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2.  Primary Blast Traumatic Brain Injury in the Rat: Relating Diffusion Tensor Imaging and Behavior 
The incidence of traumatic brain injury (TBI) among military personnel is at its highest point in U.S. history. Experimental animal models of blast have provided a wealth of insight into blast injury. The mechanisms of neurotrauma caused by blast, however, are still under debate. Specifically, it is unclear whether the blast shockwave in the absence of head motion is sufficient to induce brain trauma. In this study, the consequences of blast injury were investigated in a rat model of primary blast TBI. Animals were exposed to blast shockwaves with peak reflected overpressures of either 100 or 450 kPa (39 and 110 kPa incident pressure, respectively) and subsequently underwent a battery of behavioral tests. Diffusion tensor imaging (DTI), a promising method to detect blast injury in humans, was performed on fixed brains to detect and visualize the spatial dependence of blast injury. Blast TBI caused significant deficits in memory function as evidenced by the Morris Water Maze, but limited emotional deficits as evidenced by the Open Field Test and Elevated Plus Maze. Fractional anisotropy, a metric derived from DTI, revealed significant brain abnormalities in blast-exposed animals. A significant relationship between memory deficits and brain microstructure was evident in the hippocampus, consistent with its role in memory function. The results provide fundamental insight into the neurological consequences of blast TBI, including the evolution of injury during the sub-acute phase and the spatially dependent pattern of injury. The relationship between memory dysfunction and microstructural brain abnormalities may provide insight into the persistent cognitive difficulties experienced by soldiers exposed to blast neurotrauma and may be important to guide therapeutic and rehabilitative efforts.
PMCID: PMC3796287  PMID: 24133481
traumatic brain injury; blast neurotrauma; memory dysfunction; diffusion tensor imaging; magnetic resonance imaging
3.  Concussion Symptom Inventory: An Empirically Derived Scale for Monitoring Resolution of Symptoms Following Sport-Related Concussion 
Self-report post-concussion symptom scales have been a key method for monitoring recovery from sport-related concussion, to assist in medical management, and return-to-play decision-making. To date, however, item selection and scaling metrics for these instruments have been based solely upon clinical judgment, and no one scale has been identified as the “gold standard”. We analyzed a large set of data from existing scales obtained from three separate case–control studies in order to derive a sensitive and efficient scale for this application by eliminating items that were found to be insensitive to concussion. Baseline data from symptom checklists including a total of 27 symptom variables were collected from a total of 16,350 high school and college athletes. Follow-up data were obtained from 641 athletes who subsequently incurred a concussion. Symptom checklists were administered at baseline (preseason), immediately post-concussion, post-game, and at 1, 3, and 5 days post-injury. Effect-size analyses resulted in the retention of only 12 of the 27 variables. Receiver-operating characteristic analyses were used to confirm that the reduction in items did not reduce sensitivity or specificity. The newly derived Concussion Symptom Inventory is presented and recommended as a research and clinical tool for monitoring recovery from sport-related concussion.
PMCID: PMC2800775  PMID: 19549721
Brain injury; Post-concussion; Scale
The Clinical neuropsychologist  2007;22(5):769-800.
Little scientific attention has been aimed at the non-acute clinical care of pediatric mild TBI. We propose a clinical management model focused on both evaluation and intervention from the time of injury through recovery. Intervention strategies are outlined using a framework encompassing four relevant domains: the individual youth, family, school, and athletics. Clinical management has primary value in its potential to speed recovery, minimize distress during the recovery process, and reduce the number of individuals who subjectively experience longer lasting postconcussive problems. With proper management, most children and adolescents sustaining an uncomplicated mild TBI can be expected to recover fully.
PMCID: PMC2847840  PMID: 17896204
Mild traumatic brain injury; Minor head injury; Concussion; Pediatrics; Treatment
5.  Psychometric and Measurement Properties of Concussion Assessment Tools in Youth Sports 
Journal of Athletic Training  2006;41(4):399-408.
Context: Establishing psychometric and measurement properties of concussion assessments is important before these assessments are used by clinicians. To date, data have been limited regarding these issues with respect to neurocognitive and postural stability testing, especially in a younger athletic population.
Objective: To determine the test-retest reliability and reliable change indices of concussion assessments in athletes participating in youth sports. A secondary objective was to determine the relationship between the Standardized Assessment of Concussion (SAC) and neuropsychological assessments in young athletes.
Design: We used a repeated-measures design to evaluate the test-retest reliability of the concussion assessments in young athletes. Correlations were calculated to determine the relationship between the measures. All subjects underwent 2 test sessions 60 days apart.
Setting: Sports medicine laboratory and school or home environment.
Patients or Other Participants: Fifty healthy young athletes between the ages of 9 and 14 years.
Main Outcome Measure(s): Scores from the SAC, Balance Error Scoring System, Buschke Selective Reminding Test, Trail Making Test B, and Coding and Symbol Search subsets of the Wechsler Intelligence Scale for Children were used in the analysis.
Results: Our test-retest indices for each of the 6 scores were poor to good, ranging from r = .46 to .83. Good reliability was found for the Coding and Symbol Search tests. The reliable change scores provided a way of determining a meaningful change in score for each assessment. We found a weak relationship ( r < .36) between the SAC and each of the neuropsychological assessments; however, stronger relationships ( r > .70) were found between certain neuropsychological measures.
Conclusions: We found moderate test-retest reliability on the cognitive tests that assessed attention, concentration, and visual processing and the Balance Error Scoring System. Our results demonstrated only a weak relationship between performance on the SAC and the selected neuropsychological tests, so it is likely that these tests assess somewhat different areas of cognitive function. Our correlational findings provide more evidence for using the SAC along with a more complex neuropsychological assessment battery in the evaluation of concussion in young athletes.
PMCID: PMC1752194  PMID: 17273465
neuropsychological testing; brain injury; athletic injuries; reliability
6.  Is Neuropsychological Testing Useful in the Management of Sport-Related Concussion? 
Journal of Athletic Training  2005;40(3):139-152.
Objective: Neuropsychological (NP) testing has been used for several years as a way of detecting the effects of sport-related concussion in order to aid in return-to-play determinations. In addition to standard pencil-and-paper tests, computerized NP tests are being commercially marketed for this purpose to professional, collegiate, high school, and elementary school programs. However, a number of important questions regarding the clinical validity and utility of these tests remain unanswered, and these questions present serious challenges to the applicability of NP testing for the management of sport-related concussion. Our purpose is to outline the criteria that should be met in order to establish the utility of NP instruments as a tool in the management of sport-related concussion and to review the degree to which existing tests have met these criteria.
Data Sources: A comprehensive literature review of MEDLINE and PsychLit from 1990 to 2004, including all prospective, controlled studies of NP testing in sport-related concussion.
Data Synthesis: The effects of concussion on NP test performance are so subtle even during the acute phase of injury (1–3 days postinjury) that they often fail to reach statistical significance in group studies. Thus, this method may lack utility in individual decision making because of a lack of sensitivity. In addition, most of these tests fail to meet other psychometric criteria (eg, adequate reliability) necessary for this purpose. Finally, it is unclear that NP testing can detect impairment in players once concussion-related symptoms (eg, headache) have resolved. Because no current guideline for the management of sport-related concussion allows a symptomatic player to return to sport, the incremental utility of NP testing remains questionable.
Conclusions/Recommendations: Despite the theoretic rationale for the use of NP testing in the management of sport-related concussion, no NP tests have met the necessary criteria to support a clinical application at this time. Additional research is necessary to establish the utility of these tests before they can be considered part of a routine standard of care, and concussion recovery should be monitored via the standard clinical examination and subjective symptom checklists until NP testing or other methods are proven effective for this purpose.
PMCID: PMC1250250  PMID: 16284633
neurocognitive function; traumatic brain injury; athletic injury
9.  A Survey of Practice Patterns in Concussion Assessment and Management 
Journal of Athletic Training  2001;36(2):145-149.
To identify methods used by athletic trainers to assess concussions and the use of that information to assist in return-to-play decisions and to determine athletic trainers' familiarity with new standardized methods of concussion assessment.
Design and Setting:
A 21-item questionnaire was distributed to attendees of a minicourse at the 1999 National Athletic Trainers' Association Annual Meeting and Clinical Symposia entitled “Use of Standardized Assessment of Concussion (SAC) in the Immediate Sideline Evaluation of Injured Athletes.”
A total of 339 valid surveys were returned by the attendees of the minicourse.
We used frequency analysis and descriptive statistics.
Clinical examination (33%) and a symptom checklist (15.3%) were the most common evaluative tools used to assess concussions. The Colorado Guidelines (28%) were used more than other concussion management guidelines. Athletic trainers (34%) and team physicians (40%) were primarily responsible for making decisions regarding return to play. A large number of respondents (83.5%) believed that the use of a standardized method of concussion assessment provided more information than routine clinical and physical examination alone.
Athletic trainers are using a variety of clinical tools to evaluate concussions in athletes. Clinical evaluation and collaboration with physicians still appear to be the primary methods used for return-to-play decisions. However, athletic trainers are beginning to use standardized methods of concussion to evaluate these injuries and to assist them in assessing the severity of injury and deciding when it is safe to return to play.
PMCID: PMC155525  PMID: 12937455
mild brain injury; grading scales; head injury; evaluation
10.  Standardized Mental Status Testing on the Sideline After Sport-Related Concussion 
Journal of Athletic Training  2001;36(3):274-279.
The effects of concussion on mental status are often difficult to assess on routine clinical examination. I investigated the efficacy of standardized mental status testing on the sport sideline to detect abnormalities that result from concussion and provide an objective measure of postinjury cognitive recovery.
Design and Setting:
All subjects underwent a standardized preseason baseline mental status evaluation. Standardized testing of injured and uninjured control subjects was repeated on the sideline immediately after concussion and 48 hours after injury.
Sixty-three high school and collegiate football players with concussion and 55 uninjured control subjects were studied.
The Standardized Assessment of Concussion (SAC) was administered to evaluate neurocognitive functioning and neurologic status.
Immediately after concussion, injured subjects performed significantly below preinjury baseline and below uninjured controls on the SAC. Measurable deficits in orientation, concentration, and memory were evident immediately after concussion. A decline in SAC score at time of injury was 95% sensitive and 76% specific in accurately classifying injured and uninjured subjects on the sideline. Injured subjects demonstrated significant improvements in SAC score 48 hours after injury.
Standardized mental status testing can be a valuable tool to assist the sports medicine clinician in detecting the immediate effects of concussion on mental status, tracking resolution of immediate postconcussive mental status abnormalities, and making more informed decisions on return to play after injury.
PMCID: PMC155418  PMID: 12937496
athletic injuries; neuropsychological tests

Results 1-10 (10)