Behavioral and Cognitive Aspects of Concussion

PURPOSE OF REVIEW

This review provides the reader with an overview of concussion and mild traumatic brain injury (TBI). Key aspects of the pathophysiology, signs, and symptoms, treatment and rehabilitation, and recovery from concussion/mild TBI are reviewed with an emphasis on the variety of factors that may contribute to cognitive concerns following injury.

RECENT FINDINGS

Concussion remains a clinical diagnosis based on symptoms that occur in the immediate aftermath of an applied force and in the hours, days, and weeks thereafter. Although advances have been made in advanced diagnostics, including neuroimaging and fluid biomarkers in hopes of developing objective indicators of injury, such markers currently lack sufficient specificity to be used in clinical diagnostics. The symptoms of concussion are heterogeneous and may be seen to form subtypes, each of which suggests a targeted rehabilitation by the interdisciplinary team. Although the majority of patients with concussion recover within the first 30 to 90 days after injury, some have persistent disabling symptoms. The concept of postconcussion syndrome, implying a chronic syndrome of injury-specific symptoms, is replaced by a broader concept of persistent symptoms after concussion. This concept emphasizes the fact that most persistent symptoms have their basis in complex somatic, cognitive, psychiatric, and psychosocial factors related to risk and resilience. This framework leads to the important conclusion that concussion is a treatable injury from which nearly all patients can be expected to recover.

SUMMARY

Concussion/mild TBI is a significant public health problem in civilian, military, and organized athletic settings. Recent advances have led to a better understanding of underlying pathophysiology and symptom presentation and efficacious treatment and rehabilitation of the resulting symptoms. An interdisciplinary team is well-positioned to provide problem-oriented, integrated care to facilitate recovery and to advance the evidence base supporting effective practice in diagnosis, treatment, and prevention.

No Significant Effects of Cellphone Electromagnetic Radiation on Mice Memory or Anxiety: Some Mixed Effects on Traumatic Brain Injured Mice

Current literature details an array of contradictory results regarding the effect of radiofrequency electromagnetic radiation (RF-EMR) on health, both in humans and in animal models. The present study was designed to ascertain the conflicting data published regarding the possible impact of cellular exposure (radiation) on male and female mice as far as spatial memory, anxiety, and general well-being is concerned. To increase the likelihood of identifying possible "subtle" effects, we chose to test it in already cognitively impaired (following mild traumatic brain injury; mTBI) mice. Exposure to cellular radiation by itself had no significant impact on anxiety levels or spatial/visual memory in mice. When examining the dual impact of mTBI and cellular radiation on anxiety, no differences were found in the anxiety-like behavior as seen at the elevated plus maze (EPM). When exposed to both mTBI and cellular radiation, our results show improvement of visual memory impairment in both female and male mice, but worsening of the spatial memory of female mice. These results do not allow for a decisive conclusion regarding the possible hazards of cellular radiation on brain function in mice, and the mTBI did not facilitate identification of subtle effects by augmenting them.

Prevalence of insomnia and insomnia symptoms following mild-traumatic brain injury: A systematic review and meta-analysis

Sleep is commonly disrupted following mild traumatic brain injury (mTBI), however there is a lack of consensus in the existing literature regarding the prevalence of insomnia/insomnia symptoms after injury. The aim of this review was to conduct a systematic review and meta-analysis of insomnia and insomnia symptoms' prevalence following mTBI. Full-text articles published in English in peer-reviewed journals, including adults with a clinical or self-reported mild traumatic brain injury diagnosis, were eligible for inclusion. Studies that assessed insomnia/insomnia symptoms after injury were included. Of the 2091 records identified, 20 studies were included in the review. 19 of these were meta-analysed (n = 95,195), indicating high heterogeneity among studies. Subgroup analyses indicated pooled prevalence estimates of post-mTBI insomnia disorder of 27.0% (95% CI 6.49-54.68) and insomnia symptoms of 71.7% (95% CI 60.31-81.85). The prevalence of insomnia is significantly higher in individuals who have sustained mild traumatic brain injury compared to prevalence estimates reported in the general population but high heterogeneity and methodological differences among studies make it difficult to provide reliable prevalence estimates. Future research should continue to advance our understanding of the onset, progression and impact of post-mild traumatic brain injury insomnia to promote the recovery and wellbeing of affected individuals. PROSPERO registration CRD42020168563.

Mild Traumatic Brain Injury and Postconcussive Symptom Endorsement: A Parallel Comparison Between Two Nonclinical Cohorts

INTRODUCTION

The prevalence of mild traumatic brain injury (mTBI) is commonly estimated based on indirect metrics such as emergency department visits and self-reporting tools. The study of postconcussive symptoms faces similar challenges because of their unspecific character and indistinct causality. In this article, we compare two nonclinical, epidemiological studies that addressed these two elements and were performed within a relatively narrow period in the state of Colorado.

MATERIALS AND METHODS

De-identified datasets were obtained from a random digit-dialed survey study conducted by the Craig Hospital and a study surveying soldiers returning from deployment by Defense and Veteran Traumatic Brain Injury Center. Information pertinent to participants' demographics, a history of mTBI, and symptom endorsement was extracted and homogenized in order to establish a parallel comparison between the populations of the two studies.

RESULTS

From the 1,558 (Warrior Strong, 679; Craig Hospital, 879) records selected for analysis, 43% reported a history of at least one mTBI. The prevalence was significantly higher among individuals from the Defense and Veteran Traumatic Brain Injury Center study independent of gender or race. Repetitive injuries were reported by 15% of the total combined cohort and were more prevalent among males. Symptom endorsement was significantly higher in individuals with a positive history of mTBI, but over 80% of those with a negative history of mTBI endorsed at least one of the symptoms interrogated. Significant differences were observed between the military and the civilian populations in terms of the types and frequencies of the symptoms endorsed.

CONCLUSIONS

The prevalence of mTBI and associated symptoms identified in the two study populations is higher than that of previously reported. This suggests that not all individuals sustaining concussion seek medical care and highlights the limitations of using clinical reports to assess such estimates. The lack of appropriate mechanisms to determine symptom presence and causality remains a challenge. However, the differences observed in symptom reporting between cohorts raise questions about the nature of the symptoms, the impact on the quality of life for different individuals, and the effects on military health and force readiness.

Personality Characteristics and Acute Symptom Response Predict Chronic Symptoms After Mild Traumatic Brain Injury

OBJECTIVE

Despite consensus that personality influences mild traumatic brain injury (mTBI) recovery, it has been underexamined. We evaluated the extent to which diverse personality and psychiatric symptom dimensions predict mTBI recovery.

METHODS

This prospective cohort study involved psychological assessments of hospital patients with mTBI (n = 75; median = 2 days post-injury, range = 0-12 days) and orthopedic trauma controls (OTC; n = 79) who were used for comparison in mediation modeling. Chronic symptoms were evaluated at 3 months after mTBI (n = 50) using the Sport Concussion Assessment Tool (SCAT) symptom checklist. Linear regression analyses were used to identify the predominant predictors of chronic symptoms in mTBI. Modern mediation analyses tested the hypothesis that personality traits predict chronic symptoms through acute psychological response to injury.

RESULTS

In mTBI, trait psychoticism directly predicted chronic mTBI symptoms and was the strongest personality predictor overall. Furthermore, an internalizing personality dimension emphasizing negative affect/emotionality and detachment predicted chronic mTBI symptoms indirectly through enhancement of acute somatic complaints. In OTC, internalizing personality acted through the same mediator as in mTBI, whereas the effect of psychoticism was also mediated through acute somatic complaints. There was varying support for a moderated direct effect of personality traits at low levels of positive emotionality across models.

CONCLUSION

These causal models provide novel insights about the role of personality in mTBI symptom recovery, highlighting the complexity of how psychological processes may interact to affect recovery and revealing that some of these processes may be non-specific to brain injury.

Altered Metabolic Interrelationships in the Cortico-Limbic Circuitry in Military Service Members with Persistent Post-Traumatic Stress Disorder Symptoms Following Mild Traumatic Brain Injury

Introduction: Comorbid mild traumatic brain injury (mTBI) and post-traumatic stress disorder (PTSD) are common in military service members. The aim of this study is to investigate brain metabolic interrelationships in service members with and without persistent PTSD symptoms after mTBI by using ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography. Methods: Service members (n = 408) diagnosed with mTBI were studied retrospectively. Principal component analysis was applied to identify latent metabolic systems, and the associations between metabolic latent systems and self-report measures of post-concussive and PTSD symptoms were evaluated. Participants were divided into two groups based on DSM-IV-TR (Diagnostic and Statistical Manual of Mental Disorders, fourth edition-Text Revision) criteria for PTSD, and structural equation modeling was performed to test a priori hypotheses on metabolic interrelationships among the brain regions in the cortico-limbic circuitry responsible for top-down control and bottom-up emotional processing. The differences in metabolic interrelationships between age-matched PTSD-absent (n = 204) and PTSD-present (n = 204) groups were evaluated. Results: FDG uptake in the temporo-limbic system was positively correlated with post-concussive and hyperarousal symptoms. For the bottom-up emotional processing, the insula and amygdala-hippocampal complex in the PTSD-present group had stronger metabolic interrelationships with the bilateral rostral anterior cingulate, left lingual, right lateral occipital, and left superior temporal cortices, but a weaker relationship with the right precuneus cortex, compared with the PTSD-absent group. For the top-down control, the PTSD-present group had decreased metabolic engagements of the dorsolateral prefrontal cortex on the amygdala. Discussion: Our results suggest altered metabolic interrelationships in the cortico-limbic circuitry in mTBI subjects with persistent PTSD symptoms, which may underlie the pathophysiological mechanisms of comorbid mTBI and PTSD. Impact statement This is the first ¹⁸F-fluorodeoxyglucose positron emission tomography study to investigate brain metabolic interrelationships in service members with persistent post-traumatic stress disorder (PTSD) symptoms after mild traumatic brain injury (mTBI). We identified that the temporo-limbic metabolic system was associated with post-concussive and hyperarousal symptoms. Further, brain metabolic interrelationships in the cortico-limbic circuitry were altered in mTBI subjects with significant PTSD symptoms compared with those without them.

Extracellular vesicles as distinct biomarker reservoirs for mild traumatic brain injury diagnosis

Mild traumatic brain injury does not currently have a clear molecular diagnostic panel to either confirm the injury or to guide its treatment. Current biomarkers for traumatic brain injury rely mainly on detecting circulating proteins in blood that are associated with degenerating neurons, which are less common in mild traumatic brain injury, or with broad inflammatory cascades which are produced in multiple tissues and are thus not brain specific. To address this issue, we conducted an observational cohort study designed to measure a protein panel in two compartments—plasma and brain-derived extracellular vesicles—with the following hypotheses: (i) each compartment provides independent diagnostic information and (ii) algorithmically combining these compartments accurately classifies clinical mild traumatic brain injury. We evaluated this hypothesis using plasma samples from mild (Glasgow coma scale scores 13–15) traumatic brain injury patients (n = 47) and healthy and orthopaedic control subjects (n = 46) to evaluate biomarkers in brain-derived extracellular vesicles and plasma. We used our Track Etched Magnetic Nanopore technology to isolate brain-derived extracellular vesicles from plasma based on their expression of GluR2, combined with the ultrasensitive digital enzyme-linked immunosorbent assay technique, Single-Molecule Array. We quantified extracellular vesicle-packaged and plasma levels of biomarkers associated with two categories of traumatic brain injury pathology: neurodegeneration and neuronal/glial damage (ubiquitin C-terminal hydrolase L1, glial fibrillary acid protein, neurofilament light and Tau) and inflammation (interleukin-6, interleukin-10 and tumour necrosis factor alpha). We found that GluR2+ extracellular vesicles have distinct biomarker distributions than those present in the plasma. As a proof of concept, we showed that using a panel of biomarkers comprised of both plasma and GluR2+ extracellular vesicles, injured patients could be accurately classified versus non-injured patients.

Health symptoms after war zone deployment-related mild traumatic brain injury: contributions of mental disorders and lifetime brain injuries

PRIMARY OBJECTIVE

To gain a better understanding of the complex relationship between combat deployment-related mild traumatic brain injury (mTBI) and persistent post-concussive symptoms (PPCSs), taking into consideration a wide range of potentially mediating and confounding factors.

RESEARCH DESIGN

Cross-sectional.

METHODS AND PROCEDURES

Subjects were 613 U. S. military Veterans and Service Members who served during operations Enduring Freedom, Iraqi Freedom, or New Dawn (OEF/OIF/OND) and completed a structured interview of mental disorders and a battery of questionnaires. Hierarchical binary logistic regression analyses were used to test the hypotheses.

MAIN OUTCOMES AND RESULTS

After accounting for mental disorders, lifetime mTBIs outside of OEF/OIF/OND deployment, medical conditions, and injury/demographic characteristics, deployment-related mTBI continued to be associated with several PPCSs (headaches, sleep disturbance, and difficulty making decisions). Deployment-related mTBI was also associated with two symptoms not normally associated with mTBI (nausea/upset stomach and numbness/tingling).

CONCLUSIONS

After adjusting for a wide range of factors, OEF/OIF/OND deployment-related mTBI was still associated with PPCSs on average 10 years after the injury. These findings suggest that mTBI sustained during OEF/OIF/OND deployment may have enduring negative health effects. More studies are needed that prospectively and longitudinally track health and mental health outcomes after TBI.

Different methods for TBI diagnosis influence presence and symptoms of post-concussive syndrome in US Veterans

Common methods for evaluating history of traumatic brain injury (TBI) include self-report, electronic medical record review (EMR), and structured interviews such as the Head Trauma Events Characteristics (HTEC). Each has strengths and weaknesses, but little is known regarding how TBI diagnostic rates or the associated symptom profile differ among them. This study examined 200 Veterans recruited within the VA Portland Health Care System, each evaluated for TBI using self-report, EMR, and HTEC. Participants also completed validated questionnaires assessing chronic symptom severity in broad health-related domains (pain, sleep, quality of life, post-concussive symptoms). The HTEC was more sensitive (80% of participants in our cohort) than either self-report or EMR alone (40%). As expected from the high sensitivity, the HTEC+ group included many people with mild or no post-concussive symptoms. Participants were then grouped according to the degree of concordance across these three diagnostic methods: No-TBI, n=43; or TBI-positive in any one method (TBI-1dx, n=53), any two (TBI-2dx, n=45), or all three (TBI-3dx, n=59). The symptom profile of the TBI-1dx group was indistinguishable from the No TBI group. The TBI-3dx group carried the most severe symptom profile. These data show that understanding the method(s) used to ascertain TBI is essential when interpreting results from other studies, an issue that will be even more salient when interpreting data merged from multiple sources within centralized repositories (e.g., FITBIR). The development of a composite TBI assessment tool including self-report, medical record review, and neuropsychology outcomes is a crucial next step for the field.