A prospective study of short- and long-term neuropsychological outcomes after traumatic brain injury in children

Longitudinal neuropsychological outcomes of traumatic brain injury (TBI) were investigated in 53 children with severe TBI, 56 children with moderate TBI, and 80 children with orthopedic injuries only. Neuropsychological functioning was assessed at baseline, at 6- and 12-month follow-ups, and at an extended follow-up (a mean of 4 years postinjury). Mixed model analyses revealed persistent neuropsychological sequelae of TBI that generally did not vary as a function of time postinjury. Some recovery occurred during the first year postinjury, but recovery reached a plateau after that time, and deficits were still apparent at the extended follow-up. Further recovery was uncommon after the first year postinjury. Family factors did not moderate neuropsychological outcomes, despite their demonstrated influence on behavior and academic achievement after childhood TBI.     

Modeling of longitudinal academic achievement scores after pediatric traumatic brain injury

In a prospective longitudinal study, academic achievement scores were obtained from youth 5 to 15 years of age who sustained mild-moderate (n = 34) or severe (n = 43) traumatic brain injuries (TBI). Achievement scores were collected from baseline to 5 years following TBI and were subjected to individual growth curve analysis. The models fitted age at injury, years since injury, duration of impaired consciousness, and interaction effects to Reading Decoding, Reading Comprehension, Spelling, and Arithmetic standard scores. Although scores improved significantly over the follow-up relative to normative data from the standardization sample of the tests, children with severe TBI showed persistent deficits on all achievement scores in comparison to children with mild-moderate TBI. Interactions of the slope and age parameters for the Arithmetic and Reading Decoding scores indicated greater increases over time in achievement scores of the children injured at an older age, but deceleration in growth curves for the younger children with both mild-moderate and severe TBI. These results are compatible with the hypothesis that early brain injuries disrupt the acquisition of some academic skills. Hierarchical regression models revealed that indexes of academic achievement obtained 2 years following TBI had weak relations with the duration of impaired consciousness and socioeconomic status. In contrast, concurrent cognitive variables such as phonological processing and verbal memory accounted for more variability in academic scores. Given the significant and persistent decrement in basic academic skills in youth with severe TBI, it is clear that head-injured youth require intensive, long-term remediation and intervention not only of the academic skills themselves, but also of those cognitive abilities that support the development and maintenance of reading and math.     

Changes in working memory after traumatic brain injury in children

The impact of traumatic brain injury (TBI) on working memory (WM) was studied in 144 children (79 with mild, 23 with moderate, and 42 with severe injuries) who underwent magnetic resonance imaging (MRI) at 3 months and were tested at baseline and at 3, 6, 12, and 24 months postinjury. An n-back WM task for letter identity was administered with memory load ranging from 1- to 3-back and a 0-back condition. A TBI Severity x Quadratic Tune interaction showed that net percentage correct (correct detections of targets minus false alarms) was significantly lower in severe than in mild TBI groups. The Left Frontal Lesions x Age interaction approached significance. Mechanisms mediating late decline in WM and the effects of left frontal lesions are discussed.     

Ontogenic factors in short- and long-term recovery of discriminative behavior in rats after selective brain damage

Stereotypical behavior or response perseveration dominating early mammalian responding, especially under conditions of aversive motivation, may be radically modified through damage in the prefrontal and hippocampal systems. These observations contribute evidence to the notion that changes in neural circuitry may be supporting behavioral recovery of function after selective brain damage. The extent of behavioral deficits as well as the prognosis for recovery are governed by task-specific variables, usually related to a discriminative element in stimulus control. Conversely, reversion to earlier, stereotypical behavior may be produced in adult rats exposed to damage at points within the same sites. Specific experiments tested weanling and adult rats within tasks that differed in the (1) extent and site of damage, (2) variety of signalling stimuli, (3) complexity of the task requirements, and (4) time since surgery for initiation of training. Experiments on 1-way active avoidance, alternation and reversal learning indicated that performance deficits are attributed to developmental immaturity early in ontogeny, and enhanced neurophysiological growth with age provides a reliable predictor of recovery. However with increasing age, variables related to the subtleties of damage site and task also emerge as salient factors in behavioral deficiencies. Interestingly, the cue properties or information value contained in the conditioned stimulus (CS) and the environmental context provide differential compensation for selected types of injury-induced deficits, and there was some evidence that the utility of environmental signals can be improved over long-term recovery periods. The results support the view that relationships between age at the time of injury and extent of recovery are perhaps best explained within developmentally determined constraints.(ABSTRACT TRUNCATED AT 250 WORDS)     

Executive function outcomes following traumatic brain injury in young children: a five year follow-up

Little is known about the long-term effects of traumatic brain injury (TBI) in very young children. This study used a prospective, cross-sectional design to investigate the impact of TBI on executive function (EF) outcomes in children who sustained a TBI before the age of seven. The study aimed to identify specific or global EF deficits five years post-TBI, and to explore factors that predicted outcomes. Fifty-four children with a TBI and 17 uninjured comparison children participated. Their performance on several cognitive and behavioral EF measures was examined. Results suggested that executive difficulties were present following severe TBI, however children with mild and moderate injuries were relatively unaffected. Skills that develop early appeared to be relatively robust. Injury severity was found to be most predictive of long-term EF, however other injury, child and family-related variables also contributed to outcomes.     

Response inhibition after traumatic brain injury (TBI) in children: impairment and recovery

Children who experience traumatic brain injury (TBI) often show cognitive impairments postinjury, some of which recover over time. We examined the recovery of motor response inhibition immediately following TBI and over 2 years. We assessed the role of injury severity, age at injury, and lesion characteristics on initial impairment and recovery while considering the role of pre-injury psychiatric disorder. Participants were 136 children with TBI aged 5-16 years. Latency of motor response inhibition was measured with the stop-signal task within 1 month of the injury and again at 3, 6, 12, and 24 months. The performance of the TBI participants at each measurement occasion was standardized with 117 children of similar age, but without injury. Residualized latency scores were calculated. Growth curve analyses showed an initial impairment in response inhibition and improvement over the 2 years following injury. Younger TBI patients were initially more impaired although they exhibited greater recovery of response inhibition than did older TBI patients. Longer duration of coma, but not reactivity of pupils or Glasgow Coma Scale score, predicted initial deficit. Lesion characteristics or pre-injury attention deficit hyperactivity disorder did not predict initial impairment or recovery. Replication with longitudinal testing of a comparison group of children sustaining extracranial injury is necessary to confirm our findings.     

Mental state attributions and diffusion tensor imaging after traumatic brain injury in children

We studied social cognition in 49 children 3 months after moderate to severe traumatic brain injury (TBI) and in 39 children with orthopedic injury (OI). Children underwent diffusion tensor imaging (DTI) and a mental attribution task showing two triangles. Mental state attributions increased when one triangle reacted to intentions of the other, but less so in the TBI than the OI group. DTI identified injury to white matter microstructure in the TBI group, but the relation of DTI to mental attributions did not differ between groups. Moderate to severe TBI produces white matter disconnections that may affect social cognitive networks.     

Inflicted traumatic brain injury in infants and young children

Abstract This article will discuss the subject of inflicted or abusive head injury in infants and young children. Inflicted neurotrauma is a very common injury and a frequent problem in attempting to distinguish between inflicted and accidental injury. Inflicted head injury occurs usually in the home in the presence of the individual who has inflicted the injury outside the view of unbiased witnesses. Distinguishing between inflicted and accidental injury may be dependent upon the pathological findings and consideration of the circumstances surrounding the injury. The most common finding in an inflicted head injury is the presence of subdural hemorrhage. Subdural hemorrhage may occur in a variety of distributions and appearances. The natural history of subdural bleeding and the anatomy of the "subdural" will be considered. The anatomy of the dura and its attachment to the skull and to the arachnoid determines how subdural bleeding evolves into the cleaved dural border cell layer and as well as how bridging veins are torn and anatomically where bleeding will occur. Different biomechanical mechanisms result in different distributions of subdural blood and these differences will be discussed.     

Suicidality after traumatic brain injury: demographic,injury and clinical correlates

BACKGROUND: In spite of the high frequency of emotional distress after traumatic brain injury (TBI), few investigations have examined the extreme of such distress, namely, suicidality, and no large scale surveys have been conducted. The current study examined both the prevalence and demographic, injury, and clinical correlates of hopelessness, suicidal ideation and suicide attempts after TBI. METHODS: Out-patients (N = 172) with TBI were screened for suicidal ideation and hopelessness using the Beck Scale for Suicide Ideation and the Beck Hopelessness Scale. Data were also collected on demographic, injury, pre-morbid and post-injury psychosocial variables and included known risk factors for suicide. RESULTS: A substantial proportion of participants had clinically significant levels of hopelessness (35%) and suicide ideation (23%), and 18% had made a suicide attempt post-injury. There was a high degree of co-morbidity between suicide attempts and emotional/psychiatric disturbance. Results from regression analyses indicated that a high level of hopelessness was the most significant association of suicide ideation and a high level of suicide ideation, along with occurrence of post-injury emotional/psychiatric disturbance, were the most significant associations of post-injury suicide attempts. Neither injury severity nor the presence of pre-morbid suicide risk factors contributed to elevated levels of suicidality post-injury. CONCLUSIONS: Suicidality is a common psychological reaction to TBI among out-patient populations. Management should involve careful history taking of previous post-injury suicidal behaviour, assessment of post-injury adjustment to TBI with particular focus on the degree of emotional/psychiatric disturbance, and close monitoring of those individuals with high levels of hopelessness and suicide ideation.     

Cerebral hemodynamics after traumatic brain injury of immature brain.

These studies were designed to characterize the cerebral hemodynamic effects of fluid percussion brain injury (FPI) in the newborn pig equipped with a closed cranial window. Reductions in cerebral blood flow, pial artery diameter, and cerebral oxygenation following FPI were greater in newborn (1-3 days old) vs. juvenile (3-4 weeks old) pigs, suggesting that newborns were exquisitely sensitive to brain injury. Additionally, in piglets, there was decremented dilation to nitric oxide, cGMP, and cAMP dependent stimuli following FPI. The membrane potential of vascular muscle is an important contributor to vascular tone and the activity of K+ channels is an important regulator of membrane potential. Recent studies indicate that altered dilator responsiveness and cerebral hemodynamic control following FPI results from impaired K+ ATP sensitive (KATP) and calcium sensitive (Kca+2) channel function. Impaired KATP channel function results, at least in part, from protein kinase C activation by the peptide endothelin-1. These observations indicate that the effects of brain injury on cerebral hemodynamics in the newborn are multifaceted and multifactorial.     

Research on outcomes of pediatric traumatic brain injury: current advances and future directions

The articles in this series demonstrate the diversity of research approaches needed to enhance understanding of the sequelae of traumatic brain injury (TBI) in children. Methods ranged from assessment of information processing deficits to evaluation of the construct validity of cognitive tests, tracking of changes in academic achievement after injury, and measurement of behavior and social outcomes. Several articles considered multiple influences on sequelae, including TBI severity, age at injury, time since injury, and preinjury child characteristics. The findings provide new information on injury consequences and the cognitive correlates of postinjury problems in behavior, achievement, and discourse processing. Continued progress requires additional study of relations between specific forms of neuropathology and outcomes, more comprehensive assessments of environmental influences, and greater efforts to monitor postinjury developmental changes. Other needs include more probing assessments of the effects of TBI on daily functioning and social-emotional outcomes, investigation of the specificity of sequelae and of sources of variability in outcome, and application of models that examine mechanisms of effect. This research will benefit clinical practice, clarify processes underlying children's behavior and learning problems, and advance knowledge of normal development.     

Correlates of social problem solving during the first year after traumatic brain injury in children

Effects of pediatric traumatic brain injury (TBI) on social problem-solving were examined in a longitudinal study of 103 children with moderate-to-severe TBI (n = 52) or orthopedic injury (OI; n = 51) using the Interpersonal Negotiation Strategies task (INS). Children solved age-appropriate hypothetical social conflicts, with responses for four problem-solving steps scored by developmental level. The OI group performed better than the TBI group, but rate of change in performance over time did not differ between groups, suggesting improvement in children with TBI was not due to recovery from injury. Strong relations between INS performance and memory and language skills emerged, but emotional processing was only weakly related to INS performance. Frontal focal lesions influenced INS performance in younger (but not older) children with TBI. Diffusion tensor imaging (DTI), revealed strong relationships between the INS and increased apparent diffusion coefficient (ADC) measures indexing connectivity in the dorsolateral and cingulate regions in both TBI and OI groups, and in the temporal and parietal regions in the TBI group. These findings inform studies of social problem-solving skills during the first year post TBI. (PsycINFO Database Record (c) 2008 APA, all rights reserved).     

Porteus Maze performance following traumatic brain injury in children.

To investigate planning in traumatically brain injured children, the authors gave the Porteus Maze Test (PMT; S. D. Porteus, 1959) to 276 pediatric patients who had sustained a traumatic brain injury (TBI) at least 3 years previously. Sensitivity of the PMT to TBI severity, age at test, and volume of focal brain lesions detected by magnetic resonance imaging was also studied. The Peabody Picture Vocabulary Test-Revised (L. M. Dunn & L. M. Dunn, 1981) was also administered as a control measure. Results indicated that the PMT was highly sensitive to TBI severity and to volume of circumscribed prefrontal lesions. In contrast to the PMT data, receptive vocabulary was related to injury severity but not to discrete prefrontal lesions. Implications for mechanisms of cognitive deficit after TBI in children are discussed.     

Prospective memory in pediatric traumatic brain injury: a preliminary study

Prospective memory (PM) performance was investigated in a preliminary study of children and adolescents ages 10-19 in 3 groups: individuals with orthopedic injuries (not involving the head) requiring hospitalization (Ortho, N = 15), mild traumatic brain injury (TBI, N = 17), and severe TBI (N = 15). All participants with TBI were at least 5 years postinjury and participants in the Ortho group were at least 3 years postinjury. The PM task involved reporting words presented in blue during a category decision task in which words were presented in several different colors and participants were to determine which of two categories the word belonged. Participants were asked to make their choices as quickly as possible. After a 10- to 15-min intervening computer task in which all words were presented in black letters, a large proportion of participants with mild or severe TBI failed to indicate any blue words when they appeared. After a reminder to perform the PM task was given to all at the same point in the task, PM performance increased in the Ortho and Mild TBI groups, but remained comparably impaired in the Severe TBI group. Reaction time (RT) data indicated that mean RT was slower with increasing TBI severity. Further, there was a significant cost in RT for performing the PM task during the ongoing category decision task for all groups. The cost in terms of slowed RT increased with greater TBI severity.     

Social competence in young children with inflicted traumatic brain injury

As infants develop skills that allow for increasing independence in social and cognitive domains, they acquire the ability to identify goals, sequence behaviors to carry out goals, and to flexibly use strategies for attaining goals in both social and independent play contexts. Little is known about how brain injury in young children may disrupt the precursors to such executive processes. In this study, we examined social and cognitive competence in 25 infants ages 3 to 23 months who sustained moderate to severe traumatic brain injury (TBI) secondary to physical abuse and in 22 healthy community comparison children. Children with TBI were evaluated an average of 1.6 months after the injury. A toy-centered activity with the examiner was used to capture joint attention and social behavior and an exploratory toy play situation was used to measure independent goal-directed play. The inflicted TBI group showed significant reduction in both social and cognitive domains relative to the comparison group. Canonical correlation analyses disclosed that inflicted TBI was associated with reduction in (a) initiation of social interactions, (b) responsiveness to interactions initiated by the examiner, (c) positive affect, and (d) compliance. The groups performed comparably on indexes of gestural and verbal communication and for the occurrence of negative affect. Joint attention was an area of vulnerability for the TBI group in both social initiation and response contexts. Although general cognitive and motor scores were lower in the inflicted TBI group, the complexity of independent toy play did not differ across groups. Early brain injury causes significant disruption in behaviors regulating initiation and responsiveness in social contexts. Longitudinal follow-up will characterize the long-term consequences of early disruption in joint attention and other behaviors on the development of social and cognitive precursors to executive processes.