Mild Traumatic Brain Injury Group Research Articles

Neuropsychological outcome and diffusion tensor imaging in complicated versus uncomplicated mild traumatic brain injury.

This study examined whether intracranial neuroimaging abnormalities in those with mild traumatic brain injury (MTBI) (i.e., “complicated” MTBIs) are associated with worse subacute outcomes as measured by cognitive testing, symptom ratings, and/or diffusion tensor imaging (DTI). We hypothesized that (i) as a group, participants with complicated MTBIs would report greater symptoms and have worse neurocognitive outcomes than those with uncomplicated MTBI, and (ii) as a group, participants with complicated MTBIs would show more Diffusion Tensor Imaging (DTI) abnormalities. Participants were 62 adults with MTBIs (31 complicated and 31 uncomplicated) who completed neurocognitive testing, symptom ratings, and DTI on a 3T MRI scanner approximately 6-8 weeks post injury. There were no statistically significant differences between groups on symptom ratings or on a broad range of neuropsychological tests. When comparing the groups using tract-based spatial statistics for DTI, no significant difference was found for axial diffusivity or mean diffusivity. However, several brain regions demonstrated increased radial diffusivity (purported to measure myelin integrity), and decreased fractional anisotropy in the complicated group compared with the uncomplicated group. Finally, when we extended the DTI analysis, using a multivariate atlas based approach, to 32 orthopedic trauma controls (TC), the findings did not reveal significantly more areas of abnormal DTI signal in the complicated vs. uncomplicated groups, although both MTBI groups had a greater number of areas with increased radial diffusivity compared with the trauma controls. This study illustrates that macrostructural neuroimaging changes following MTBI are associated with measurable changes in DTI signal. Of note, however, the division of MTBI into complicated and uncomplicated subtypes did not predict worse clinical outcome at 6-8 weeks post injury.

Language-based embedded performance validity measures in traumatic brain injury

No studies to date have investigated the Boston Naming Test (BNT) as an embedded performance validity test (PVT). This study investigated the classification accuracy of the Boston Naming Test (BNT) and the Verbal Fluency Test (FAS and Animal Fluency), as embedded PVTs in a compensation-seeking mild traumatic brain injury (MTBI) sample (N = 57) compared to a non-compensation-seeking moderate-to-severe TBI (STBI) sample (N = 61). Participants in the MTBI sample who failed two or more PVTs were included, as were STBI participants who passed all PVTs. The classification accuracy of the individual tests and a logistically derived combined (LANGPVT) measure were studied. Results showed significant group differences (p < .05) on BNT, Animal Fluency, and LANGPVT between the MTBI and STBI groups. However, receiver operating characteristic (ROC) analyses indicated that only LANGPVT had acceptable classification accuracy (area under the curve > .70). Setting specificity at approximately .90, the recommended LANGPVT cutoff scores had sensitivity of .26. Results indicated that, similar to other embedded PVTs, these measures had low sensitivity when adequate specificity levels were maintained. However, extremely low scores on these measures are unlikely to occur in non-compensation-seeking, non-language-impaired, STBI cases.

Specificity of cognitive and behavioral complaints in post-traumatic stress disorder and mild traumatic brain injury.

Characterization of cognitive and behavioral complaints is explored in Post-traumatic stress disorder (PTSD) and mild traumatic brain injury (MTBI) samples according to the severity of PTSD, depression and general anxiety conditions. Self-reported questionnaires on cognitive and behavioral changes are administered to PTSD, MTBI, MTBI/PTSD and control groups. Confounding variables are controlled. All groups report more complaints since the traumatic event. PTSD and MTBI/PTSD groups report more anxiety symptoms, depression and complaints compared to the MTBI group. Relatives of the PTSD group confirm most of the behavioral changes reported. Results suggest the utility of self-reported questionnaires to personalize cognitive and behavioral interventions in PTSD and MTBI to cope with the impacts of the traumatic event.

Posttraumatic Stress Disorder Exacerbates Emotional Complaints but not Cognitive Impairments in Individuals Suffering from Postconcussional Disorder after Mild Traumatic Brain Injury

The aim of this study was to examine the effect of posttraumatic stress disorder (PTSD) on (a) neuropsychological test performance and (b) self-reported emotional complaints within individuals suffering from postconcussional disorder (PCD) after a mild traumatic brain injury (MTBI). A two-group comparative research design was employed. Two MTBI samples with and without PTSD were assessed with a neuropsychological test battery and the Ruff Neurobehavioral Inventory (RNBI). On the neurocognitive test performances no significant between group differences were found, but the MTBI group with PTSD endorsed a significantly greater number of emotional complaints, especially in the RNBI subscales of anxiety and depression. The patients with PTSD also endorsed a significantly greater number of premorbid sequelae in the RNBI emotional composite scale as well as the RNBI premorbid subscales of pain, anxiety and abuse. In sum, PTSD has a negative impact on emotional but not cognitive functioning within individuals suffering from PCD after a mild TBI.

Diffusion tensor imaging findings and postconcussion symptom reporting six weeks following mild traumatic brain injury.

The purpose of this study is to examine the relation between the microstructural architecture of white matter, as measured by diffusion tensor imaging (DTI), and postconcussion symptom reporting 6-8 weeks following mild traumatic brain injury (MTBI). Participants were 108 patients prospectively recruited from a Level 1 Trauma Center (Vancouver, BC, Canada) following an orthopedic injury [i.e., 36 trauma controls (TCs)] or MTBI (n = 72). DTI of the whole brain was undertaken using a Phillips 3T scanner at 6-8 weeks postinjury. Participants also completed a 5 h neurocognitive test battery and a brief battery of self-report measures (e.g., depression, anxiety, and postconcussion symptoms). The MTBI sample was divided into two groups based on ICD-10 criteria for postconcussional syndrome (PCS): first, PCS-present (n = 20) and second, PCS-absent (n = 52). There were no significant differences across the three groups (i.e., TC, PCS-present, and PCS-absent) for any of the neurocognitive measures (p = .138-.810). For the self-report measures, the PCS-present group reported significantly more anxiety and depression symptoms compared with the PCS-absent and TC groups (p < .001, d = 1.63-1.89, very large effect sizes). For the DTI measures, there were no significant differences in fractional anisotropy, axial diffusivity, radial diffusivity, or mean diffusivity when comparing the PCS-present and PCS-absent groups. However, there were significant differences (p < .05) in MD and RD when comparing the PCS-present and TC groups. There were significant differences in white matter between TC subjects and the PCS-present MTBI group, but not the PCS-absent MTBI group. Within the MTBI group, white-matter changes were not a significant predictor of ICD-10 PCS.

Long-Term Executive Functioning Outcomes for Complicated and Uncomplicated Mild Traumatic Brain Injury Sustained in Early Childhood

This study investigated long-term executive functioning following early mild traumatic brain injury (TBI), differentiating between complicated (n = 34) and uncomplicated injuries (n = 18). Children post mild TBI were compared to 33 controls at least 7-years post-injury. The complicated mild TBI group performed significantly worse on divided attention compared to both groups, with younger age at injury and neurological symptoms predictors of outcome. No significant group differences existed on speed of information processing, selective attention, working memory, or goal setting. These findings indicate that specific aspects of executive function are compromised by early complicated mild TBI and argue for a stratified definition of mild TBI.

Health-related quality of life after mild, moderate and severe traumatic brain injury: Patterns and predictors of suboptimal functioning during the first year after injury

BackgroundThe Glasgow Outcome Scale Extended (GOSE) is the established functional outcome scale to assess disability following traumatic brain injury (TBI), however does not capture the patient's subjective perspective. Health-related quality of life (HRQL) does capture the individual's perception of disability after TBI, and has therefore been recognized as an important outcome in TBI. In contrast to GOSE, HRQL enables comparison of health outcome across various disease states and with healthy individuals. We aimed to assess functional outcome, HRQL, recovery, and predictors of 6 and 12-month outcome in a comprehensive sample of patients with mild, moderate or severe TBI, and to examine the relationship between functional impairment (GOSE) and HRQL. MethodsA prospective cohort study was conducted among a sample of 2066 adult TBI patients who attended the emergency department (ED). GOSE was determined through questionnaires or structured interviews. Questionnaires 6 and 12 months after ED treatment included socio-demographic information and HRQL measured with Short-Form Health Survey (SF-36; reflecting physical, mental and social functioning) and Perceived Quality of Life Scale (PQoL; measuring degree of satisfaction with functioning). Results996 TBI survivors with mild, moderate or severe TBI completed the 6-month questionnaire. Functional outcome and HRQL after moderate or severe TBI was significantly lower than after mild TBI. Patients with moderate TBI showed greatest improvement. After one year, the mild TBI group reached outcomes comparable to population norms. TBI of all severities highly affected SF-36 domains physical and social functioning, and physical and emotional role functioning. GOSE scores were highly related to all SF-36 domains and PQoL scores. Female gender, older age, co-morbidity and high ISS were strongest independent predictors of decreased HRQL at 6 and 12 months after TBI. ConclusionsHRQL and recovery patterns differ for mild, moderate and severe TBI. This study indicates that GOSE, although clinically relevant, fails to capture the subjective perspective of TBI patients, which endorses the use of HRQL as valuable addition to established instruments in assessing disability following TBI. Influence of TBI severity on recovery, together with female gender, older age, co-morbidity and high ISS should be considered in long-term follow-up and intervention programs.

Assessment of mild traumatic brain injury with the King-Devick Test® in an emergency department sample

Objective: The King-Devick Test® (K-D) is a brief measure of cognitive processing speed and rapid gaze shifting that appears sensitive to the effects of sport-related concussion. This study evaluated its diagnostic and incremental validity in civilian patients with mild traumatic brain injury (MTBI).Methods: Participants with MTBI (n = 26) and controls with non-head injuries (n = 33) were prospectively recruited from an Emergency Department (ED). They underwent a clinical evaluation including the K-D test and the Sport Concussion Assessment Tool 2 (SCAT2). Magnetic resonance imaging (MRI) was conducted within 10 days post-injury.Results: The patients with MTBI differed from those without MTBI on components of the SCAT2, including the Symptom Scale (Cohen’s d = 1.02–1.15, p < 0.001) and Standardized Assessment of Concussion (d = 0.81, p = 0.004), but not the K-D test (d = 0.40, p = 0.148). In a logistic regression analysis, the K-D Test did not contribute over and above these two measures in predicting group membership (MTBI vs. control), p = 0.191. Low K-D Test scores in the MTBI group (<1 SD below controls) were not associated with poor SCAT2 performance, loss of consciousness or traumatic abnormalities on MRI, suggesting these cases may have been false positives.Conclusions: The present findings do not support the K-D Test for the assessment of civilian MTBI in an ED setting.

A prospective study of the influence of acute alcohol intoxication versus chronic alcohol consumption on outcome following traumatic brain injury.

The purpose of the study was to disentangle the relative contributions of day-of-injury alcohol intoxication and pre-injury alcohol misuse on outcome from TBI. Participants were 142 patients enrolled from a Level 1 Trauma Center (in Vancouver, Canada) following a traumatic brain injury (TBI; 43 uncomplicated mild TBI and 63 complicated mild-severe TBI) or orthopedic injury [36 trauma controls (TC)]. At 6-8 weeks post-injury, diffusion tensor imaging (DTI) of the whole brain was undertaken using a Phillips 3T scanner. Participants also completed neuropsychological testing, an evaluation of lifetime alcohol consumption (LAC), and had blood alcohol levels (BALs) taken at the time of injury. Participants in the uncomplicated mild TBI and complicated mild-severe TBI groups had higher scores on measures of depression and postconcussion symptoms (d = 0.45-0.83), but not anxiety, compared with the TC group. The complicated mild-severe TBI group had more areas of abnormal white matter on DTI measures (all p < .05; d = 0.54-0.61) than the TC group. There were no difference between groups on all neurocognitive measures. Using hierarchical regression analyses and generalized linear modeling, LAC and BAL did provide a unique contribution toward the prediction of attention and executive functioning abilities; however, the variance accounted for was small. LAC and BAL did not provide a unique and meaningful contribution toward the prediction of self-reported symptoms, DTI measures, or the majority of neurocognitive measures. In this study, BAL and LAC were not predictive of mental health symptoms, postconcussion symptoms, cognition, or white-matter changes at 6-8 weeks following TBI.

A Preliminary Study to Identify Locomotor-Cognitive Dual Tasks That Reveal Persistent Executive Dysfunction After Mild Traumatic Brain Injury

ObjectiveTo identify different combinations of physical (level, obstacle avoidance, stepping down) and cognitive (visual, mental) demands within a locomotor navigational context that best discriminates between persons with mild traumatic brain injury (MTBI) and control subjects for an eventual clinical tool to assess residual executive dysfunction. DesignGroup comparison study. SettingRehabilitation facility. ParticipantsVolunteer sample (N=14) of persons with MTBI (n=7) (6 women; age, 20±1.6y) and a comparison group (n=7) of subjects without neurologic problems (6 women; age, 22.4±1.4y). InterventionsNot applicable. Main Outcome MeasuresGait speed (m/s) and dual-task cost calculated as the relative change in gait speed from single (no cognitive task) to dual tasks for the same gait condition. ResultsThere were significant interactions between groups and cognitive tasks and between groups and cognitive and physical tasks for gait speed. Specifically, the MTBI group walked slower than control subjects in the dual-task conditions when stepping over an obstacle combined with each cognitive task. When gait speed was measured as dual-task costs, group differences were more evident, except for stepping down. ConclusionsThese preliminary results suggest that both absolute gait speed and calculated dual-task costs during the combination of stepping over an obstacle with a simultaneous cognitive task are sensitive to revealing executive dysfunction in persons with MTBI. Gait speed can be easily measured in the clinic to provide important information to make diagnoses and decide about return to play or function. Continued work building on these preliminary results is needed toward the development of a clinical tool.

Potholes and Molehills: Bias in the Diagnostic Performance of Diffusion-Tensor Imaging in Concussion

To investigate the extent of bias in a clinical study involving "pothole analysis" of diffusion-tensor imaging (DTI) data used to quantify white matter lesion load in diseases with a heterogeneous spatial distribution of pathologic findings, such as mild traumatic brain injury (TBI), and create a mathematical model of the bias. Use of the same reference population to define normal findings and make comparisons with a patient group introduces bias, which potentially inflates reported diagnostic performance. In this institutional review board-approved prospective observational cohort study, DTI data were obtained in 20 patients admitted to the emergency department with mild TBI and in 16 control subjects. Potholes and molehills were defined as clusters of voxels with fractional anisotropy values more than 2 standard deviations below and above the mean of the corresponding voxels in the reference population, respectively. The number and volume of potholes and molehills in the two groups were compared by using a Mann-Whitney U test. Standard analysis showed significantly more potholes in mild TBI than in the control group (102.5 ± 34.3 vs 50.6 ± 28.9, P < .001). Repeat analysis by using leave-one-out cross-validation decreased the apparent difference in potholes between groups (mild TBI group, 102.5 ± 34.3; control group, 93.4 ± 27.2; P = .369). It was demonstrated that even with 100 subjects, this bias can decrease the voxelwise false-positive rate by more than 30% in the control group. The pothole approach to neuroimaging data may introduce bias, which can be minimized by independent training and test groups or cross-validation methods. This bias is sufficient to call into question the previously reported diagnostic performance of DTI for mild TBI.

Biopsychosocial Outcome after Uncomplicated Mild Traumatic Brain Injury

The purpose of this study was to examine the biopsychosocial outcome from uncomplicated mild traumatic brain injury (MTBI) within the first 3 weeks post injury. Participants were 48 prospectively enrolled patients from the Emergency Department of Tampere University Hospital, Finland, who sustained an uncomplicated MTBI. At 3 weeks post injury, diffusion tensor imaging (DTI) of the whole brain was undertaken using a Siemens 3T scanner. Measures of fractional anisotropy (FA) were calculated for 16 regions of interest (ROIs) and measures of apparent diffusion coefficient (ADC) were calculated for 10 ROIs. Twenty-four healthy control participants also completed DTI of the whole brain for comparison. Participants were administered a brief battery of self-report (e.g., postconcussion symptoms, depression, and fatigue) and neurocognitive measures (e.g., verbal learning and memory). There were no significant differences between the uncomplicated MTBI and healthy control group on any measures of learning and memory. Compared to the control group, the uncomplicated MTBI group reported a greater number of postconcussion symptoms and fatigue, but not depression. When considering all DTI ROIs simultaneously, the MTBI group had a significantly larger number of low DTI measures (FA values) compared to the healthy controls. MTBI patients with multifocal white matter changes did not show evidence of worse symptoms, cognitive impairment, or slower return to work compared to MTBI patients with broadly normal white matter.

Instrumenting the Balance Error Scoring System for Use With Patients Reporting Persistent Balance Problems After Mild Traumatic Brain Injury

ObjectiveTo determine whether alterations to the Balance Error Scoring System (BESS), such as modified conditions and/or instrumentation, would improve the ability to correctly classify traumatic brain injury (TBI) status in patients with mild TBI with persistent self-reported balance complaints. DesignCross-sectional study. SettingOutpatient clinic. ParticipantsSubjects (n=13; age, 16.3±2y) with a recent history of concussion (mild TBI group) and demographically matched control subjects (n=13; age, 16.7±2y; control group). InterventionsNot applicable. Main Outcome MeasuresOutcome measures included the BESS, modified BESS, instrumented BESS, and instrumented modified BESS. All subjects were tested on the noninstrumented BESS and modified BESS and were scored by visual observation of instability in 6 and 3 stance conditions, respectively. Instrumentation of these 2 tests used 1 inertial sensor with an accelerometer and gyroscope to quantify bidirectional body sway. ResultsScores from the BESS and the modified BESS tests were similar between groups. However, results from the instrumented measures using the inertial sensor were significantly different between groups. The instrumented modified BESS had superior diagnostic classification and the largest area under the curve when compared with the other balance measures. ConclusionsA concussion may disrupt the sensory processing required for optimal postural control, which was measured by sway during quiet stance. These results suggest that the use of portable inertial sensors may be useful in the move toward more objective and sensitive measures of balance control postconcussion, but more work is needed to increase sensitivity.

Mild and moderate pediatric traumatic brain injury

Opinion is divided on the role of routine repeat head computed tomography (RHCT) for guiding clinical management in pediatric patients with blunt head trauma. We hypothesize that routine RHCT does not lead to change in management in mild and moderate traumatic brain injury (TBI). This is a 3-year retrospective study of all patients of age 2 years to 18 years with blunt TBI admitted to our Level 1 trauma center with an abnormal head CT. Indications for RHCT (routine vs. neurologic deterioration) and their findings (progression or improvement) were recorded. Neurosurgical intervention was defined as extraventricular drain placement, craniectomy, or craniotomy. Primary outcome was a change in management after RHCT. A total of 291 pediatric patients were identified; of which 191 patients received an RHCT. Routine RHCT did not lead to neurosurgical intervention in the mild and moderate TBI group. In patients who received RHCT due to neurologic decline (n = 7), radiographic progression was seen on 85% of the patients (n = 6), with subsequent neurosurgical interventions in three patients. Two of these patients had a Glasgow Coma Scale (GCS) score of less than 8 at admission. Our study showed that the neurologic examination can be trusted and is reliable in pediatric blunt TBI patients in determining when an RHCT scan is necessary. We recommend that RHCT is required routinely in patients with intracranial hemorrhage with GCS score of 8 or less and in patients with GCS greater than 8 and that RHCT be performed only when there are clinical indications. Diagnostic/therapeutic study, level IV.

Wechsler Adult Intelligence Scale–Third Edition profiles and their relationship to self-reported outcome following traumatic brain injury

Neuropsychological assessments of outcome after traumatic brain injury (TBI) are often unrelated to self-reported problems after TBI. The current study cluster-analyzed the Wechsler Adult Intelligence Scale–Third Edition (WAIS–III) subtest scores from mild, moderate, and severe TBI (n = 220) and orthopedic injury control (n = 95) groups, to determine whether specific cognitive profiles are related to people’s perceived outcomes after TBI. A two-stage cluster analysis produced 4- and 6-cluster solutions, with the 6-cluster solution better capturing subtle variations in cognitive functioning. The 6 clusters differed in the levels and profiles of cognitive performance, self-reported recovery, and education and injury severity. The findings suggest that subtle cognitive impairments after TBI should be interpreted in conjunction with patient’s self-reported problems.

Unravelling the influence of mild traumatic brain injury (MTBI) on cognitive-linguistic processing: A comparative group analysis

Background: Cognitive-linguistic deficits often accompany traumatic brain injury (TBI) and can negatively impact communicative competency. The linguistic sequelae underpinning mild TBI (MTBI) remain largely unexplored in contemporary literature.Objectives: The present research methods aim to provide group evidence pertaining to the influence of MTBI on linguistic and higher-level language processing. Extrapolating on the findings of recent case reports, it is hypothesized that performance of the MTBI patients will be significantly reduced compared to normal controls performance on the employed high-level linguistic tasks.Methods: Sixteen patients with MTBI and 16 age- and education-matched normal control participants were assessed using a comprehensive battery of cognitive-linguistic assessments.Results: The results demonstrated statistically significant differences between MTBI and normal control group performance across a number of higher-level linguistic, general cognitive and general language tasks. MTBI group performance was significantly lower than the normal control group on tasks requiring complex lexical semantic operations and memory demands, including: Recall, organization, making inferences, naming and perception/discrimination.Conclusions: These outcomes confer that post-MTBI, cognitive, high-level language and isolated general language performance (e.g. naming) is significantly reduced in MTBI patients, compared to normal controls. Furthermore, the detailed cognitive-linguistic profile offered provides a necessary direction for the identification of areas of linguistic decline in MTBI and targets for therapeutic intervention of impaired cognitive-linguistic processes to ultimately improve communicative outcomes in MTBI.

Motor proficiency in children with mild traumatic brain injury compared with a control group

To assess motor proficiency and movement disorders in children with mild traumatic brain injury compared with an uninjured control group. Inclusion criteria were based on the definitions issued by the American Congress of Rehabilitation Medicine. A group of 27 children with mild traumatic brain injury (age range 4-17 years) and a control group of 79 healthy children. Bruininks-Oseretsky Test of Motor Proficiency (BOTMP) was administered. This is a standardized comprehensive test of gross- and fine-motor function that produces standard scores for children in this age group. It is divided into 4 gross-motor tasks, 3 fine-motor tasks, 1 combined task, and a test of hand and foot dominance. Tremor was also evaluated. The mean standard scores for both groups were within the normal range. For balance, the mild traumatic brain injury group had a significantly poorer performance than controls (p = 0.03). Tremor was significantly more frequent in the mild traumatic brain injury group (p = 0.004), and mixed-handedness was significantly over-represented in the mild traumatic brain injury group (p = 0.02). In this study, children with mild traumatic brain injury did not differ from the norm in terms of fine- or gross-motor proficiency compared with a control group of uninjured children, but a difference in balance skill (p = 0.03), mixed-handedness (p = 0.02) and tremor (p = 0.004) was detected, to the injured children's detriment.

Self-Reported Mild TBI and Postconcussive Symptoms in a Peacetime Active Duty Military Population

To investigate the potential cumulative impact of mild traumatic brain injury (MTBI) on postconcussive symptoms. A total of 224 active duty soldiers reporting MTBI within 1 year of testing. For 101, this MTBI was their only reported traumatic brain injury (TBI); 123 had sustained at least 1 additional MTBI during their lifetime. A No TBI control group (n = 224) was included for comparison. Self-report symptoms data via questionnaire. Within time since injury subgroups (≤3 months; Post-3 months), symptom endorsement (no symptoms, 1 or 2 symptoms, 3+ symptoms) among soldiers with 1 MTBI was compared with that of soldiers with 2 or more MTBIs. Injured soldiers' symptom endorsement was compared with that of soldiers who had not sustained a TBI. Among the recently injured (≤3 months), those with 2 or more MTBIs endorsed significantly more symptoms than those with 1 MTBI: 67% of soldiers with 2 or more MTBIs reported 3+ symptoms, versus 29% of One MTBI soldiers. Among Post-3 month soldiers, there were no significant differences between MTBI groups. Overall, soldiers with MTBI endorsed significantly more symptoms than those without TBI. Past experience of MTBI may be a risk factor for increased symptom difficulty for several months postinjury. Clinicians should ascertain lifetime history of brain injury when evaluating patients for MTBI.

Heterogeneity of brain lesions in pediatric traumatic brain injury.

Magnetic resonance imaging (MRI) provides a method to identify and quantify abnormalities resulting from traumatic brain injury (TBI). MRI abnormalities in children with TBI have not been fully characterized according to the frequency, location, and quantitative measurement of a range of pathologies critical for studies of neuropsychological outcome. Here, we report MRI findings from a large, multicenter study of childhood TBI, the Social Outcomes of Brain Injury in Kids (SOBIK) study, which compared qualitative and quantitative neuroimaging findings in 72 children with complicated mild-to-severe TBI to 52 children with orthopedic injury (OI). Qualitative analyses of MRI scans coded white matter hyperintensities (WMHs), hemosiderin deposits reflecting prior hemorrhagic lesions, regions of encephalomalacia and/or atrophy, and corpus callosum atrophy and traumatic shear lesions. Two automated quantitative analyses were conducted: (a) FreeSurfer methods computed volumes for total brain, white matter (WM), gray matter (GM), corpus callosum, ventricles, amygdala, hippocampus, basal ganglia, and thalamus along with a ventricle-to-brain ratio (VBR); and (b) voxel-based morphometry (VBM) to identify WM, GM, and cerebrospinal fluid. We also examined performance on the Processing Speed Index (PSI) from the Wechsler Intelligence Scale for Children, Fourth Edition, in relation to the above-mentioned neuroimaging variables. WMHs, hemosiderin deposits, and focal areas of encephalomalacia or atrophy were common in children with TBI, were related to injury severity, and were mostly observed within a frontotemporal distribution. Quantitative analyses showed volumetric changes related to injury severity, especially ventricular enlargement and reduced corpus callosum volume. VBM demonstrated similar findings, but, in addition, GM reductions in the inferior frontal, basal forebrain region, especially in the severe TBI group. The complicated mild TBI group showed few differences from the OI group. PSI was significantly associated with global atrophy, as measured by VBR. MRI findings after childhood TBI are diverse and particularly influenced by injury severity, and they involve common features, group heterogeneity, and individual variability.

Poster 40 Comparing Patients With Mild Traumatic Brain Injury to Trauma Controls on CNS Vital Signs

To compare performance on a computerized neuropsychological test battery, CNS Vital Signs (CNS-VS), in a sample of patients with mild traumatic brain injury (MTBI) and trauma controls. Quasi-Experimental, Two-Group, Between-Subjects Design. Participants were 50 patients who met the WHO Collaborating Center Task Force criteria for MTBI and 31 trauma controls. Groups were similar in age, years of education, and estimated intellectual ability. A substantial minority (28%) of the MTBI group had a trauma-related abnormality on day-of-injury CT (i.e., a “complicated MTBI”). Participants were recruited from the Emergency Department of Vancouver General Hospital. The CNS-VS, which generates a Neurocognition Index (NCI) and five primary domain scores, was administered approximately six to eight weeks post injury. Differences in mean performance were examined with a MANOVA and exploratory ANOVAs. Differences in the frequency of low scores at four cutoffs (1SD, <10th percentile, ≤5th percentile, and there was no significant difference between groups for the NCI. A MANOVA using the five domain scores did not reveal statistically significant differences between the groups. Moreover, there were no group differences on any of the domain scores on exploratory ANOVAs. The frequencies of low scores at each cutoff, although more common in the MTBI sample, were not statistically different. At the group level, participants with MTBI did not differ on computerized testing when compared to trauma controls six to eight weeks following injury.