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Objective: The long-term cognitive effects of mild traumatic brain injury (MTBI) and sport-related concussion (SRC) are not always clear. Higher-level longer-term cognitive difficulties can indicate enduring neurological damage, as part of a post-concussion syndrome (PCS). This study aimed to investigate whether cognitive performance and self-reported PCS symptoms of athletes (rugby players) relate to SRC and whether gender moderates these effects. Method: Eighty-six participants completed a questionnaire detailing SRC history (frequency and severity) and rated long-term symptoms using the Sport Concussion Assessment Tool 3 (SCAT3) symptom evaluation scales, before completing the CogState Brief Battery and STOP-IT (stop-signal response inhibition task). Results: No significant relationships between SRC dosage (frequency/severity), self-reported PCS symptoms, and cognitive test performance were identified. A greater proportion of males reported SRC compared to females, but no effect of gender was found on any of the cognitive outcome measures or self-reports of PCS symptoms. Conclusions: The results show that SRC has no observable long-term effects on cognitive test performance or PCS symptom self-reports. The analysis may have lacked power to detect effects. Analysis of individual performance over time against baseline scores may be more relevant for accurate diagnosis than relying on normative test scores. Recommendations for future research were made.

College student athletes (CSA) can experience a variety of cognitive symptoms during the early recovery phase of a mild traumatic brain injury (mTBI) which can affect written text processing and academic performance. Research examining eye movement patterns during the early recovery phase is lacking despite some individuals with chronic mTBI endorsing difficulties reading (Ratiu et al., 2022). Utilizing eye tracking technology to compare CSA with mTBI in the early recovery phase to college students (CS) when reading can reveal eye movement patterns that are unknown during observation. The goal of this study was to examine average forward fixations, regression patterns, processing time and the average fixation duration CSA and CS experience when reading paragraphs. Nine CSAs were matched to nine CS participants in gender, education, and age. Eye movements and processing time were measured using a Tobii Dynavox © Pro Spectrum eye tracker. No significant differences were found between groups for the average number of forward fixations, regressions, and processing time. However, CSA demonstrated significantly longer fixation durations than CS participants. Further research is needed with a larger, more diverse sample to examine possible differences in eye movement patterns and processing time experienced by CSA and CS participants.

Mild traumatic brain injury (mTBI) accounts for approximately 73-83% of all traumatic brain injuries (TBI) and continues to be a serious clinical challenge [1]. The role of injury mechanism in TBI has been widely debated, and it is believed that although there are differences between diffuse and focal TBI, the resulting injury is not influenced by the way in which it was acquired [1], [2]. It is known that TBIs can cause cognitive impairments that are often due to injury experienced in the hippocampus [2]. In response to insult, quiescent neural stem cell (NSC) populations within the dentate gyrus region of the hippocampus become activated. Stem cell differentiation following injury is hypothesized to be unique for diffuse and impact TBIs, primarily due to the differences in mechanotransduction pathways triggered by each respective injury. By quantifying the lineage of stem cells through immunohistochemistry, this study examined the dentate gyrus following mTBI in a rodent model, and the contribution that injury mechanism plays in mTBI outcomes. Additionally, the behavioral effects of mTBI were assessed through open field testing at 72 hours and four weeks following injury. Overall, these findings indicated that after four weeks following mTBI, there are not significant differences between impact and blast both from an immunohistochemical and behavioral standpoint. Despite there being few differences between injury groups, these findings help clarify the role of injury mechanism not only in the context of neurogenesis, but they also inform future studies addressing preventative and treatment strategies for mTBI.

Background: Athletic identity is the extent to which one identifies with the athlete role, but we do not know what that looks like in club sports and its effect on concussion reporting intention. The athletic identity of club sport athletes and their intention to report concussive injuries is limited and needs further research. Purpose: Describe athletic identity in club sport athletes and determine its influence on concussion reporting in club sport participants. Methods: A convenience sample of 149 (age 18-28 (M= 19.95±1.81) years old) club sport athletes at Georgia Southern University completed the Athletic Identity Measurement Scale (AIMS) and Intention to Report Subscale (Theory of Planned Behavior Scale) during the 2022-2023 calendar year. Scores from the AIMS and Intention to Report Subscale served as dependent variables. Correlation analyses utilizing Pearson and Spearman’s Rho correlations examined the relationship between age, sex, sport, level of involvement, previous history of concussions, previous history of concussion education, athletic identity, and intention to report. Results: Participants averaged 11.16 years (SD = 5.34) of sport involvement with lacrosse (20.1%), men’s volleyball (12.5%), dance (11.1%), women’s volleyball (9.0%), cheer (7.6%), and quidditch (6.9%) providing the most responses. The average AIMs score for the entire sample was relatively moderate (M= 35.24± 7.77). The total number of years that athletes participated in sports was significantly associated with athletic identity (r= .387, p < 0.001). Age was negatively associated with athletic identity (r= -0.23, p= 0.006). A moderate-high intent to report (M= 16.82±4.60) concussion was obtained. No correlations existed between athletic identity, age, sex, club sport, years in sport, and intention to report a concussion in club sport athletes. Conclusions: Club sport athletes do have an established athletic identity which could be impacted by years of participation in sport and age. No relationship existed between athletic identity and intention to report a concussion; however, the influence of identity playing a role in concussion reporting intention in club sport athletes should not be discounted because of the moderate-high intention to report found in this study.

This study examines the background and qualifications of plaintiff and defense experts using the H-Index score as quantification of expert background and qualifications. The goal is to better understand the similarities and differences among the professionals offering paid expert witness testimony in mild traumatic brain injury (mTBI) civil litigation. In this quantitative study, descriptive statistics include the mean and standard deviation scores for the data to support examining measures of central tendency and variance, respectively. The study includes the use of logistic regression and the Wilcoxon signed-rank test, and their statistical assumptions were tested to determine whether they would be used or if it was more appropriate to use a non-parametric test. The study included two research questions: How do the qualifications of plaintiff and defense expert witnesses in mild traumatic brain injury civil litigation compare? and to what extent does a higher h-index correlate with a favorable litigation outcome in a mild traumatic brain injury case? The findings for the hypothesis tests associated with the research questions led to the acceptance of the null hypothesis in each test. There was a lack of asymptotic significance in Hypothesis 1 and a lack of significance in Hypothesis 2. The findings from these tests shall support the discussion of the implications of this research and the direction of future research.

Concussions affect millions of young adults annually, many of whom are enrolled in post-secondary education. To date, concussion research has yet to establish evidence-based protocols to assist university students in returning to the classroom (i.e., return to learn [RTL]) after concussion. Without clear guidelines, students are left to independently navigate the complex medical and university systems. In order to understand and address barriers to receiving and implementing post-concussion academic supports within higher education, this dissertation was conducted using an exploratory-sequential mixed methods approach comprised of three main aims: (1) to collate the experiences of academic stakeholders and previously concussed university students; (2) to develop the Post-Concussion Collegiate RTL Protocol and additional concussion management recommendations for higher education through a multidisciplinary Delphi procedure; and (3) to assess perceptions surrounding implementation of the novel RTL Protocol among clinicians and academic stakeholders across the Power 5 Conferences. The first investigation was conducted using semi-structured interviews among previously concussed undergraduate students (n=21) and university academic stakeholders (n=7). Using a Grounded Theory approach, several emerging themes arose among the two cohorts. Specifically, students recalled empathetic interactions with their instructors; however, academic stakeholders indicated they lacked sufficient information and/or resources on how to appropriately develop academic supports to facilitate the RTL process for students recovering from concussion. The second study sought to mediate the discrepancies in post-concussion RTL support within higher education by developing concussion management guidelines through a modified Delphi procedure. The Delphi panel was comprised of twenty-two multidisciplinary professionals (n=9 clinicians, n=8 researchers, n=5 university academic stakeholders). The iterative process resulted in consensus across four main categories including: recommendations for medical discharge documentation, procedures for developing and maintaining a multidisciplinary RTL approach within post-secondary institutions, processes for university students to obtain academic supports following concussion, as well as the development of the novel Post-Concussion Collegiate RTL Protocol. The third project explored perceptions of prospective utility of the Post-Concussion Collegiate RTL Protocol among clinicians and university faculty/staff within the Power 5 Conferences (Atlantic Coast Conference, Southeastern Conference, Big 10 Conference, Big 12 Conference, and the Pacific 12 Conference). Participants (N=49; n=25 clinicians, n=24 university faculty/staff) completed an electronic survey comprised of four validated implementation outcome measures including the Acceptability of Implementation Measure (AIM), Implementation Appropriateness Measure (IAM), Feasibility of Implementation Measure (FIM), and Organizational Readiness for Implementing Change (ORIC). Mann-Whitney U analyses yielded no significant between-group differences on the protocol’s acceptability, appropriateness, and feasibility in their setting. However, group differences within the change commitment and change efficacy subscales of the ORIC were noted, with university faculty/staff indicating lower organizational readiness for change in contrast to clinicians within the Power 5 Conferences. Collectively, these findings serve as a framework for future university policy to standardize the RTL process for students who require academic support after concussion. Additional research is warranted to investigate university infrastructure to develop implementation pathways to support the Post-Concussion Collegiate RTL Protocol across all institutions of higher learning.

Alzheimer’s disease (AD) is the most common form of dementia with various risk factors including age, environmental factors such as brain injury and genetic factors, such as the E4 allele of the Apolipoprotein gene. Presence of the APOE4 allele increases AD risk by two- to four- fold. Recent studies have shown that mild traumatic brain injury (mTBI), even without loss of consciousness, increases risk of dementia diagnosis by more than two-fold in military personnel and is also a significant environmental risk factor for developing dementia in the general population. The gut-brain axis (GBA) or bi-directional communication between the brain and gut microbiome, has been a topic of investigation in mitigating symptoms after mTBI and throughout AD development. The gut microbiome can be modulated to improve one’s overall health. One way to manipulate the composition of the gut microbiome is by the ingestion of prebiotics, non-digestible carbohydrates that promote the growth of beneficial bacteria. The prebiotic that will be employed in these studies is inulin, which is found in chicory root and other vegetables, such as broccoli. The literature suggests that manipulation of the gut microbiome may be actionable to reduce symptoms after mTBI and decrease risk for dementia. We will test the hypothesis that modulating the gut microbiome with prebiotic inulin will reduce symptoms of mTBI and will decrease risk of AD-like symptoms in animal models.

Concussion (also known as mild traumatic brain injury) is a neurological injury that occurs after a blow to the head or neck area and can have affects to movement based on the severity of the injury. Mild traumatic brain injury has possible linkage to an increased risk of anterior cruciate ligament (ACL) injury. The purpose of this thesis was to assess the impact of prior concussion on lower extremity mechanics that are associated with risk of ACL injury. A total of 11 individuals with prior history of concussion and 11 healthy individuals without prior history of concussion (56.5 months since prior concussion) were recruited and tested in this study. Each study participant underwent a three-dimensional gait analysis while performing a single leg jump landing on the dominant and non-dominant limbs. Overall, there were no between group differences in lower extremity mechanics in the dominant and non- dominant limbs of the participants with prior history of concussion and the healthy individuals. Within the concussion group, the non-dominant limb exhibited a higher peak knee abduction angle and lower peak knee abduction moment compared to the dominant limb and suggests a biomechanical pattern that may help to offload the ACL during this landing task. The findings add to the growing amount of research that individual with prior concussion could are at a higher risk of ACL injury. Further research should be performed to assess the more acute phase of concussion (3 months to 2 years) on risk of ACL injury.

The rate of concussion in women’s lacrosse is alarmingly high despite the sport being non-contact. Conflicting opinions on the potential effectiveness of helmet use in the sport led to the development of an ASTM standard in 2015 for optional headgear. These headgears are unique to most other head protection in that they do not have a hard outer shell because it could endanger players that choose not to wear the optional headgear. Because these headgears are so new and have unique design constraints, there is still much to learn about their ability to protect the players wearing them. The purpose of this research was to determine the impact mitigation properties of two commercially available women’s lacrosse headgears (the Cascade LX and the Hummingbird v2) across a variety of impact types and severities and to incorporate rotational velocity kinematic concussion metrics in impact analysis because of their correlation to brain strains. Because polymers that are commonly used in sports headgears have been shown to exhibit cold temperature hardening, the influence of cold temperatures on the ability of the headgears to mitigate impacts was also studied. Linear impactor and ball impact testing was performed on ambient and cold conditioned headgears. The kinematic concussion metrics peak linear acceleration (PLA), peak rotational acceleration (PRA), peak rotational velocity (PRV), head injury criterion (HIC15), and brain injury criterion (BrIC) were calculated for each impact. Results showed that both headgears were able to significantly reduce all five metrics, but that this reduction was much more subtle for the two rotational velocity metrics (PRV and BrIC). Cold conditioning did not have significant effects on the headgears’ ability to mitigate impacts. Materials that were used in the headgears were then tested in compression at various strain rates and at ambient and cold temperatures to acquire their mechanical characterizations. These characterizations can be used in future finite element analysis studies to more accurately investigate how the headgears are able to protect against concussions through brain strain analysis and to study how much they may endanger other players that are not wearing headgear.

Traumatic Brain Injury (TBI) is a highly prevalent and serious public health concern. TBI is defined as an alteration in brain functioning or brain pathology initiated by external impacts, such as blunt trauma, penetrating objects, or blast waves which can cause a wide range of functional short- or long-term changes affecting thinking, sensation, language, and emotion, and perhaps most prominently, sleep. Most cases of TBI are mild in nature, yet some individuals may develop following-up persistent disability. The pathophysiologic causes for those with persistent post-concussive symptoms are most likely multifactorial and the underlying mechanism is not well understood. Currently, there are no prognostic markers to predict individuals who are most at risk. Thus, novel approaches to the precise detection and prognostication of mTBI is of utmost importance. The sleep electroencephalogram (EEG) provides a direct window into neuronal activity during an otherwise highly stereotyped behavioral state and represents a promising quantitative measure for TBI diagnosis and prognosis. With the ever-evolving domain of machine learning, deep convolutional neural networks, and the development of better architectures, these approaches hold promise to solve some of the long-entrenched challenges of personalized medicine for uses in recommendation systems and/or in health monitoring systems. In particular, advanced EEG analysis to identify putative EEG biomarkers of neurological disease could be highly relevant in the prognostication of mild TBI, an otherwise heterogeneous disorder with a wide range of affected phenotypes and disability levels. In this work, we investigate the use of various machine learning techniques on a cohort of mice and human subjects with sleep EEG recordings from overnight, in-lab, diagnostic polysomnography (PSG) from human subjects and 24 hours recording from mice subjects. An optimal scheme is explored for the classification of TBI versus non-TBI control subjects. The results are promising with an accuracy of ∼95\% in mice and ∼75\% in humans. We are thus confident that, with additional data and further studies, we would be able to build a generalized model to detect TBI accurately, not only via attended, in-lab PSG recordings, but also in practical scenarios such as EEG data obtained from simple wearables in daily life.

Mild Traumatic Brain Injury (mTBI) sustained during adolescence commonly leads to executive dysfunction. This study investigated executive function changes noted in adolescents (age of injury between 14 and 18 years) who had sustained an mTBI three months to two years prior to study enrollment (n = 7). The study compared both their pre-injury (T1) and post-injury performance (T2) and the performance of an uninjured gender-matched control group (n = 7) using the Behavioral Regulation Inventory for Executive Function: Parent Form (BRIEF-P). Results indicated heterogeneity within the behavioral regulation components of the BRIEF-P for the mTBI group with no overall within group effects between T1 and T2. Although there were few statistically significant differences between the two groups BRIEF-P scores, there is clear evidence that these children are still suffering from concussion symptoms indicating a need for more sensitive measures for this population.

Background: Traumatic Brain Injury (TBI) is a leading cause of morbidity and mortality among adults in the US (Ma, Chan, & Carruthers, 2014; Raj et al., 2015). According to epidemiological estimates put forth by the CDC, of the 1.7 million TBIs that occur annually in the United States, 80% are mild TBI (mTBI) (Ma, Chan, & Carruthers, 2014). At the sub-acute stage, mTBI patients often report experiencing post-concussion symptoms that include somatic (nausea, headache, dizziness), cognitive (poor attention, memory, and executive function), and behavioral or emotional changes (irritability, depression, emotional lability, anxiety) following their injury (Levin & Diza-Arrastia, 2015). Study Aims: The specific aims of the current study were to: 1) investigate the relationship between mood, subjective complaints of cognitive symptoms, and executive functioning (EF) performance in mTBI and control participants at the sub-acute time point; 2) evaluate the role of mood in understanding group differences in EF and subjective cognitive symptom complaints; 3) examine changes in mood and subjective cognitive symptom complaints in the mTBI group over time and determine if demographic factors, specifically ethnicity, impact mood, EF, and their relationship. Participants and Methods: Participants were 52 individuals recruited from the Departments of Neurosurgery and Emergency Medicine from UNMHSC within two weeks following a mTBI. Control participants included 32 sex- and age- matched individuals from the Albuquerque, New Mexico community. Participants attended two assessment sessions; the first session was 3-14 days post injury and the second session was ~2 months post injury. Participants completed self-report measures of post-concussion symptoms (the Neurobehavioral Symptom Inventory, the Frontal Systems Behavior Scale, the Patient-Reported Measurement Information System, the Rivermead Post-Concussion Symptoms Questionnaire) and a depression measure (BDI-II), as well as an objective neuropsychological functioning measure (the Executive Abilities: Measure and Instruments for Neurobehavioral Evaluation and Research assessment battery (NIH-EXAMINER) and a measure of premorbid intelligence (the Test of Premorbid Intelligence). Results: mTBI patients reported experiencing significantly worse mood and more subjective cognitive symptom complaints compared to healthy controls at two weeks post injury. While mTBI participants and healthy controls differed in estimates of premorbid intelligence, they did not differ in objectively measured EF. Across all self-report measures individuals with a mTBI did not demonstrate improvements in mood or symptoms between the first and second session. The current estimate of a small, non-significant effect size (d = .14) for group differences on the NIH-EXAMINER is consistent with reports from previous studies. Effect sizes for mood (d = .90) and subjective symptom reporting (d = .94) were much larger, and represent important targets for clinical intervention. Conclusions: EF deficits were not present in the sub-acute time frame, but group differences in depressive mood and the number of subjective complaints were prominent. Depression appears to be a critical treatment target for improving quality of life in mTBI patients, in contrast to EF functioning.

Traumatic brain injury (TBI) effects a large number of individuals, both civilians and military personnel, every year. The neuroinflammatory response mounted in the brain following a head injury continues long after the effects of initial subside. While it was initially thought to only occur in moderate or severe TBI, the deleterious effects of this cascade have recently been identified in patients with mild TBI (mTBI). Hypopituitarism is an often underreported condition and can result from TBI of all severity. The long-term sequelae of TBI can manifest in or exacerbate many other comorbidities of brain injury, such as neuroendocrine dysfunction or mental health conditions. Both TBI and hypopituitarism can present with symptoms similar to some psychiatric disorders, or exacerbation comorbid conditions. Veteran patients presenting to their primary care providers with symptoms of irritability, depression, anxiety, or cognitive and behavioral changes may meet criteria to receive diagnoses of psychiatric illnesses prevalent in the military population, while not being evaluated for pituitary dysfunction, and thus receive inadequate treatment. The proposed study aims to identify the prevalence of patients that are receiving psychiatric treatment that have both a history of mTBI and reduced levels of pituitary hormones on serum assays. By identifying a significant portion of this population, future studies can assess the impact that hormonal replacement has on success of psychotherapy, resolution of symptoms, and impact on functional status, among other factors.

Efficient protective structures are needed to ensure safe transport of fragile devices, cushioning of delicate objects in mechanically hazardous environments, like spacecraft launch, and protection of humans during collisions in athletics and automotive accidents. Compliant delicate objects, that are enclosed in rigid shells, are protected from indentation, but are vulnerable to impacts that involve large accelerations and high coefficients of restitution. The human brain is an example of such a delicate object. Early theories of traumatic brain injury identified two kinematic injury regimes, which are separated by a characteristic time. Depending on the duration of the impact, either a maximum tolerable acceleration or velocity governs risk, and common cushioning strategies that rely solely on reducing force may be inadequate for impacts that are shorter than the object's natural period. First, we introduce a dissipative cushioning strategy that uses the fractional derivative visco-elastic model known as the fractional Standard Linear Solid (FSLS). The FSLS is capable of describing the complex modulus of a variety of materials accurately with a smaller number of parameters than a multi-term Prony series. Material selection criteria and a framework for optimizing cushions for minimum size are also presented. The cushions that dissipate most efficiently have relaxation times which are slightly shorter than the impact, and have high loss factors. The acceleration of the impact can be reduced more efficiently with a visco-elastic cushion than a purely elastic collision. The successful implementation of this cushioning strategy requires knowledge of the characteristic time of the object and threshold values for its maximum tolerable velocity and acceleration. Therefore, the calculation of the characteristic time and approximate kinematic tolerances for the brain, obtained by analyzing an idealized two-dimensional cylindrical model, are sought in the second part of this thesis. Both rotation and linear translation of the cylinder's shell are evaluated, and the resulting pressure and shear strain are calculated. This approach is based on the theory that dangerous strain arises from rotational motion, and that dangerous levels of pressure come from linear motion. The rotation of the skull primarily produces shear stress and strain. Linear motion would produce both shear stress and strain, but the high bulk modulus of the brain suppresses volumetric strain and the low shear modulus suppresses high shear stress. The strain from linear motion is found to be relatively small. The final chapters, which consider the strain due to rotation, provide scaling laws for estimating shear strain from rotational loads. In particular, shear strain is either dependent on angular velocity or the angular velocity times a fractional power of the impact duration, when the impact is short. The points of transition between different types of response are identified as the characteristic times of the brain, and their dependence on material properties and dimensions of the brain are discussed. Knowing which types of motion bring about more or less deformation is important for knowing which aspects of the impact should be mitigated. This can be paired with the analysis of the cushion response, addressed initially, to design cushions that meet design criteria based on the kinematic damage criteria. Therefore, the correlations between strain and kinematics can be coupled with the cushion design framework to optimize the design of helmets and evaluate their performance with simple experiments that measure easily-observable kinematic quantities rather than internal strain.

Context: Lack of concussion reporting remains a problem as high school athletes report about fifty percent of all concussions. Purpose: The study sought to determine if there is a relationship between athletic identity and athlete’s intention to report concussions. Methods: The sample consisted of 78 high school athletes (m age = 16.19 + 0.88, 56 males, 22 females). Participants were administered the Athletic Identity Measurement Scale (AIMS) and Intention to Report Subscale which served as dependent measures. The presence of AI was determined by comparing AIMS score to previous norms. A linear regression was used to determine the relationship between AI and intention to report. Regression analysis examined the influence of demographic variables on AI and intention to report. Finally, multiple one-way analysis of variance (ANOVA) were conducted to examine differences between groups for AI and intention to report. All statistical analyses were conducted utilizing SPSS 25.0. Significance levels were set at an a priori 0.05. Results: Athletes in the study had an athletic identity as demonstrated by similar AIMS scores to previous norms. AI was not related to intention to report (p = 0.740). Age significantly influenced reporting intention (p = 0.20), as athletes get older their intention to report decreased. Athletes with a previous history of a “ding/bellringer” had significantly lower intention (p = 0.048), but previous history of concussion did not affect reporting intention to report (p = 0.118). Additionally, previous concussion education did not influence intention (p =0.612). Discussion: Adolescents do have an established AI as compared to other athletes. This study sought to find out if there was a relationship between AI and intention. No relationship existed between AI and intention; however, clinicians should not discount the influence identity may play in concussion reporting intention. Although AI did not influence intention to report in our study, other identities may be more influential. Additionally, incorrect terminology when discussion concussions, such as ding and bellringer, lead to decreased reporting. Clinicians should continue to work to educate athletes on the importance of concussion reporting and utilizing proper terminology.

The purpose of this qualitative case study was to explore how a student-athlete suffering a concussion/mild traumatic brain injury copes academically in a high school environment. This case study sought to answer the question of how these student-athletes cope with their return to the classroom and are affected academically, physically, socially, and emotionally from multiple perspectives. Guiding this instrumental case study was an analytic generalization of the theory of planned behavior, social norm theory, Bandura’s social learning cognition theory, and the theory of mind. This bounded case study included one participant who had suffered a concussion and was returning to a high school educational environment in South Carolina. In addition to the case study participant, data were collected from teachers, family, friends, coach, school nurse, and others who were involved during the student’s concussion recovery. This data were collected through interviews, documentation, journaling, and focus groups. Data analysis includes coding for themes and triangulation of data to establish trustworthiness through credibility, dependability, confirmability, and transferability. The results of this case study revealed how the student was affected by her concussion in all areas researched: physical, academic, social, and emotional. The findings demonstrate the need for support as concussed student-athletes return to the classroom through better communication with all involved in the return to learn process, homebound instruction, and continuous reassessment of concussion protocols. Additionally, cognitive assessments should be developed to assist in determining timing for concussed students to return to the learning environment.

Self-esteem, shame, and depression are three factors which can impact quality of life. Mental health counseling and perceived satisfaction of mental health services can also have an impact on quality of life. This study focused on the how mild and moderate traumatic brain injury survivors within a small sample population perceived how self-esteem, shame, and depression were predictors of quality of life. Through survey research, an online survey was utilized to solicit responses to questions related to self-esteem, shame, depression, quality of life, counseling services, and counseling service satisfaction among mild and moderate traumatic brain injury survivors who participate in brain injury support groups within the State of Colorado. Responses indicated mild and moderate traumatic brain injury survivors did seek more counseling services and were more satisfied than dissatisfied with the services they received post-injury. The research also indicated that while shame and depression do have a small predictor proportion to quality of life, self-esteem was the greatest predictor of the three independent variables to perceived quality of live among mild and moderate traumatic brain injury survivors who participated in the survey for this study.

Context: Concussions have been declared an epidemic in sport participation by the Centers for Disease Control. While concussions cannot be prevented, researchers and clinicians believe concussion education is the cornerstone for early recognition and management. Concussion education has been mandated by state legislation and governing athletic bodies as a part of concussion management strategies at both secondary and post-secondary levels. However, neither of these entities have specified how concussion education should be delivered to the student athlete population. Purpose: Evaluate the effectiveness of a multimodal approach to concussion education on knowledge and retention in collegiate athletes. Methods: A multimodal concussion education that included a PowerPoint lecture, video, and discussion was conducted by the head athletic trainer during pre-season team meetings. The ROCKI survey was administered to examine concussion knowledge during three time points, pre-intervention, immediate post-intervention and three months later. Repeated Measures Analyses of Variance (ANOVA) was used to compare the knowledge scores over time (pre-, post-, retention). Semi-structured interviews examined (1) attitudes towards the intervention and (2) perceived increase in knowledge of the athletes during the intervention using content analysis. Credibility and trustworthiness were established through member checks and using the Certified Athletic Trainer as an auditor. Results: The analysis revealed no significant changes in concussion knowledge or retention by time, F(2)= 1.95, p= 0.147, n2= 0.034. Thirteen teams were examined and yielded a total of 57 participants. Ten interviews were conducted (six freshmen, four returners) and four main themes emerged: (1) no perception of formal education in high school, (2) intervention enabled respondents to recall symptoms, (3) perceived increase in knowledge, and (4) multimodal approach was perceived as successful. Conclusion: A multimodal concussion education intervention did not significantly increase student-athlete knowledge, however qualitative analysis revealed student-athletes liked the multimodal approach and all respondents had a perceived increase in concussion knowledge after the intervention. Further studies should examine the use of a multimodal approach with active learning strategies to increase student-athlete knowledge on concussions.

Abstract: Concussion in sports has become one of the main concerns for the health of athletes (McCrory et al., 2017). In response, preventative initiatives have been put in place to educate the public about concussion management (Mrazik, Dennison, Brooks, Yeates, Babul, & Naidu, 2015). Despite attempts to further the public’s knowledge of concussion, research reveals that athletes often fail to report concussions to authority figures (Delaney, Caron, Correa, & Bloom, 2018; Williamson & Goodman, 2006). Therefore, my study builds on existing research examining psychological factors relevant to athletes reporting concussions. Current Study: The purpose of this study was to examine concussion reporting intention from the theory of planned behaviour and a stress-response to injury framework. Constructs from these theories were used in predicting intentions, delay, and the actual behaviour of reporting concussion symptoms. Methods: In this cross-sectional quantitative design, data was collected via convenience-sampling methods from 113 junior varsity athletes playing team sports at the University of Alberta. Inferential statistics included multiple regression models predicting both an athlete’s reporting intention and the anticipated delay of reporting. Subsequent analyses included logistic regression models in predicting the actual occurrence of athletes’ reporting their concussion. Findings: Results provide support for my proposed models using constructs from the theory of planned behaviour and the stress-response to injury model to predict reporting intention (F(5,102)= 7.01, p < .001, R2 = .26) and an anticipated reporting delay (F(5,103)= 10.35, p < .001, R2 = .33). Perceived control in reporting concussions and emotional help seeking coping were found to have significant associations with greater intentions for reporting and lower delays in anticipated reporting times. Logistic regression analyses reveal that reporting intentions and perceived control in reporting were significantly predictive of an athlete reporting they had a “bell ringer” in the previous season (χ2 (2) = 6.04, p < .05). Implications, limitations and directions for future research are discussed in relation to the existing literature.

This paper investigates research literature on mild traumatic brain injury and supports for students, guardians, and the implications for educators. Students who experience mild traumatic brain injury will encounter a variety of symptoms (i.e., dizziness, amnesia, headache, sensitivity to sound) throughout their recovery. Students may also experience difficulties in their academic performance: occlusion errors, academic dysfunction, and deficits in long-term cognitive control. Medical staff, guardians, students, and educators must support students, on an individual basis, to serve the multiple needs of students recovering from mild traumatic brain injury.

Mild traumatic brain injuries (mTBI) comprise the majority of TBI’s sustained. For most individuals with mTBI, post-injury sequelae resolve within approximately three months after injury, yet a minority experience prolonged post-concussion symptoms (PCS) associated with poor long-term functioning, including inability to return to work (RTW). Research on RTW following mTBI has found moderate support for pre-injury and post-injury factors on employment outcomes, while injury factors have largely demonstrated a weak relationship. However, critical factors that may predict long-term outcome in mTBI are often not included in these studies, such as pre-morbid psychopathology, prior TBI, occupational decision-making latitude, litigation-seeking, and insurance provider. In addition, little is understood about the contribution of multidisciplinary rehabilitation to RTW. The purpose this study was to elucidate pre-injury, injury, post-injury, and rehabilitation factors that predict employment outcomes after mTBI. An archival medical record review was completed with 79 mTBI patients who completed an initial evaluation for multidisciplinary rehabilitation for PCS. RTW status was collected by follow-up telephone interview and served as the primary outcome measure. A total of 58 participants (73.4%) resumed employment when reached at follow-up on average two years and 10 months post-injury. Among several factors considered, three post-injury variables obtained at rehabilitation admission explained 23.1% of the variance in successful RTW: lower self-reported PCS, lower anxiety symptoms, and better performance on a measure of verbal memory recognition. With regard to multidisciplinary rehabilitation factors, only increased number of speech-language pathology therapy sessions was associated with poorer employment outcomes. Overall, findings suggest that anxiety, particularly as it relates to PCS, deserves increased attention in empirical research and rehabilitation efforts. Furthermore, individuals with cognitive symptoms requiring more intensive rehabilitation may be at increased risk of poor employment outcomes. Advisor: Debra A. Hope

Mild traumatic brain injury (mTBI) is a major public health concern, linked with post-concussive syndrome and chronic traumatic encephalopathy. At present, standard clinical imaging fails to reliably detect traumatic axonal injury associated with mTBI and post-concussive symptoms. Diffusion tensor imaging (DTI) is an MR imaging technique that is sensitive to changes in white matter microstructure. Prior studies using DTI to investigate mTBI did not separate contact sport athletes, a population at high risk for mTBI and subconcussive head traumas, and there has been a dearth of longitudinal studies of mTBI patients. In this study, we used Tract-Based Spatial Statistics to perform cross-sectional and longitudinal analysis describing changes in DTI scalar parameters in emergency room (ER) patients and in scholastic contact sport athletes. In the acute post-injury period, athletes demonstrated an elevated rate of regional decreases in axial diffusivity compared to controls. These decreases were especially pronounced in the cerebellar peduncles, and were more pronounced in contact sport athletes compared to the ER patient population. These results lend credence to the hypothesis that post-concussive symptoms are caused by shearing of axons of an attention network in the brain with timing mediated by the cerebellum, and warrant further study of the correlation between cerebellar DTI findings and clinical outcomes in mTBI patients.

Rationale: A subset of Operation Enduring Freedom/Operation Iraqi Freedom (OEF/OIF) Veterans who incur a mild traumatic brain injury (mTBI) experience persisting post-concussive symptoms (PCS) and objective cognitive deficits (e.g., slowed processing speed). However, these symptoms are not unique to mTBI; overlapping symptoms and similar cognitive deficits are also observed in post-traumatic stress disorder (PTSD), depression, and after deployment and blast exposure not resulting in mTBI, all of which are common for OEF/OIF Veterans. Although advanced neuroimaging techniques have improved our understanding of white matter changes after mTBI, measuring myelin integrity has the potential to be a sensitive and specific measure of slowed processing speed and PCS related to mTBI, and to help disentangle these symptoms from conditions with overlapping features. Design: Utilizing a novel neuroimaging method, multicomponent-driven equilibrium single-pulse observation of T1 and T2 (mcDESPOT), the present study aimed to assess the relationship between myelin integrity and 1) injury variables (i.e., number of TBIs, loss of consciousness and post-traumatic amnesia, blast-related TBI), 2) cognitive variables including objective tests of working memory/attention that require speeded processing and simple measures of processing and motor speed (n = 4), and 3) subjective PCS in OEF/OIF combat Veterans with and without TBI history. This cross-sectional study assessed 57 OEF/OIF Veterans with history of mTBI (n = 31), history of moderate TBI (n = 4), or without history of TBI (n = 22). Across the entire sample, the prevalence of PTSD was 52.6%. Groups did not significantly differ with regard to presence/severity of current PTSD or depression, self-reported alcohol use (current substance use disorder was exclusionary), or demographic variables. Myelin integrity was measured using mcDESPOT’s myelin water fraction (MWF) across multiple regions-of-interest (ROIs) in fronto-striatal and fronto-limbic circuits, and callosal fibers. Veterans were administered a comprehensive battery of neuropsychological tests including measures of simple and complex processing speed as well as PCS. Using partial correlations and multiple linear regression, relationships between myelin integrity and 1) injury variables, 2) cognition, and 3) subjective persistent PCS in the context of PTSD and depression were assessed. Results: There were no differences between the combat comparison (CC), mTBI, or moderate TBI (modTBI) groups with respect to myelin integrity or cognitive performance. However, PTSD was significantly and positively associated with MWF. Injury variables demonstrated inconsistent relationships with myelin integrity, such that number of TBIs and blast-related mTBI were positively associated with MWF, although the majority of these relationships did not survive Bonferroni correction and/or remain significant once controlling for PTSD. Significant and positive relationships were observed between MWF and objective cognitive measures (most notably a measure of speeded attention and processing) across multiple ROIs, when controlling for psychiatric diagnoses and/or symptoms. Furthermore, the relationship between MWF and cognition was significant within the mTBI, but not the CC group. Finally, no significant relationships were observed between MWF and PCS after controlling for psychiatric symptoms and/or diagnoses. Conclusions: Given the prevalence of TBI and psychiatric comorbidities in OEF/OIF Veterans, the identification of reliable and objective biomarkers of brain damage after mTBI would provide the foundation for more accurate diagnosis of nonspecific symptoms, prognosis, and therapeutic opportunities. Results suggest that assessing myelin integrity using mcDESPOT may be a useful tool in delineating nonspecific reports of cognitive difficulties occurring after TBI in the context of commonly comorbid psychiatric disorders.

Adults with mild traumatic brain injury (MTBI) experience a variety of memory, pragmatic, social, and cognitive changes that have significant long-term effects. Though the majority of traumatic brain injuries (TBI) are mild, there is a lack of objective and reliable diagnostic markers for the assessment of MTBI. This report provides a critical review of eye tracking as a possible diagnostic procedure for the evaluation of MTBI. Specifically, the purpose of this paper is to describe the characteristics, classification and assessment of TBI, review methods used to evaluate MTBI, and discuss the emergence of eye tracking as an effective diagnostic tool for the disorder.

Every year an estimated 42 million people worldwide suffer a mild traumatic brain injury (MTBI) or concussion, with approximately 3.6 million sports related concussions occurring yearly in the United States alone (Bailes, 2015, Azad et al., 2015). An MTBI is an acute brain injury resulting from mechanical energy to the head from external forces (Bailes 2015). Symptoms of an MTBI include visual disturbances, dizziness, nausea and vomiting, light sensitivity, loss of balance, and a general feeling of fatigue (Bailes 2015). MTBI’s are first diagnosed through changes in ImPACT baseline scores as well as Vestibular Ocular Motor Screening (Mucha et al., 2014). Repetitive MTBI and/or repetitive sub-concussive head trauma have been tentatively linked to increased risk for a variety of neurodegenerative diseases including chronic traumatic encephalopathy (CTE) (Gardner et al., 2015). The major limitation of the link between MTBI and CTE is that CTE can only be diagnosed post-mortem (Azad et al., 2015). Due to that limitation, the prevalence of CTE is unknown and the amount of MTBI or sub-concussive trauma exposure necessary to produce CTE is unclear (Gardner et al., 2015). Newer methods of research including SNTF immunostaining and L-COSY are being further developed and studied to better diagnose MTBI and its link to CTE by exploring changes in brain protein formation and brain neurochemistry (Johnson et al., 2015, Lin et al., 2015). Through research development and case studies on professional American football players and boxers, a link between MTBI, particularly repetitive MTBI and CTE has been formed (Maroon et al., 2014).

Blast-related mild traumatic brain injury (mTBI) is a common injury among Operation Enduring Freedom/Operation Iraqi Freedom (OEF/OIF) veterans due to the frequent use of improvised explosive devices (IEDs). A significant minority of veterans with blast-related mTBI complain of postconcussion symptoms (PCS) and cognitive difficulties, even years after the injury. Studies have suggested that these behavioral sequelae are primarily linked to mental health disorders such as posttraumatic stress disorder (PTSD). However, mTBI is associated with neural changes and the impact of these changes on behavioral sequelae is unclear. As such, this dissertation had three goals. First, this dissertation assessed whether the severity of PCS in blast-exposed individuals is associated with the extent of mTBI-related neural injury. Results revealed that individuals with mTBI with loss of consciousness (LOC) had significantly more white matter abnormalities than no-TBI controls and that these white matter abnormalities were spatially variable across individuals. Importantly, the extent of white matter abnormality was associated with physical PCS severity and mediated the relationship between mTBI with LOC and physical PCS. Second, this dissertation examined whether these white matter abnormalities were also associated with overall cognitive impairment. In light of the observed variability in white matter injury, a measure of overall cognitive status that takes into account heterogeneity of cognitive impairment was used. Results showed that the extent of white matter abnormality was associated with cognitive status and mediated the relationship between mTBI with LOC and cognitive impairment. Third, this dissertation examined performance and brain function in the context of an experimental measure of cognitive control known to be sensitive to residual effects of mTBI. Results revealed that although behavioral performance was similar across groups, the mTBI group had enhanced functional connectivity between brain networks important for task performance, suggesting a potential compensatory mechanism in mTBI. Together, the findings of this dissertation suggest that mTBI is associated with structural and functional connectivity alterations years after the injury. Further, this dissertation suggests that whereas structural connectivity changes may have negative behavioral consequences, changes in functional connectivity may serve as a compensatory mechanism for successful performance.

More than 1.3 million people seek emergency care following a mild traumatic brain injury (MTBI) each year. While most MTBI patients are safely discharged, a small proportion experience serious intracranial processes. The wide availability of computed tomography (CT) has generated a dramatic increase in the number of CTs performed to identify those patients with clinically important traumatic brain injury (ciTBI), generating expense and radiation exposure risks for patients. To address unwarranted variation in practice, we implemented an electronic best practice advisory (eBPA) based upon a validated clinical prediction rule that appears when emergency department (ED) clinicians order CT following MTBI.

Abstract: Objectives: To compare the self-report of symptoms on two commonly used tools: Sideline Concussion Assessment Tool 2 (SCAT2), and Immediate Post-Concussion Assessment and Cognitive Test (ImPACT). To identify potential variables on ImPACT and a preseason questionnaire that might predict concussion. Results: Eighteen “matched” symptoms were analyzed for 349 athletes. There were significant differences between 10 symptoms. Athletes who scored in the lowest 10th percentile at baseline on ImPACT for the visual memory composite score were 2.5 (95% CI 1.09 – 5.46) times more likely to suffer a concussion. Male athletes with a family history of concussion were 0.4 (95% CI 0.17-0.93) times less likely to suffer a concussion. Conclusions: Athletes’ self-report of post-concussion symptoms differed, depending on the type of concussion evaluation tool used. ImPACT may be able to identify athletes at increased risk for concussion. More research is needed on preseason screening questionnaires.

Within the past few decades brain injury, or traumatic brain injury (TBI), has gained widespread attention. Early focus was on more severe forms of TBI; severity typically measured using the Glasgow Coma Scale. In more recent years, however, mild traumatic brain injury (mTBI), most notably concussions, has gained increasing interest due to the high frequency of concussions suffered in athletes of all levels and, recently, in military personnel due to blast injuries. Studies being performed have focused not only on ways to help minimize the incidence of concussion as well as treating concussive symptoms, but also on detecting concussions. Many concussions go unreported due to inadequate knowledge of concussive symptoms amongst the general population. Because many concussions go unnoticed and hence unreported the individual who has sustained a concussion is at risk for a more serious injury in the future. One such injury is Second Impact Syndrome (SIS). Second Impact Syndrome is essentially a synergistic event where the sum of two seemingly mild concussions combine to create an event that is potentially fatal. The findings during the autopsy are that there is insignificant damage to the brain to cause death. The damage that occurs, however, is on a molecular level causing a strain on the metabolic processes of the brain called dysautoregulation. Without an understanding of the changes that have occurred on a molecular level in SIS the assignment of cause and manner of death is difficult for the medical examiner. Currently, in order to diagnose SIS, a thorough scene investigation, along with the documentation of a previous head injury is needed. Without a full understanding of SIS and the pathophysiology changes that take place a medical examiner (ME) could misclassify the cause and manner of death in a death due to SIS. In the future, eliminating the prerequisite of identification and documentation of previous head injuries in order to diagnose SIS is needed. This paper evaluates the literature on the current knowledge of TBI and concussions in an attempt to create a protocol on how a medical examiner should approach a case where autopsy findings are unremarkable.

Objective: To demonstrate the utility of a novel, objective tool, the Nintendo™ Wii Balance Board (WBB), in identifying postural instability acutely following mild traumatic brain injury (mTBI) in children. Design: Prospective case-control study over a twelve month period Setting: Emergency department (ED) of a pediatric level-one trauma hospitalParticipants: Cases included children aged 11-16 years presenting to the ED within six hours of sustaining a witnessed mTBI and who were simultaneously enrolled into a parent study evaluating biomarkers predicting post-concussion syndrome. Controls, matched on gender, height, and age, consisted of children presenting to the ED for a minor chief complaint.Methods: In the ED, all children rated their perceived level of postural instability using two questions from the validated Post-Concussion Symptom Scale, yielding a balance subscore (PCSS-B). WBB measurements were then obtained using four different stances (single limb eyes open, single limb eyes closed, double limb eyes open, double limb eyes closed). Cases had repeat WBB measurements and PCSS-B scores taken within 72 hours and again at one week post-injury.Results: Seventeen mTBI cases were enrolled, four of which were too dizzy to complete balance testing in the ED so were excluded from this analysis. Of the remaining thirteen, cases were mostly male (92.3%), white (61.5%), and had been injured while playing sports (69.2%). The average age was 12.8 +/- 1.5 years. One case had incomplete demographic data; for each of the remaining twelve, two controls, matched on age, height, and gender, were enrolled. In the ED, one of the WBB measurements (double limb eyes open) was significantly higher in cases than in controls (p=0.03), reflecting increased postural instability. The PCSS-B did not predict performance on any of the WBB stances in cases or controls. By one week post-mTBI, there was not a significant change among the four WBB measurements. Conclusions: Children demonstrate postural instability following mTBI when performing a simple standing balance task with two legs and their eyes open. This postural instability remains present at one week post-injury. An objective measure of postural instability would be useful in the ED to ensure safe return to activities. The WBB may be a tool which can modernize the ED physician’s examination and improve anticipatory guidance.

Concussion affects the adolescent population in large numbers, primarily because of the popularity of team sports that are played in middle and high school. This adolescent age group is more susceptible to the adverse effects of concussion due to physiological immaturity, and recovery for this population takes longer than in adults. Speech-language pathologists, who are trained to treat cognitive-communication deficits, are present in the majority of school systems throughout the United States, and could be a useful resource to manage and treat students who incur concussion. However, speech-language pathologists historically have not treated students with concussion, and may not be receiving adequate education regarding concussion in graduate programs. This study sought to ascertain the education, training, and experience regarding concussion of speech-language pathologists in Texas secondary schools. Anonymous survey responses were collected via an Internet survey platform, yielding 49 respondents for the final data pool. The answers provided by these respondents indicate Texas speech-language pathologists are not yet receiving adequate concussion education and training. Respondents reported low confidence levels in several key areas of concussion knowledge, and doubt regarding the speech-language pathologist's role in managing concussion. Recommendations include concussion-targeted graduate school curriculum as an extension of traumatic brain injury curriculum, increased continuing education efforts by ASHA regarding concussion and the speech-language pathologist's role in treating concussion, and further advocacy by ASHA for speech-language pathologists to be part of concussion management teams based in schools.

Veterans of the Iraqi and Afghanistan conflicts have frequently returned with injuries such as mild traumatic brain injury (mTBI) and posttraumatic stress disorder (PTSD). More recently, concern has been raised about the large number of returning soldiers who are diagnosed with both. Literature exists on the neuropsychological factors associated with either alone, however far less research has explored the effects when combined (PTSD+mTBI). With a sample of 206 OEF/OIF veterans, the current study employed neuropsychological and psychological measures to determine whether participants with PTSD+mTBI have poorer cognitive and psychological outcomes than participants with PTSD-o, mTBI-o, or veteran controls (VC), when groups are matched on IQ, education, and age. The PTSD+mTBI and mTBI-o groups exhibited very similar neuropsychology profiles, and both PTSD+mTBI and mTBI-o performed significantly (α=.01) worse than VC on executive functioning and processing speed measures. There were no significant differences between VC and PTSD-o on any notable neuropsychology measures. In contrast, on the psychological measures, the PTSD+mTBI and PTSD-o groups were identical to each other and more distressed than either mTBI-o or VC. These findings suggest there are lasting cognitive impairments following mTBI that are unique to the condition and cannot be attributed to known impairments associated with distress.

Background: A cluster of cognitive, physical, emotional / behavioral and sleep problems referred to as post-concussion syndrome (PCS) occurs following mild traumatic brain injury (mild TBI) in a subset of children. Limited evidence suggests that patient and injury characteristics contribute to the development of PCS.Objective: To determine the acute predictors associated with the development of PCS in children. Methods: Retrospective analysis of a prospective observational study of children ages 5 to 18 years presenting to the Emergency Department (ED) with mild TBI. All patients had data related to the injury recorded during the initial ED visit. Telephone follow-up administration of the Rivermead Postconcussion Questionnaire was conducted at three months post injury. In a convenience sample, serum was analyzed for the biomarker S100B. Univariable and multivariable logistic regressions were performed.Results: 29% of children presenting to the ED with mild TBI developed had PCS. The most frequent PCS symptom was headache. Predictors of the development of PCS were age, headache on presentation in the ED and admission to the hospital, while controlling for other covariates. S100B levels alone did not predict development of PCS. Children who developed PCS missed, on average, 7.4 (SD 4.9) days of school.Conclusions: Children, who were older, had headache on ED presentation and required hospital admission at ED encounter, were at high risk of PCS following TBI. Interventions to identify and begin early treatment for this population may be of benefit to improve outcomes and reduce burden of disease.

The widespread use of Improvised Explosive Devices (IEDs) in the Wars in Iraq and Afghanistan has caused a dramatic increase in shockwave-induced mild Traumatic Brain Injury (mTBI), leading mTBI to be dubbed the 'signature injury' of modern warfare. Currently, the pathology of shockwave-induced mTBI is unknown , and it is diagnosis is based on self-reported symptoms and combat history. While the etiological mechanism has not yet been determined , it is becoming increasingly accepted that shockwaves themselves are the brain-damaging agent that emanate from IEDs. To assess how mild, sub-lethal shockwaves might damage brain tissue, we developed an in vitro assay to deliver shockwaves to neuronal cells in culture, and then assayed several properties of these cells that affect their function. This assay involved exposing rat cortical and hippocampal primary neuronal cultures to shockwaves of increasing magnitude generated with a biolistic Gene Gun. The Gene Gun produces shockwaves of sufficient overpressure to cause cognitive impairment in animal models of shockwave-induced mTBI. Our results show that overpressures of ~1.0 pound per square inch (psi) caused transient membrane permeability for molecules up to ~12 nanometers in diameter. This change in membrane permeability was accompanied by a transient decrease in cellular ATP levels and synaptic densities. This synaptic degeneration correlated with changes in the level and phosphorylation state of several synaptic proteins examined. Similar results were observed in dissected rat retinas suggesting that these shockwave-induced effects can occur in complex tissues, such as the brain. Based on these findings we propose that shockwaves damage cellular membranes, leading to a decrease in intracellular ATP, and ultimately to a reduced numbers of synapses, the part of neurons most important for learning, memory and behavior. Additional experiments in whole animals will be required to ascertain whether shockwave-induced cellular damage and synaptic degeneration plays an etiological role in shockwave-induced mTBI.

Mild traumatic brain injury (mTBI) is a prevalent and costly public health problem with potentially disabling consequences. Interventions aimed at alleviating cognitive, emotional and behavioral sequelae are underdeveloped. This prospective, quasi-experimental cohort study evaluated a brief social work delivered intervention (SWDI) for adults with mTBI discharged from the emergency department. The SWDI included education, reassurance, coping strategies and community resource information. Participants were recruited from consecutive admissions to the emergency department. A total of 64 persons with confirmed mTBI diagnoses were assessed 3 months post-injury. Participants in the Usual Care group (N=32) were identified via medical record; confirmation of mTBI was based on World Health Organization definition. Participants in the SWDI group (N=32) were identified and mTBI diagnosis confirmed by emergency department medical staff. Both groups completed standardized assessments of post-concussion symptoms, depression, anxiety, Posttraumatic Stress Disorder, alcohol use, and community functioning three months after injury. To assess change in alcohol use and community functioning, participants were asked to recall pre-injury drinking levels and functioning and then asked about current status three months post injury. The SWDI group also completed an open-ended Patient Experience Survey following their ED service. The paired sample t test was used to assess community functioning outcomes. For all other standardized measures, non-parametric Mann Whitney or Wilcoxon Signed Rank tests were used to compare groups. Qualitative themes from the Patient Experience Survey were identified through systematic review of all survey responses.Three months post injury, both groups reported pre-injury drinking in the "hazardous" range. The SWDI group reported significantly reduced alcohol use from pre-injury to post-intervention (p < 0.05). The Usual Care group maintained their pre-injury level of drinking. Analysis of the community functioning measure revealed the SWDI group maintained pre-injury levels of community functioning, while the Usual Care group reported significant decline in functioning (p = 0.05). All other analyses of standardized measures (anxiety, depression, PTSD, post-concussive symptoms) trended in favor of the intervention group, but were not statistically significant. Results from the SWDI Patient Experience Survey indicate that 96% of participants who remembered receiving the intervention (N=25) found it helpful. In response to an open ended question about the most helpful aspects of the intervention, 60% reported it was most helpful to learn about symptoms to expect because this decreased anxiety about symptoms, 28% reported that the recovery tips were most helpful and 24% reported that education about ceasing alcohol use was most helpful. The study provides support for the use of the SWDI in the emergency department. Decrease in alcohol use and maintenance of community functioning are clinically and functionally significant outcomes. Alcohol use is a risk factor for re-injury and poor outcome, and the measure of community functioning includes probes about work, school and social activity attendance as well as ability to complete household and daily living activities. In addition, the SWDI group overwhelmingly found the intervention helpful. Education about symptoms to expect and decreasing alcohol use was particularly salient for participants. Future studies should consider survey themes and ways to enhance the intervention in order to increase the impact on additional outcomes of interest.

The purpose of this study was to measure athletes’ consistency in self-report of symptoms following concussion. Types of inconsistencies were recorded to determine if any patterns exist that would suggest self-awareness impairment versus denial of deficits. Concussed college athletes (n= 6) were tested using the Immediate Post-concussion Assessment and Cognitive Test (ImPACT) within 48 hours of sustaining a concussion. Responses to 22 symptoms on ImPACT were recorded and compared to athlete report on a survey that addressed the same 22 symptoms. ANOVA revealed a significant increase in proportional agreement between the first and last assessment trials (F (1,4)= 15.30, p= .0174). Trends observed suggest that athletes are not reliable or consistent in their report of symptoms to multiple sources. Future research is needed to develop a more reliable subjective assessment to ensure athletes are cognitively and physically stable before returning to play.

Between 1.6 and 3.8 million sports-related concussions are sustained by persons living in the United States annually. While sports-related concussion was once considered to only result in immediate neurocognitive impairment and symptoms that are transient in nature, recent research has correlated long-term neurodegenerative effects with a history of sports-related concussion. Increased awareness and current media attention have contributed to concussions becoming a primary health concern. Although much research has been performed investigating the biomechanics of concussion, little is understood about the biomechanics that cause concussion in humans. The research presented in this dissertation investigates human tolerance to head acceleration using methods that pair biomechanical data collected from human volunteers with clinical data. Head impact exposure and injury risk are quantified and presented. In contrast to the publicly available data on the safety of automobiles, consumers have no analytical mechanism to evaluate the protective performance of football helmets. With this in mind, the Summation of Tests for the Analysis of Risk (STAR) evaluation system was developed to evaluate the impact performance of footballs helmets and provide consumers with information about helmet safety. The STAR evaluation system was designed using real world data that relate impact exposure to injury risk.

This quasi-experimental study investigates neuropsychological functioning differences between 63 active duty soldiers who were placed into three groups (MTBI, PTSD, control) to provide better information for differentiating PTSD and MTBI. The ANAM and MicroCog were utilized to measure psychomotor speed, memory, and attention. Participants with PTSD performed worse on most measures of psychomotor speed and attention, and endorsed more symptoms of depression and anxiety when compared to MTBI and control participants. Further, attention appears to be the best cognitive domain for differentiating PTSD from MTBI, whereas memory variables did not differentiate these groups. Clinical and research implications of these findings are discussed.

Abstract: This thesis investigates head injuries (HIs) occurring in sports and recreation (SR) that presented to emergency departments (EDs) in Edmonton, Alberta, from April 1st, 1997 to March 31st, 2008. There were 4,950 SR HIs identified over the 11 years (5.13 HIs per 1,000 ED injury visits). Individuals less than 18 years old were 3.4 times more likely, and males were 1.25 times more likely to present with a head injury from SR (p < 0.0001). A history of one or two previous SR HIs increased the odds of subsequent HI by 2.62 and 5.94 times, respectively, while children aged 7 – 13 and 14 – 17 were more than four times more likely to sustain a HIs from SR (p < 0.001). The effects of multiple HIs occurring in children participating in SR activities needs to be addressed, due to the chronic neurobehavioral effects of HIs.

Several studies in the pediatric literature have demonstrated that increases in post-concussive symptoms (PCS) are correlated with worse outcomes or greater neurological damage following mild traumatic brain injury (mTBI). This study assessed whether it is possible to predict injury severity from PCS presentation in children. The sample included 285 children ages 8 to 15, 186 with mTBI and a comparison group of 99 with orthopedic injuries (OI). Both parent and child rated frequency and severity of PCS at baseline (within 2 weeks post-injury) and follow-up visits at 3 and 12 months post-injury. The mTBI group was divided into high and low injury severity using either the incidence of LOC or the presence of intracranial abnormalities on MRI. A series of discriminant function analyses revealed that ratings of PCS collected at baseline differentiated children with mTBI from OI while those at later time points could not. Somatic PCS accounted for most of the discriminatory power. Only parent ratings as baseline were able to discriminate between all three groups. Overall, predicted group classification was poor with a large proportion of false negatives. While it is clear that children with mTBI endorse more PCS than children with OI, accurate prediction of injury severity from symptom presentation is not yet possible.

The outcomes of mild traumatic brain injuries (MTBI) in children are largely unknown and controversial. Both parents and children frequently report somatic, cognitive, emotional and behavioral symptoms following MTBI, yet these symptoms often occur in the absence of objective evidence of brain injury such as abnormal neuroimaging findings or cognitive deficits. This prospective, longitudinal study examined whether the relationship between MTBI and postconcussive symptoms (PCS) in children over time is moderated by cognitive ability measured within 2 weeks postinjury. Participants included 186 children with MTBI and a comparison group of 99 children with orthopedic injuries (OI), from 8-15 years of age when injured. Assessments were completed within 2 weeks of injury, and again at 1, 3, and 12 months post-injury. The baseline assessment included standardized cognitive tests, as well as a retrospective rating of pre-injury PCS, by parents only. PCS were also rated by children and parents at baseline, 1, 3, and 12 months postinjury. Principal components analysis of cognitive test data with orthogonal rotation resulted in two factors: verbal cognitive ability and nonverbal cognitive ability. A general hierarchical linear modeling (HLM) analysis was used to examine parent and child rated PCS symptoms longitudinally. The analysis was a group X cognitive ability X time design. Results supported the hypothesis that the presence of postconcussive symptoms after a MTBI is moderated by cognitive ability, and confirmed that cognitive ability is a stronger moderator of PCS symptoms among children who sustain a TBI of greater severity. Children with higher cognitive ability may be protected from the effects of a more severe injury, while those with less cognitive reserve (i.e., lower cognitive ability) demonstrate greater vulnerability to the development of PCS immediately after and up to 3 months postinjury. The results also suggest that there are additional risk factors for the development of PCS, which include greater injury severity, lower cognitive ability, younger age at time of injury and lower socioeconomic background.

Over 800 athletes suffer from concussion in the United States each day, resulting in over 300,000 concussions each year. Recent data has revealed that the incidence of mild traumatic brain injury is on the rise for many different sports, placing athletes at higher risk. Damage is caused by the shearing of axons, which results in swelling and loss of limited function. Electrophysiologic techniques, specifically event-related potentials are one of the most frequently used cognitive assessments. Event-related potentials are a non-invasive method to gather a baseline of cognitive processes and to evaluate cognitive deficits. The current study investigated the sensitivity of event-related potentials in the identification of cognitive deficits following concussion in college athletes. Neuropsychological and electrophysiological measures were collected from two groups of participants allocated by injury versus non-injury. Results from the study found important differences between non-concussed and concussed athletes using electrophysiological measures and neuropsychological test measures.

Mild traumatic brain injury (MTBI) affects more than 28,000 individuals annually in Thailand; however, little information about outcome after MTBI is known. This investigation aimed to explore adaptation, determine factors associated with adaptation, and identify the predictors of adaptation among Thai adults who experienced MTBI in the previous 3-12 months. Roy’s Adaptation Model was the framework for this study. A descriptive-predictive, cross-sectional design was used. A sample of 135 adults was interviewed. Subjects were typically men, middle aged, and about half were married. All of them finished the compulsory level of education and had low income. Subjects had Glasgow Coma Scores 14 at 30 minutes after injury and 15 (full score) after 3 days. Duration of posttraumatic amnesia was six minutes while the duration of loss of consciousness was two minutes. Subjects reported low postconcussion symptoms scores, few stressful life events and few depressive symptoms. Scores of coping, social support and quality of life (QOL) were high. All subjects worked or studied before the injury and almost of them returned to normal lives at the time of interview. However, 18% did experience moderately severe disability and 1.5% suffered severe disabilities. Social support was positively correlated with QOL whereas none of the other stimuli were significantly associated with QOL and the Extended Glasgow Outcome Scale (GOSE). All stimuli, coping and depressive symptoms significantly explained 15.8% of QOL, with social support as the only significant predictor. The same set of stimuli could not successfully explain the GOSE. Although the mediator effects of coping and depressive symptoms in the original conceptual model were not supported, moderator effects with social support were found. Future studies with longitudinal, comparison, or predictive methodology with reduced but relevant variables are suggested. Developing a middle range theory is recommended to continue investigating QOL conceptually equivalent to adaptation. Measures used in this study demonstrated reliability, supporting their use in Thailand. Providing of health education or printed information about outcomes especially problems after MTBI is recommended. Further study of the small but clinically important percentage of subjects who experience ongoing disability after MTBI is needed.

1.5 millions Americans sustain a traumatic brain injury (TBI) annually; 75% are mild TBI. Mild injury victims report persistent recognition, temporal order memory and spatial learning problems. Recognition memory is necessary for discriminating between familiar and new items, as well as remembering the items' order. Spatial learning is essential for new information about one's environment encoding and retrieval. Yet, little research targets recognition memory and learning performance after mild TBI. Spontaneous object recognition and temporal order memory behavioral pattern after mild TBI, at 6, 24, 48, & 72 hrs and 7, 14, 21 and 35 days post trauma were examined using validated spontaneous object recognition and temporal order memory tests. Animals were placed in a Y shape maze for 2 min/trial; on trial 1, the animals explored two identical objects (A A), on trials 2 & 3 (1 & 15 min delay) the animals explored one familiar object (A) and one novel object (B then C), and on trial 4, (60 min delay) the animals explored recently explored object (C) and oldest object (B). The time each animal spent exploring novel and familiar objects and discrimination ratios were calculated. The simvastatin and environmental enrichment effect on recognition and temporal order memory were compared. Also, mild and severe TBI effects' on spatial learning performance were tested using a modified Morris water maze task at 20 days post trauma. Escape latency and percentage of time traveled within each quadrant was calculated. Animals with mild TBI showed significant recognition and temporal memory impairment up to 35 days post injury, in addition to familiarity preference up to 72 hours following the trauma. Simvastatin and environmental enrichment treatment led to improved cognitive function at different time points. Mild and severe TBI animals spent significantly less time in the target quadrant searching for the escape platform than the sham animals and mild injured animals needed prolonged time to improve their escape latency. We conclude that mild TBI leads to recognition and temporal order memory and spatial learning deficits. Further, simvastatin and environmental enrichment are promising therapies for memory deficits that follow mild TBI.

Traumatic brain injury (TBI) affects millions of individuals each year, and is the leading cause of death and disability for individuals under age 40. For many individuals who incur mild, moderate, or severe TBI, college attendance is an age-appropriate and feasible activity despite the presence of cognitive, communicative, behavioral, and physical impairments associated with the injury, many of which may be subtle. However, it is asserted that many individuals with TBI who attempt to meet the challenges of college entry or re-entry require a strong network of support in order to successfully manage the transition from post-injury convalescence or rehabilitation to the rigors of the academic environment. An important link in such a support network can be the provision of cognitive-linguistic therapy designed to remediate higher-level cognitive skills necessary for academic success. The present study sought to determine if academically oriented cognitive-linguistic therapy services are desired by high school and college-age students with mild, moderate, and severe TBI. Demographic data and information about provision of inpatient and outpatient speech-language services were collected from patient charts at two local facilities. Telephone interviews were then conducted to acquire additional information. Overall, results of the study indicate that there is a desire for cognitive-linguistic therapy designed to address higher-order cognitive and communication skills among local high school and college-age students who have incurred TBI. Results also show that improved identification of individuals with mild TBI and broader knowledge of potentially significant impairments associated with mild TBI are needed in order for individuals with mild TBI to receive the patient education and services they need for facilitation of successful recovery.