Background and aims: The provenance of post-concussion symptoms (PCS) and post-traumatic stress (PTSD) after mild traumatic brain injury (mTBI) is controversial. This thesis investigated factors influencing these two conditions separately, as well as the interplay between PCS and PTSD, in individuals with mTBI and a control sample without mTBI (orthopaedic injuries). Method: Consecutive adult attendees of an Emergency Department with mTBI or orthopaedic injury were prospectively recruited and completed the Rivermead Post-concussion Questionnaire (RPQ) and Trauma Screening Questionnaire (TSQ) for PTSD at two weeks (T1) and three months (T2) post-injury. The sample at T1 consisted of 34 with complicated mTBI, 76 with uncomplicated mTBI and 47 with orthopaedic injury, and 18 with complicated mTBI, 43 with uncomplicated mTBI and 33 orthopaedic controls at T2. Results: Although there were no differences in overall PCS symptomology between groups, a subset of PCS symptoms (headaches, dizziness and nausea) was found to be specific to mTBI at both time points. These symptoms are proposed to have a neurological basis, as opposed to a psychological basis. PTSD interacted with PCS, particularly in mTBI, such that PTSD was associated with greater “neurogenic” and “psychogenic” symptomology in this group, but only a moderate increase in psychogenic symptoms for controls. A model of the influence of PTSD on PCS is presented. PTSD was influenced by poor memory quality for the traumatic event and attribution of blame to others, but not by mTBI. Discussion and conclusions: Though mTBI may set the scene for at least neurogenic symptoms of PCS to occur, psychological mechanisms, particularly PTSD, have a significant role in the persistence of PCS. Our findings suggest the need for a clear story and sense of meaning for a traumatic event for good recovery from PTSD. Taken together, the results suggest that psychological interventions, particularly aimed at PTSD, may be most effective after mTBI.

L’âge, le génotype et les traumatismes crâniens (TCC) sont trois facteurs de risque majeurs du développement de la maladie d’Alzheimer (MA). Avec une accumulation d’évidences démontrant la persistance d’anomalies cérébrales suite aux plus légers des TCC, qui affichent d’ailleurs la plus haute incidence, il devient impératif de tester l’hypothèse selon laquelle même les commotions cérébrales puissent interagir avec l’âge et les gènes afin de précipiter la neurodégénération. Trente ex-athlètes de haut niveau (âge M = 60 ans), dont la moitié a subi des commotions cérébrales il y a plus de 30 ans, ont été évalués en neuropsychologie, en neuroimagerie multimodale ainsi qu’en génétique. De nombreuses mesures neuroanatomiques, dont l’expansion du volume des ventricules latéraux, se trouvent à corréler avec divers déficits cognitifs (mémoire différée et de reconnaissance) détectés chez les participants commotionnés. D’un intérêt particulier, certains de ces résultats sont modulés par le polymorphisme nucléotidique simple du gène Apolipoprotéine E. Ces résultats appuient l’hypothèse selon laquelle la commotion cérébrale chez de jeunes athlètes serait un facteur de risque de neurodégénération dans le vieillissement normal. / Age, genotype and traumatic brain injury (TBI) are three of the most important risk factors of Alzheimer’s Disease. With a growing body of evidence showing the persistent deleterious effects of the mildest form of TBI, it becomes imperative to test the hypothesis that sports concussion could interact with aging to precipitate neurodegeneration. Thirty former high-level athletes (mean age = 60 yrs), half of them having sustained sports concussion during their young adulthood, underwent neuropsychological, neuroanatomical and APOE genotype examination. Data analysis revealed numerous neurobiological anomalies, such as ventricular enlargement, correlating with cognitive deficits (delayed and recognition memory) in concussed participants. Of particular interest, some neuroanatomical measures were found to be modulated by APOE single-nucleotide polymorphisms. These findings support the idea that sports concussions sustained in early adulthood are a risk factor of neurodegeneration in late adulthood.

Background: Concussion in adolescent american football occurs frequently and can give serious damage, especially to the younger brain. SAFF has guidelines for management and rehabilitation. The guidelines to be followed are called “Hjärntrappan”.  Purpose: To investigate a group of coaches experiences of management and rehabilitation after concussion, in adolescent american football in Sweden. Design and method: Qualitative exploratory design, based on semi structured interviews. Five coaches were included in the study. The data was analyzed using content analysis according to Graneheim and Lundman. Results: The coaches experienced limited skills in management and rehabilitation in concussions. There was a major responsibility for the medical staff, were competence varied widely and there was no requirement regarding education about concussion. There was limited knowledge of the work of the football association and its guidelines were not fully implemented. The coach education contained a limited part regarding concussions. A mandatory part about concussion for both coaches and medical staff was suggested to improve current management and rehabilitation. Conclusion: Treatment and rehabilitation regarding concussion need to be expanded in the coaches education courses. A knowledge certificate should be introduced for the medical staff for management and rehabilitation of junior players as well. Future research could study how rehabilitation is followed after concussions, or mapping risks in the management and rehabilitation of brain shocks in junior teams. / Bakgrund: Hjärnskakning inom amerikansk fotboll, i ungdomsleden, är ett känt problem och sker frekvent. Svenska Amerikansk Fotbollförbundet har riktlinjer för hantering och rehabilitering vid hjärnskakning, som kallas Hjärntrappan. Syfte: Undersöka vilka upplevelser och erfarenheter juniortränare, till pojk- och flicklag mellan åldrarna 14 - 19 år inom amerikansk fotboll i Sverige, har av hantering och rehabilitering vid hjärnskakningar. Metod: Kvalitativ explorativ design, som baserades på semistrukturerade intervjuer. Fem tränare ingick i studien. Datan analyserades med hjälp av innehållsanalys enligt Graneheim och Lundman. Resultat: Tränarna upplevde en begränsad kompetens gällande hantering och rehabilitering vid hjärnskakning. Ett stort ansvar låg på den medicinska personalen där kompetensen varierade mycket och det saknades krav på utbildning angående hjärnskakningar. Det saknades kunskap om förbundets arbete och dess riktlinjer var inte fullt implementerade. Tränarutbildningen innehöll en begränsad del gällande hjärnskakningar. En obligatorisk del om hjärnskakningar för tränare och medicinsk personal ansågs kunna förbättra nuvarande hantering och rehabilitering. Konklusion: Behandling och rehabilitering rörande hjärnskakningar behöver utökas i tränarutbildningen. Utbildningskrav bör införas för medicinsk personal för hantering och rehabilitering även på juniornivå. Framtida forskning skulle kunna studera hur rehabilitering följs efter hjärnskakningar, eller kartlägga risker vid hantering och rehabilitering av hjärnskakningar inom juniorlag.

While the media frenzy focuses on the physical risks of concussion, there is also growing concern about the academic repercussions for students who sustain the injury. We do not currently have a uniform evidence-based approach for optimally returning a student back to learning activities after a concussion. We also do not understand how the diverse consequences of a concussion may affect academic self-efficacy and performance. The purpose of this study is to explore the effects a concussion may have on college students who are navigating the return to learn (RTL) process. This research aims to inform whether there are measureable deficits in academic self-efficacy using the previously validated and abridged survey measure, the Self-Efficacy of Learning Form (SELF-A). Time of injury during the academic semester is also considered, as we hypothesize greater healing should negate the concussion's effects on the measure of self-efficacy. In addition, the research explores students' experiences with RTL using a semi-structured interview approach. The results suggest that college students who suffer a concussion during an academic semester have lower measures of academic self-efficacy compared to a control group of their peers. In addition, results show that students are returning to learn while still suffering from the effects of their concussion. This study found no significant correlation between the healing time of a concussion and the scores on the SELF-A. The interviews served to underscore the diverse myriad physical and psychological challenges a student faces, as well as the precarious variance in RTL strategies. This study highlights the challenges that students face while they RTL following a concussion, and begs the investigation of whether better RTL practices can help mitigate the negative effects. It underscores the necessity for further research, evidence-based medical care, instructor accommodations, and institutional policies to support students' safe RTL and ability to perform at their maximal academic potential.

A dissertation submitted to the Faculty of Arts, University of the Witwatersrand, in partial fulfilment of the requirements of the degree of Master of Arts / The study reviews the literature concerning mild head injury and post concussion symptoms. It then investigates the applicability of international findings to South African patients. Three groups of subjects are compared: mildly injured, noninjured, and instructed malingerers. The study establishes base rates of postconcussive symptoms in the noninjured subjects, scores on tests of cognitive ability among the noninjured subjects, expectations regarding postconcussive sequelae among the noninjured subjects, the perceptions of injured subjects of their preand postmorbid status, and relationships between subjectively experienced symptoms and cognitive deficits am.ong injured subjects. Injured subgroups are examined to investigate pre-, peri-, and post-injury factors associated with development of postconcussive complaints. No differences in cognitive performance were found between the injured and noninjured groups. Time since injury did not affect cognitive performance, apart from on a copy task. It was found that injured subjects reported lower pre-injury levels of incidence of symptoms than those reported by noninjured subjects. No differences were found between post-injury reporting of postconcussive complaints and those symptoms reported by noninjured controls. Some postconcussive symptoms were nevertheless found to correlate with certain measures of cognitive performance. Instructed malingerers responded differently noninjured injured and not injured subjects, reporting fewer pre-injury complaints and mere post-injury complaints. They also performed more poorly on several cognitive measures. Test scores that effectively identified malingerers were then re-examined, and cut-off rates suggested for differentiating malingerers from genuinely injured subjects. / Andrew Chakane 2018

Mild traumatic brain injuries (MTBI) are the leading type of head injuries with appreciable risque of sequelae leading to functional and psychological deficits. Although mild traumatic brain injuries are frequently underdiagnosed by conventional imaging modalities, rapidly evolving techniques such as diffusion tensor imaging (DTI) reveal subtle changes in white matter integrity as a result of head trauma and play an important role in refining diagnosis, therapeutic interventions and management of MTBI. In this dissertation we use diffusion tensor imaging to detect the microstructural changes induced by axonal injuries and to monitor their evolution during the recovery process. DTI data were previously acquired from 11 subjects, football players of age 19-23 years (median age 20 years). Three players had suffered a mild traumatic brain injury during the season and underwent scanning within 24 hours after the injury with follow-ups after one and two weeks. A set of diffusion indices, such as fractional anisotropy, axial, radial and mean diffusivity were derived from the diffusion tensor. Changes in diffusion indices in concussed subjects were analyzed based on two different approaches: whole brain analysis, using tract-based spatial statistics (TBSS) and region of interest analysis (ROI). In both approaches we use a voxelwise analysis to examine group differences in diffusion indices between five controls and three concussed subjects for all DTI scans. Additional statistical analysis was performed between control groups consisting of five and three non-injured players. Both analyses demonstrated that the MTBI group reveals increase in fractional anisotropy and decreases in transversal and mean diffusivity in cortical and subcortical areas within 24 hours after the injury. / No changes were detected in TBSS analysis for the follow-up data sets. Furthermore, our ROI approach revealed multiples regions with significantly different voxels, non-uniformly distributed throughout the brain, for all diffusion indices in all three scans. Three of the diffusion indices fractional anisotropy, mean and transversal diffusivity showed higher vulnerability to head trauma in subcortical and cortical areas than in regions in the lower brain. Recovery of white matter pathways occured at different locations in the brain at one and two weeks after head trauma. Strong recovery was observed in mean and transversal diffusivity in subcortical areas that correspond to the corticospinal tract. No recovery was found for fractional anisotropy and axial diffusivity in the same region. Also, decreases in fractional anisotropy and increases in transversal and axial diffusivity were observed in the spleninum of the corpus callosum. As voxelwise analysis performed on DTI data revealed white matter regions, which exhibit changes in diffusion parameters in the concussed group for all three scans, we conclude that diffusion tensor imaging is a powerful technique for early detection of axonal injuries and may serve as an important tool for monitoring microstructural changes during the recovery process. / by Angelica Hotiu. / Thesis (Ph.D.)--Florida Atlantic University, 2010. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2010. Mode of access: World Wide Web.

Football safety has increased over time, in part due to improvements in equipment and body mechanics, but there are still inherent risks involved, including exposure to repetitive head impacts (RHI). Significant head impacts can result in a constellation of symptoms including nausea, vomiting, headache, dizziness, and amnesia, which typically assist in the diagnosis of concussion. However, it has been shown that subconcussive impacts may result in microstructural changes and physiological alterations in the brain. This is particularly concerning because athletes may be undergoing changes in the brain in the absence of outwardly visible symptoms. Poorer neurologic outcomes later in life have been associated with cumulative exposure rather than number of diagnosed concussions. Accelerometers installed in helmets have shown that college football players may receive up to 1,850 head impacts throughout the course of one season. The concussion rate is obviously much lower, indicating there are a high number of head impacts per diagnosed concussion. Axons are especially susceptible to damage from RHI because of their extension throughout the nervous system. The subtle changes thought to result from RHI are not easy to measure, but several modalities have been proposed. These include diffusion tensor imaging (DTI), plasma tau protein, and King-Devick testing. The proposed study will look to quantify cumulative head impact exposure in college football players prior to the start of a season and see if this has any impact on the variables. They will then participate in one season of football wearing helmet accelerometers to measure the number of head impacts sustained. Changes in the variables will be compared to non-contact sport college athletes. Data will be analyzed to determine if number of head impacts correlates with changes in variables and if prior head impact exposure has any effect on these changes. Data obtained from this study will have significant implications in the field of head injury. It may strengthen the use of several markers of brain injury that could be utilized in the future. Additionally, the effects of cumulative head impact exposure and one season of head impacts will be thoroughly examined. This information can be provided to trainers, coaches, and athletes to further improve football safety.

BACKGROUND: Although concussion and sport-related traumatic brain injury is being acknowledged as a major public issue, especially in professional football players, current study is mostly limited to retrospective studies and post-mortem autopsies. The purpose of this study is to identify a potential association between concussion and neurodegenerative disease in athletes, and propose a prospective approach of studying concussion and its effect. METHODS: A total of 26 studies related to concussion in athletes and published after January 2000 were collected from PubMed and Google Scholar. More recent papers with higher citation counts were given the priority. RESULTS: Retired professional football players showed five times greater risk for mild cognitive impairment, three times greater risk for memory loss, and four times greater risk for amyotrophic lateral sclerosis and Alzheimer disease. Autopsy results from football players also revealed findings consistent with chronic traumatic encephalopathy. Population with the Apolipoprotein E (APOE) promoter G-219T TT (Thymine-Thymine) genotype showed increased susceptibility for concussion. CONCLUSION: This study revealed that a history of concussion has statistically significant associations with high incidence of neurodegenerative diseases in professional athletes. In addition, the results suggest the 2-(1-{6-[(2-[F-18]fluoroethyl)(methyl)amino]-2-naphthyl}ethylidene)malononitril(FDDNP)-positron emission tomography tau binding patterns and the APOE promoter G-219T TT genotype provide a new approach to study and monitor the progression of neurodegenerative conditions in athletes.

Objective: Following a sport related concussion (SRC) visible symptoms generally dissipate in 7-10 days post-injury. However, little is known about the cumulative effects of SRCs both in terms of structural damage to the white matter of the brain and neurocognitive performance. To address this issue, the relationship between the number of SRCs (frequency), axonal white matter (WM) damage and neurocognitive performance was examined. There were three predictions. First, increases in SRC frequency will be associated with decreases in performance on neurocognitive tests. Second, the frequency of SRC will be associated with axonal injury measured three WM tracts: the corpus callosum, the fronto-occipital fasciculus and the inferior longitudinal fasciculus. Third, less accurate and slower performance on a response inhibition task (STOP-IT) will be associated with greater axonal injury. Methods: A cross-sectional correlational design was utilised. Participants were rugby players with a history of SRC, rugby players with no history of SRC and control athletes (N=40) who completed a neurocognitive test battery and had a DTI brain scan. The neurocognitive battery consisted of the following standardised tests: Speed and Capacity of Language Processing Test, CogState Electronic Battery, Stroop Colour and Word Test, Controlled Oral Word Association Test, the Trail Making Test and the experimental test STOP-IT Electronic Test. White matter axonal injury was measured by DTI using fractional anisotropy (FA) and mean diffusivity (MD) metrics. The DTI data was processed using FSL to extract FA and MD DTI metrics in three a-priori regions of interest. Results: Spearman’s correlation analyses did not find significant associations between SRC frequency and neurocognitive performance on the FAS (rs=0.053, 95% CI [-0.27, 0.36]), TMT-A (rs=0.058, 95% CI [-0.26, 0.37]), TMT-B (rs= -0.046, 95% CI [-0.27, 0.36]) and the Stroop Interference (rs= -0.25, 95% CI [-0.07, 0.52]). Similarly, no significant Spearman’s correlations were found between SRC frequency and the computerised neurocognitive tests STOP-IT-SSRT (rs= -0.04, 95% CI [-0.28, 0.35])), STOP-IT–Accuracy (rs= -0.05, 95% CI [-0.27, 0.36]), CogState Detection subtest (rs= -0.15, 95% CI [-0.17, 0.44]), CogState Identification subtest (rs= -0.065, 95% CI [-0.26, 0.37]), CogState One card learning subtest (rs= 0.24, 95% CI [-0.08, 0.52]) or the CogState One back task subtest (rs= 0.06, 95% CI [-0.26, 0.37]). In terms of the DTI data there were no significant associations between SRC frequency and axonal injury measured by FA values in the CC (rs= 0.005, 95% CI [-0.31, 0.32]), ILF (rs= 0.028, 95% CI [-0.29, 0.34]) or FOF (rs= -0.022, 95% CI [-0.30, 0.33]). The same was pattern was found for MD values in the CC (rs= 0.081, 95% CI [-0.24, 0.39]), ILF (rs= -0.16, 95% CI [-0.16, 0.45]) or FOF (rs= -0.15, 95% CI [-0.17, 0.44]) Finally, there were no significant Spearman’s correlations between axonal injury FA values and the STOP-IT SSRT in any of the ROIs: CC (rs= 0.005, 95% CI [-0.31, 0.32]), ILF (rs= 0.028, 95% CI [-0.29, 0.34]) or FOF (rs= -0.022, 95% CI [-0.30, 0.33]). Equally, there were no significant correlations between MD values STOP-IT SSRT in the CC (rs= -0.028, 95% CI [-0.29, 0.34]), ILF (rs= -0.16, 95% CI [-0.16, 0.45]) or FOF (rs= -0.15, 95% CI [-0.17, 0.44]). Likewise, there were no significant Spearman’s correlations between accuracy on the STOP-IT and FA values and in any of the ROIs: CC (rs= 0.19, 95% CI [-0.13, 0.48]), ILF (rs= -0.045, 95% CI [-0.27, 0.35]) and FOF (rs= -0.032, 95% CI [-0.29, 0.34]), or MD values in the CC (rs= -0.11, 95% CI [-0.21, 0.41]), ILF (rs= 0.017, 95% CI [-0.30, 0.33]) or FOF (rs= 0.082, 95% CI [-0.24, 0.39]). This study did not find support for the hypothesis that cumulative SRCs are associated with poorer performance on neurocognitive tests or with axonal injury as measured by FA and MD DTI metrics. Conclusion: The null findings suggest that there are no cumulative effects of SRCs. The current findings are inconsistent with previous cross-sectional research that indicates that there are long-term changes to diffusivity measures present after single SRCs as well as cumulative effects in contact sport athletes. Likewise they are at odds with evidence suggesting that after three SRCs neurocognitive performance can be affected. The study needs to be extended to include a larger sample to ensure the results are not due to low statistical power.

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