Pediatric traumatic brain injury (TBI) is the leading cause of disability in children under the age of 15, often resulting in executive function deficits and poor behavioral outcomes. Damage to white matter tracts may be a driving force behind these difficulties. We examined if whether 1) greater TBI severity was associated with worse neurobehavioral outcome, 2) greater TBI severity was associated with tract-based white matter microstructure, and 3) worse neurobehavioral outcome was associated with white matter microstructure.

Twelve children with complicated-mild TBI (cmTBI; Mage=12.59, nmale=9), 17 with moderate-to-severe TBI (msTBI; Mage =11.50, nmale=11), and 21 with orthopedic injury (OI; Mage =11.60, nmale=16), 3.94 years post injury on average, were recruited from a large midwestern children’s hospital with a Level 1 Trauma Center. Parents completed the Behavior Rating Inventory of Executive Function (BRIEF) and Child Behavior Checklist (CBCL) while children completed 64-direction diffusion tensor imaging in a Siemens 3T scanner. White matter microstructure was quantified with FMRIB’s Diffusion Toolbox (FSLv6.0.4). Tract-Based Spatial Statistics computed fractional anisotropy (FA) and mean diffusivity (MD) for the cingulum bundle (CB), inferior fronto-occipital fasciculus (IFOF), superior longitudinal fasciculus (SLF), and uncinate fasciculus (UF), bilaterally.

Group differences were assessed using one-way ANOVA. Children with msTBI were rated as having worse Sluggish Cognitive Tempo on the CBCL than children with cmTBI and OI (p=.02, eta2=.143); no other parent-rated differences reached significance. Group differences were found in left SLF FA (p=.031; msTBI<cmTBI=OI) and approached significance in left UF FA (p=.062, eta2=.114; msTBI<OI). Group differences were also found in right IFOF MD (p=.048; msTBI>OI) and left SLF MD (p=.013; msTBI>cmTBI=OI). Bivariate correlations assessed cross-domain associations. Higher left IFOF FA was associated with better BRIEF Metacognitive Skills (r=-.301, p=.030) and CBCL School Competence (r=.280; p=.049). Higher left SLF FA was associated with better BRIEF Behavioral Regulation and Metacognitive Skills (r=-.331, p=.017 and r=-.291, p=.036, respectively), and CBCL School Competence and Attention Problems (r=.398, p=.004 and r=-.435, p=.001, respectively). Similarly, higher right UF FA was broadly associated with better neurobehavioral outcomes, including Behavioral Regulation and Metacognitive Skills (r=-.324, p=.019 and r=-.359, p=.009, respectively), and School Competence, Attention Problems, and Sluggish Cognitive Tempo (r=.328, p=.020, r=-.398, p=.003, and r=-.356, p=.010, respectively). Higher right CB MD was associated with worse Behavioral Regulation (r=.327, p=.018) and more Attention Problems (r=.278, p=.046); higher left and right SLF MD was associated with Sluggish Cognitive Tempo (r=.363, p=.008, r=.408, p=.003, respectively).

Children with TBI, particularly msTBI, were rated as having cognitive slowing; while other anticipated group differences in neurobehavioral outcomes were not found, this appears driven by milder difficulties in cmTBI and OI groups. In fact, across CBCL and BRIEF subscales, children with msTBI were rated as approaching or exceeding a full standard deviation deficit based on normative data. TBI severity was also associated with white matter microstructure and cross-domain associations linked microstructure with observable neurobehavioral morbidities, suggesting a possible mechanism post-injury. Future longitudinal studies would be useful to examine the temporal evolution of deficits.

The Coma Recovery Scale-Revised (CRS-R) is the gold standard assessment of adults with disorders of consciousness (DoC); however few studies have examined the psychometric properties of the CRS-R in pediatric populations. This study aimed to demonstrate preliminary intra-rater and inter-rater reliability of the CRS-R in children with acquired brain injury (ABI).

Participants included 3 individuals (ages 10, 15, and 17 years) previously admitted to an inpatient pediatric neurorehabilitation unit with DoC after ABI who were followed in an outpatient brain injury clinic due to ongoing severe disability. ABI etiology included traumatic brain injury (TBI; n=2) and encephalitis (n=1). Study participation took place on average 4.6 years after injury (range 2-9). The Glasgow Outcome Scale-Extended, Pediatric Version (GOS-E Peds), a measure of outcome after pediatric brain injury, was administered as part of screening. Two participants were placed in the GOS-E Peds “lower severe disability” category (i.e., score of 6) and one was placed in the “upper severe disability” category (i.e., score of 5). The CRS-R includes 6 subscales measuring responsivity including Auditory (range 0-4), Visual (range 05), Motor (range 0-6), Oromotor/Verbal (range 03), Communication (range 0-2), and Arousal (range 0-3) with higher scores indicating higherlevel function. Subscales are totaled for a CRS-R Total score. Behaviors shown during the CRS-R are used to determine state of DoC [Vegetative State (VS), Minimally Conscious State (MCS) or emergence from a minimally conscious state (eMCS)] based on 2002 Aspen Guidelines. Participants were administered the CRS-R three consecutive times on the same day. Administrations were completed by two raters in this order: Rater 1 (1A), Rater 1 (1B) and Rater 2. Intra-rater reliability was deemed by percent agreement across the 6 subscales between Rater 1A and 1B. Inter-rater reliability was deemed by percent agreement across the 6 subscales between 1A and 2.

Mean CRS-R Total score for Rater 1A was 22 (SD=1.73, range 20-23), Rater 1B was 22 (SD=1.73, range 20-23), and Rater 2 was 21.33 (SD=2.08, range 19-23). Intra-rater reliability was 100% and inter-rater reliability was 94% across all subscales. All participants were deemed eMCS at all 3 ratings.

Data from this very small sample of children suggests that the CRS-R demonstrates both intra-rater and inter-rater reliability in patients with a history of DoC after ABI. Given that all children were at the high end of the scale (eMCS), further research is needed with a larger sample of children with a range of states of DoC.

Integration of neuropsychological services into multidisciplinary clinics for pediatric patients requiring neurocritical care has previously been shown to improve access to care and promote connection to vital services for children recovering from traumatic brain injuries or other serious insults or infections impacting the brain. As such, the objective of this study is two-fold. First, to explore the unique model of care provided by a neuropsychological inpatient service at the Medical College of Wisconsin/Children’s Wisconsin. Secondly, to describe the benefit of neuropsychology in the Brain Recovery Assessment and Interdisciplinary Needs Clinic (BRAIN) a neurocritical care outpatient follow-up multidisciplinary clinic.

Participants include N =298 pediatric inpatients from a Level 1 Pediatric Trauma center referred to the neuropsychological inpatient consultation service from February 2020 to July 2022. Qualitative methods were used to describe the flow and number of patients initially referred to the neuropsychological inpatient service and then those who followed up in outpatient neuropsychological care prior to and after the implementation of a multi-disciplinary clinic for children admitted to the Neurocritical Care Unit. Rates of follow-up with neuropsychological care were compared pre- and post-establishment of the multidisciplinary clinic. Additional analyses were conducted to explore factors known to impact follow-up with care post-hospitalization (e.g., socioeconomic status, race, ethnicity).

Prior to the establishment of the BRAIN clinic, approximately 60 to 70% of patients were referred for outpatient neuropsychological follow-up. Approximately 30% of patients referred to the inpatient neuropsychological service following the establishment of the BRAIN clinic were referred for multidisciplinary care, while 20% did not require additional intervention and 50% were referred for outpatient neuropsychological follow-up. Analyses indicated increased follow-up rates with neuropsychological care following the establishment of the BRAIN clinic.

Integration of neuropsychology into inpatient care and subsequent multidisciplinary settings for pediatric patients with traumatic brain injuries or other serious insults and CNS infections increased access to neuropsychological care. Additional clinical implications will be discussed.

Inflicted traumatic brain injury (TBI) is one of the leading causes of childhood injury and death. Studies have consistently demonstrated worse outcomes for children with inflicted TBIs compared to accidental TBIs. Out of home placement, a known developmental risk factor, is a frequent occurrence in inflicted TBI, which may also contribute to worse outcomes for children. Little is known about what injury, child, and family factors predict out-of-home versus in-home placements. We hypothesize that injury severity, child, and family risk factors will be predictive of out-of-home placement after hospital discharge from an inflicted TBI.

Participants included 175 children with inflicted head injuries ages who received care at a large children’s hospital from 2012 to 2021. 88% of children were alive at discharge and were included in the study. The total sample included 154 children. Ages ranged from 0.2 to 76 months (M = 11.81, SD = 14.50) and 64.9 % were male. Race/Ethnicity distribution was as follows: 66.9% White, 29.9% Latinx or Hispanic, 4.6% Black, 3.3% American Indian or Alaskan, and 22.5% identified another race or ethnicity or identified as multiracial. Measures included injury severity (e.g., days spent in the PICU, post-resuscitation GCS), child (e.g., race/ethnicity, gender), and family factors (e.g., prior history of domestic violence, type of insurance). Individual logistic regressions were run to assess the effect of each injury severity, child, and family factor on placement after hospital discharge.

Results indicated that having a caregiver with a history of mental health difficulties and/or a history of substance abuse increased the likelihood of an out-of-home placement for the child after an inflicted TBI. Results also demonstrated that the more caregiver psychosocial concerns reported, the higher the risk of an out-of-home placement for the child after discharge from the hospital. Finally, results indicated that having public insurance significantly increased the risk of an out-of-home placement for the child after discharge from the hospital. Post-hoc analyses were conducted to assess the effect of insurance type on out-of-home placement, while controlling for psychosocial concerns. Results indicated that, even when taking total psychosocial concerns into account, having public insurance significantly increased the risk of an out-of-home placement. Logistic regressions were carried out to assess the effect of injury severity, child, and every other family factor (e.g., prior criminal history) on placement after hospital discharge and the overall models were not significant.

One explanation for these findings is that families with public insurance have less of a social safety net and, thus, are unable to meet the needs of a child with an inflicted TBI. However, we cannot rule out the effect of bias in child welfare practices. Similarly, caregivers with histories of mental health difficulties and substance abuse are likely to have a harder time meeting their child’s needs and providing a stable household, increasing the likelihood of an out-of-home placement. Despite expectations, child and injury severity factors did not play a role in placement decisions after an inflicted TBI, indicating that placement decisions rely more heavily on caregivers’ abilities to meet the child’s needs rather than the child’s medical complexity or the severity of the inflicted TBI.

Evidence-based consensus in children and adolescents following uncomplicated mTBI indicates acute cognitive symptoms resolve over time with minimal long-term impact. However, traditional paper-and-pencil neuropsychological measures used in many studies have been criticized for lacking sensitivity to subtle changes in attention and executive functions. The National Institutes of Health Toolbox Cognition Battery (NIHTB-CB) is a computerized tool assessing overall cognition, fluid cognition, and crystallized cognition with few studies in pediatric mTBI. The aim of this study is to continue to explore the utility of the NIHTB-CB in adolescents recovering from mTBI compared to orthopedic injuries (OI) and healthy controls (HC).

The current pilot study utilized a prospective cohort design with longitudinal follow-up in three cohorts of high school student-athletes aged 14-18 (N= 52). Participants with mTBI (n= 17) or OI (n= 15) sustained during sport were recruited within 10 days of injury from a quaternary care setting. An age- and gender-matched cohort of healthy controls (HC) in an active sport season was included for community comparison (n= 20). The NIHTB-CB was administered as part of a neuropsychological screening battery at enrollment and one month after medical clearance (mTBI and OI) or eight weeks after enrollment (HC).

Results of a 3(group) x 2(time) ANOVA revealed a main effect of time (p < .001), but not group (p = .06), on the overall Fluid Cognition Composite. The mTBI group showed significantly lower performance on a measure of attention/inhibitory control (Flanker) compared to healthy controls acutely post-injury (p = .04; d = 0.72) and following clinical recovery (p < .01; d = 0.98), with no decline observed in the magnitude of group differences over time. The mTBI and OI groups exhibited deficits in performance on a measure of cognitive flexibility (Dimensional Change Card Sort) compared to the HC group acutely post-injury (both p < .01; d = 1.09-0.93). The magnitude of group differences between the OI and HC groups declined over time (p > .05; d = 0.68), whereas the mTBI group continued to show significantly lower performance following clinical recovery compared to the HC group (p = .02; d = 0.81). The mTBI, OI, and HC groups did not exhibit significant differences in working memory, explicit memory, or processing speed acutely post-injury and following clinical recovery (all p > .05; all d = 0.52 - 0.05). No significant effects of group (p = .16), time (p = .67), or the interaction (p = .45) were found on the Crystalized Cognition Composite.

Adolescents with mTBI demonstrated deficits on the NIHTB-CB measures of attention and executive functions acutely post-injury and extending beyond clinical recovery compared with healthy controls in this study. These subtle yet persistent deficits in cognitive performance lend support to the growing body of literature suggesting that alterations in neurotransmission may persist beyond resolution of clinical symptoms of mTBI. Further work is needed in larger samples to better understand trends in cognitive deficits and to identify clinical correlates persisting beyond clinical recovery from mTBI.

Recent studies have begun to explore the role of psychological resilience in pediatric mTBI recovery, with findings associating higher levels of resilience with shorter recovery and lower levels of resilience mediated by pre-injury anxiety and depression associated with persistent symptoms. The purpose of this study is to extend the current literature by further exploring the relationship between resilience, post-injury emotional changes, and length of recovery from pediatric mTBI. Based upon previous literature, we predicted that resilience would explain a unique portion of the variance in length of recovery above and beyond acute post-injury emotional symptoms in adolescents recovering from mTBI compared with orthopedic injured (OI) controls.

The current study pulled data from a larger project utilizing a prospective cohort design in two cohorts of high school student-athletes aged 14-18 (N = 32). Participants with mTBI (n = 17) or OI (n = 15) sustained during sport were recruited within 10 days of injury from a quaternary care setting. Participants completed a neuropsychological screening evaluation within one week of enrollment, including self-report rating scales of resilience (Connor-Davidson Resilience Scale-10; CD-RISC) and self- and parent-reported post-concussion symptoms (Post-Concussion Symptom Inventory, Second Edition; PCSI-2). Hierarchical regression analysis was performed with days from injury to recovery as the dependent variable. Predictors were entered in three steps: (1) group (mTBI/OI) and sex, (2) PCSI self- and parent-reported post-injury change in emotional symptoms, and (3) CD-RISC raw score. Bonferroni correction was utilized to control for multiple comparisons.

Group and sex did not provide significant prediction when entered into the first block of the model (p= .61). Introducing PCSI emotional ratings in the second block showed statistically significant improvement, F (2,26) = 5.12, p< .01), accounting for 31% of the variance in recovery length. Addition of the CD-RISC in the third block was not statistically significant (p=.59). Post hoc testing indicated parent ratings on the PCSI were significantly associated with recovery length t(32) = 3.16, p < .01, while self-reported ratings were not (p=.54).

Findings indicated that psychological resilience did not explain a unique portion of the variance in length of recovery above and beyond acute parent report of postinjury emotional symptoms in adolescents recovering from mTBI compared with orthopedic injured (OI) controls. Interestingly, sex, group (mTBI vs. OI), and self-reported acute postinjury emotional symptoms were not significant predictors of recovery length in this sample. Results highlight the significant role of acute changes in emotional symptoms in adolescents recovering from mTBI and OI in predicting length of recovery, as well as the importance of obtaining separate caregiver report. A more robust understanding of factors contributing to recovery from injury can help inform and improve preventive measures and treatment plants for those at risk or impacted; however, psychological resilience may not uniquely contribute to predicting length of recovery in acutely injured adolescents, limiting value added to the clinical exam. Future studies should explore the relationship between type of injury and recovery time in larger samples.

Many Operation Enduring Freedom/Operation Iraqi Freedom (OEF/OIF) Veterans have sustained a mild traumatic brain injury (mTBI) during their military service and a substantial “miserable minority” frequently report significant cognitive complaints long after injury. Although existing studies have shown associations between genetic factors (e.g., apolipoprotein E [APOE] and brain-derived neurotrophic factor [BDNF]) and cognitive performance in this vulnerable population, the TBI-genetics literature has generally been varied and inconsistent. Although past findings suggest that individuals who possess APOE £4 and BDNF Met alleles have worse cognitive outcomes after mTBI, this has not been consistently reported. Additionally, the influence of any gene-by-gene interactions on cognition has not been sufficiently explored and therefore remains a critical area of interest. Thus, we examined relationships between APOE and BDNF genotypes on neuropsychological function in a well-characterized sample of younger Veterans with mTBI histories.

Participants included Veterans with a history of mTBI who adequately completed performance validity testing. In total, 78 Veterans (84.6% male; age: M=32.95, SD=7.00; race/ethnicity: 51.3% White, 28.2% Hispanic/Latino, and 20.5% Another Race/Ethnicity) completed a structured clinical interview to collect detailed information on TBI history and underwent a comprehensive neuropsychological exam. A buccal swab was also collected to determine APOE and BDNF allele status for each participant. Three cognitive composite scores were computed reflecting memory (8 items), attention/processing speed (7 items), and executive functioning (10 items). Two-way analyses of covariance (ANCOVAs) adjusting for age, sex, and race/ethnicity were used to assess the effects of APOE (ε4+ vs. ε4-) and BDNF (Met+ vs. Met-) on cognitive functioning (ε4+/Met-: n=12, ε4+/Met+: n=8, £4-/Met-: n=35, and ε4-/Met+: n=23).

ANCOVAs revealed no significant main effects for APOE or BDNF genotypes on cognitive functioning; however, there was a significant APOE x BDNF genotype interaction for all three cognitive composites (memory: p=.026, np2=.068; attention/processing speed: p=.045, np2=.055; and executive functioning: p=.031, np2=.064). Specifically, the interaction was such that Veterans in the ε4+/Met+ group demonstrated the poorest cognitive functioning relative to all other allele group combinations (ε4+/Met-, ε4-/Met+, ε4-/Met-).

The results of this preliminary study demonstrate that, compared to the other genetic subgroups in the TBI sample, Veterans with APOE £4 and BDNF Met alleles demonstrated the poorest cognitive functioning across several domains known to be negatively affected in the context of head injury (i.e., memory, attention/processing speed, and executive functioning). These findings are the first to show an APOE x BDNF interaction in Veterans with histories of mTBI. Further

research is necessary to replicate and extend this study in larger samples. Moreover, future work should incorporate neuroimaging variables to better interrogate structural and functional correlates of these observed genetic polymorphism associations in Veterans with mTBI histories.

Mild traumatic brain injury (mTBI) is an important public health problem, due to its high incidence and the failure of at least 20% of patients to successfully recover from injury. Cognitive symptoms, in particular, are an important area of research in mTBI, due to their association with return to work and referral to neuropsychological services. Understanding the predictors of cognitive symptoms may help to improve outcomes after mTBI. This study explored female sex, psychological distress, coping style and illness perceptions as potential predictors of cognitive symptoms following adult civilian mTBI.

Sixty-nine premorbidly healthy adults with mTBI (mean age = 36.7, SD = 14.7, range = 18-60; 15 females) were recruited from trauma wards at two public hospitals in Australia and assessed 6-12 weeks following injury. Cognitive complaint was measured using a comprehensive 30-item scale (CCAMCHI) assessing mTBI-specific symptoms in the domains of processing speed, attention, memory and executive function. Participants additionally completed the following measures: Brief-COPE, Illness Perceptions Questionnaire-Revised, Inventory of Depressive Symptomatology, Beck Anxiety Inventory, and PTSD Checklist for DSM-5. The latter three measures were combined to create an index of psychological distress.

Bivariate nonparametric correlational analyses indicated that female sex (r[67] = .26, 95% CI [.14, .55], p = .03) and psychological distress (r[66] = .54, 95% CI [.40, .72], p < .001) were each significantly associated with cognitive symptom reporting following mTBI. Additionally, while none of the three coping style factors were associated with cognitive symptom reporting, seven of the eight dimensions of illness perceptions were associated with symptom reporting (|r| = .25 - .58, p < 0.05). In a linear regression model assessing the combined effects of each variable, female sex, greater psychological distress, and overall negative illness perceptions were each significant independent predictors of increased cognitive complaint (adj. R2 = .47, F[4,63] = 15.59, p < .001).

These findings implicate female sex, psychological distress, and illness perceptions as key factors associated with cognitive symptom reporting after mTBI. This research suggests that these factors may be useful in clinical practice when considering early identification of individuals at risk of poor recovery. Specifically, this research implicates females, individuals with high psychological distress, and individuals with negative illness perceptions as important to subgroups to consider for potential intervention after mTBI. Additionally, as psychological distress and illness perceptions are both potentially modifiable, this research suggests that these factors may be useful targets for intervention.

To examine relationships between history of mild traumatic brain injury (mTBI), neuropsychological measures of executive function, and lifetime history of criminal justice (CJ) involvement among combat-exposed Veterans and Service Members (V/SM).

Participants were combat-exposed V/SM who completed a baseline assessment for the multicenter Long-term Impact of Military-Relevant Brain Injury Consortium - Chronic Effects of Neurotrauma Consortium study (N=1,341) and had adequate engagement/symptom reporting on measures of performance and symptom validity (i.e., Medical Symptom Validity Test and Mild Brain Injury Atypical Symptoms Scale). Neuropsychological battery included the Trail Making Test (A and B), Wechsler Adult Intelligence Scale-IV (WAIS-IV) Digit Span subtest, and the National Institute of Health (NIH) Toolbox Flanker subtest. Lifetime history of brain injury, criminal justice involvement, and demographics were collected. Participants were 87% male, 72% white, with a mean age of 40 years (SD=9.67). Eighty-one percent had at least some college education. Nineteen percent were active duty. Eighty percent of Veterans and 86% of Service Members reported a history of >1 mTBI, and of these 31% and 47% respectively experienced 3+ mTBIs.

Three groups were composed based on level of involvement with the CJ system: 1.) No history of arrests or incarcerations (3+ mTBIs: 64%), 2.) A lifetime history of arrest but no felony incarceration (3+ mTBIs: 34%), and 3.) A lifetime history of felony incarceration (3+ mTBIs: 2%). Ordinal regression analyses revealed that performance on a working memory task (Digit Span; b= 0.024, p= .041; OR= 1.024) was significantly associated with increased CJ involvement after adjusting for age, education, service status, and mTBIs. Performance on measures of processing speed (Trails A), set-shifting (Trails B), and inhibition (Flanker) were not significantly associated with CJ involvement. Number of mTBIs was significantly and positively associated with level of CJ involvement in all four models; Digit Span (p= .016), Trails A (p= .016), Trails B (p= .020), and Flanker (p= .008).

Performance on most measures of executive functioning was not significantly associated with CJ involvement in this large, representative sample of V/SM who served in combat. Although performance on a working memory task was significantly associated with CJ involvement, the size of the effect was small and the association was in the opposite direction as expected. Number of mTBIs was significantly associated with level of CJ involvement, indicating that sustaining multiple mTBI may be linked to greater risk of CJ involvement. These findings suggest that social and psychological factors beyond executive dysfunction may better explain the relationship between history mTBIs and CJ involvement. Some aspects of military service and veteran status, such as interdisciplinary treatment for brain injury and physical, mental, and psychosocial health needs, may be protective against previously identified risk factors for arrest (e.g., deficits in executive functioning). Contextualizing mTBI within the larger behavioral health profile of V/SM, with emphasis placed on intervention for related co-morbidities, may reduce the impact of previous arrest on wellbeing and/or reduce the risk of future CJ involvement.

Investigate the relationship of chronic neurobehavioral and cognitive symptoms in military personnel with history of blast-related mild TBI and compare to a well-matched group of combat-deployed controls.

274 participants (mean age=34 years; mean education=14.75 years; 91.2% male) enrolled in the EVOLVE longitudinal study of combat-deployed military personnel were subdivided into those with history of blast TBI (n=165) and controls without history of blast exposure and TBI (n=109). As part of a larger study, we conducted a sub-analysis of 5-year follow up data. We focused on group differences (Mann-Whitney U) and correlational relationships between self-report neurobehavioral symptoms via the Frontal Systems Behavior Scale (FrSBE) and cognitive performances on measures of attention, working memory, processing speed, and executive functioning including D-KEFS Color Word Interference (CWI), Trailmaking A and B, and the Conners Continuous Performance Test (CPT).

The Blast TBI group reported higher levels of neurobehavioral symptoms on the FrSBE (p<.001), including domains of apathy (p<.001), disinhibition (p<.001), and executive dysfunction (p<.001), compared to Controls. On cognitive measures, group differences were observed on CWI Inhibition/Switching (p=.008), Trails B time (p=.010), and CPT commission errors (p=.014), such that the Blast TBI group performed worse than Controls. No significant group differences were observed for CPT omission errors or CPT hit rate (p’s>.05). After adjustment for multiple comparisons, greater FrSBE apathy correlated with slower performance on Trails A for Blast TBI (r=0.22, p=.014) but not Controls. Apathy endorsement was not significantly related to CPT omission errors for either group (p’s>.05). Higher endorsement of disinhibition symptoms was associated with worse performance on CWI Inhibition (Blast TBI: r=-0.19, p=.036; Controls: r=-0.28, p=.012) and Inhibition/Switching (Blast TBI: r=-0.23, p=.010; Controls: r=-0.29, p=.010) conditions for both groups, whereas only the Blast TBI group showed significant relationships between disinhibition symptoms and Trails B-A time (r=0.20, p=.025) and CPT commission errors (r=.18, p=.038). Higher endorsement of executive dysfunction correlated with poorer performance for Trails B-A for both groups (Blast TBI: r=.24, p=.009; Controls: r=.24, p=.030).

Our findings reveal that at 5-year follow up, military personnel with history of blast-related mild TBI reported significantly greater neurobehavioral symptoms and performed lower on standardized measures of executive functioning, relative to combat-deployed controls without TBI or blast exposure. Significant relationships between neurobehavioral symptoms and cognitive performance were present in both groups. However, these relationships were more pronounced in the Blast TBI group, including greater apathy associated with slower visual tracking as well as greater endorsement of disinhibition associated with set-switching. Objective measures of response inhibition were related to disinhibition endorsement for both groups, though impulsive errors were more pronounced for the Blast TBI group. Our results suggest chronic cognitive and neurobehavioral symptoms are present in military personnel with history of blast TBI exposure, and also discrepant from a well-matched control group of combat deployed military personnel. Future studies of this population should explore models to predict cognitive performance from neurobehavioral symptoms in military personnel, as this could inform treatment approaches for those at greatest risk of cognitive change.

Individuals who have experienced a mild traumatic brain injury, or concussion, often experience a variety of cognitive and emotional sequelae. Specifically, concussions can place individuals at increased risk for experiencing symptoms of depression. It is important to understand if loss of consciousness (LOC) is related to higher rates of depression in order to improve care and cognitive functioning by appropriately monitoring for mood-related symptoms post-concussion. The current study sought to examine the relationship between depressive symptoms (measured using the PHQ-9), working memory (WM; measured using RBANS Digit Span subtest), and presence of LOC in individuals who have sustained a head injury. The relationships between presence of LOC, depressive symptoms, and WM performance were examined, as it was expected LOC would result in greater depressive symptoms and negatively impact WM performance. Finally, the relationship between depressive symptoms and WM performance, while controlling for LOC, was also assessed.

Data was drawn from archival medical records of 40 patients who underwent brief neuropsychological screening in an outpatient, community clinic after being referred following a head injury. Patients ranged in ages from14 to 75, with a mean age of 39.1. The average years of education amongst patients was 14.62. Twenty-five (62%) of the patients were women. Ten individuals endorsed LOC secondary to their head injury.

The average PHQ-9 score was 9.68 (SD=7.69). LOC did not impact reported depressive symptoms (p >.05). The correlation between LOC and WM performance was also nonsignificant (p >.05). While it was predicted there would be an inverse relationship between PHQ-9 scores and WM performance, there was no statistical significance (p >.05). Similarly, there was no significant relationship between PHQ-9 and WM performance when controlling for LOC (p >.05).

While the relationships between LOC, depressive symptoms, and WM performance were found to be nonsignificant, understanding the course and best supports of cognitive and emotional sequelae of head injuries is of paramount importance. Future research exploring these relationships with larger, diverse populations would likely prove beneficial.

Utilization of an objective measure to evaluate history of head trauma has been demonstrated to have a significant effect on the amount of sustained trauma reported by the individual, in athletic male populations. The ability to generalize this definition across a more diverse population remains an opportunity; a report from the World Health Organization recognized that 93% of current research on mild traumatic brain injuries omitted gender specific data. Further, relative to reports in young adults, research on the effects of concussions in midlife remain sparse. Researchers hypothesized that women between the ages of 30 and 50 from a general population would report additional head injuries when provided with an objective definition similar to those previously used in male athletes.

Highly educated (M=16.7 years, SD=2.1 years) women between the ages of 30 and 50 (M=40.3, SD= 5.1) completed an online web-based survey. The survey probed for demographic information tied to participation in sports & related activities, individual history of head trauma, as well as a series of objective measures. Participants were first asked to provide a history of head trauma, in absence of an objective definition; they were then provided with an objective definition similar to what was previously documented to be effective in the literature, and then asked to provide a reassessment of sustained trauma.

A Wilcoxen Signed Rank test indicated a significant change in number of reported head injuries, pre and post definition (z= 4.06, p<.0001). The number of head injuries reported increased for 42% of the population, for this portion of the sample the median increased fourfold. To better understand the differences between those who reported an increase, and those who didn’t, researchers performed an examination of commonalities between those groups. A Chi-Square Test of Independence indicated a significant relationship (chi=7.03, p<.01) between participation in sports (recreational, organized) and change in reported head injuries: 21% of individuals without a sport history increased the number of reported head injuries, in contrast 58% of individuals with a sport history increased the number of head injuries reported.

Consistent with the literature in male athletes, providing a definition of a head injury significantly increased the number of reported head injuries in women, between 30 and 50 years of age. This finding indicates that providing a definition can improve reported concussion history within a more diverse population. This fourfold increase for 42% of our population could bear significant implications for those receiving clinical care. Further, given that the definition utilized was especially effective at correcting history of reported head injury in those who participated in sports, it’s adoption within clinical communities evaluating athletic populations seems especially promising.

Mild traumatic brain injury (mTBI) remains one of the most prevalent brain injuries, affecting approximately one-in-sixty Americans. Previous studies have shown an association between white matter integrity and aggression at chronic stages (either 6-months or 12 months post-mTBI) however, the association between white matter axonal damage, neuropsychological outcomes, and elevated aggression in multiple stages since time-since-injury (TSI) is unclear. We hypothesized that functional connectivity between the default mode network (DMN), a key brain network involved in cognitive, self-reflective, and emotional processes, and other cortical regions would predict elevated aggression and emotional disturbances across multiples stages of recovery in mild TBI.

Participants healthy controls (HC: n=35 total [15 male, 20 female], age M=24.40, SD=5.95; mTBI: n=121 total [43 male; 78 female], age M = 24.76, SD=7.48). Participants completed a cross-sectional study design at specific post-injury time points ranging from (2W, 1M,3M,6M,12M). Participants completed a comprehensive neuropsychological battery and a neuroimaging session, including resting state functional connectivity (FC). Here, we focus on the FC outcomes for the DMN. During the neuropsychological assessment, participants completed tests that measured learning and memory, speed of information processing, executive function, and attention. To predict neuropsychological performance from brain connectivity, we conducted a series of stepwise linear regression analyses with the 11 functional brain connections (extracted as Fisher’s z-transformed correlations between regions) as predictors and each of the 13 neurocognitive factor scores separately.

Consistent with our hypothesis, one predictor materialized as significant (R = .187, R2 = .035, F = 5.55, p = .020) for the Total Sample. Largely, positive connectivity between Right Inferior Frontal Gyrus and the PCC (seed) was associated with increased aggression in the Total Sample of all participants (ß = .187, t = 2.36, p = .020). One predictor materialized as significant in Individuals the 2W group, (R = .719, R2 = .518, F = 8.58, p = .019). In general, greater negative (anticorrelated) connectivity between the Left Lateral Occipital Cortex (ß = -.719, t = -2.93, p = .019) and the PCC (seed) and was associated with greater aggression at 2W, but no predictors emerged at 1M or 3M. Individuals in the 6M group showed one significant predictor (R = .675, R2 = .455, F = 16.71, p = .001). Specifically, greater positive connectivity between the Right Lateral Occipital Cortex (/? = .675, t = 4.09, p = .001) and PCC (seed) was associated with greater aggression at 6M. No associations were evident at 12M.

Overall, these findings suggest functional connectivity between the posterior hub of the DMN and cortical regions within the occipital cortex was predictive of higher aggression in individuals with mTBI. However, the direction of this connectivity differed at 2W versus 6M, suggesting a complex process of recovery that may contribute differentially to aggression in patients with mTBI. As these regions are involved in self-consciousness and visual perception, this may point toward future avenues for aiding in functional recovery of emotional dysregulation in patients with persistent post-concussion syndrome.

Mild traumatic brain injury (mTBI) remains one of the most silent recurrent head injuries reported in the United States. mTBI accounts for nearly 75 percent of all traumatic brain injuries in the American population. Brain injury is often associated with impulsivity, but the association between resting state functional connectivity (rsFC) and impulsivity at multiple stages since time-since-injury (TSI) is unclear. We hypothesized that rsFC within the default mode network (DMN) would predict impulsivity across multiples stages of recovery in mild TBI.

Participants healthy controls (HC: n=35 total [15 male, 20 female], age M=24.40, SD=5.95; mTBI: n=121 total [43 male; 78 female], age M=24.76, SD=7.48). Participants completed a cross-sectional study design at various post-injury time points ranging from (2W, 1M,3M,6M,12M). Participants a neuroimaging session and behavioral tasks including a psychomotor vigilance task. Impulsivity was assessed as a combination of false starts and impulsive responses on behavioral tasks. The neuroimaging session included a rsFC scan. To predict impulsivity from brain connectivity, we conducted a series of stepwise linear regression analyses with the 11 functional brain connections (extracted as Fisher’s z-transformed correlations between regions) as predictors and each of the 13 neurocognitive factor scores separately. We focus here on the outcomes for the impulsivity factor.

Results showed greater positive connectivity between the and Right Frontal Pole and the anterior cingulate cortex (ACC; seed) (ß = .158, t = 1.98, p = .049) which was associated with greater impulsivity. Individuals in the 2W group demonstrated one significant predictor (R = .632, R2 = .399, F = 5.32, p = .050). Largely, there was greater positive connectivity between the Right Frontal Pole and the ACC (seed) and (ß = .632, t = 2.31, p = .050) which was associated with higher impulsivity at the 2W time-since-injury. No predictors emerged for the 1M, 3M, or 6M conditions. However, individuals in the 12M group demonstrated two significant predictor connections (R = .497, R2 = .247, F = 5.73, p = .007). Overall, a linear combination of greater negative (anticorrelated) connectivity between the Right Frontal Pole and the mPFC (seed) (/? = -.576, t = -3.53, p = .002) and greater positive connectivity between the Paracingulate Cortex (seed) and the Left Lateral Prefrontal Cortex (ß = .368, t = 2.14, p = .039) was also associated with greater impulsivity in individuals with mTBI at 12M.

These findings suggest functional connectivity between the anterior node of the DMN and prefrontal cortex regions involved in behavioral control was predictive of higher impulsivity in individuals with mTBI at 2W and 12M post injury, but not at other time frames. Interestingly, these connections differed at the two time points. Acutely, greater impulsivity was associated with greater connectivity among regions involved in error detection, exploration, and emotion. At one year, the connections involve regions associated with error monitoring and inhibitory processes. This may reflect compensatory strategy development during recovery.

Veterans with a history of mild traumatic brain injury (mTBI) often endorse enduring postconcussive symptoms (PCS) including cognitive and neuropsychiatric complaints. However, although several studies have shown associations between these complaints and brain structure and cerebrovascular function, few studies have examined relationships between structural and functional brain alterations and PCS in the context of remote mTBI. We therefore examined whether PCS were associated with cortical thickness and cerebral blood flow (CBF) in a well-characterized sample of Veterans with a history of mTBI.

116 Veterans underwent structural neuroimaging and a clinical interview to obtain detailed TBI history and injury-related information. Participants also completed the following self-report measures: the Neurobehavioral Symptom Inventory (NSI) for ratings of cognitive, emotional, somatic-sensory, and vestibular symptoms, and the Posttraumatic Stress Disorder (PTSD) Checklist for PTSD symptom severity. Regional brain thickness was indexed using FreeSurfer-derived cortical parcellations of frontal and temporal regions of interest (ROIs) including the superior frontal gyrus (SFG), middle frontal gyrus (MFG), inferior frontal gyrus (IFG), orbitofrontal cortex (OFC), anterior cingulate cortex (ACC), medial temporal lobe (MTL), and lateral temporal lobe (LTL). A subset of Veterans (n=50) also underwent multi-phase pseudo-continuous arterial spin labeling (MPPCASL) to obtain resting CBF. T1-weighted structural and MPPCASL scans were co-registered and CBF estimates were extracted from the 7 bilateral parcellations of ROIs. To assess the relationship between NSI total and subscale scores and ROI thickness and CBF, multiple regression analyses were conducted adjusting for age, sex, and PTSD symptom severity. False Discovery Rate was used to correct for multiple comparisons.

NSI total and subscale scores were not associated with cortical thickness of any ROI. However, higher NSI scores were associated with increased ROI CBF of the SFG (q=.014) and MFG CBF (q=.014). With respect to symptom subscales, higher affective subscale scores were associated with increased SFG (q=.001), MFG (q=.001), IFG (q=.039), ACC (q=.026), and LTL CBF (q=.026); higher cognitive subscale scores were associated with increased SFG (q=.014) and MFG CBF (q=.032); and higher vestibular subscale scores were associated with increased ACC CBF (q=.021). NSI somatic-sensory subscale scores were not associated with ROI CBF.

Results demonstrate that in TBI-susceptible anterior ROIs, alterations in CBF but not cortical thickness are associated with postconcussive symptomatology in Veterans with a history of mTBI. Specifically, postconcussive total symptoms as well as affective, cognitive, and vestibular subscale symptoms were strongly linked primarily to CBF of frontal regions. Remarkably, these results indicate that enduring symptoms in generally younger samples of Veterans with head injury histories may be closely tied to cerebrovascular function rather than brain structure changes. These findings may provide a neurological basis for negative clinical outcomes (e.g., enduring PCS and poor quality of life) that is frequently reported by many individuals following mTBI. Future work is needed to examine unique effects of blast exposure as well as associations with repeated injury on brain-behavior relationships.

The objective of the study was to examine longitudinal changes in the white matter tracts with diffusion tensor imaging (DTI), neuropsychological performance, and the associate between the two in adults with a mild traumatic brain injury (mTBI).

Sixteen adult patients (age = 38.5(12.8); 75% female) seeking medical care at an emergency department for their first mTBI and 15 healthy adults (age = 30.5(11.3); 33% female) from the community were recruited. DTI and the neuropsychological evaluation were performed at 7 days and 4-months post-injury. The neuropsychological evaluation consisted of the CNS Vital Signs computerized neurocognitive test battery and 2 trials of the Paced Auditory Serial-Addition Test.

Results showed a significant decrease in fractional anisotropy (FA) and an increase in radial diffusivity (RD) of the right uncinate fasciculus as well as a significant decrease in FA and axial diffusivity (AD) of the right inferior fronto-occipital fasciculus over the 4-month follow-up period in the mTBI group compared to the Control group.

The FA of multiple white matter tracts at baseline were positively associated with working memory, sustained attention, and complex attention at baseline in the mTBI group but not the Control group. The global mean cerebral diffusivity for FA at baseline was positively associated with working memory and sustained attention at 4-months post-injury.

The current findings of abnormal white matter suggest an oxidative stress reaction as a result of mTBI altering the diffusivity of some white matter tracts. Furthermore, the disruption of the white matter tracts at baseline may serve as a biomarker for identifying mTBI and those who may have prolonged cognitive difficulties in working memory and attention as a result of the mTBI.

Few concussion studies have investigated the psychological domain of concussions. Of the 22 postconcussion symptoms assessed on the Graded Symptom Checklist of the SCAT-5, five do not overlap with core symptoms of anxiety and depression. 43% of patients report at least one psychiatric symptom, the median is four after injury. Previous studies focus on total scores and not individual items; furthermore, few consider resilience as part of psychological factors that impact recovery. This research aims to describe general and specific characteristics of psychological functioning in males/females ages 12-18 after concussion to help guide treatment. We compared total scores for each measure between males/females and looked at the differences between the genders for individual items in each measure.

Participants were evaluated at an outpatient concussion clinic participating in the North Texas Concussion Registry (ConTex; N=1238, 53% female, mean age=15.4 years, SD=1.16 years). The Generalized Anxiety Disorder 7-item Scale (GAD-7, the Patient Health Questionnaire-8 (PHQ-8), the Brief Resilience Scale (BRS), and the Pittsburgh Sleep Quality Index (PSQI) were used to determine levels of anxiety, depression, resilience, and sleep quality.

Utilizing Mann-Whitney U tests (median, interquartile range) to examine group distributions for the GAD-7, PHQ-8, and BRS, females had significantly higher scores than males for the GAD (p<0.001; Female: 4, 1-9 v. Male: 2, 0-5) and PHQ (p<0.001; Female: 5, 210 v. Male: 3, 1-7). For the BRS, total scores for females were significantly lower than males (p<0.001; Female: 3.67, 3-4 v. Male: 3.83, 3.214.33). The PSQI media score was significantly different between males and females: item 2, p=.016 and item 4 p=.007 using an exact sampling distribution for U. Pearson Chi square tests were used to examine sex differences for each item of the psychological measures. Items 1-7 within the GAD-7 were significant between sexes (i.e. male or female). The seven items assess (1) Feelings of nervousness, (2) Inability to stop/control worry, (3) Worrying too much about different things, (4) Trouble relaxing, (5) Inability to sit still due to restlessness, (6) Irritability, and (7) Feeling afraid. Items 2-8 within the PHQ were significant between sexes. The items assess (2) Feeling down/depressed/hopeless, (3) Trouble falling/staying asleep, (4) Feeling tired/no energy, (5) Appetite changes, (6) Lowered/poor self-esteem, (7) Concentration issues, and (8) Feeling slowed down or unable to be still. There was a statistically significant difference between genders and Items 2 and 4 within the BRS were significant between sexes. The items assess (2) Difficulty surviving hard times and (4) Difficulty snapping back from something bad.

Like other studies, this study found females have higher levels of negative affect (i.e., depressive and anxious symptoms). Females displayed lower resilience and reported poorer sleep. By analyzing psychiatric measures, treatment protocols can be tailored to address specific problems, and mental health difficulties can be mitigated by teaching specific coping techniques. These results suggest clinicians should consistently be providing education on depression, anxiety, sleep, and resilience, particularly to female patients, who appear at greater risk for psychological distress.

There is growing evidence to indicate that blast exposure military personnel experience throughout their career can have a negative impact on their brain health. The majority of research in the area of blast related neurotrauma has been focused on traumatic brain injury (TBI); however, the blast exposure may often be independent of TBI. It is common in both active duty military and veterans to report years of blast exposure from combat and training. The objective of this study was to explore the relationship between blast exposure and cognitive functioning in military personnel seeking treatment for a mild TBI.

Participants were recruited from a military hospital while enrolled in a multidisciplinary treatment program for TBI. All patients had at least one diagnosed mTBI as well as persistent cognitive complaints. Exclusion criteria included invalid performance on a performance validity test and a symptom validity test. 97 participants were included in the analysis with an average age of 34.0 (SD = 7.9) and average 4.0 combat deployments (SD = 3.6). Blast exposure history was measured by the overall score from the Blast Exposure Threshold Survey (BETS) which assessed the frequency and duration of use of various blast sources. Outcomes included the Neurobehavioral Symptom Inventory (NSI) and the Global Deficit Scale (GDS) an objective measure of cognitive deficiency. GDS was calculated from seven measures: Hopkins Verbal Learning Test-Revised Total and Delayed Recall (HVLT-TR and HVLT-DR); DKEFS System Color-Word Condition 3 Inhibition (CW3), Color-Word Condition 4 Switching (CW4) and Trail Making Condition 3 Letter Sequencing (TM3), Paced Auditory Serial Addition Test (PASAT), and the Symbol Digit Modality Test (SDMT). Demographically corrected t-scores (M=50, SD = 10) were converted to deficit scores and averaged to calculate GDS. To adjust for nonnormal distributions, non-parametric statistics were examined.

The BETS was not related to GDS (rho = -.055); however, there was a significant correlation between higher levels on the BETS and better performance on measures of selective attention (PASAT rho = .307) and processing speed (SDMT rho = .218). The correlation between BETS and the other neuropsychological measures were not meaningful (all rho’s <.10). Those with an impaired GDS, did not differ from others on the BETS. BETS was also not associated with neurobehavioral symptoms (rho = .125). BETS had moderate correlations with number of combat deployments (rho =.483), severity of combat exposure (rho =.556). It was not related to education (rho = .004) or pre-morbid intelligence (rho =-.029).

The BETS was not related to GDS (rho = -.055); however, there was a significant correlation between higher levels on the BETS and better performance on measures of selective attention (PASAT rho = .307) and processing speed (SDMT rho = .218). The correlation between BETS and the other neuropsychological measures were not meaningful (all rho’s <.10). Those with an impaired GDS, did not differ from others on the BETS. BETS was also not associated with neurobehavioral symptoms (rho = .125). BETS had moderate correlations with number of combat deployments (rho =.483), severity of combat exposure (rho =.556). It was not related to education (rho = .004) or pre-morbid intelligence (rho =-.029).

Pre- and post-morbid mental health conditions can prolong recovery from concussion and are generally detrimental to athletic performance and quality of life. If psychiatric conditions can be identified in athletes at the time of baseline testing, psychological/psychiatric intervention can be implemented to prevent these complications. Given the time constraints on neuropsychological baseline testing, it is important to have time-efficient screening measures. As such, the purpose of this study was to develop and calibrate a psychiatric screening measure within the Post-Concussion Symptom Scale (PCSS) from the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT), which is commonly administered to athletes at baseline, thereby “killing two birds with one stone”: (1) screening for psychiatric conditions and (2) obtaining a baseline measurement of concussion-like symptoms.

Participants were 278 undergraduate students from a Canadian university with a mean age of 21.87 years (SD=4.87, range=18 to 52) and a sex composition of 64% females (n=179, Age: M=21.29 years-old, SD=4.34, range: 18 to 52) and 36% males (n=179, Age: M=22.93 years-old, SD=5.57, range: 18 to 50). Participants were a convenience sample collected via online survey platform in exchange for bonus points toward courses through a participant pool system between January and July 2021. The psychiatric screener consisted of the affective subscale from the PCSS (irritability, sadness, feeling more emotional, nervousness) and the criterion measure was the Depression, Anxiety, and Stress Scales (DASS-42). Statistical analyses were conducted in R v.4.3 and included confirmatory factor analysis and receiver operating characteristic (ROC) curve analyses. Although a balance was sought between sensitivity and specificity, the former was prioritized given that this is intended as a screening measure. Males and females were analyzed separately as females tend to report more symptoms than males. Mild, moderate, and severe elevations were predicted for depression, anxiety, and stress, based on standard DASS cutoffs.

The CFA analyses revealed good fit for both the PCSS (CFI=.992; TLI=.991; RMSEA=.053; SRMR=.066) and DASS (CFI=.995; TLI=.995; RMSEA=.053; SRMR=.065) models. Cutoffs of >3, >4, and >8 (SENS= .77-.80, SPEC= .52-.83) optimally classified males as having mild, moderate, and severe depression, respectively; and cutoffs of >8, >8, and >9 (SENS= .79-.83, SPEC= .63-.67) optimally classified females as having mild, moderate, and severe depression, respectively. A cutoff of >2 (SENS= .78-.81, SPEC= .35-.39) optimally classified males as having both mild and moderate anxiety (insufficient n in severe group); and >7, >8, and >9 (SENS= .80-.85, SPEC= .63-.68) optimally classified females as having mild, moderate, and severe anxiety. Cutoffs of >5and >8(SENS= .80-.86, SPEC= .70-.85) were optimal for detecting mild and moderate stress in males (insufficient n in severe group); and >8, >8, and >9 (SENS= .80.89, SPEC= .60-.75) were optimal in females.

The affective subscale within the PCSS operates well as a psychiatric screening measure. In general, females had higher cutoffs and the cutoffs for mild and moderate levels of the conditions tended to be similar. Males were less onsistent, with cutoffs varying widely depending on the construct and severity.

Given that at least 75% of traumatic brain injuries in the U.S. are mild, concussions are a serious public health concern that cause significant neurological damage and negatively impact individuals’ quality of life. Due to the rotational forces that occur during a concussion, immediate damage to the corpus callosum is common, resulting in neurological and behavioral deficits. However, the longitudinal damage to the integrity of the corpus callosum is unclear and may differ across sections of the corpus callosum. Our primary aim was to compare the white matter integrity across eight corpus callosum tracts in concussed individuals to healthy controls 3-4 weeks after injury and at a 10-month follow-up.

Seventeen concussed participants completed a diffusion tensor imaging (DTI) scan 3-4 weeks after receiving a concussion and again 10 months after injury. Nineteen control participants completed a single DTI scan. DTI data were analyzed using the automated fiber quantification (AFQ) pipeline, which extracts fractional anisotropy (FA) values from 100 nodes in eight tracts of the corpus callosum (listed anterior to posterior): orbital frontal, anterior frontal, superior frontal, motor, superior parietal, posterior parietal, occipital, and temporal. Given the non-linearity, high multicollinearity, and large number of data points, a cubic smoothing spline was used to fit a penalized regression to the FA values in each tract, allowing us to compare the FA values of each node in each tract between groups and across time. To assess acute damage, a spline model for the concussed participants at 3-4 weeks was compared to a spline model for the control participants in each tract. To assess longitudinal damage, a spline model of the FA difference value (10-month minus acute visit) in concussed participants was compared to a spline model of the FA difference value for controls (zero, representative of a theoretical no change in FA values). Significant nodes were defined as p-values less than 0.006 (alpha of .05/8, given 8 tracts).

Acutely following injury, concussed participants showed lower FA values than controls in the anterior frontal, posterior parietal, occipital, and temporal tracts. In the orbital frontal tract, concussed participants had higher FA values on the left, but decreased FA values compared to controls in the middle. Longitudinally, concussed participants showed continued decreased white matter integrity in the orbital frontal, superior parietal, and occipital tracts, but improved white matter integrity in the anterior frontal and superior frontal tracts. The motor, posterior parietal, and temporal tracts showed mixed longitudinal results of decreased or improved white matter integrity within each tract.

Concussed individuals show decreased white matter integrity across the corpus callosum acutely after injury. Longitudinally, the most anterior and posterior portions of the corpus callosum (i.e., genu and splenium) show continued damaged while the more medial sections of the corpus callosum may show some recovery. Results suggest the corpus callosum displays differential patterns of damage acutely and longitudinally following concussion, with some tracts improving while others continue to deteriorate.