In recent years, concussions and the effect this injury has on the human brain has been an area of concern for many people involved in sports. And perhaps rightfully so, as between 1.6 and 3.8 million people each year sustain a sports-related concussion in the United States. In the past, concussions have been solely linked to transient symptoms; however, recent research suggests that the injury can also result in long term neurocognitive impairment. Thus, there is much needed research to better understand concussions and assist in the development of safety techniques that will reduce the occurrence of such injury. Participants of youth football are at an extreme disadvantage as very little research has been conducted on this population. The research presented in this dissertation attempts to characterize head impact exposure of a variable subgroup of youth football, middle school football, in order to better understand concussions in youth. In addition to better understanding concussions, it is imperative that correct laboratory techniques are developed to accurately simulate realistic head impacts. This dissertation also presents results from the evaluation of current testing procedures that can be used for laboratory testing of sports equipment and simulation of actual field impacts. Evaluation of these techniques will further validate their ability to act as methods for both safety and research in sports injury. Thus, the overall goal of this dissertation is to provide results that will both further understanding of concussions and evaluate the realistic performance of laboratory techniques, influencing informed decisions to reduce the risk of concussions. / Ph. D.

Yes / This article discusses the current evidence for the short- and long-term effects of concussion in sport and how occurrences of concussion should be managed. The article also considers the potential role of medical imaging in terms of assessing both acute and chronic head injuries. Greater awareness of when medical imaging could be used will aid the practitioner's understanding of its potential contribution while still maintaining the fundamental importance of clinical judgement.

The research presented herein is an analysis of acceleration measurements of the head during helmet-helmet impacts, where a player's helmet impacts another player's helmet, and with a youth population in football. This research is aimed at advancing current understanding of impact biomechanics for two specialized groups. The first study is an observational analysis focusing on helmet-helmet impacts, and the difference in effective mass and head acceleration measurements between the striking player and the struck player. The study involved working with football players outfitted with a sensor integrated into their helmets containing a 6 accelerometer array, capable of measuring linear accelerations and estimating angular accelerations. To evaluate helmet-helmet impacts, video analysis of past NCAA football competitions between Virginia Tech and University of North Carolina (UNC) were utilized to identify these impacts between instrumented players. A force balance was then carried out for the observed impacts and their respective acceleration measurements to compute the effective mass of the players. It was determined that the total mass recruited by the striking player was 28% to 77% more than that of the struck player. The second study focused on documenting the head impact biomechanics of a youth population. To accomplish this objective, unique accelerometer arrays, capable of measuring linear and angular accelerations, were integrated into existing youth football helmets for 7 players on a local team. Acceleration data were collected for every practice and game during the 2011 season to amass a total of 748 impacts. No instrumented player sustained a concussion during the 2011 season. Results of the study indicated impacts of greater magnitudes were more likely to occur in practices, and can be minimized by augmenting practice activities. / Master of Science

One of the consequences of traumatic brain injury is the postconcussion syndrome. The symptoms in this syndrome include headache, dizziness, poor memory, poor concentration, easy fatigue, drowsiness, irritability, sensitivity to light, sensitivity to noise, low alcohol tolerance, visual problems, auditory problems, nausea, vomiting, anxiety, and depression. Several factor analytic studies have shown that these symptoms load onto cognitive and noncognitive factors (Bohnen, Twijnstra, & Jolles, 1992). The aim of this study was to determine whether patients who report different symptoms also evidence differences in cognitive deficits, as indexed by reaction time. For this purpose 106 subjects (mean age 25.92 years; SD=6.05) of both sexes were tested on 8 reaction time tasks adapted from Shum, McFarland, Bain, and Humphreys (1990). There were 54 traumatic brain injury patients (mean age 26.40 years; SD=6.23) drawn from three Pretoria hospitals. They were heterogeneous with respect to diagnosis and severity of injury. For the controls (N=52), the mean age was 25.43 years (SD=5.88). The eight reaction time tasks constituted 4 task variables, each with 21evels. From these tasks, 36 reaction time indexes were derived. The indexes were classified into 4 groups, viz., reaction time (RT), movement time (MT), total reaction time (TT), and subtraction scores (SB, the difference between the 2 levels for each task variable). RT reflects the decision component and MT reflects the response execution component of reaction time. Partial correlation coefficients for all symptoms (p0,01) showed that some symptoms were most frequently associated with RT whilst others were most frequently associated with MT. On factor analysis with varimax rotation, symptoms loaded predominantly with SB scores. Symptoms also loaded with different task variablseuiggesting that they correlated with deficits on different stages of information processing. Taking into account possible methodological constraints that were discussed, these results confirm that different symptoms within the postconcussion syndrome correlate with different cognitive deficits. The correlations between symptoms and indices of reaction time are moderated by the characteristics of the symptoms (frequency & intensity), and the duration since injury. These findings have significance for understanding the aetiology of the postconcussion symptoms and for planning treatment. / Psychology / Ph. D. (Psychology)

Korupcija yra labai sena ir aptinkama įvairiose visuomeninio gyvenimo srityse. Tai ypač latentiškas ir sukeliantis daug problemų jį kvalifikuojant nusikaltimas. Pagrindinės problemos susijusios su subjektu, kyšiu ir jo dydžiu, korupcinių veikų atskyrimu nuo kitų nusikaltimų. Itin aktuali problema – kyšio ir dovanos santykis. Šis nusikaltimas padaromas tiek privačiame, tiek viešajame sektoriuje. Korupcinio pobūdžio nusikalstamos veikos sukelia didelę žalą valstybės, jos institucijų, gyventojų interesams. Štai kodėl visuomenė privalo suprasti, kad korupcija nėra “nusikaltimas be aukų”. Šiuo metu korupcija laikoma pasauline problema. Kadangi esame Europos Sąjungos nariai ir mums privaloma jos aqius communautaire, darbe nagrinėjami tiek nacionaliniai baudžiamieji įstatymai, tiek tarptautiniai teisės aktai, liečiantys korupciją. Prieinama išvados, jog nėra įtvirtintos bendros korupcijos sampratos, taip pat skirtingai traktuojama pareigūno sąvoka valstybėse narėse. Praktikoje, bandant patraukti baudžiamojon atsakomybėn už kyšininkavimą, tai gali sukelti problemų. Todėl siūloma įtvirtinti bendrą visiems korupcijos apibrėžimą Europos Sąjungos teisės aktuose. Istorija parodė, kad griežtos bausmės neduoda trokštamų rezultatų, tad rekomenduojama šviesti visuomenę korupcijos prevencijos klausimais. Būtų naudinga, jei Lietuvos Aukščiausiasis Teismas pateiktų korupcinio pobūdžio bylų baudžiamąjį teisinį vertinimą. / -. / La corruption est ancienne crime, qu’ on la trouve dans toutes les domaines de la vie publique. Mais la corruption est crime très latente et donne beaucoup de problèmes quand, on veut la qualifier. Les principaux des eux sont les problèmes du subjet, de la grandeur du pot-de-vin, de la delimitation des corruptions et d’ autres crimes. Très ancienne problème est la rélation entre le cadeau et le pot-de-vin. On peut faire ce crime dans la vie privée et dans la vie publique. La corruption cause beaucoup de dommages aux interêts de pays, des habitant, des institutions, c’ est pourquoi la societe doit comprendre, que la corruption n’ est pas „la crime sans victimes“. Maintenant cette crime est le problème de tout le monde. On analyse les textes juridiques nationaux ir internationaux, qui déterminent la resposabilité pénale pour la concussion dans ce travail. Nous devons mettre en pratique sa aqius communautaire, parce que nous sommes les membres d’ Union Européen. On tire la conséquence, qu’il n’y a pas de notion générale de la corruption; qu’on comprend qu’est que c’est le fonctionnaire aux droit national différemment. Quand on met en pratique la resposabilité pénale pour la concussion, les problèmes peuvent se poser. Nous proposons affermir la notion générale de la corruption aux acts juriques européens. L’ histoire montre, que les peines sévères ne donnent pas des resultats sensibles. On dit, qu’ il faut instructer la societe, prendre des mésures de la prevention, avoir... [to full text]

Mild Traumatic Brain injury (mTBI) is one of the most common forms of acquired neurological damage. However, the term 'mild' TBI is misleading because the physical, cognitive and emotional impairments that can follow from mTBI can be significant. In order to provide objective, prognostic measures for diagnosing the severity of mTBI and identifying individuals who may be at risk for poor outcomes a battery of neuropsychological measures for detecting cognitive impairment was evaluated. The Rapid Screen of Concussion (RSC) is a collection of tests assessing verbal recall, orientation, processing speed and speed of language comprehension. Previous studies have demonstrated that the RSC has acceptable reliability, validity and sensitivity to cognitive impairment that arises during the acute stages of injury. However, no studies have investigated the predictive validity of this instrument. Moreover it is unclear what additional patient or post injury variables could assist in identifying those individuals who may be at risk of poor neuropsychological outcomes following mTBI. These were among the main issues that were addressed across the five empirical studies in this thesis. A pragmatic, prospective, longitudinal and cross-sectional study of the sequelae of mTBI in patients presenting to the Department of Emergency Medicine of the Royal Brisbane and Women's hospital was the basis of this project. The first empirical chapter (chapter 2), examined the psychometric properties of two measures of verbal learning and memory and investigated their potential for discriminating between mTBI and orthopaedic controls. The performance of 93 patients with mTBI and 68 participants with orthopaedic injuries was analysed to identify the number of individuals who performed at ceiling on the Hopkins Verbal Learning test (HVLT-R) versus a 5-word test of immediate and delayed recall. While both of these verbal recall measures were effective in separating the mTBI and orthopaedic groups, overall, the HVLT-R was shown to be a more suitable measure for screening for deficits in verbal learning and memory after mTBI. Given the superiority of the HVLT-R as a measure of verbal learning and memory, chapter 3 aimed to examine whether inclusion of this test could improve the sensitivity of the RSC in mTBI compared to orthopaedic and uninjured control samples. Results were generally within the direction predicted. Significant differences were found between groups on the majority of cognitive indices assessed. Both the orthopaedic and mTBI group performed more poorly than the uninjured group on all measures except the Hopkins delayed recognition. Additional performance decrements shown by the mTBI group compared to the orthopaedic group illustrate that factors beyond the general effects of trauma influence performance and may be related to cognitive impairment specific to sustaining mTBI. Overall it was concluded that the revised RSC is a sensitive instrument deserving investigation in assessing the more long term cognitive effects following mTBI. Chapter 4 applied this sensitive battery for investigation of group and individual recovery of neuropsychological test performance and post-concussive symptom reporting up to 3-months after mTBI. A sample of 30 mTBI participants and 30 uninjured controls were serially assessed on cognitive measures and symptom report scales immediately after injury and after 1-week, 1-month and 3-months. Symptom reporting on the Rivermead post-concussive inventory separated the mTBI and control groups after 1-week but diagnostic accuracy was no greater than chance at 1 and 3-months. In contrast the mTBI group performed more poorly than controls on measures on neuropsychological measures acutely, at 1-week and 1-month, with group differences still evident after 3-months. Nonethless, a trend of progressive recovery over time was seen in the mTBI group. In chapter 5, criteria utilising the concepts of reliable and statistically significant change were applied to the data. Overall, 73% of mTBI patients were impaired on one or more tests acutely. Significant recovery was demonstrated by 20% of mTBI participants by 3-months; however recovery remained incomplete for half of the mTBI participants by 3-months. These results highlighted the importance of an individual approach to the assessment of mTBI and support the notion that a proportion of mTBI cases may have protracted difficulties. Chapter 6 extended these findings by showing that the RSC has prognostic ability. It was found that acute neuropsychological performance on the RSC was a significant predictor of performance on an extended battery at 3-months. The final chapter provides a general discussion and synthesis of the findings. In summary, the present dissertation demonstrated that inclusion of a sensitive measure of verbal recall led to improved diagnostic validity of the RSC. Neuropsychological measures rather than symptom reporting were sensitive in detecting cognitive impairment at 3-months. Analysis of individuals showed that up to 50% of the group had failed to – demonstrate reliable recovery – that is, make improvements over and above practice effects after 3-months. Finally, acute neuropsychological performance was predictive of long term performance. Overall, the present thesis has identified a short battery of tests that is suitable for assessment of mTBI within 24 hours and may assist in identifying individuals at risk of poor cognitive outcomes after mTBI.

Mild Traumatic Brain injury (mTBI) is one of the most common forms of acquired neurological damage. However, the term 'mild' TBI is misleading because the physical, cognitive and emotional impairments that can follow from mTBI can be significant. In order to provide objective, prognostic measures for diagnosing the severity of mTBI and identifying individuals who may be at risk for poor outcomes a battery of neuropsychological measures for detecting cognitive impairment was evaluated. The Rapid Screen of Concussion (RSC) is a collection of tests assessing verbal recall, orientation, processing speed and speed of language comprehension. Previous studies have demonstrated that the RSC has acceptable reliability, validity and sensitivity to cognitive impairment that arises during the acute stages of injury. However, no studies have investigated the predictive validity of this instrument. Moreover it is unclear what additional patient or post injury variables could assist in identifying those individuals who may be at risk of poor neuropsychological outcomes following mTBI. These were among the main issues that were addressed across the five empirical studies in this thesis. A pragmatic, prospective, longitudinal and cross-sectional study of the sequelae of mTBI in patients presenting to the Department of Emergency Medicine of the Royal Brisbane and Women's hospital was the basis of this project. The first empirical chapter (chapter 2), examined the psychometric properties of two measures of verbal learning and memory and investigated their potential for discriminating between mTBI and orthopaedic controls. The performance of 93 patients with mTBI and 68 participants with orthopaedic injuries was analysed to identify the number of individuals who performed at ceiling on the Hopkins Verbal Learning test (HVLT-R) versus a 5-word test of immediate and delayed recall. While both of these verbal recall measures were effective in separating the mTBI and orthopaedic groups, overall, the HVLT-R was shown to be a more suitable measure for screening for deficits in verbal learning and memory after mTBI. Given the superiority of the HVLT-R as a measure of verbal learning and memory, chapter 3 aimed to examine whether inclusion of this test could improve the sensitivity of the RSC in mTBI compared to orthopaedic and uninjured control samples. Results were generally within the direction predicted. Significant differences were found between groups on the majority of cognitive indices assessed. Both the orthopaedic and mTBI group performed more poorly than the uninjured group on all measures except the Hopkins delayed recognition. Additional performance decrements shown by the mTBI group compared to the orthopaedic group illustrate that factors beyond the general effects of trauma influence performance and may be related to cognitive impairment specific to sustaining mTBI. Overall it was concluded that the revised RSC is a sensitive instrument deserving investigation in assessing the more long term cognitive effects following mTBI. Chapter 4 applied this sensitive battery for investigation of group and individual recovery of neuropsychological test performance and post-concussive symptom reporting up to 3-months after mTBI. A sample of 30 mTBI participants and 30 uninjured controls were serially assessed on cognitive measures and symptom report scales immediately after injury and after 1-week, 1-month and 3-months. Symptom reporting on the Rivermead post-concussive inventory separated the mTBI and control groups after 1-week but diagnostic accuracy was no greater than chance at 1 and 3-months. In contrast the mTBI group performed more poorly than controls on measures on neuropsychological measures acutely, at 1-week and 1-month, with group differences still evident after 3-months. Nonethless, a trend of progressive recovery over time was seen in the mTBI group. In chapter 5, criteria utilising the concepts of reliable and statistically significant change were applied to the data. Overall, 73% of mTBI patients were impaired on one or more tests acutely. Significant recovery was demonstrated by 20% of mTBI participants by 3-months; however recovery remained incomplete for half of the mTBI participants by 3-months. These results highlighted the importance of an individual approach to the assessment of mTBI and support the notion that a proportion of mTBI cases may have protracted difficulties. Chapter 6 extended these findings by showing that the RSC has prognostic ability. It was found that acute neuropsychological performance on the RSC was a significant predictor of performance on an extended battery at 3-months. The final chapter provides a general discussion and synthesis of the findings. In summary, the present dissertation demonstrated that inclusion of a sensitive measure of verbal recall led to improved diagnostic validity of the RSC. Neuropsychological measures rather than symptom reporting were sensitive in detecting cognitive impairment at 3-months. Analysis of individuals showed that up to 50% of the group had failed to – demonstrate reliable recovery – that is, make improvements over and above practice effects after 3-months. Finally, acute neuropsychological performance was predictive of long term performance. Overall, the present thesis has identified a short battery of tests that is suitable for assessment of mTBI within 24 hours and may assist in identifying individuals at risk of poor cognitive outcomes after mTBI.

Mild Traumatic Brain injury (mTBI) is one of the most common forms of acquired neurological damage. However, the term 'mild' TBI is misleading because the physical, cognitive and emotional impairments that can follow from mTBI can be significant. In order to provide objective, prognostic measures for diagnosing the severity of mTBI and identifying individuals who may be at risk for poor outcomes a battery of neuropsychological measures for detecting cognitive impairment was evaluated. The Rapid Screen of Concussion (RSC) is a collection of tests assessing verbal recall, orientation, processing speed and speed of language comprehension. Previous studies have demonstrated that the RSC has acceptable reliability, validity and sensitivity to cognitive impairment that arises during the acute stages of injury. However, no studies have investigated the predictive validity of this instrument. Moreover it is unclear what additional patient or post injury variables could assist in identifying those individuals who may be at risk of poor neuropsychological outcomes following mTBI. These were among the main issues that were addressed across the five empirical studies in this thesis. A pragmatic, prospective, longitudinal and cross-sectional study of the sequelae of mTBI in patients presenting to the Department of Emergency Medicine of the Royal Brisbane and Women's hospital was the basis of this project. The first empirical chapter (chapter 2), examined the psychometric properties of two measures of verbal learning and memory and investigated their potential for discriminating between mTBI and orthopaedic controls. The performance of 93 patients with mTBI and 68 participants with orthopaedic injuries was analysed to identify the number of individuals who performed at ceiling on the Hopkins Verbal Learning test (HVLT-R) versus a 5-word test of immediate and delayed recall. While both of these verbal recall measures were effective in separating the mTBI and orthopaedic groups, overall, the HVLT-R was shown to be a more suitable measure for screening for deficits in verbal learning and memory after mTBI. Given the superiority of the HVLT-R as a measure of verbal learning and memory, chapter 3 aimed to examine whether inclusion of this test could improve the sensitivity of the RSC in mTBI compared to orthopaedic and uninjured control samples. Results were generally within the direction predicted. Significant differences were found between groups on the majority of cognitive indices assessed. Both the orthopaedic and mTBI group performed more poorly than the uninjured group on all measures except the Hopkins delayed recognition. Additional performance decrements shown by the mTBI group compared to the orthopaedic group illustrate that factors beyond the general effects of trauma influence performance and may be related to cognitive impairment specific to sustaining mTBI. Overall it was concluded that the revised RSC is a sensitive instrument deserving investigation in assessing the more long term cognitive effects following mTBI. Chapter 4 applied this sensitive battery for investigation of group and individual recovery of neuropsychological test performance and post-concussive symptom reporting up to 3-months after mTBI. A sample of 30 mTBI participants and 30 uninjured controls were serially assessed on cognitive measures and symptom report scales immediately after injury and after 1-week, 1-month and 3-months. Symptom reporting on the Rivermead post-concussive inventory separated the mTBI and control groups after 1-week but diagnostic accuracy was no greater than chance at 1 and 3-months. In contrast the mTBI group performed more poorly than controls on measures on neuropsychological measures acutely, at 1-week and 1-month, with group differences still evident after 3-months. Nonethless, a trend of progressive recovery over time was seen in the mTBI group. In chapter 5, criteria utilising the concepts of reliable and statistically significant change were applied to the data. Overall, 73% of mTBI patients were impaired on one or more tests acutely. Significant recovery was demonstrated by 20% of mTBI participants by 3-months; however recovery remained incomplete for half of the mTBI participants by 3-months. These results highlighted the importance of an individual approach to the assessment of mTBI and support the notion that a proportion of mTBI cases may have protracted difficulties. Chapter 6 extended these findings by showing that the RSC has prognostic ability. It was found that acute neuropsychological performance on the RSC was a significant predictor of performance on an extended battery at 3-months. The final chapter provides a general discussion and synthesis of the findings. In summary, the present dissertation demonstrated that inclusion of a sensitive measure of verbal recall led to improved diagnostic validity of the RSC. Neuropsychological measures rather than symptom reporting were sensitive in detecting cognitive impairment at 3-months. Analysis of individuals showed that up to 50% of the group had failed to – demonstrate reliable recovery – that is, make improvements over and above practice effects after 3-months. Finally, acute neuropsychological performance was predictive of long term performance. Overall, the present thesis has identified a short battery of tests that is suitable for assessment of mTBI within 24 hours and may assist in identifying individuals at risk of poor cognitive outcomes after mTBI.

Mild Traumatic Brain injury (mTBI) is one of the most common forms of acquired neurological damage. However, the term 'mild' TBI is misleading because the physical, cognitive and emotional impairments that can follow from mTBI can be significant. In order to provide objective, prognostic measures for diagnosing the severity of mTBI and identifying individuals who may be at risk for poor outcomes a battery of neuropsychological measures for detecting cognitive impairment was evaluated. The Rapid Screen of Concussion (RSC) is a collection of tests assessing verbal recall, orientation, processing speed and speed of language comprehension. Previous studies have demonstrated that the RSC has acceptable reliability, validity and sensitivity to cognitive impairment that arises during the acute stages of injury. However, no studies have investigated the predictive validity of this instrument. Moreover it is unclear what additional patient or post injury variables could assist in identifying those individuals who may be at risk of poor neuropsychological outcomes following mTBI. These were among the main issues that were addressed across the five empirical studies in this thesis. A pragmatic, prospective, longitudinal and cross-sectional study of the sequelae of mTBI in patients presenting to the Department of Emergency Medicine of the Royal Brisbane and Women's hospital was the basis of this project. The first empirical chapter (chapter 2), examined the psychometric properties of two measures of verbal learning and memory and investigated their potential for discriminating between mTBI and orthopaedic controls. The performance of 93 patients with mTBI and 68 participants with orthopaedic injuries was analysed to identify the number of individuals who performed at ceiling on the Hopkins Verbal Learning test (HVLT-R) versus a 5-word test of immediate and delayed recall. While both of these verbal recall measures were effective in separating the mTBI and orthopaedic groups, overall, the HVLT-R was shown to be a more suitable measure for screening for deficits in verbal learning and memory after mTBI. Given the superiority of the HVLT-R as a measure of verbal learning and memory, chapter 3 aimed to examine whether inclusion of this test could improve the sensitivity of the RSC in mTBI compared to orthopaedic and uninjured control samples. Results were generally within the direction predicted. Significant differences were found between groups on the majority of cognitive indices assessed. Both the orthopaedic and mTBI group performed more poorly than the uninjured group on all measures except the Hopkins delayed recognition. Additional performance decrements shown by the mTBI group compared to the orthopaedic group illustrate that factors beyond the general effects of trauma influence performance and may be related to cognitive impairment specific to sustaining mTBI. Overall it was concluded that the revised RSC is a sensitive instrument deserving investigation in assessing the more long term cognitive effects following mTBI. Chapter 4 applied this sensitive battery for investigation of group and individual recovery of neuropsychological test performance and post-concussive symptom reporting up to 3-months after mTBI. A sample of 30 mTBI participants and 30 uninjured controls were serially assessed on cognitive measures and symptom report scales immediately after injury and after 1-week, 1-month and 3-months. Symptom reporting on the Rivermead post-concussive inventory separated the mTBI and control groups after 1-week but diagnostic accuracy was no greater than chance at 1 and 3-months. In contrast the mTBI group performed more poorly than controls on measures on neuropsychological measures acutely, at 1-week and 1-month, with group differences still evident after 3-months. Nonethless, a trend of progressive recovery over time was seen in the mTBI group. In chapter 5, criteria utilising the concepts of reliable and statistically significant change were applied to the data. Overall, 73% of mTBI patients were impaired on one or more tests acutely. Significant recovery was demonstrated by 20% of mTBI participants by 3-months; however recovery remained incomplete for half of the mTBI participants by 3-months. These results highlighted the importance of an individual approach to the assessment of mTBI and support the notion that a proportion of mTBI cases may have protracted difficulties. Chapter 6 extended these findings by showing that the RSC has prognostic ability. It was found that acute neuropsychological performance on the RSC was a significant predictor of performance on an extended battery at 3-months. The final chapter provides a general discussion and synthesis of the findings. In summary, the present dissertation demonstrated that inclusion of a sensitive measure of verbal recall led to improved diagnostic validity of the RSC. Neuropsychological measures rather than symptom reporting were sensitive in detecting cognitive impairment at 3-months. Analysis of individuals showed that up to 50% of the group had failed to – demonstrate reliable recovery – that is, make improvements over and above practice effects after 3-months. Finally, acute neuropsychological performance was predictive of long term performance. Overall, the present thesis has identified a short battery of tests that is suitable for assessment of mTBI within 24 hours and may assist in identifying individuals at risk of poor cognitive outcomes after mTBI.

Mild Traumatic Brain injury (mTBI) is one of the most common forms of acquired neurological damage. However, the term 'mild' TBI is misleading because the physical, cognitive and emotional impairments that can follow from mTBI can be significant. In order to provide objective, prognostic measures for diagnosing the severity of mTBI and identifying individuals who may be at risk for poor outcomes a battery of neuropsychological measures for detecting cognitive impairment was evaluated. The Rapid Screen of Concussion (RSC) is a collection of tests assessing verbal recall, orientation, processing speed and speed of language comprehension. Previous studies have demonstrated that the RSC has acceptable reliability, validity and sensitivity to cognitive impairment that arises during the acute stages of injury. However, no studies have investigated the predictive validity of this instrument. Moreover it is unclear what additional patient or post injury variables could assist in identifying those individuals who may be at risk of poor neuropsychological outcomes following mTBI. These were among the main issues that were addressed across the five empirical studies in this thesis. A pragmatic, prospective, longitudinal and cross-sectional study of the sequelae of mTBI in patients presenting to the Department of Emergency Medicine of the Royal Brisbane and Women's hospital was the basis of this project. The first empirical chapter (chapter 2), examined the psychometric properties of two measures of verbal learning and memory and investigated their potential for discriminating between mTBI and orthopaedic controls. The performance of 93 patients with mTBI and 68 participants with orthopaedic injuries was analysed to identify the number of individuals who performed at ceiling on the Hopkins Verbal Learning test (HVLT-R) versus a 5-word test of immediate and delayed recall. While both of these verbal recall measures were effective in separating the mTBI and orthopaedic groups, overall, the HVLT-R was shown to be a more suitable measure for screening for deficits in verbal learning and memory after mTBI. Given the superiority of the HVLT-R as a measure of verbal learning and memory, chapter 3 aimed to examine whether inclusion of this test could improve the sensitivity of the RSC in mTBI compared to orthopaedic and uninjured control samples. Results were generally within the direction predicted. Significant differences were found between groups on the majority of cognitive indices assessed. Both the orthopaedic and mTBI group performed more poorly than the uninjured group on all measures except the Hopkins delayed recognition. Additional performance decrements shown by the mTBI group compared to the orthopaedic group illustrate that factors beyond the general effects of trauma influence performance and may be related to cognitive impairment specific to sustaining mTBI. Overall it was concluded that the revised RSC is a sensitive instrument deserving investigation in assessing the more long term cognitive effects following mTBI. Chapter 4 applied this sensitive battery for investigation of group and individual recovery of neuropsychological test performance and post-concussive symptom reporting up to 3-months after mTBI. A sample of 30 mTBI participants and 30 uninjured controls were serially assessed on cognitive measures and symptom report scales immediately after injury and after 1-week, 1-month and 3-months. Symptom reporting on the Rivermead post-concussive inventory separated the mTBI and control groups after 1-week but diagnostic accuracy was no greater than chance at 1 and 3-months. In contrast the mTBI group performed more poorly than controls on measures on neuropsychological measures acutely, at 1-week and 1-month, with group differences still evident after 3-months. Nonethless, a trend of progressive recovery over time was seen in the mTBI group. In chapter 5, criteria utilising the concepts of reliable and statistically significant change were applied to the data. Overall, 73% of mTBI patients were impaired on one or more tests acutely. Significant recovery was demonstrated by 20% of mTBI participants by 3-months; however recovery remained incomplete for half of the mTBI participants by 3-months. These results highlighted the importance of an individual approach to the assessment of mTBI and support the notion that a proportion of mTBI cases may have protracted difficulties. Chapter 6 extended these findings by showing that the RSC has prognostic ability. It was found that acute neuropsychological performance on the RSC was a significant predictor of performance on an extended battery at 3-months. The final chapter provides a general discussion and synthesis of the findings. In summary, the present dissertation demonstrated that inclusion of a sensitive measure of verbal recall led to improved diagnostic validity of the RSC. Neuropsychological measures rather than symptom reporting were sensitive in detecting cognitive impairment at 3-months. Analysis of individuals showed that up to 50% of the group had failed to – demonstrate reliable recovery – that is, make improvements over and above practice effects after 3-months. Finally, acute neuropsychological performance was predictive of long term performance. Overall, the present thesis has identified a short battery of tests that is suitable for assessment of mTBI within 24 hours and may assist in identifying individuals at risk of poor cognitive outcomes after mTBI.