History Of Mild Traumatic Brain Injury Research Articles

Effects of mTBI with loss of consciousness on neurobehavioral symptoms, depression, and insomnia in former collegiate and NFL football athletes

ABSTRACT Objective Considering that diagnostic decisions about mTBI are often predicated on clinical symptom criteria, it is imperative to determine which initial presentation features of mTBI have prognostic significance for identifying those at high risk for long-term functional impairment. Setting Zoom interview Participants: Male, former NCAA Division I, and professional-level National Football League (NFL) athletes (n = 177) between the ages of 27 and 85 (M = 54.1, SD = 14.7). Design Cross-sectional case-control. Main Measures: History of mild TBI, history of loss of consciousness (LOC), depression symptoms, insomnia, neurobehavioral symptoms. Results Number of mTBI exposures did not predict neurobehavioral symptoms (B = 0.21, SE = 0.18, p = 0.23), but number of mTBI + LOC events did (B = 2.27, SE = 0.64, p = <.001). Further analysis revealed that the number of mTBI + LOC events predicted neurobehavioral symptoms indirectly through both depression (B = 0.85, 95% CI = [0.27, 1.52) and insomnia (B = 0.81, 95% CI = [0.3, 1.4]). Further, the direct effect of mTBI + LOC events on neurobehavioral symptoms became non-significant when depression and insomnia were added to the model (B = 0.78, SE = 0.45, p = 0.08). Conclusions Findings support LOC at time of injury as an important predictor of long-term outcomes. Additionally, results suggest depression and insomnia as potential mediators in the association between mTBI + LOC and neurobehavioral symptoms. These findings provide justification for early depression and insomnia symptom monitoring following mTBI + LOC.

A Proof-of-Concept Study Demonstrating How FITBIR Datasets Can be Harmonized to Examine Posttraumatic Stress Disorder-Traumatic Brain Injury Associations

Background: Although posttraumatic stress disorder (PTSD) is common following traumatic brain injury (TBI), the specific associations between these conditions is difficult to elucidate in part due to the diverse methodologies, small samples, and limited longitudinal data in the extant literature. Objective: Conduct a proof-of-concept study demonstrating our ability to compile patient-level TBI data from shared studies in the Federal Interagency Traumatic Brain Injury Research (FITBIR) Informatics System to address these shortcomings and improve our understanding of TBI outcomes including the rates PTSD comorbidity. Method: We searched the FITBIR database for shared studies reporting rates of probable PTSD among participants with no TBI, history of mild TBI, or history of moderate/severe TBI. We merged and harmonized data across the relevant studies and analyzed rates of probable PTSD across TBI history and severity categories. Results: Four FITBIR studies with 2,312 participants included PTSD outcome data. The final sample for comparative analyses comprised 1,633 participants from two studies with TBI group comparison data. Approximately 79% had a history of mild TBI and 32-37% screened positive for probable PTSD. Participants with a history of mild TBI had 2.8 greater odds of probable PTSD compared to those without TBI (95% CI: 2.0, 3.7). Conclusions: Only two FITBIR studies reported data examining PTSD outcomes for mild TBI as of January 2021. The analyses are consistent with prior literature, suggesting mild TBI is associated with higher rates of probable PTSD than no TBI. This study developed the methods, shared the harmonization and analysis code, and publicly shared the TBI and PTSD meta-dataset back to FITBIR for dissemination through their website, allowing future research teams to update these and other, related analyses as more studies are contributed to and shared via the FITBIR platform.

Harmonizing federal interagency traumatic brain injury research data to examine depression and suicide-related outcomes.

This proof-of-concept study was conducted to establish the feasibility of compiling Federal Interagency Traumatic Brain Injury Research (FITBIR) data pertaining to depression and suicide risk, with the secondary goal of improving understanding regarding these outcomes. FITBIR is a national repository of participant-level traumatic brain injury (TBI) data designed to address methodological limitations (e.g., small sample size, heterogeneity of injuries). FITBIR studies with TBI severity and measures related to depression and suicidal ideation were identified. Data were harmonized across relevant studies and grouped to identify "probable depression" and suicidal ideation, resulting in a large, combined sample. Rates of probable depression and suicidal ideation were described across the available studies, considering the influence of demographic and/or injury-related factors on outcomes. Cross-sectional studies meeting criteria included four studies with depression outcomes and two with suicidal ideation outcomes. Two studies reported data appropriate for comparative analyses on depression. Combined results suggested that approximately 71% of participants were categorized as having probable depression. Participants with a history of mild TBI had 2.54 greater odds of probable depression (95% confidence interval [1.93, 3.34]) than those without a history of TBI. Methods, harmonization code, and meta-databases related to TBI, probable depression, and suicidal ideation are now publicly available on the FITBIR website. Even with limited data, harmonization of FITBIR studies can serve as the basis for ongoing TBI and mental health research. Analyses will be more robust in the future as more studies with relevant outcome data are added to the FITBIR database. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Associations Between Auditory Working Memory, Self-Perceived Listening Effort, and Hearing Difficulty in Adults With Mild Traumatic Brain Injury.

Mild traumatic brain injury (TBI) can have persistent effects in the auditory domain (e.g., difficulty listening in noise), despite individuals having normal pure-tone auditory sensitivity. Individuals with a history of mild TBI often perceive hearing difficulty and greater listening effort in complex listening situations. The purpose of the present study was to examine self-perceived hearing difficulty, listening effort, and performance on an auditory processing test battery in adults with a history of mild TBI compared with a control group. Twenty adults ages 20 to 53 years old participated divided into a mild TBI (n = 10) and control group (n = 10). Perceived hearing difficulties were measured using the Adult Auditory Processing Scale and the Hearing Handicap Inventory for Adults. Listening effort was measured using the National Aeronautics and Space Administration-Task Load Index. Listening effort ratings were obtained at baseline, after each auditory processing test, and at the completion of the test battery. The auditory processing test battery included (1) dichotic word recognition, (2) the 500-Hz masking level difference, (3) the Listening in Spatialized Noise-Sentences test, and (4) the Word Auditory Recognition and Recall Measure (WARRM). Results indicated that individuals with a history of mild TBI perceived significantly greater degrees of hearing difficulty and listening effort than the control group. There were no significant group differences on two of the auditory processing tasks (dichotic word recognition or Listening in Spatialized Noise-Sentences). The mild TBI group exhibited significantly poorer performance on the 500-Hz MLD and the WARRM, a measure of auditory working memory, than the control group. Greater degrees of self-perceived hearing difficulty were significantly associated with greater listening effort and poorer auditory working memory. Greater listening effort was also significantly associated with poorer auditory working memory. Results demonstrate that adults with a history of mild TBI may experience subjective hearing difficulty and listening effort when listening in challenging acoustic environments. Poorer auditory working memory on the WARRM task was observed for the adults with mild TBI and was associated with greater hearing difficulty and listening effort. Taken together, the present study suggests that conventional clinical audiometric battery alone may not provide enough information about auditory processing deficits in individuals with a history of mild TBI. The results support the use of a multifaceted battery of auditory processing tasks and subjective measures when evaluating individuals with a history of mild TBI.

Phenotyping Depression After Mild Traumatic Brain Injury: Evaluating the Impact of Multiple Injury, Gender, and Injury Context.

The chronic mental health consequences of mild traumatic brain injury (TBI) are a leading cause of disability. This is surprising given the expectation of significant recovery after mild TBI, which suggests that other injury-related factors may contribute to long-term adverse outcomes. The objective of this study was to determine how number of prior injuries, gender, and environment/context of injury may contribute to depressive symptoms after mild TBI among deployed United States service members and veterans (SMVs). Data from the Long-term Impact of Military-Relevant Brain Injury Consortium Prospective Longitudinal Study was used to assess TBI injury characteristics and depression scores previously measured on the Patient Health Questionnaire-9 (PHQ-9) among a sample of 1456 deployed SMVs. Clinical diagnosis of mild TBI was defined via a multi-step process centered on a structured face-to-face interview. Logistical and linear regressions stratified by gender and environment of injury were used to model depressive symptoms controlling for sociodemographic and combat deployment covariates. Relative to controls with no history of mild TBI (n = 280), the odds ratios (OR) for moderate/severe depression (PHQ-9 ≥ 10) were higher for SMVs with one mild TBI (n = 358) OR: 1.62 (95% confidence interval [CI] 1.09-2.40, p = 0.016) and two or more mild TBIs (n = 818) OR: 1.84 (95% CI 1.31-2.59, p < 0.001). Risk differences across groups were assessed in stratified linear models, which found that depression symptoms were elevated in those with a history of multiple mild TBIs compared with those who had a single mild TBI (p < 0.001). Combat deployment-related injuries were also associated with higher depression scores than injuries occurring in non-combat or civilian settings (p < 0.001). Increased rates of depression after mild TBI persisted in the absence of post-traumatic stress disorder. Both men and women SMVs separately exhibited significantly increased depressive symptom scores if they had had combat-related mild TBI. These results suggest that contextual information, gender, and prior injury history may influence long-term mental health outcomes among SMVs with mild TBI exposure.

Subcortical functional connectivity and its association with walking performance following deployment related mild TBI.

The relation between traumatic brain injury (TBI), its acute and chronic symptoms, and the potential for remote neurodegenerative disease is a priority for military research. Structural and functional connectivity (FC) of the basal ganglia, involved in motor tasks such as walking, are altered in some samples of Service Members and Veterans with TBI, but any behavioral implications are unclear and could further depend on the context in which the TBI occurred. In this study, FC from caudate and pallidum seeds was measured in Service Members and Veterans with a history of mild TBI that occurred during combat deployment, Service Members and Veterans whose mild TBI occurred outside of deployment, and Service Members and Veterans who had no lifetime history of TBI. FC patterns differed for the two contextual types of mild TBI. Service Members and Veterans with deployment-related mild TBI demonstrated increased FC between the right caudate and lateral occipital regions relative to both the non-deployment mild TBI and TBI-negative groups. When evaluating the association between FC from the caudate and gait, the non-deployment mild TBI group showed a significant positive relationship between walking time and FC with the frontal pole, implicated in navigational planning, whereas the deployment-related mild TBI group trended towards a greater negative association between walking time and FC within the occipital lobes, associated with visuo-spatial processing during navigation. These findings have implications for elucidating subtle motor disruption in Service Members and Veterans with deployment-related mild TBI. Possible implications for future walking performance are discussed.

26 Improvement in Executive Function Following Goal-Oriented Attentional Self-Regulation Training in Veterans with mTBI

Objective:Goal-Oriented Attentional Self-Regulation (GOALS) is a cognitive rehabilitation training that targets difficulties with executive control functions. Prior research has found that GOALS training improves executive function, functional outcomes, and PTSD symptoms in Veterans with comorbid PTSD and TBI. The objective of this study is to assess the effects of GOALS training versus an active time-matched Behavioral Health Education (BHE) intervention in military Veterans with history of mTBI and executive function difficulties.Participants and Methods:Thirty-four veterans with a history of mild TBI (&gt;6 months post-injury) and cognitive difficulties were randomized to GOALS or BHE group intervention. GOALS is a cognitive rehabilitation intervention that incorporates mindfulness-based attention regulation training, and goal management strategies applied to participant-defined goals. It consists of ten 2-hour sessions administered in small group format, and three individual 1-hour sessions. The BHE group is a matched control condition that mirrors GOALS in terms of duration and level of involvement. Participants completed a comprehensive evaluation consisting of neuropsychological and ecologically valid functional performance measures of complex attention and executive function, before and after GOALS or BHE intervention. Overall neuropsychological attention/executive functioning included measures of working memory (Letter Number Sequencing, Auditory Consonant Trigrams), mental flexibility (Design &amp; Verbal Fluency Switching, Trails B, Stroop Inhibition/Switching), inhibition (Stroop Inhibition), and sustained attention (Digit Vigilance). The Goal Processing Scale (GPS) was used to measure ecologically valid complex functional performance.Results:Post GOALS training, but not post BHE, participants significantly improved on measures of attention /executive function including overall performance (p=.02), working memory (p=.04), sustained attention (p=.03)., and inhibition (p=.01). On measures of complex functional task performance, post GOALS participants significantly improved in the domain of planning (p=.02).Conclusions:GOALS training improved performance on neuropsychological and ecologically valid functional measures of complex attention and executive function in Veterans with mild TBI and cognitive difficulties. The current study highlights how mindfulness-based attention regulation and goalmanagement strategies applied to personal goals has positive effects across various outcomes. A percentage of individuals with mTBI continue to report persistent problems with cognition and daily functioning. Cognitive rehabilitation training such as GOALS may be beneficial for those with persistent difficulties following mTBI, even in chronic phase.

A - 138 Using the Federal Interagency Traumatic Brain Injury Research (FITBIR) Informatics System to Understand Complex Associations between Traumatic Brain Injury and Alcohol or Substance Use.

Associations between traumatic brain injury (TBI) and alcohol or substance use are complex and likely bidirectional. The purpose of this project was to conduct a proof-of-concept study demonstrating our ability to compile patient-level TBI data from shared studies in the Federal Interagency Traumatic Brain Injury Research (FITBIR) Informatics System to improve our understanding of key TBI outcomes. We searched the FITBIR database for shared studies reporting alcohol or substance use among participants with TBI. We merged and harmonized data across the relevant studies to determine rates of alcohol or substance use by TBI severity. In the alcohol use sample (N = 1539), 82% of participants had a history of mild TBI and 46% met criteria for alcohol use disorder (AUD). Participants with a history of mild TBI had 1.34 greater odds of screening positive for AUD (95% CI: 0.98, 1.82) and males had 2.48 increased odds of screening positive for AUD (95% CI: 1.67, 3.68). Unfortunately, due to limited data on substance use we were unable to conduct the intended analyses for this outcome. Data support research and theory suggesting that rates of AUD are higher among individuals with mild TBI versus those without, particularly among males. Additionally, this proof-of-concept study established methods, created data harmonization and analysis code, and provided the TBI-SUD meta dataset back to FITBIR for dissemination. Further, numerous additional datasets have been shared with the FITBIR platform since the time of these analyses, which will allow our team and others to extend these analyses over time.

A - 10 Comorbid Traumatic Brain Injury and Posttraumatic Stress Disorder: Evidence from the Federal Interagency Traumatic Brain Injury Research (FITBIR) Informatics System.

Although posttraumatic stress disorder (PTSD) is common following traumatic brain injury (TBI; Greer et al., 2020), the complex association between these conditions requires further explication. Data repositories, such as FITBIR, which is the product of a national effort to compile individual participant-level TBI data from multiple studies into a unified database, provide a useful avenue for exploring the PTSD-TBI relationship. The present project is a proof-of-concept study demonstrating the ability to harmonize data from numerous shared studies to better understand comorbid PTSD following TBI. We searched for, merged, and harmonized data from studies with TBI and PTSD variables to analyze rates of probable PTSD across TBI severity categories. The methods and code used to extract, clean, standardize, and harmonize the data have been publicly shared and as additional studies are contributed to FITBIR, they will be added to these meta-datasets. After harmonizing key variables across FITBIR datasets, the final sample consisted of 1633 participants. Approximately 79% of participants across studies had a history of mild TBI (mTBI) and 32-37% screened positive for PTSD. Those with mTBI had 2.8 greater odds of screening positive for PTSD compared to those with no TBI (95% CI: 1.90, 3.90). Study findings show that unifying patient-level data is possible and can contribute to knowledge of complex medical and psychiatric comorbidity. These methods allow for nuanced analyses addressing diversity, equity, and inclusion issues often left out of single studies due to small sample sizes of minoritized groups within individual studies.

Headache among combat-exposed veterans and service members and its relation to mild traumatic brain injury history and other factors: a LIMBIC-CENC study.

Headache (HA) is a common persistent complaint following mild traumatic brain injury (mTBI), but the association with remote mTBI is not well established, and risk factors are understudied. Determine the relationship of mTBI history and other factors with HA prevalence and impact among combat-exposed current and former service members (SMs). Secondary cross-sectional data analysis from the Long-Term Impact of Military-Relevant Brain Injury Consortium-Chronic Effects of Neurotrauma Consortium prospective longitudinal study. We examined the association of lifetime mTBI history, demographic, military, medical and psychosocial factors with (1) HA prevalence ("lately, have you experienced headaches?") using logistic regression and (2) HA burden via the Headache Impact Test-6 (HIT-6) using linear regression. Each lifetime mTBI was categorized by mechanism (blast-related or not) and setting (combat deployed or not). Participants with non-credible symptom reporting were excluded, leaving N = 1,685 of whom 81% had positive mTBI histories. At a median 10 years since last mTBI, mTBI positive participants had higher HA prevalence (69% overall, 78% if 3 or more mTBIs) and greater HA burden (67% substantial/severe impact) than non-TBI controls (46% prevalence, 54% substantial/severe impact). In covariate-adjusted analysis, HA prevalence was higher with greater number of blast-related mTBIs (OR 1.81; 95% CI 1.48, 2.23), non-blast mTBIs while deployed (OR 1.42; 95% CI 1.14, 1.79), or non-blast mTBIs when not deployed (OR 1.23; 95% CI 1.02, 1.49). HA impact was only higher with blast-related mTBIs. Female identity, younger age, PTSD symptoms, and subjective sleep quality showed effects in both prevalence and impact models, with the largest mean HIT-6 elevation for PTSD symptoms. Additionally, combat deployment duration and depression symptoms were factors for HA prevalence, and Black race and Hispanic/Latino ethnicity were factors for HA impact. In sensitivity analyses, time since last mTBI and early HA onset were both non-significant. The prevalence of HA symptoms among formerly combat-deployed veterans and SMs is higher with more lifetime mTBIs regardless of how remote. Blast-related mTBI raises the risk the most and is uniquely associated with elevated HA burden. Other demographic and potentially modifiable risk factors were identified that may inform clinical care.

Mild traumatic brain injury history is associated with lower brain network resilience in soldiers.

Special Operations Forces combat soldiers sustain frequent blast and blunt neurotrauma, most often classified as mild traumatic brain injuries. Exposure to repetitive mild traumatic brain injuries is associated with persistent behavioural, cognitive, emotional and neurological symptoms later in life. Identifying neurophysiological changes associated with mild traumatic brain injury exposure, in the absence of present-day symptoms, is necessary for detecting future neurological risk. Advancements in graph theory and functional MRI have offered novel ways to analyse complex whole-brain network connectivity. Our purpose was to determine how mild traumatic brain injury history, lifetime incidence and recency affected whole-brain graph theoretical outcome measures. Healthy male Special Operations Forces combat soldiers (age = 33.2 ± 4.3 years) underwent multimodal neuroimaging at a biomedical research imaging centre using 3T Siemens Prisma or Biograph MRI scanners in this cross-sectional study. Anatomical and functional scans were preprocessed. The blood-oxygen-level-dependent signal was extracted from each functional MRI time series using the Big Brain 300 atlas. Correlations between atlas regions were calculated and Fisher z-transformed to generate subject-level correlation matrices. The Brain Connectivity Toolbox was used to obtain functional network measures for global efficiency (the average inverse shortest path length), local efficiency (the average global efficiency of each node and its neighbours), and assortativity coefficient (the correlation coefficient between the degrees of all nodes on two opposite ends of a link). General linear models were fit to compare mild traumatic brain injury lifetime incidence and recency. Nonparametric ANOVAs were used for tests on non-normally distributed data. Soldiers with a history of mild traumatic brain injury had significantly lower assortativity than those who did not self-report mild traumatic brain injury (t148 = 2.44, P = 0.016). The assortativity coefficient was significantly predicted by continuous mild traumatic brain injury lifetime incidence [F1,144 = 6.51, P = 0.012]. No differences were observed between recency groups, and no global or local efficiency differences were observed between mild traumatic brain injury history and lifetime incidence groups. Brain networks with greater assortativity have more resilient, interconnected hubs, while those with lower assortativity indicate widely distributed, vulnerable hubs. Greater lifetime mild traumatic brain injury incidence predicted lower assortativity in our study sample. Less resilient brain networks may represent a lack of physiological recovery in mild traumatic brain injury patients, who otherwise demonstrate clinical recovery, more vulnerability to future brain injury and increased risk for accelerated age-related neurodegenerative changes. Future longitudinal studies should investigate whether decreased brain network resilience may be a predictor for long-term neurological dysfunction.

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

ABSTRACT 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.

High molar ratios of tumor necrosis factor α (TNF α) soluble receptors I and II to the TNF ligand in human plasma from male veterans with comorbid posttraumatic stress disorder (PTSD) and mild traumatic brain injury (mTBI)

Background and ObjectivesPosttraumatic stress disorder (PTSD) and traumatic brain injury (TBI) are associated with chronic inflammation, as inferred from increased, but variable, peripheral levels of cytokines. We sought proof of concept for the notion that peripheral cytokine binding proteins and/or soluble receptors can confound measures of cytokines in those with a history of physical and psychological traumatic exposures. Efforts were focused on one of the major cytokines involved in inflammation, tumor necrosis factor-α (TNF- α). MethodsWe examined blood plasma concentrations of TNF-α, its soluble receptors (TNF-soluble receptors (sR) I and TNFsRII), and C-reactive protein (CRP-1) in a cohort of US Veterans. In a previous study, CRP-1 was shown to be reduced by probiotic anti-inflammatory treatment in this patient cohort. All participants (n = 22) were diagnosed with PTSD and had a history of mild TBI with persistent post-concussive symptoms. Exclusion criteria included medications directly targeting inflammation. ResultsMolar concentrations of soluble TNFsRI and II exceeded concentrations of the TNF-α ligand. TNFsRI, but not TNFsRII, was significantly associated with CRP-1 (Spearman Rho correlations = 0.518; p=.016 and 0.365; p = .104, respectively). ConclusionsTNF soluble receptors may bind to and sequester free TNF-α, suggesting that only measuring ligand concentrations may not provide a fully comprehensive view of inflammation, and potentially lead to inaccurate conclusions. TNFsRI concentration may provide a better estimate of inflammation than TNF-α for those with PTSD and post-acute mTBI with post-concussive symptoms, a hypothesis that invites further testing in larger studies.

A-285 Malingering of Executive Function in Traumatic Brain Injury

Abstract Objective: The current study explored whether the Delis-Kaplin Executive Functioning System (D-KEFS) Stroop test and Barkley Deficits in Executive Function System (BDEFS) measure are vulnerable to malingering and whether cutoffs on each could be identified to detect malingering. Method: Using a simulator design, students recruited from the psychology participant pool at Ohio University (Mage=21.20, SD=5.85; 77.3% white, 52% freshmen, 68% assigned female, 12% prior ADHD diagnosis, 20% history of mild TBI, and 38.7% current psychological diagnoses) were randomly assigned to either malinger (simulator condition) Traumatic Brain Injury or perform normally (control condition). Participants were virtually administered the Test of Pre-Morbid Functioning, the D-KEFS, Test of Memory Malingering, and BDEFS. They also completed Qualtrics adherence items. Participants were excluded based on their Qualtrics response and for insufficient data. Results: As hypothesized, malingerers scored worse than controls on both measures. The Inhibition subtest (both raw and scaled scores) of the D-KEFS Stroop discriminated simulators from controls and a cutoff for the raw score was identified that detected 48% of simulators, with 90% specificity. The BDEFS total score also discriminated malingerers from controls, and a cutoff was identified that detected 56% of simulators, with 90% specificity. Supplemental chi square analysis showed poor congruence between the two measures, p=.262. Conclusions: The present study provides support for the potential utility of the D-KEFS Inhibition raw scores and BDEFS total scores as indicators of malingered executive functioning in TBI. Overall, results support the need to include both Performance Validity Tests and Symptom Validity Tests in assessment.

Depression and Anxiety in Patients With a History of Traumatic Brain Injury: A Case-Control Study.

BackgroundThe burden of psychiatric illness following a head injury may have implications on the disease prognosis. The present study evaluated the association of depression and anxiety with traumatic brain injury (TBI).MethodsA case-control study was conducted in Karachi, Pakistan, from 2nd July 2021 and 30th January 2022, including individuals of age 18 and above of both genders, with or without a mild head trauma history, forming the case and control groups, respectively. Individuals with previous head trauma/congenital neurological dysfunction were excluded. A mental health assessment of the participants was carried out with two scales, the Generalized Anxiety Disorder-7 (GAD-7) scale and the Public Health Questionnaire-9 (PHQ-9) scale. Other parameters like age, gender, socioeconomic status, education status, and comorbidities were also documented.ResultsA total of 62 participants were enrolled with 31 cases and 31 controls. The majority were males aged between 18 and 39 years. About 29% of the patients with a history of mild TBI had moderate to severe depression while only 22.6% of them did not have depression or had minimal depression. We found that about 29.3% of patients with TBI had severe anxiety as compared to the only two healthy controls. The majority of the control group participants did not have anxiety.ConclusionTraumatic head injuries and their long-term side effects can predispose patients to a myriad of psychiatric comorbidities. In this study, we found definitive evidence that both anxiety and depression had a significantly higher incidence in cohorts that suffered from mild TBI. However, we recommend large-scale and multicenter studies in the future to explore these relationships more thoroughly and comprehensively.

Associations between Intra-Individual Neurocognitive Variability and Prospective Memory in Veterans with Mild Traumatic Brain Injury History and Posttraumatic Stress Disorder.

Mild traumatic brain injury (mTBI) and posttraumatic stress disorder (PTSD) frequently co-occur and are associated with neurocognitive intra-individual variability (IIV) and difficulty with prospective memory (PM). The current study aimed to examine associations between IIV and PM in this comorbid group. Fifty veterans with a history of blast mTBI and current comorbid PTSD completed a standardized neurocognitive battery to measure IIV, and the Memory for Intentions Screening Test measuring PM. Adjusting for age, education, and race, higher IIV was associated with poorer time-based PM (p < .001, f2 = .34), but not event-based PM. In a subset of the sample with self-report data, higher IIV was associated with poorer self-reported retrospective memory, but not PM. Cognitive variability on a standardized neuropsychological battery was associated with strategically demanding PM, which is an ecologically relevant ability and highlights the possible connection between subtle cognitive difficulties in-clinic and those experienced in daily life.

Relationship between Anterior Pituitary Volume and IGF-1 Serum Levels in Soldiers with Mild Traumatic Brain Injury History.

A high mild traumatic brain injury (mTBI) incidence rate exists in military and sport. Hypopituitarism is an mTBI sequela; however, few studies have examined this phenomenon in those with an mTBI history. This cross-sectional study of Special Operations Forces combat soldiers aimed 1) to relate anterior pituitary gland volumes (actual and normalized) to insulin-like growth factor 1 (IGF-1) concentrations, 2) to examine the effect of mTBI history on anterior pituitary gland volumes (actual and normalized) and IGF-1 concentrations, and 3) to measure the odds of demonstrating lower anterior pituitary gland volumes (actual and normalized) or IGF-1 concentrations if self-reporting mTBI history. Anterior pituitary gland volumes were manually segmented from T1-weighted 3D brain MRI sequences; IGF-1 serum concentrations were quantified using commercial enzyme-linked immunosorbent assays. Correlations and linear regression were used to determine the association between IGF-1 serum concentration and anterior pituitary gland volume (n = 74). Independent samples t-tests were used to compare outcomes between mTBI groups and logistic regression models were fit to test the odds of demonstrating IGF-1 concentration or anterior pituitary volume less than sample median based on mTBI group (n = 54). A significant linear relationship between the subjects' anterior pituitary gland volumes and IGF-1 concentrations (r72 = 0.35, P = 0.002) was observed. Soldiers with mTBI history had lower IGF-1 concentrations (P < 0.001) and lower anterior pituitary gland volumes (P = 0.037) and were at greater odds for IGF-1 serum concentrations less than the sample median (odds ratio = 5.73; 95% confidence interval = 1.77-18.55). Anterior pituitary gland volume was associated with IGF-1 serum concentrations. Mild TBI history may be adversely associated with anterior pituitary gland volumes and IGF-1 concentrations. Longitudinal IGF-1 and anterior pituitary gland monitoring may be indicated in those who report one or more mTBI.

Factor analysis of the neurobehavioral symptom inventory in veterans with PTSD and no history of mild TBI

It is well established that long-term postconcussive symptoms following a mild traumatic brain injury (mTBI) are associated with underlying physical, emotional, and behavioral conditions. The Neurobehavioral Symptom Inventory (NSI) is a measure used to assess neurobehavioral symptoms that can occur following a mTBI and has demonstrated a 3- or 4-factor structure in veterans. The present study aimed to investigate the factor structure of veterans with PTSD without a history of mTBI. A confirmatory factor analysis (CFA) was conducted on a sample of 221 treatment-seeking veterans and service members with PTSD and without a history of mTBI. Results supported a 4-factor structure comprised of vestibular, somatic, cognitive, and affective domains in veterans with PTSD. Subsequent, correlational analyses between the four NSI factors and the four subscales of the Posttraumatic Stress Disorder Checklist – Fifth Edition (PCL-5) revealed high correspondence between the cognitive and affective factors of the NSI and the negative alterations in mood and cognitions and hyperarousal symptom subscales of PTSD. Collectively, findings demonstrated that the NSI functions similarly in veterans with PTSD with or without a history of mTBI. Findings suggest that neurobehavioral symptoms assessed by the NSI appear to be nonspecific and not explicitly associated with mTBI.

Effects of blast exposure on psychiatric and health symptoms in combat veterans

Blast exposure is common among service members, but the chronic psychiatric effects associated with blast exposure are not well-characterized independent of a resulting mild traumatic brain injury (TBI). This analysis evaluated whether blast exposure severity was independently associated with or exacerbated symptom report beyond posttraumatic stress disorder (PTSD) and mild TBI. Participants were Iraq and Afghanistan combat veterans (N = 275; 86.55% male), 71.27% with history of blast exposure, 29.82% current diagnosis of PTSD, and 45.45% with mild TBI. All participants completed diagnostic interviews for PTSD, lifetime TBI, and lifetime blast exposure. Self-reported psychiatric and health outcomes included posttraumatic stress symptoms, depressive symptoms, neurobehavioral symptoms, sleep quality, pain interference, and quality of life. Blast severity was associated with PTSD (B = 2.00), depressive (B = 0.76), and neurobehavioral (B = 1.69) symptoms beyond PTSD diagnosis and mild TBI history. Further, blast severity accounted entirely (i.e., indirect/mediation effect) for the association between TBI and posttraumatic stress (B = 1.62), depressive (B = 0.61), and neurobehavioral (B = 1.38) symptoms. No interaction effects were present. Exposure to blast is an independent factor influencing psychiatric symptoms in veterans beyond PTSD and mild TBI. Results highlight that blast exposure severity may be a more relevant risk factor than deployment mild TBI in combat veterans and should be considered in the etiology of psychiatric symptom presentation and complaints. Further, severity of psychological distress due to the combat environment may be an explanatory mechanism by which blast exposure mediates the relationship between mild TBI and symptom outcomes.

A-128 Intraindividual Neurocognitive Variability Is Associated with Poorer Prospective Memory in OEF/OIF/OND Veterans with Comorbid Mild Traumatic Brain Injury History and Current Posttraumatic Stress Disorder

Abstract Objective Mild Traumatic Brain Injury (mTBI) and Posttraumatic Stress Disorder (PTSD) frequently co-occur in service members, and each are associated with increased neurocognitive intraindividual variability (IIV), a proposed indicator of subtle disruptions in executive control, and prospective memory (PM), or “remembering to remember.” The current study sought to examine possible associations between IIV and PM performances among Veterans with comorbid mTBI and PTSD. Methods 46 OEF/OIF/OND Veterans with a history of mTBI and current PTSD enrolled in a VA research study of mTBI completed a standardized neurocognitive battery of 12 measures used to calculate the coefficient of variation (CoV) as an index of IIV, and the Memory for Intentions Screening Test (MIST) as a measure of PM. Veterans also completed clinical questionnaires (i.e., Patient Health Questionnaire-9, PTSD Checklist-Military), and a subset of the sample (n = 31) Veterans completed the Prospective and Retrospective Memory Questionnaire (PRMQ) as a measure of self-reported PM. Results Controlling for age and education, higher CoV was associated with time-based MIST scores (β = −0.02, p = 0.008, η2 = 0.16) and event-based MIST scores (β = −0.02, p = 0.031, η2 = 0.11). CoV was not associated with mood factors in the sample (ps &amp;gt;0.10). In a subset of the total sample, higher CoV was associated with elevated self-reported PM symptoms (r = −0.36, p = 0.046). Conclusions Among Veterans with a history of mTBI and current PTSD, elevated variability of performances across neurocognitive measures was associated with poorer performance-based PM and self-reported PM symptoms. Future studies are needed to examine IIV as a predictor of real-world PM performances (e.g., medication adherence).