Pediatric traumatic brain injury: an update of research to understand and improve outcomes

Trajectory of Long-Term Outcome in Severe Pediatric Diffuse Axonal Injury: An Exploratory Study

Introduction: Pediatric severe traumatic brain injury (TBI) is one of the leading causes of disability and death. One of the classic pathoanatomic brain injury lesions following severe pediatric TBI is diffuse (multifocal) axonal injury (DAI). In this single institution study, our overarching goal was to describe the clinical characteristics and long-term outcome trajectory of severe pediatric TBI patients with DAI.

Methods: Pediatric patients (<18 years of age) with severe TBI who had DAI were retrospectively reviewed. We evaluated the effect of age, sex, Glasgow Coma Scale (GCS) score, early fever ≥ 38.5°C during the first day post-injury, the extent of ICP-directed therapy needed with the Pediatric Intensity Level of Therapy (PILOT) score, and MRI within the first week following trauma and analyzed their association with outcome using the Glasgow Outcome Score—Extended (GOS-E) scale at discharge, 6 months, 1, 5, and 10 years following injury.

Results: Fifty-six pediatric patients with severe traumatic DAI were analyzed. The majority of the patients were >5 years of age and male. There were 2 mortalities. At discharge, 56% (30/54) of the surviving patients had unfavorable outcome. Sixty five percent (35/54) of surviving children were followed up to 10 years post-injury, and 71% (25/35) of them made a favorable recovery. Early fever and extensive DAI on MRI were associated with worse long-term outcomes.

Conclusion: We describe the long-term trajectory outcome of severe pediatric TBI patients with pure DAI. While this was a single institution study with a small sample size, the majority of the children survived. Over one-third of our surviving children were lost to follow-up. Of the surviving children who had follow-up for 10 years after injury, the majority of these children made a favorable recovery.

Evidence Limitations in Determining Sexually Dimorphic Outcomes in Pediatric Post-Traumatic Hypopituitarism and the Path Forward

Neuroendocrine dysfunction can occur as a consequence of traumatic brain injury (TBI), and disruptions to the hypothalamic-pituitary axis can be especially consequential to children. The purpose of our review is to summarize current literature relevant to studying sex differences in pediatric post-traumatic hypopituitarism (PTHP). Our understanding of incidence, time course, and impact is constrained by studies which are primarily small, are disadvantaged by significant methodological challenges, and have investigated limited temporal windows. Because hormonal changes underpin the basis of growth and development, the timing of injury and PTHP testing with respect to pubertal stage gains particular importance. Reciprocal relationships among neuroendocrine function, TBI, adverse childhood events, and physiological, psychological and cognitive sequelae are underconsidered influencers of sexually dimorphic outcomes. In light of the tremendous heterogeneity in this body of literature, we conclude with the common path upon which we must collectively arrive in order to make progress in understanding PTHP.

Longitudinal Neuroimaging in Pediatric Traumatic Brain Injury: Current State and Consideration of Factors That Influence Recovery

Traumatic brain injury (TBI) is a leading cause of death and disability for children and adolescents in the U.S. and other developed and developing countries. Injury to the immature brain varies greatly from that of the mature, adult brain due to numerous developmental, pre-injury, and injury-related factors that work together to influence the trajectory of recovery during the course of typical brain development. Substantial damage to brain structure often underlies subsequent functional limitations that persist for years following pediatric TBI. Advances in neuroimaging have established an important role in the acute management of pediatric TBI, and magnetic resonance imaging (MRI) techniques have a particular relevance for the sequential assessment of long-term consequences from injuries sustained to the developing brain. The present paper will discuss the various factors that influence recovery and review the findings from the present neuroimaging literature to assess altered development and long-term outcome following pediatric TBI. Four MR-based neuroimaging modalities have been used to examine recovery from pediatric TBI longitudinally: (1) T1-weighted structural MRI is sensitive to morphological changes in gray matter volume and cortical thickness, (2) diffusion-weighted MRI is sensitive to changes in the microstructural integrity of white matter, (3) MR spectroscopy provides a sensitive assessment of metabolic and neurochemical alterations in the brain, and (4) functional MRI provides insight into the functional changes that occur as a result of structural damage and typical developmental processes. As reviewed in this paper, 13 cohorts have contributed to only 20 studies published to date using neuroimaging to examine longitudinal changes after TBI in pediatric patients. The results of these studies demonstrate considerable heterogeneity in post-injury outcome; however, the existing literature consistently shows that alterations in brain structure, function, and metabolism can persist for an extended period of time post-injury. With larger sample sizes and multi-site cooperation, future studies will be able to further examine potential moderators of outcome, such as the developmental, pre-injury, and injury-related factors discussed in the present review.

Role of routine repeat head imaging in paediatric traumatic brain injury

BACKGROUND

Paediatric traumatic brain injuries (TBI) remain a leading cause of morbidity and mortality in Australia. There are clear guidelines on head imaging for children with TBI, but there is conflicting evidence on the role of routine repeat head computed tomography (CT) scan. This study aims to determine whether routine repeat head CT scans in paediatric TBI alter surgical or medical management.

METHODS

A retrospective study was performed at a level 1 tertiary paediatric trauma centre between January 2002 and July 2012. Patients with TBI who were admitted with acute intracranial injury and at least one repeat head CT scan were included. Mechanism of injury, severity of TBI, Glasgow Coma Score, use of intracranial pressure monitoring and operative procedures were listed. The need for operative management was compared for routine and clinically indicated head scans.

RESULTS

Routine head CT scan was done in 36 out of 71 patients (51%). None from this group required craniotomy, but two children (6%) needed delayed ICP monitoring. Three patients with moderate to severe TBI required intracranial pressure monitor or external ventricular drain insertion based on a clinically indicated repeat head CT.

CONCLUSION

Repeat head imaging is more likely to alter management of children with moderate to severe TBI. There is no role for routine repeat CT scan on mild TBI. Results of repeat cranial imaging should be correlated with the clinical status of the patient.

The unique features of traumatic brain injury in children. review of the characteristics of the pediatric skull and brain, mechanisms of trauma, patterns of injury, complications, and their imaging findings--part 2

Traumatic brain injury (TBI) is a major cause of morbidity and mortality in children. The unique biomechanical, hemodynamical, and functional characteristics of the developing brain and the age-dependent variance in trauma mechanisms result in a wide range of age specific traumas and patterns of brain injuries. Detailed knowledge of the main primary and secondary pediatric injuries, which enhance sensitivity and specificity of diagnosis, will guide therapy and may give important information about the prognosis. In recent years, anatomical but also functional imaging methods have revolutionized neuroimaging of pediatric TBI. The purpose of this article is (1) to comprehensively review frequent primary and secondary brain injuries and (2) to give a short overview of two special types of pediatric TBI: birth related and nonaccidental injuries.

The unique features of traumatic brain injury in children. Review of the characteristics of the pediatric skull and brain, mechanisms of trauma, patterns of injury, complications and their imaging findings--part 1

Traumatic head/brain injury (TBI) is a leading cause of death and life-long disability in children. The biomechanical properties of the child's brain and skull, the size of the child, the age-specific activity pattern, and higher degree of brain plasticity result in a unique distribution, degree, and quality of TBI compared to adult TBI. A detailed knowledge about the various types of primary and secondary pediatric head injuries is essential to better identify and understand pediatric TBI. The goals of this review article are (1) to discuss the unique epidemiology, mechanisms, and characteristics of TBI in children, and (2) to review the anatomical and functional imaging techniques that can be used to study common and rare pediatric traumatic brain injuries and their complications.

Community integration following severe childhood traumatic brain injury

PURPOSE OF REVIEW

Severe childhood traumatic brain injury (TBI) is the leading cause of death and acquired disability in children, causing impairments in children's sensory-motor, cognitive and behavioural functioning, with devastating consequences on community integration. Community integration is the ultimate goal of rehabilitation; it is a complex outcome, with many variables contributing to it.

RECENT FINDINGS

Community integration and quality of life (QOL) are lower in children who sustained severe TBI at a younger age. Further, a wide range of injury-related, demographic and postinjury factors influence outcomes, and should serve as targets for specific interventions. An increasing number of interventions targeting cognitive, behavioural or family-related issues have been developed, with promising results.

SUMMARY

Children should benefit from early integrated patient and family-centred specific care, and receive long-term follow-up until early adulthood, with regular assessments, enabling detection and treatment of any emerging problem, and to ensure the acquisition of independent living skills and stable vocational outcome when this is possible. So far, few well conducted intervention studies are available, but their number is increasing with positive results on the trained skills. Well designed studies using large samples and looking at generalization of the skills in everyday life are needed.

Relationship between increases in pancreatic enzymes and cerebral events in children after traumatic brain injury

OBJECTIVE

To describe the risk factors of early and delayed increases in pancreatic enzymes (PE) in children after severe traumatic brain injury (TBI) and to determine if cerebral events (such as intracranial hemorrhage or intracranial hypertension) are associated with increases in PE.

DESIGN AND SETTINGS

Retrospective analysis of prospectively collected Pediatric Neurotrauma Registry for children with severe TBI (GCS ≤ 8). We assessed the association of clinical characteristics with the development of increases in PE using regression analyses.

PATIENTS

Fifty-one children with severe TBI were classified into three groups [normal PE; early PE (PE increases within first 24 h); delayed PE (PE increases after 24 h)].

MEASUREMENTS AND MAIN RESULTS

Increases in PE were observed in 29/51 children [57% total; n = 9 (18%) early; n = 20 (39%) delayed]. Multisystem trauma was more prevalent in patients with early increases in PE compared to those without increases in PE (70 vs. 30%, RR = 2.8, 95% CI 1.1-7) but not different between delayed PE and normal PE groups. In the bivariate analyses, increasing age (odds ratios, [95% CI]; 1.2, [1.05-1.4]), intracranial hypertension (14.6, [2.6-80.5]), intracranial hemorrhage (6.2, [1.15-33.7]), receipt of pentobarbital (9.3, [2.1-39.9]), mannitol (13.2, [2.7-62.2]), and vasoactive medications (6.9, [1.5-31.3]) were associated with the development of delayed increases in PE, whereas sex, initial Glasgow Coma Scale, severity of injury (PRISM, Injury Severity Score), therapeutic hypothermia, morphine and furosemide were not associated. Both intracranial hypertension and intracranial hemorrhage independently predicted the development of increases in PE (14.6, [2.6-80.5], and 9.1, [1.31-63.3], respectively).

CONCLUSIONS

Increases in PE, often used as the only measures of pancreatitis in children with other severe injuries, are common in children after severe TBI and delayed presentation appears related to intracranial events. This suggests a possible interaction between the brain and the gastrointestinal system, implying that disturbances in cerebral hemodynamics may lead to pancreatic dysfunction.

Severe traumatic brain injury in children elevates glial fibrillary acidic protein in cerebrospinal fluid and serum

OBJECTIVES

1) To determine the levels of glial fibrillary acidic protein (GFAP) in both cerebrospinal fluid and serum; 2) to determine whether serum GFAP levels correlate with functional outcome; and 3) to determine whether therapeutic hypothermia, as compared with normothermia, alters serum GFAP levels in children with severe traumatic brain injury (TBI).

DESIGN

Laboratory-based analyses; postrandomized, controlled trial.

SETTING

Four Canadian pediatric intensive care units and a university-affiliated laboratory.

PATIENTS

Twenty-seven children, aged 2-17 yrs, with severe TBI (Glasgow Coma Scale score of ≤ 8).

INTERVENTIONS

Hypothermia therapy (32.5°C) for 24 hrs with cooling started within 8 hrs of injury and rewarming at a rate of 0.5°C every 2 hrs or normothermia (37.0°C).

MEASUREMENTS AND MAIN RESULTS

GFAP was measured in cerebrospinal fluid and serum, using enzyme-linked immunosorbent assay. Levels of GFAP were maximal on day 1 post-TBI, with cerebrospinal fluid GFAP (15.5 ± 6.1 ng/mL) 25-fold higher than serum GFAP (0.6 ± 0.2 ng/mL). Cerebrospinal fluid GFAP normalized by day 7, whereas serum GFAP decreased gradually to reach a steady state by day 10. Serum GFAP measured on day 1 correlated with Pediatric Cerebral Performance Category scores determined at 6 months post-TBI (ρ = 0.527; p = .008) but failed to correlate with the injury scoring on admission, physiologic variables, or indices of injury measured on computerized tomography imaging. The areas under the receiver operating characteristic curves for pediatric intensive care unit day 1 serum GFAP in determining good outcome were 0.80 (pediatric cerebral performance category, 1-2; normal-mild disability) and 0.91 (pediatric cerebral performance category, 1-3; normal-moderate disability). For a serum GFAP cutoff level of 0.6 ng/mL, sensitivity and specificity were 88% to 90% and 43% to 71%, respectively. Serum GFAP levels were similar among children randomized to either therapeutic hypothermia or normothermia.

CONCLUSIONS

GFAP was markedly elevated in cerebrospinal fluid and serum in children after severe TBI and serum GFAP measured on pediatric intensive care unit day 1 correlated with functional outcome at 6 months. Hypothermia therapy did not alter serum GFAP levels compared with normothermia after severe TBI in children. Serum GFAP concentration, together with other biomarkers, may have prognostic value after TBI in children.

Predictors of outcome following acquired brain injury in children

Acquired brain injury (ABI) in children and adolescents can result from multiple causes, including trauma, central nervous system infections, noninfectious disorders (epilepsy, hypoxia/ischemia, genetic/metabolic disorders), tumors, and vascular abnormalities. Prediction of outcomes is important, to target interventions, allocate resources, provide education to family or caregivers, and begin appropriate planning for the future. Researchers have identified several factors associated with better or worse outcomes after ABI, including variables related to the injury itself, postinjury factors related to intervention or trajectory of recovery, and preinjury or demographic factors. When examining the scientific literature, it is important to identify how "outcome" is defined, as the predictors may change depending on the outcome studied. In addition, key variables may be specific to the etiology of injury. Therefore, predictors of outcome cannot be generalized across the various etiologies of ABI, and this review will discuss predictors within the context of multiple etiologies of ABI. This article reviews the current literature on predicting outcomes after pediatric ABI, and areas in need of further research are discussed.

Acute clinical grading in pediatric severe traumatic brain injury and its association with subsequent intracranial pressure, cerebral perfusion pressure, and brain oxygenation

Object

The goal of this paper was to examine the relationship between methods of acute clinical assessment and measures of secondary cerebral insults in severe traumatic brain injury in children.

Methods

Patients who underwent intracranial pressure (ICP), cerebral perfusion pressure (CPP), and brain oxygenation (PbtO2) monitoring and who had an initial Glasgow Coma Scale score, Pediatric Trauma Score, Pediatric Index of Mortality 2 score, and CT classification were evaluated. The relationship between these acute clinical scores and secondary cerebral insult measures, including ICP, CPP, PbtO2, and systemic hypoxia were evaluated using univariate and multivariate analysis.

Results

The authors found significant associations between individual acute clinical scores and select physiological markers of secondary injury. However, there was a large amount of variability in these results, and none of the scores evaluated predicted each and every insult. Furthermore, a number of physiological measures were not predicted by any of the scores.

Conclusions

Although they may guide initial treatment, grading systems used to classify initial injury severity appear to have a limited value in predicting who is at risk for secondary cerebral insults.