Browsing by Author "Ewing-Cobbs, Linda"
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Item Age effects in the recovery of motor, somatosensory, and visual-spatial skills following pediatric head injury(1988) Thompson, Nora M.; Fletcher, Jack M.; Levin, Harvey S.; Ewing-Cobbs, Linda; Foorman, Barbara R.; Miner, Michael E.; Power, Thomas G.This prospective, longitudinal study of the recovery of motor, somatosensory, and visual-spatial functions following pediatric closed head injury supports previous literature describing a systematic relationship of performance levels with injury severity. Furthermore, systematic relationships were demonstrated between injury severity and the rate of recovery during the first post-injury year. Age effects were found suggesting greater vulnerability for children on a somatosensory and a constructional task. In addition, adolescents were at greater risk for deficits in fine motor speed and on a grapho-motor task. These age effects lend support to the functional maturation hypothesis. Correlates of recovery from hemiparesis included the type of pathological process and proximity to the corticospinal pathways. Site of injury was not significantly related to performance in most task domains. Differential recovery patterns for speed and accuracy were demonstrated on a somatosensory task. Finally, this study supports the utility of Hierarchical Linear Modelling for assessing the correlates of change.Item Attention and memory in children and adolescents with traumatic brain injury(1988) Kaufmann, Paul M.; Fletcher, Jack M.; Breitmeyer, Bruno G.; Ewing-Cobbs, Linda; Foorman, Barbara R.; Levin, Harvey S.; Miner, Michael E.Attention and memory were investigated in fifty-two children and adolescents at one and two years following closed-head injury. Subjects were divided into three injury severity groups (mild, moderate, and severe) based on neurological criteria. Attention and memory skills were assessed using the following battery: 1) WISC-R Digit Span, 2) Continuous Performance Task, 3) Continuous Recognition Memory, and 4) Verbal Selective Reminding Task. Subjects with more severe brain injuries had a greater degree of attention and memory impairment. Children under 13 years of age demonstrated greater impairment on the CPT when compared to adolescents. Deficits were most pronounced on tasks requiring selective attention and inhibition of responses to distracting stimuli. Attention skills made a significant contribution to overall memory performance. These results support the view that attention is a prerequisite skill for memory. There was no evidence of greater sparing of attention in younger children. Implications for new learning and development were discussed.Item Cognitive and behavioral attention in children with math difficulties(Child Neuropsychology, 2013) Gold, Alanna B.; Ewing-Cobbs, Linda; Cirino, Paul T.; Fuchs, Lynn S.; Stuebing, Karla K.; Fletcher, Jack M.Cognitive assessments and behavioral ratings of attention were used to examine the relation of inattention to math performance in children. Third grade students with math difficulties (MD; n = 17) and math and reading difficulties (MDRD; n = 35) were administered the Attentional Network Test (ANT), as well as achievement and intelligence measures. Strengths and Weaknesses of ADHD-Symptoms and Normal-Behavior-IV (SWAN-IV) Inattention ratings were collected from teachers. Two comparison groups were also recruited: a typically achieving group (n = 23) and a group that responded to a math-tutoring intervention (responders; n = 54). On the ANT, children with MD and MDRD did not perform significantly different than typically achieving children or responders on measures of alerting and orienting attention and executive control. All subgroups did demonstrate performance patterns that were expected on the ANT. However, performance across blocks of the task was inconsistent, suggesting poor reliability. There were no relations between ANT performance and SWAN-IV behavioral inattention scores, though behavioral ratings of inattention correlated significantly with math performance. Children with MD and MDRD may have more difficulty with distraction and attention to detail in contextual situations, as opposed to impulsive responding in these settings. The lack of relation between cognitive attention and math performance may suggest that either the ANT does not assess the relevant attention constructs associated with math difficulties or may parallel studies of attention deficit/hyperactivity disorder (ADHD) in which cognitive and behavioral assessments are weakly related.Item Development and aging of the healthy human brain uncinate fasciculus across the lifespan using diffusion tensor tractography(Brain Research, 2009-06) Hasan, Khader M.; Iftikhar, Amal; Kamali, Arash; Kramer, Larry A.; Ashtari, Manzar; Cirino, Paul T.; Papanicolaou, Andrew C.; Fletcher, Jack M.; Ewing-Cobbs, LindaThe human brain uncinate fasciculus (UF) is an important cortico-cortical white matter pathway that directly connects the frontal and temporal lobes, although there is a lack of conclusive support for its exact functional role. Using diffusion tensor tractography, we extracted the UF, calculated its volume and normalized it with respect to each subject's intracranial volume (ICV) and analyzed its corresponding DTI metrics bilaterally on a cohort of 108 right-handed children and adults aged 7-68 years. Results showed inverted U-shaped curves for fractional anisotropy (FA) with advancing age and U-shaped curves for radial and axial diffusivities reflecting white matter progressive and regressive myelination and coherence dynamics that continue into young adulthood. The mean FA values of the UF were significantly larger on the left side in children (p = 0.05), adults (p = 0.0012) and the entire sample (p = 0.0002). The FA leftward asymmetry (Left > Right) is shown to be due to increased leftward asymmetry in the axial diffusivity (p < 0.0001) and a lack of asymmetry (p > 0.23) for the radial diffusivity. This is the first study to provide baseline normative macro and microstructural age trajectories of the human UF across the lifespan. Results of this study may lend themselves to better understanding of UF role in future behavioral and clinical studies.Item Errors in multi-digit arithmetic and behavioral inattention in children with math difficulties(Journal of Learning Disabilities, 2009-12) Raghubar, Kimberly P.; Cirino, Paul T.; Barnes, Marcia A.; Ewing-Cobbs, Linda; Fletcher, Jack M.; Fuchs, Lynn S.Errors in written multi-digit computation were investigated in children with math difficulties. Third-and fourth-grade children (n = 291) with coexisting math and reading difficulties, math difficulties, reading difficulties, or no learning difficulties were compared. A second analysis compared those with severe math learning difficulties, low average achievement in math, and no learning difficulties. Math fact errors were related to the severity of the math difficulties, not to reading status. Contrary to predictions, children with poorer reading, regardless of math achievement, committed more visually based errors. Operation switch errors were not systematically related to group membership. Teacher ratings of behavioral inattention were related to accuracy, math fact errors, and procedural bugs. The findings are discussed with respect to hypotheses about the cognitive origins of arithmetic errors and in relation to current discussions about how to conceptualize math disabilities.Item Frontostriatal White Matter Integrity Relations with ‘Cool’ and ‘Hot’ Self-Regulation Following Pediatric Traumatic Brain Injury(2019-05) Fischer, Jesse T.; Ewing-Cobbs, Linda; Cirino, Paul T.; Fan, Weihua; Alfano, Candice A.; Bick, Johanna R.Traumatic brain injury (TBI) produces microstructural damage to white matter pathways connecting neural structures that support top-down control of prefrontal regions over striatal regions involved in self-regulation (SR). Frontostriatal white matter can be separated into dorsal and ventral pathways, and has been linked to cognitive (‘cool’) and emotional (‘hot’) types of SR. The aims of the current study were to (1) evaluate the impact of pediatric TBI, age at injury, and sex on the integrity of dorsal (dorsal anterior cingulate, ventrolateral prefrontal cortex, and dorsolateral prefrontal cortex to caudate) and ventral (medial orbitofrontal cortex and rostral anterior cingulate cortex to nucleus accumbens) frontostriatal pathways assessed 2 months after injury, and on the cool and hot self-regulatory behaviors they are believed to support; and (2) investigate whether the impact of TBI on cool and hot self-regulatory behaviors at 6 months after injury was mediated by the integrity of dorsal and ventral frontostriatal pathways, respectively. The current study used archival data from a prospective, longitudinal study consisting of 84 children and adolescents with TBI (24 uncomplicated mild, 30 complicated mild, 6 moderate, 24 severe) and 55 typically developing (TD) children, aged 8-15. Children with TBI were classified into uncomplicated mild TBI (mTBI), and more severe TBI (sTBI; complicated mild, moderate, and severe TBI). Diffusion tensor tractography was used to map dorsal and ventral white matter pathways. Measures of cool SR included focused and sustained attention (Continuous Performance Task omission errors and reaction time by block), and parent reported attention via the Strengths and Weaknesses of ADHD and Normal Behavior scale. Hot SR measures included risk-taking via Balloon Analogue Risk Task pumps and emotional control via the Behavior Rating in Executive Functioning parent report. Multivariate general linear models (GLM) showed that, in comparison to TD children, children with sTBI had lower fractional anisotropy (FA) in dorsal pathways connecting bilateral dorsal anterior cingulate to caudate and the ventral pathway linking the right medial orbitofrontal cortex to nucleus accumbens. Children with sTBI also had significantly greater difficulties than healthy children with parent reported cool and hot SR, but not on task performance of SR (focused or sustained attention and risk taking). Focused attention, risk taking, and emotional control were significantly correlated with FA of specific dorsal and ventral pathways. Although frontostriatal white matter integrity predicted both cool and hot SR difficulties, only the effect of TBI on focused attention 6 months after injury was mediated by dorsal pathway integrity 2 months post-TBI. Frontostriatal pathways may serve as a biomarker to identify children at risk for specific SR difficulties as well as to assess response to interventions targeted at cool or hot SR. Findings can guide future research on dorsal and ventral neural correlates of SR difficulties following pediatric TBI, and can inform theoretical and clinical understanding of attention and frontostriatal neural circuitry in broader neurodevelopmental populations.Item Language function in children with Tourette syndrome(1988) Brookshire, Bonnie; Fletcher, Jack M.; Ewing-Cobbs, Linda; Kessel, Frank S.; Butler, Ian J.In this study, the psycholinguistic abilities of children with Tourette Syndrome (TS) were investigated. Assessment of oral and written language included measures of syntactic comprehension, verbal fluency, oral and written story narration, word recognition and spelling, and writing to dictation and copy. Seventeen children, aged 10-16 years, composed the TS experimental group. The comparison group consisted of 12 children who were siblings of a child with TS. In comparison to the sibling group, children with TS demonstrated adequate syntactic comprehension, verbal fluency, story recall, and word recognition. Significant differences between the two groups were observed on written language measures, including the story generation task and word spelling. Children in the TS group used a story grammar model, but their written stories contained fewer clauses and fewer story components. Differences between the two groups were not statistically significant on handwriting measures; however, qualitative analysis of writing skills revealed the children in the TS group to have poorer handwriting, and to make more frequent errors in capitalization, punctuation, and spacing. The difficulty which the children with TS had on the written story task might be attributed to their poorer handwriting. Children in the TS group may have restricted their responses to the written task, thus reducing the potential content of their stories. In addition to mechanical writing skills, the picture story task requires the execution of a number of linguistic and cognitive abilities. The child is required to analyze the three picture story sequence and infer the intended meaning. Thus, the picture story task may have been sensitive to difficulties which children with TS may have in perceiving and comprehending complex visual information. The child must then generate a story in which the events are organized in appropriate temporal, spatial, and causal sequence. An acceptable written story must contain appropriate vocabulary and the correct application of rules of syntax and morphology, as well as spelling, capitaiization, and punctuation. This type of task appears to tap the child's ability to integrate all aspects of language knowledge. The TS children in this study demonstrated a pattern of language abilities and deficits which is similar to clinical descriptions of children who have been identified as having nonverbal learning disabilities (Rourke, 1987). This study demonstrated the potential contribution of discourse analysis in the investigation of higher order psycholinguistic abilities. This type of analysis might also be applied in the study of other learning disabled populations.Item Linguistic functions following closed head injury in children and adolescents(1984) Ewing-Cobbs, Linda; Levin, Harvey S.; Sheer, Daniel E.; Fletcher, Jack M.; Siegel, Alexander W.An important issue in the field of developmental neuropsychology concerns the effect of age at the time of cerebral insult upon cognitive status. The Neurosensory Center Comprehensive Examination for Aphasia was used to examine linguistic performance in 57 children and adolescents who sustained either a mild or a moderate/severe closed head injury. The design was a 2 (Age) X 2 (Severity) factorial. Analysis of variance indicated no sparing of language functions in children. Moreover, as compared to adolescents, children were disproportionately affected on measures of written language. Naming and writing functions were adversely affected by moderate/severe injury. In contrast, neither expressive nor receptive language skills were differentially influenced by the severity of injury. Coma duration was a better predictor of linguistic functioning than the Glasgow Coma Scale score. Results were discussed in terms of previous studies of acquired language disorders in children. Implications of the effect of cerebral injury on developing cognitive skills were examined.Item Neocortical reorganization in spina bifida(NeuroImage, 2008-05) Juranek, Jenifer; Fletcher, Jack M.; Hasan, Khader M.; Breier, Joshua I.; Cirino, Paul T.; Pazo-Alvarez, Paula; Diaz, Javier D.; Ewing-Cobbs, Linda; Dennis, Maureen; Papanicolaou, Andrew C.Normal brain development throughout childhood and adolescence is usually characterized by decreased cortical thickness in the frontal regions as well as region-specific patterns of increased white matter myelination and volume. We investigated total cerebral volumes, neocortical surface area, and neocortical thickness in 16 children with a neural tube defect, spina bifida myelomeningocele (SB), and 16 age-matched typically developing controls using a semi-automated, quantitative approach to MRI-based brain morphometry. The results revealed no significant group differences in total cerebral volume. However, group differences were observed in the global distribution of distinct tissue classes within the cerebrum: the SB group demonstrated a significant 15% reduction in total white matter and a 69% increase in cerebrospinal fluid, with no differences in total gray matter. Group comparisons of neocortical surface area assessments were significantly smaller in the occipital regions for SB, with no significant group differences in the frontal regions. Group comparisons of cortical thickness measurements demonstrated reduced cortical thickness in all regions except the frontal regions, where the SB group exhibited an increase relative to the PC group. Although regional patterns of thinning may be associated with the mechanical effects of hydrocephalus, the overall reduction in white matter and increased neocortical thickness in the frontal regions suggest that SB reflects a long-term disruption of brain development that extends far beyond the neural tube defect in the first weeks of gestation.Item Neuropsychological functions following closed head injury in infants and preschoolers(1985) Ewing-Cobbs, Linda; Sheer, Daniel. E.; Fletcher, Jack M.; Levin, Harvey S.; Johnson, Dale L.; Foorman, Barbara R.; Miner, Michael E.The traditional plasticity hypothesis proposes that recovery from brain injury is enhanced in children as compared with adults. To evaluate the plasticity hypothesis, performance on intelligence, motor, expressive language, and receptive language tests was examined during the subacute stage of recovery as well as eight months post-injury in 21 infants and preschoolers who sustained a closed head injury (CHI). Children with severe injuries (n=13) exhibited impaired consciousness for at least one day while children sustaining mild-moderate injuries (n=8) were rendered comatose for less than 24 hours. The design was a 2 (severity) x 2 (time of testing) factorial. To evaluate the effect of severity of CHI and to compare neuropsychological performance on baseline and follow up examinations, a repeated measures multivariate analysis of variance (MANOVA) was performed on summary scores from each of the four neuropsychological areas. On the baseline evaluation, children sustaining severe CHI were impaired on intelligence (p<.005), motor (p<.005), expressive language (p<.05), and receptive language (p<.001) functions relative to children with mild-moderate injuries. To determine which skill areas were most disrupted by CHI, the baseline and follow up summary scores from the 1) intelligence and motor and 2) expressive and receptive language areas were compared using a within-subjects MANOVA. Motor scores were more impaired than the intelligence scores on the baseline (p<.05) and follow up (p<.05) evaluations. Expressive language skills were significantly impaired relative to the receptive language skills on the baseline evaluation (p<.05). However, no significant differences were present on the follow up evaluation. The level of expressive language skills improved considerably over time while changes in performance on receptive language tasks was modest. The duration of impaired consciousness was a better predictor of the level of neuropsychological performance during the subacute stage of recovery from CHI than Glasgow Coma Scale scores obtained either at admission or 24 hours post Injury. Significant disruption of ability was observed in all of the skill areas examined and persistent behavioral deficits were apparent eight months post injury in children sustaining severe injuries. These findings are incompatible with the traditional plasticity hypothesis. Moreover, the incidence of dysphasia/dyspraxia was higher in the severely injured children than previously reported in older children and adults sustaining CHI. Since language skills develop rapidly during the preschool years, these findings support the hypothesis that skills in a rapid stage of development are more vulnerable to the effects of cerebral injury than are well consolidated skills.Item Prediction and stability of mathematics skill and difficulty(Journal of Learning Disabilities, 2012-05) Martin, Rebecca B.; Cirino, Paul T.; Barnes, Marcia A.; Ewing-Cobbs, Linda; Fuchs, Lynn S.; Stuebing, Karla K.; Fletcher, Jack M.The present study evaluated the stability of math learning difficulties over a 2-year period and investigated several factors that might influence this stability (categorical vs. continuous change, liberal vs. conservative cut point, broad vs. specific math assessment); the prediction of math performance over time and by performance level was also evaluated. Participants were 144 students initially identified as having a math difficulty (MD) or no learning difficulty according to low achievement criteria in the spring of Grade 3 or Grade 4. Students were reassessed 2 years later. For both measure types, a similar proportion of students changed whether assessed categorically or continuously. However, categorical change was heavily dependent on distance from the cut point and so more common for MD, who started closer to the cut point; reliable change index change was more similar across groups. There were few differences with regard to severity level of MD on continuous metrics or in terms of prediction. Final math performance on a broad computation measure was predicted by behavioral inattention and working memory while considering initial performance; for a specific fluency measure, working memory was not uniquely related, and behavioral inattention more variably related to final performance, again while considering initial performance.Item Recovery of Working Memory Following Pediatric Traumatic Brain Injury: A Longitudinal Analysis(2013-08) Gorman, Stephanie 1985-; Fletcher, Jack M.; Ewing-Cobbs, Linda; Swank, Paul R.; Barnes, Marcia A.; Alfano, Candice A.The purpose of this dissertation was to investigate the developmental trajectories of verbal and visual-spatial WM in children following traumatic brain injury, and to determine how age at injury and injury severity affects growth. As part of a larger assessment, the sample included 42 children with severe head injury, 13 children with complicated mild-moderate head injury, and 47 children with orthopedic injury. Longitudinal data was collected at 2, 6, 12 and 24 months post-injury. A multivariate approach to individual growth curve modeling was utilized and the data was centered at 12 months post-injury. Results indicated that at 12 months post-injury, children in all three injury groups with varying age at injury did not differ significantly on verbal or visual-spatial working memory performance. The injury groups did not differ on working memory performance when age at injury was held constant. A significant rate of change (slope) by age at injury by injury group interaction for verbal working memory (and a similar pattern for visual-spatial working memory) revealed that children injured at a younger age with more severe injuries demonstrated the slowest working memory growth, but that as age at injury increased, older children with severe injuries exhibited faster growth. A significant positive relation was found between level of performance on verbal and visual-spatial working memory tasks at 12 months post-injury, but not for rate of growth. This study lends further support to an early vulnerability hypothesis, which suggests that children brain-injured at a younger age are more vulnerable to cognitive deficits.Item Sleep disturbances following pediatric traumatic brain injury(2016-08) Fischer, Jesse T.; Ewing-Cobbs, Linda; Hannay, H. Julia; Alfano, Candice A.; Taylor, PatriciaTraumatic brain injury (TBI) remains a glaring issue for public health in the United States, particularly in children and adolescents. One of the most frequent complaints of patients following TBI is the presence of sleep disturbances (SD). Bodily injury in children and adolescents also presents a public health concern as well. The association between pediatric TBI and SD is vastly understudied, and even less is known regarding SD after bodily injury. Importantly, SD in children and adolescents has been linked independently to a number of adverse health outcomes, such as internalizing behavior problems. Additionally, posttraumatic stress symptoms have been linked to traumatic injury and to SD. The current study aimed to investigate chronic SD after TBI and bodily injury in children and adolescents, as well as relations between SD, internalizing behavior problems, and posttraumatic stress after injury. Study design utilized data from 8-15 year olds following TBI, extracranial/bodily injury (EI), and typically developing children. At 6 and 12-month time points, mixed model analyses of variance were used to assess group differences in SD, internalizing behavior problems, and posttraumatic stress, while multiple mediation models analyzed mechanisms of action. SD was significantly positively associated with severity of injury in the EI group. SD was higher in injury groups than in typically developing children when TBI and EI groups were combined. Internalizing behavior problems were higher in both injury groups. SD and internalizing behavior problems had a persisting bidirectional association where each mediated the other in each injury group when compared to typically developing children. Posttraumatic stress symptoms did not vary between injury groups and were not mediated by SD after injury. Findings are relevant for further understanding and clinical management of SD and their relation to internalizing problems after traumatic injury.Item The impact of pediatric traumatic brain injury on written expression: a diffusion tensor imaging study utilizing tract-based spatial statistics(2015-08) Harik, Lindsey M.; Hannay, H. Julia; Ewing-Cobbs, Linda; Juranek, Jenifer; Massman, Paul J.; Taylor, PatriciaThe aim of this study was to determine if cerebral white matter integrity is predictive of Written Expression (WE) performance in children, and if the relation between white matter integrity and WE performance differs between children with traumatic brain injury (TBI) and children with orthopedic injury (OI). White matter integrity was approximated via diffusion tensor imaging (DTI) using tract-based spatial statistics. The current study utilized two DTI metrics, fractional anisotropy (FA) and mean diffusivity (MD), to assess integrity of white matter tracts. White matter tract integrity values were used to predict WE performance in the TBI group and the OI comparison group. General linear modeling (GLM) and multiple mediation analyses were used to predict performance on measures of WE at twelve months post-injury from white matter integrity at three months post-injury. Measures of WE included Thematic Maturity, Writing Fluency, and Spelling. Children with OI demonstrated significantly stronger performance on Writing Fluency and Spelling than children with TBI but there was no significant difference between groups on TMI performance. Children with TBI showed significantly decreased white matter integrity three months post-injury as compared to children with OI. Writing Fluency and TMI performance were fully mediated by FA values of the anterior thalamic radiation and corticospinal tract and Writing Fluency performance was also predicted by group differences in cingulum bundle microstructure. Taken together, these findings suggest that TBI negatively impacts the microstructural integrity of specific pathways that support WE performance and that these microstructural alterations account for post-traumatic changes in the content and fluency of production of written narratives. These findings are relevant for further understanding the role of white matter in academic performance and the impact of TBI on the developing brain.Item The Role of Executive Functioning, Anxiety, and Family Burden on Mathematical Performance in Children with Traumatic Brain Injury(2015-08) Maxwell, Emily C.; Cirino, Paul T.; Ewing-Cobbs, Linda; Sharp, Carla; Stuebing, Karla K.Mathematical performance is closely linked with anxiety and executive processes, which are both adversely impacted by traumatic brain injury (TBI) in children. The present study examined the impact of executive functioning, anxiety, and family burden of injury on mathematical performance in children with TBI or orthopedic injuries (OI) at 2 months and 2 years post-injury. Participants (ages 6 to 15 years) had been hospitalized for complicated-mild/moderate and severe TBI (n = 51) or OI (n = 47) and were enrolled in a prospective longitudinal study. Children completed two measures of mathematics (calculation and problem solving), and parents completed measures of family burden, anxiety, and executive function. Mediation and path analyses were used to evaluate contributions of the above variables to mathematical outcomes. Compared to children with OI, children with TBI had lower calculation and problem solving scores, higher family burden, and executive functioning impairment persisting 2 years post-injury (p < 0.05). Mediation analyses revealed that executive functioning at 2 months partially mediated the role of group on calculation at 2 months (b = -0.71; 95% bootstrap confidence interval CI of -1.93 to -0.06). Problem solving at 2 months and calculation at 2 months mediated the relation of group to problem solving and calculation scores at 2 years post-injury, respectively. Neither anxiety nor family burden significantly impacted mathematical performance (p < 0.05). Executive functioning difficulties at 2 months post-injury in children with complicated-mild/moderate to severe TBI predicts long-term functioning and may serve as a red flag regarding the need for interventions to improve educational and psychological health outcomes.Item WRITTEN EXPRESSION FOLLOWING PEDIATRIC TRAUMATIC BRAIN INJURY IN SCHOOL-AGED CHILDREN(2012-05) Harik, Lindsey M.; Ewing-Cobbs, Linda; Hannay, H. Julia; Swank, Paul R.; Fletcher, Jack M.; Tian, T. SivaThe purpose of this thesis was to investigate the effect of traumatic brain injury on written expression in school-aged children. In particular, the mediating effect of core and supporting processes of written expression on the effect of traumatic brain injury on written expression was explored. Core skills are those that are thought to be specific to written expression, and in particular, the mechanical execution of written language. The core skills assessed in this study were graphomotor speed, fine motor speed and coordination, spelling and writing fluency. Supporting skills are those processes that are not unique to writing but are necessary for completing most cognitive tasks, and are frequently affected by traumatic brain injury. The supporting skills assessed in this study were processing speed, working memory, and sustained and focused attention. The performance of children with traumatic brain injury was compared to a group of children with orthopedic injuries. Principal components analysis was used to elucidate the primary core and supporting components of written expression. Four components were retained: orthographic output, fine motor skills, working memory and vigilance. Consistent with previous literature, children in the head-injured group performed more poorly on the primary outcome measure of written expression, both core components and working memory. There was no difference between groups, however, on vigilance performance. Bootstrap regression analyses revealed that the effect of traumatic brain injury on written expression was significantly mediated by orthographic output. This finding is relevant for intervening on written expression difficulties in children with traumatic brain injury. Emphasizing orthographic output as a part of already well-established written expression interventions may provide added benefit in this population.