Browsing by Subject "Brain Injuries"
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Item Activation of Early Neural Progenitors Is Required for Traumatic Brain Injury-Induced Hippocampal Neurogenesis(2008-09-19) Yu, Tzong-Shiue; Kernie, Steven G.Traumatic brain injury (TBI) is the most common form of acquired brain injury in both children and adults in the United States. TBI causes neuronal loss and results in a variety of neurological impairments and deficits in hippocampus-dependent functions. However, cognitive recovery commonly occurs though the mechanism is unknown. Exploration of post-natal neurogenesis in the hippocampus raises the possibility that adult-born neurons may contribute to cognitive recovery from TBI. Several studies in animal models that mimic TBI demonstrate there is enhanced generation of adult-born neurons in the dentate gyrus and those adult-born neurons may correlate with cognitive recovery. Due to the limits of current methodology in studying neurogenesis, it remains unclear what relevance injury-induced neurogenesis may have in the recovery process following TBI. In order to explore the relevance of injury-induced neurogenesis, I have characterized a previously generated transgenic mouse line that has rtTA-IRES-eGFP expression under the control of a nestin promoter and also contains a neural progenitor-specific regulatory element. By using this line, I have demonstrated that eGFP-expressing cells represent early neural progenitors in the adult dentate gyrus. Performing unilateral controlled cortical injury (CCI) demonstrates that this injury depletes doublecoritn (Dcx)-expressing late neural progenitors while activating eGFP-expressing early neural progenitors. To address whether the subsequent recovery of Dcx-expressing late progenitors was derived from activation of early neural progenitors, I generated a transgenic line that expresses modified herpes simplex viral thymidine kinase (delta-HSV-TK) under the control of the neural progenitor-specific regulatory element of the nestin gene. This allows for temporally regulated ablation of dividing neural progenitors by exposing the animal to ganciclovir. Using this line, I demonstrate that ablation of dividing GFP-expressing early neural progenitors in neurogenic areas occurs only in the presence of ganciclovir. CCI on these mice, reveals that no newly born Dcx-expressing late neural progenitors are observed seven days after injury when exposed to ganciclovir. However, the repopulation of Dcx-expressing cells is apparent when ganciclovir was removed one day before injury. Four weeks after injury, those newly born Dcx-expressing cells became mature NeuN-expressing neurons. This suggests that injury-induced activation of early neural progenitors is required for the recovery of injured hippocampal neurons.Item Administration of Fatty Acid Emulsions to Reduce Secondary Brain Injury in Mice(2018-01-23) Rodgers, Clifford; Chowdary, Ashish; Liu, Ming-Mei; Carlson, Deborah; Wolf, Steven E.; Minei, Joseph P.; Gatson, JoshuaBACKGROUND: Mild traumatic brain injuries are the most common type of injury to the head. Seventy-five to eighty percent of all traumatic brain injuries (TBI) are considered a mild TBI, or concussions, and involve only a short interruption of mental state and consciousness. Although the FDA reports no nutrition supplements for TBI therapy and/or symptom prevention, preclinical data has suggested that omega-3 poly unsaturated fatty acid (PUFAs) treatment decreases apoptosis, inflammation, and neurodegeneration following brain trauma. In this study, we hypothesized that Smoflipid® reduces inflammation in the brain of adult mice that have suffered a mild-to-moderate brain injury. Smoflipid® is an injectable liquid emulsion solution that contains omega-3, omega-6, omega-9, and medium chain triglycerides. METHODS: In this study, mice were subjected to a moderate brain injury using the controlled skull impact device (Leica microsystems) and we administered Smoflipid® intraperitoneally at day 1 and 3 after injury. At Day 14 after injury and treatment the mouse brains were harvested, processed, and stained using immunohistochemistry for the inflammatory markers, glial fibrillary acidic protein (GFAP) and Iba1. RESULTS: In this study after TBI, within the corpus callosum (C.C.) and cerebral cortex there was a significant increase in the levels of activated microglia (Day 14 p=0.05) compared to the control animals. Treatment with Smoflipid® shortly after injury, resulted in a significant decrease in the number of active microglia within these brain regions. CONCLUSIONS: Chronic activation of microglia and heightened inflammation in the cerebral cortex/C.C. after TBI, results in cognitive decline and long-term memory deficits. As a therapeutic strategy, by targeting these pro-inflammatory cells with Smoflipid®, we hypothesize that a reduction in the activity of microglia will improve results in better neurological outcomes. More definitive studies will be conducted to test the efficacy of Smoflipid® at reducing secondary brain injury after TBI.Item Apolipoprotein E Isoform Influence on Outcomes after Pediatric Traumatic Brain Injury(2016-01-19) Usala, Claire; Huang, Rong; Hernandez, Ana; Miles, DarrylINTRODUCTION: The ε4 allele of the apolipoprotein E gene (APOε) is associated with poor outcomes in adults with traumatic brain injury (TBI), but its influence on recovery after pediatric TBI is uncertain. The primary aims of this study were to determine if an association exists in the outcome of children after TBI between those with at least one ε4 allele and non ε4 genotypes. Using the Glasgow outcome score (GOS), we examined three outcome variables between the two groups 1) GOS at hospital discharge, 2) GOS at long-term follow-up, and 3) the magnitude of change in GOS from discharge to > 6 month assessment (Δ GOS). METHODS: Data were prospectively collected from 220 children presenting with moderate or severe blunt head trauma between the ages of 0 and 17 years old from 2002-2013. Outcomes were assessed at hospital discharge and 12.7±8.4 months post-injury. Patients in the ε4 and non ε4 groups did not differ in injury mechanism, severity, or demographics; 23.4% had at least one ε4 allele and ε3/ ε3 was the most common genotype (67.4%). Multiple regression model analysis was conducted to determine if associations existed between the genotype combinations and outcome while controlling for age, ER GCS, ICP monitor placement, and whether CPR was performed. For ε4 genotypes analysis, we also stratified patients by admission Glasgow Coma Scale (GCS) into severe (GCS 3-8) versus non-severe (9-15), as well as moderate and severe (3-12) versus mild (13-15) groups. RESULTS: For aim 1, the GOS at discharge did not differ significantly in ε4 versus non- ε4 patients in any injury severity category before or after controlling for cofounding variables. However, after controlling for confounding variables, patients with at least one ε2 allele in the moderate or severe injury category had significantly worse GOS at discharge. For aim 2, after controlling for confounding variables, patients with the ε3/ε3 genotype had significantly better long-term GOS than patients with the genotype ε3/ε2 (p<0.05). However, we did not find a significant difference in long-term outcome between ε4 and non ε4 genotypes in the primary analysis or when stratified by injury severity groups. Finally, between ε4 and non ε4 genotypes, the Δ GOS and neuropsychological scores did not differ significantly between genotypes. DISCUSSION: Overall these results propose that unlike adults, the ε4 allele may not be associated with 12-month outcome or the rate of recovery (ΔGOS) from hospital discharge following pediatric TBI. Our results implicating worse outcomes for the ε2 genotypes suggest that this allele may be a candidate for further study to delineate its role in TBI outcome in children. Unique to this study was our analysis of neuropsychological measures, which were also not affected by the presence of ε4 in a smaller cohort of children. This study adds to current literature suggesting that unlike adults APOε4 may not exert a significant effect on pediatric TBI outcome. However, these results are limited in that any genotypic effect on neurologic repair may not be apparent for much longer time periods in pediatric brain injury as the child continues to develop and grow.Item Assessing Approach Motivation in Depressed Individuals with a History of Concussion(2020-12-01T06:00:00.000Z) Cecil, Audrey Lorraine; Cullum, C. Munro; Trivedi, Madhukar; Cooper, Crystal; Greer, Tracy L.; Carmody, Thomas; Pop, RaduDepression is the leading cause of disability worldwide. Anhedonia, a core symptom of depression, has been described as a lack of pleasure or interest, though it is a much more complex process than simply lack of pleasure. Anhedonia is made up of anticipation, motivation, enjoyment, and learning related to rewards. When an individual's motivation is impaired, reward perception is blunted as the drive to work for it is reduced. This "approach motivation" is generally subserved by the ventral striatum and orbitofrontal cortex, two areas which can be affected in a variety of neurologic conditions, including traumatic brain injury, as these subcortical structures can be affected by pathophysiological sequalae of trauma. To explore this concept, we examined data from a large ongoing study of adult depression (Dallas 2K). A total of 110 participants with depression with (n=40) and without a history (n=70) of self-reported concussion were tested on a measure of approach motivation, the Energy Expenditure for Rewards Task (EEfRT). We also analyzed depression symptom severity and the relationship between anhedonia severity to approach motivation on the EEfRT. Results revealed no significant differences between depressed adults with and without a history of concussion on approach motivation. Exploratory analyses revealed differences between high and low depression severity groups, such that high depression severity participants were less likely to select low probability/high reward tasks, but this was irrespective of concussion history. Though the main study results were nonsignificant, exploratory analyses present an opportunity for future direction of studies related to approach motivation and cognition in co-morbid depression and concussion.Item Beating the Weekend Trend: Increased Mortality in Older Adult Traumatic Brain Injury (TBI) Patients Admitted on Weekends(2015-04-03) Hirani, Salman; Mortensen, EricBACKGROUND: Weekend admission is associated with mortality in cardiovascular emergencies and stroke but the effect of weekend admission for trauma is not well defined. We sought to determine whether differences in mortality outcomes existed for older adults with substantial head trauma admitted on a weekday versus over the weekend. METHODS: Data from the 2006, 2007, and 2008 Nationwide Inpatient Sample were combined and head trauma admissions were isolated. Abbreviated injury scale (AIS) scores were calculated using ICDMAP-90 Software. Individuals aged 65 to 89 y with head AIS equal to 3 or 4 and no other region score <3 were included. Individual Charlson comorbidity scores were calculated and individuals with missing mortality, sex, or insurance data were excluded. Wilcoxon rank sum and Student t-tests compared demographics, length of stay, and total charges for weekday versus weekend admissions. The X2 tests compared sex and head injury severity. Logistic regression modeled mortality adjusting for age, sex, injury severity, comorbidity, and insurance status. RESULTS: Of the 38,675 patients meeting criteria, 9937 (25.6%) were admitted on weekends. Mean age was similar (78.4 versus 78.4, P = 0.796) but more weekend admissions were female (51.6% versus 50.2%, P = 0.022). Weekend patients demonstrated slightly lower comorbidity (mean Charlson = 1.07 versus 1.14, P<0.001) and head injury severity (58.3% versus 60.8% AIS = 4, P < 0.001). Median weekend length of stay was shorter (4 versus 5 d, P < 0.001). Weekend and weekday median total charges did not differ (USD 27,128 versus USD 27,703, respectively, P = 0.667). Proportional mortality was higher among weekend patients (9.3% versus 8.4%, P = 0.008). After adjustment, weekend patients demonstrated 14% increased odds of mortality (OR 1.14, 95% CI 1.05--1.23). CONCLUSION: Older adults with substantial head trauma admitted on weekends are less severely injured, carry less comorbidity, and generate similar total charges compared with those admitted on weekdays. However, after accounting for known risk confounders, weekend patients demonstrated 14% greater odds of mortality. Mechanisms behind this disparity must be determined and eliminated.Item Connectivity within the Default Mode Network after Traumatic Axonal Injury(2011-12-12) Arenivas, Ana; Marquez de la Plata, CarlosTraumatic axonal injury (TAI) is a common consequence of TBI in which the brain’s white matter is mechanically torn by deceleration and rotational forces. Injury to axons after this type of injury causes significant impairments in cognitive functioning, but the association between disruption of structural connections (i.e., axons) and the brain’s functional connectedness is not well understood. Studies examining integrity of white matter after TAI have found significant compromise to structures likely involved in the connectivity of the default mode network (DMN), a reliably elicited functional neural network with clinical implications. The discriminant and prognostic utilities of the DMN following traumatic axonal injury (TAI) have not been previously investigated. This broad investigation was comprised of two related studies examining the utility of neuroimaging modalities as biomarkers of TAI. Resting-state magnetic resonance imaging (RS-MRI) and diffusion tensor imaging (DTI) sequences were acquired 6-11 months post-injury using a 3T scanner from 25 patients with TAI and 17 controls. Functional and neurocognitive outcomes were assessed the same day. The first study examined the utility of three approaches analyzing DMN integrity using RS-fMRI. The purpose was to identify the utility of each approach to distinguish between healthy and brain-injured individuals, and determine whether observed differences have clinical significance. The second study integrated functional and structural connectivity measures of the DMN to determine whether compromise to functional connectivity within this network can be explained by the degree of white matter compromise commonly observed after TAI. The first study concluded that connectivity within the DMN is compromised after TAI, as all three methods demonstrated good ability to discriminate between healthy and injured brains. The second study suggests the functional disconnectedness within the DMN is in part due to compromise in structural connections observed after TAI. Neither the degree of functional or structural compromise to the DMN has clinical implications in TAI. In general, the two investigations suggest the DMN undergoes compromise after TAI, and connectivity between nodes of the network are valid markers of axonal injury.Item Elucidating the Impact of Previous Head Injury on Cognition, Brain Structure, and Pathophysiology in Cognitively Normal Individuals Across the Adult Lifespan(2020-08-01T05:00:00.000Z) Munro, Catherine Elizabeth; Cullum, C. Munro; Park, Denise C.; Davenport, Elizabeth; Didehbani, Nyaz; Rodrigue, KarenMild traumatic brain injury (mTBI), or concussion, is a common experience and awareness of mTBI has been increasing. There has been growing concern regarding potential long-term effects of concussion on cognition and risk for neurodegenerative disorders. This concern is heightened for athletic populations, particularly in high-contact sports, at risk for repetitive mTBI. Short-term effects of mTBI are heterogeneous, but well-documented, and the majority of individuals recover from post-concussive symptoms within several months. However, long-term effects of mTBI on brain structure and function are more poorly understood. The current studies sought to determine potential long-term effects of mTBI history and history of sports participation on 1) cognitive performance and change and 2) white matter hyperintensities (WMH) and hyperphosphorylated tau (pTau) burden, a protein associated with neurodegenerative disorders. Participants from the Dallas Lifespan Brain Study (DLBS) (aged 20-90 at baseline) completed two assessments related to head injury: the novel Head Injury Exposure and Assessment Data (HEAD) questionnaire and the current "gold standard," the Ohio State University TBI Identification Method (OSU TBI-ID). MTBI exposure variables were: number of mTBI and HEAD Total Index Score (overall seriousness of mTBI history) from the HEAD questionnaire and history of "concerning" head injury per OSU TBI-ID criteria. The HEAD questionnaire assessed history of participation in sports and average number of years played across no, limited, and high contact sports. Participants underwent longitudinal neuropsychological testing and magnetic resonance imaging, and cross-sectional positron emission tomography. Composite indices were created to represent the domains of Memory, Executive Functioning, and Processing Speed. The results did not find any evidence to suggest mTBI negatively affects cognitive performance, cognitive change, or perceived memory capacity. Longer participation in high-contact sports was not predictive of cognitive performance and there was no difference in mean cognitive index scores across highest level of contact sport played. There was also no evidence to support any relationship between history of mTBI/participation in high-contact sports and increased cerebral WMH volume or regional pTau burden. Thus, prior history of mTBI/participation in high-contact sports does not appear to be related to changes in brain structure or function in these otherwise healthy adults.Item Factors Affecting Resting-State Functional Connectivity Across Three Intrinsically Connected Networks in Traumatic Brain Injury(2014-07-28) Bosworth, Christopher Charles; Marquez de la Plata, Carlos; Cullum, C. Munro; Krawczyk, Daniel; Aslan, Sina; Spence, JeffreyThis study investigated the factors that influence post-TBI functional connectivity within three intrinsically connected networks; the default mode network (DMN), central executive network (CEN), and salience network (SN). The aim was to develop a predictive model for each network, based off a combination of cognitive performance, brain volumetric factors, aging/demographic factors, and TBI-related factors. A secondary aim was to examine the relationship between the SN and the anticorrelation (i.e., between-network BOLD signal correlation) between the DMN and CEN. Participants (n=63) sustained a mild-to-moderate TBI within six-months of participating in the study. They completed a cognitive assessment battery consisting of measures of executive functioning, language, memory, reasoning, and intelligence estimates. They also underwent structural MRI, resting-state fMRI, and completed mood symptom questionnaires. A seed-based, resting-state functional connectivity analysis was conducted for the DMN, CEN, and SN. Measures of brain volumetrics were calculated from the structural MRI. Stepwise multiple linear regressions using cognitive factors, demographic and injury factors, functional outcomes, brain volumetric factors, and symptoms of depression were preformed in order to develop predictive models of DMN, CEN, and SN functional connectivity. A Pearson correlation was used to examine the relationship between SN functional connectivity and DMN/CEN anticorrelation. The predictive model for the DMN accounted for approximately 50% of the variance within the network, and was comprised of factors which included TBI severity, age at assessment, volumetric factors, and cognitive factors (including attention and abstract verbal reasoning). The predictive model for the CEN accounted for 37% of the network’s variance, and was comprised solely of cognitive factors, including verbal ability, attention, and inhibition. The SN model accounted for 45% of the variance, and was comprised of factors that included gender, functional outcomes, volumetric factors, and cognitive factors (including attention and cognitive switching). The functional connectivity within the SN had a trending positive correlation with the degree of anticorrelation between the DMN and CEN. These results not only reveal the factors that contribute to functional connectivity, but they also highlight the differences between networks, including that the DMN may be more sensitive to volumetric changes and TBI severity than the CEN or SN.Item Longitudinal Changes in Resting-State Connectivity after Traumatic Axonal Injury(2014-07-24) Krishnan, Kamini; Marquez de la Plata, Carlos; Cullum, C. Munro; Ringe, Wendy; Aslan, Sina; Spence, JeffreyLittle is known about neural network connectivity immediately after a traumatic axonal injury (TAI). This is the first longitudinal study in TAI to examine functional connectivity in the Default Mode Network (DMN) and Central Executive Network (CEN) within 48 hours after traumatic brain injury with repeat imaging 7 months later. Aims: (a) characterize connectivity in these networks at the sub-acute stage of injury, (b) evaluate longitudinal change in networks with recovery, and (c) explore how this change might be associated with structural connectivity and neurocognitive outcome. Resting-state fMRI and diffusion tensor imaging (DTI) scans were acquired from 21 patients with moderate-severe brain injuries consistent with TAI compared with 8 non-injured controls. Neurocognitive outcome was assessed at 7 months. Results revealed lower resting-state DMN connectivity 48 hours after TAI compared to non-injured controls, and this persisted 7 months after injury. CEN connectivity was comparable between acutely injured patients and controls, though patients demonstrated increased CEN connectivity at 7 months. These patterns of functional connectivity in patients were associated with alterations in structural connectivity, where areas of decreased functional connectivity were associated with decreased integrity of white matter tracts connecting those regions. However, some regions within these networks demonstrated increased functional connectivity despite presence of structural damage. Taken together, results suggest disruptions in functional and structural connectivity are present as early as 48 hours after a TAI. Alterations in functional connectivity during the recovery period may be explained either by structural damage or could suggest the presence of neural compensation in functional connectivity.Item Mild Traumatic Brain Injury Rehabilitation: A Model for ADHD Treatment(2016-11-18) Yates, Ashley Nicole; Silver, Cheryl H.; Brewer-Mixon, Karen; Fulbright, Richard L.Attention Deficit Hyperactivity Disorder (ADHD) is a condition that affects approximately 4.4% of adults in the U.S. (Kessler et al., 2006) and is most commonly treated with psychopharmacological interventions. More recently, non-pharmacological interventions have been developed for ADHD. Cognitive Behavioral Therapy (CBT) has emerged as an efficacious treatment for ADHD and typically consists of training compensatory strategies and the use of external aids. The aims of this thesis were to examine the similarities between ADHD and mild Traumatic Brain Injury (mTBI) as well as review treatment options for mTBI and discuss their possible usefulness in treating ADHD. Based on the literature reviewed, there were striking similarities of deficits between ADHD and mTBI, specifically in the executive functioning of both. It is hypothesized that treatment for mTBI could also be beneficial for ADHD. Currently, some of the techniques used to treat ADHD and mTBI overlap. However in, cognitive rehabilitation (CR) for TBI, there is more emphasis on remediation of deficits compared to treatment of ADHD. Also, cognitive tasks for mTBI are more often completed in a real-life setting or as close to a real-life setting as possible. At this time, the literature regarding cognitive rehabilitation specific to mTBI is somewhat limited because it continues to be a growing field of literature. However, CR in general may be a beneficial treatment for the executive functioning deficits that also commonly affect ADHD.Item Neuropsychological Functioning in Aging National Football League Retirees(2020-08-01T05:00:00.000Z) Schaffert, Jeffrey Michael; Cullum, C. Munro; Didehbani, Nyaz; LoBue, Christian; Motes, Michael A.; Hart, John, Jr.Concussive and sub-concussive head impacts sustained over a National Football League (NFL) career have been proposed to increase risk for later cognitive impairment. However, research is generally limited on the neuropsychological functioning among NFL retirees, and no studies to date have investigated the cognitive performance of NFL retirees over time. Study One was a critical review of research on neuropsychological functioning among NFL retirees. Findings were mixed, but studies suggested some NFL retirees have lower verbal memory, confrontation naming, and executive functioning abilities compared to control groups. Investigations of dose-response relationships between cognition and head-injury exposure also generated mixed findings which may be related to small samples, sampling bias, small effect sizes, and the measurement of different head-injury exposure variables. Study Two was a prospective cohort design investigating neuropsychological functioning and head-injury exposure in NFL retirees aged 50 and up. Retirees underwent baseline (N = 53) and follow-up (N = 29) comprehensive neuropsychological evaluations. Cognitively normal retirees (n = 26) were age, education, and IQ-matched to healthy controls (n = 26). Retirees diagnosed with MCI or dementia (n = 27) were matched as closely as possible to a clinical sample of patients with MCI and dementia by age, education, and diagnosis (n = 22). Independent samples t-tests and repeated measures ANCOVAs were used to evaluate neuropsychological scores between groups. Pearson correlations, partial correlations, and quadratic regressions were used to examine relationships between head-injury exposure and neuropsychological scores. Head-injury exposure variables included concussions, number of concussions with loss of consciousness, years playing professionally, games played, games started, and age beginning tackle football. Overall, NFL retirees did not significantly differ on the majority of measures at baseline or on any measures over time compared to their respective control groups. Furthermore, the vast majority of neuropsychological scores were not significantly related to head-injury exposure, regardless of cognitive diagnosis. In totality, findings suggest that NFL retirees do not have lower cognitive functioning compare to non-athlete controls later in life, and that head-injury exposure obtained over an NFL career is not related to cognitive functioning later-in-life.Item [Southwestern News](2001-11-01) Wren, Worth, Jr.Item [Southwestern News](1997-06-19) Martinez, EmilyItem [Southwestern News](2002-11-12) Bedrick, BarbaraItem [UT Southwestern Medical Center News](2008-07-01) Stafford, Erin PratherItem The Validity of Hourly Neurologic Assessments in the Intensive Care Unit for Patients with Traumatic Brain Injury(2017-01-17) Kabangu, Jean-Luc; Bedros, Nicole; Williams, Brian; Aoun, Salah; Geoffrion, Tracy; Provenzale, Natalie; Baker, Stacy; Minshall, ChristianLEARNING OBJECTIVES: Traumatic brain injury (TBI) is a leading cause of disability and mortality worldwide. The standard of care at many trauma centersis to admit patients with TBI to the Intensive Care Unit (ICU) for hourly neurologic assessments. There is a proven discrepancy between documented GCS (Glasgow Coma Scale score) and the presence of significant organic intracranial injuries and their clinical impact. Additionally, unnecessary ICU stay incurs significant financial costs to and resource utilization, and may adversely affect patient outcomes. There is no consensus regarding the optimal duration or frequency of hourly neurologic assessments. METHODOLOGY: As a feasibility study we retrospectively reviewed data from the trauma registry at our urban, level I trauma center over a 2-month period, Data points included head injury type, admission GCS, lowest GCS within 24 hours of admission, lowest GCS during hospitalization, ICU length of stay, total length of stay; and unplanned surgical, medical, or diagnostic intervention prompted by a decline in GCS. RESULTS: Twenty-two patients were admitted to the ICU based on the radiographic and clinical diagnoses of traumatic brain injury. Eighty-two percent of patients did not experience a decline in GCS within the first 24 hours of admission. Among them, 17% experienced a decline after 24 hours for non-neurological reasons. Of the 18% that did experience a decline within 24 hours, none prompted an unplanned intervention in their previously management plan. CONCLUSIONS: All patients with TBI may not require hourly neurologic assessments in the ICU. The majority of patients in our review did not experience a decline in GCS. Additionally, those that did decline did not trigger a significant change in clinical management. Further data is required to elucidate certain patient or injury criteria to separate patients that truly require hourly neurologic assessments from those that can be monitored in a lower acuity setting.Item Working Memory Differences in Pediatric Moderate and Severe Traumatic Brain Injury(2010-01-12) Fitzpatrick, Stephanie Ann; Stavinoha, Peter L.Traumatic brain injury is one of the leading causes of disability and impairment in children and adolescents. This study sought to determine the effects of severity on verbal working memory and verbal short-term memory. It was hypothesized that increased severity of injury would be associated with decreased performance on working memory tasks. Participants, aged 6-16 years, were tested 6 to 12 months after injury. The sample was comprised of 12 children and adolescents who had sustained a severe TBI and 11 children and adolescents who had sustained a moderate TBI. Results indicated that there were no significant differences between the moderately injured group and subjects with severe injuries on tasks of verbal working memory or verbal short-term memory. However, inspection of the data indicated that children in the severe group performed in the Low Average range, while children in the moderate group performed in the Average range. Results may be limited by the small sample size.