sustained multiple concussions may be at risk of cumulative impairment. The role of neuropsychological testing in the management of sports-related concussion is a contentious and challenging issue which has gained credibility given the lack of clear and well-established guidelines pertaining to the diagnosis, assessment and return-to-play decisions following concussion. Despite various traditional paper and pencil tests being shown to be effective indicators of postconcussive neuropsychological dysfunction, testing has not been widely implemented, due to time- and labour-demands. ImPACT, a computer-based neuropsychological assessment instrument, has been recognised as a valid and reliable tool in the monitoring of athletes' symptoms and neurocognitive functioning preseason and postconcussion. As a part of larger-scale concussion research conducted on top-team university rugby players, this is an in-depth case study conducted on a 20-year old participant with a history of multiple concussions, who was referred following a concussion sustained during the season. The objectives of the study were: (i) to determine the sensitivity of ImPACT versus WAIS-III Digit Span and Trail Making Test during the acute postconcussive phase; and (ii) to examine the sensitivity of ImPACT versus a comprehensive battery of neuropsychological tests to possible residual deficits as a result of the multiple concussions. ImPACT was determined to be more sensitive to acute postconcussive impairment following concussion than Digit Span and Trail Making Test. Furthermore, the ImPACT preseason baseline scores appear to be sensitive to neurocognitive dysfunction, possibly due to cumulative concussive injuries.

xvi, 68 p. : ill. / Approximately 1.5 million concussions occur annually in the United States, many affecting individuals between the ages of 15 and 18. Little is known about this age group's response to a concussion as they have been thought to respond differently than adults due to immature brain development. Additionally, relying on symptoms alone to determine level of brain function may lead to early return back to sport participation. Through the use of 3 computerized tests, neuropsychological and attentional deficit recovery post concussion was assessed between 12 subjects with concussions and 12 controls up to 2 months after injury. Memory tasks and symptoms resolved within a week after injury. Executive function tests showed small group differences up to two months post injury, suggesting these types of tests may be a useful tool in the evaluation of concussion recovery and provide an objective measure in evaluation. / Committee in charge: Dr. Li-Shan Chou, Chair; Dr. Lou Osternig, Member; Dr. Sierra Dawson, Member; Dr. Grace Golden, Member

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)

Neuropsychological testing is recognised as one of the cornerstones of concussion evaluation, contributing significantly to both an understanding of the injury as well as management of the recovery process. Despite the high incidence of concussion at school level, traditional paper-and-pencil neuropsychological testing has generally been absent from school concussion management programmes, largely due to time and cost constraints. Now, the recent development of computerised neuropsychological testing is providing the opportunity for including neurocognitive assessment in this process. The Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) is a valid and reliable instrument of this type and normed on 13 - 18 year old North American high school athletes, as well as adult groups. The current recommendation is that athletes are baselined preseason in order to provide an individualised comparative level against which to monitor recovery and provide return-to-play recommendations. This in itself is quite a cumbersome process, thus the present study set out to ascertain whether baseline testing of all athletes is necessary, or whether the use of US or SA normative data alone would provide an appropriate standard against which to interpret the postinjury scores. From a leading South African rugby playing school, the 1st and 2nd rugby teams, (16 - 18 years) were baselined using ImPACT. Three athletes, who were subsequently referred with concussion during the rugby season, were followed up with serial testing on ImPACT. An analysis of the follow up scores was conducted to chart the athletes' recovery process, in relation to the athletes own baseline scores (using US and SA reliable change indices) and age appropriate US and SA normative ranges. The relative utility of individual baselines scores versus these normative ranges was then critically evaluated. It was concluded that a combination of both baseline and normative data provided optimal management of the athlete, with the methods complementing each other in the interpretation of post-injury results. Overall, the SA normative ranges seemed to provide slightly better management guidelines than the US normative ranges when used with this sample of South African high school athletes.

A number of computerised tests have been especially developed to facilitate the medical management of the sports-related concussion. Probably the most widely used of these programmes is the ImPACT test that was developed in the USA and that is registered with the HPCSA for use in the South African context. A recent Afrikaans version of the test served as the basis of the present study with the following objectives: (i) to collect Afrikaans ImPACT normative data on a cohort of Afrikaans first language adolescent rugby players with Model C education for comparison with existing South African English first language adolescent rugby players with Private/Model C schooling, and (ii) to investigate the pre-versus postseason ImPACT neurocognitive test profiles of this cohort of Afrikaans first language adolescent rugby players versus equivalent noncontact sports controls. The results for Part 1 of the study generally demonstrate poorer performance in respect of the Afrikaans cohort, which is understood to be the result of poorer quality of education. The results for Part 2 demonstrated failure of the rugby group to benefit from practice on the ImPACT Visual Motor Speed composite score to the same extent as the control group. It is argued that this apparent cognitive vulnerability in the rugby group is due to lowered cognitive reserve capacity in association with long term exposure to concussive and sub-concussive injury.

The present study comprises part of an ongoing research study investigating the effects 0 f cumulative mild head injuries 0 n Rugby Union p layers. The aim 0 f t he study was to ascertain whether there are neuropsychological effects of cumulative mild head injuries sustained during the rugby-playing careers of senior schoolboy rugby players. Participants were top-level rugby players from high schools in Grahamstown and Cape Town (n = 79) and non-contact sport controls of top-level field hockey players from the same schools (n = 58). Group mean comparisons across a battery of neuropsychological tests were carried out between the Total Rugby versus the Total Field Hockey group, and the Rugby Forwards versus the Rugby Backs group. Comparisons between Total Rugby versus Total Field Hockey revealed impaired performance by the rugby players on two tests of visuoperceptual tracking, namely Digit Symbol Substitution and Trail Making Test (Part A). For Rugby Forwards versus Rugby Backs, there were no consistent differences to support the expectation that forwards would perform worse than backs. Forwards performed more poorly than backs on WMS Associate Learning Subtest - Hard (Delayed Recall), whereas backs performed more poorly than forwards on Digits Backwards. This suggests that some individuals in the cohort were starting to exhibit verbal memory deficit, albeit not clearly in association with forward positional play. Overall, results of the present study provide tentative support for the hypothesis that school level rugby players are more susceptible to the effects of cumulative concussive and sub-concussive head injuries than are non-contact sport controls. / KMBT_363 / Adobe Acrobat 9.54 Paper Capture Plug-in

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Incidents and awareness of sports-related concussion have grown in recent years, attracting attention in both the academic and popular press. These concussions can lead to the rapid onset of neurological dysfunctions, as well as a variety of subjective symptoms. Although concussive sequelae are typically considered transient, debate remains about the persistent effects of repeated traumatic contact during sport participation. Although research has examined the complications of head trauma found in traditionally popular sports (e.g., football, soccer, boxing), little research has focused on the growing sport of mixed-martial-arts (MMA). Research specifically pertaining to MMA is in nascent stages, but to-date studies suggest that concussive injuries for this sport are prevalent and the training regimens of these athletes may place them at a high risk for concussive or subconcussive head traumas—as well as the accompanying neurological difficulties. The current study is the first to assess cognitive profiles of MMA athletes using an objective neuropsychological assessment instrument. Among 56 athletes (28 MMA athletes and 28 athletes not exposed to head traumas), no neuropsychological differences were found between groups of athletes. Additionally, no aspects of MMA training regimen shared a reliable relationship with neuropsychological performance or subjective concussive symptoms. This suggests non-professional participation in MMA may not typically pose a significant risk for cumulative concussions and associated adverse neuropsychological consequences.

Graduation date: 2004