Modern approaches to pediatric brain injury therapy

Decompressive Craniectomy for Pediatric Traumatic Brain Injury in Low-and-Middle Income and High Income Countries

Traumatic brain injury is one of the leading causes of mortality and morbidity in children worldwide. In severe cases, high intracranial pressure is the most frequent cause of death. When first-line medical management fails, the neurosurgical procedure of decompressive craniectomy (DC) has been proposed for controlling intracranial pressure and improving the long-term outcomes for children with severe traumatic brain injury. However, the use of this procedure is controversial. The evidence from clinical trials shows some promise for the use of DC as an effective second-line treatment. However, it is limited by conflicting trial results, a lack of trials, and a high risk of bias. Furthermore, most research comes from retrospective observational studies and case series. This narrative review considers the strength of evidence for the use of DC in both a high income country and low-and-middle income country setting and examine how we can improve study design to better assess the efficacy of this procedure and increase the clinical translatability of results to centers worldwide. Specifically, we argue for a need for further studies with higher pediatric participant numbers, multicenter collaboration, and the use of a more consistent methodology to enable comparability of results among settings.

Decompressive craniectomy for severe traumatic brain injury in children: analysis of long-term neuropsychological impairment and review of the literature

OBJECTIVE

The effectiveness of decompressive craniectomy (DC) in the context of neurocritical care in adult patients has been recently under debate. The aim of our study was to evaluate the impact of decompressive craniectomy in severe traumatic brain injury (TBI) in children, focusing on short and long-term neurological and neuropsychological outcomes.

METHODS

Retrospective review of the medical records of children admitted at a level I trauma center, between January 2012 and December 2015, submitted to DC due to severe TBI. Additionally, an extensive review of literature on this subject was carried out.

RESULTS

Sixteen patients underwent DC for TBI at our institution during the evaluated period. 62.5% were males and the mean age was 12 years. Road traffic accident (RTA) was the main mechanism of trauma (62.5%). Average Glasgow Coma Scale (GCS) at admission was 5.2, whereas 75% of the patients presented with pathological pupillary reaction. Initial computed tomography (CT) showed skull fractures in 62.5% and acute subdural hemorrhage (ASH) in 56.3% of the patients. The mean intracranial pressure (ICP) was 27.2 mmHg prior to surgery, and the mean time window between admission and DC was 36.3 h. Unilateral DC was performed in 68.8% of the cases. The average Glasgow Outcome Scale (GOS) at 6-month follow-up was 3.7, whereas 70% of the survivors presented good recovery (GOS 4-5). Abnormal pupillary reaction at hospital admission increased 3-fold the risk of long-term neuropsychological disturbances. Follow-up evaluation revealed cognitive abnormality in 55.6% of the patients. The overall mortality at 6-month follow-up was 37.5%.

CONCLUSION

The present study indicates towards a potential benefit of DC in children with severe TBI; nevertheless, our data demonstrated a high incidence of neuropsychological impairment in the long-term follow-up. Psychological and cognitive assessment should be computed in prognosis evaluation in future prospective studies.

Pediatric Trauma Update

Trauma is the leading cause of mortality in children, accounting for over 11,000 deaths and more than 8 million nonfatal injuries in 2015 for ages 1-19 years.1 Current issues garnering particular attention and research efforts include traumatic brain injury (TBI), blunt solid organ injuries, imaging guidelines and trauma-induced coagulopathy. This article reviews the evaluation and management of the pediatric trauma patient while focusing on recent updates.

Granulocyte-colony stimulating factor and umbilical cord blood cell transplantation: Synergistic therapies for the treatment of traumatic brain injury

Traumatic brain injury (TBI) is now characterized as a progressive, degenerative disease and continues to stand as a prevalent cause of death and disability. The pathophysiology of TBI is complex, with a variety of secondary cell death pathways occurring which may persist chronically following the initial cerebral insult. Current therapeutic options for TBI are minimal, with surgical intervention or rehabilitation therapy existing as the only viable treatments. Considering the success of stem-cell therapies in various other neurological diseases, their use has been proposed as a potential potent therapy for patients suffering TBI. Moreover, stem cells are highly amenable to adjunctive use with other therapies, providing an opportunity to overcome the inherent limitations of using a single therapeutic agent. Our research has verified this additive potential by demonstrating the efficacy of co-delivering human umbilical cord blood (hUCB) cells with granulocyte-colony stimulating factor (G-CSF) in a murine model of TBI, providing encouraging results which support the potential of this approach to treat patients suffering from TBI. These findings justify ongoing research toward uncovering the mechanisms which underlie the functional improvements exhibited by hUCB + G-CSF combination therapy, thereby facilitating its safe and effect transition into the clinic. This paper is a review article. Referred literature in this paper has been listed in the reference section. The datasets supporting the conclusions of this article are available online by searching various databases, including PubMed. Some original points in this article come from the laboratory practice in our research center and the authors’ experiences.

Single Center Outcomes of Status Epilepticus at a Paediatric Intensive Care Unit

BACKGROUND

Status epilepticus (SE) is a frequent admission diagnosis to paediatric intensive care units (PICUs) and is associated with variable outcomes. We have audited our experience of patients presenting in SE at a Canadian PICU to determine unfavorable outcome variables.

METHODS

Charts of patients <18 years of age presenting in SE to a tertiary care PICU over a 10-year period were audited. Data were analyzed at three care-points: transport, the emergency department (ED) and the PICU. Patient outcome before PICU discharge was categorized as "favorable" for return to pre-status functioning level or "unfavorable" for new deficit/death. Student's t-test and the Kruskal-Wallis test were used for analysis of normal and skewed continuous variables, respectively, and either Chi-square test or Fisher's exact test for categorical variables.

RESULTS

189 patients (54% males) were identified with a median age of 1.9 years. Idiopathic SE had the highest incidence; infectious/vascular etiologies were associated with more unfavorable outcomes. Progression to refractory SE in the ED had a higher incidence of death (p<0.05). Patients with an unfavorable outcome had a higher incidence of apnea during transport (p=0.01), longer hospital stays (p<0.05), need for therapeutic coma (p=0.01), longer duration of therapeutic coma (p<0.05), need for mechanical ventilation (p<0.05), and recurrent or refractory seizures during inpatient stay (p<0.05). Multivariate analysis of unfavorable outcomes of patients in SE presenting to the PICU included renal failure, cerebral edema, apnea during transport, refractory seizures, and recurrent seizures.

CONCLUSIONS

Refractory seizures in children presenting with SE are associated with worsened outcomes in the PICU.

Transcranial magnetic stimulation facilitates neurorehabilitation after pediatric traumatic brain injury

Traumatic brain injury (TBI) is the leading cause of death and disability among children in the United States. Affected children will often suffer from emotional, cognitive and neurological impairments throughout life. In the controlled cortical impact (CCI) animal model of pediatric TBI (postnatal day 16-17) it was demonstrated that injury results in abnormal neuronal hypoactivity in the non-injured primary somatosensory cortex (S1). It materializes that reshaping the abnormal post-injury neuronal activity may provide a suitable strategy to augment rehabilitation. We tested whether high-frequency, non-invasive transcranial magnetic stimulation (TMS) delivered twice a week over a four-week period can rescue the neuronal activity and improve the long-term functional neurophysiological and behavioral outcome in the pediatric CCI model. The results show that TBI rats subjected to TMS therapy showed significant increases in the evoked-fMRI cortical responses (189%), evoked synaptic activity (46%), evoked neuronal firing (200%) and increases expression of cellular markers of neuroplasticity in the non-injured S1 compared to TBI rats that did not receive therapy. Notably, these rats showed less hyperactivity in behavioral tests. These results implicate TMS as a promising approach for reversing the adverse neuronal mechanisms activated post-TBI. Importantly, this intervention could readily be translated to human studies.

Safety of therapeutic hypothermia in children on veno-arterial extracorporeal membrane oxygenation after cardiac surgery

OBJECTIVE

The aim of this study was to evaluate whether the use of therapeutic hypothermia in patients receiving extracorporeal membrane oxygenation after paediatric cardiac surgery is associated with increased complication rates.

METHODS

We undertook a retrospective study to compare the complication rates and clinical course of children after cardiac surgery in two groups – extracorporeal membrane oxygenation without therapeutic hypothermia (group 1) and extracorporeal membrane oxygenation with therapeutic hypothermia (group 2). Therapeutic hypothermia was performed via the extracorporeal membrane oxygenation circuit heater-cooler device.

RESULTS

A total of 96 patients were included in this study (59 in group 1 and 37 in group 2). Complications were comparable between group 1 and group 2, except that more patients with therapeutic hypothermia had hypertension while on extracorporeal membrane oxygenation. Therapeutic hypothermia was not independently associated with in-hospital mortality (adjusted odds ratio 1.16, 95% CI: 0.33-4.03; p=0.82).

CONCLUSION

Therapeutic hypothermia can be safely provided to children on extracorporeal membrane oxygenation after cardiac surgery without an increase in complication rates.

Autologous bone marrow mononuclear cells reduce therapeutic intensity for severe traumatic brain injury in children

OBJECTIVES

The devastating effect of traumatic brain injury is exacerbated by an acute secondary neuroinflammatory response, clinically manifest as elevated intracranial pressure due to cerebral edema. The treatment effect of cell-based therapies in the acute post-traumatic brain injury period has not been clinically studied although preclinical data demonstrate that bone marrow-derived mononuclear cell infusion down-regulates the inflammatory response. Our study evaluates whether pediatric traumatic brain injury patients receiving IV autologous bone marrow-derived mononuclear cells within 48 hours of injury experienced a reduction in therapeutic intensity directed toward managing elevated intracranial pressure relative to matched controls.

DESIGN

The study was a retrospective cohort design comparing pediatric patients in a phase I clinical trial treated with IV autologous bone marrow-derived mononuclear cells (n = 10) to a control group of age- and severity-matched children (n = 19).

SETTING

The study setting was at Children's Memorial Hermann Hospital, an American College of Surgeons Level 1 Pediatric Trauma Center and teaching hospital for the University of Texas Health Science Center at Houston from 2000 to 2008.

PATIENTS

Study patients were 5-14 years with postresuscitation Glasgow Coma Scale scores of 5-8.

INTERVENTIONS

The treatment group received 6 million autologous bone marrow-derived mononuclear cells/kg body weight IV within 48 hours of injury. The control group was treated in an identical fashion, per standard of care, guided by our traumatic brain injury management protocol, derived from American Association of Neurological Surgeons guidelines.

MEASUREMENTS AND MAIN RESULTS

The primary measure was the Pediatric Intensity Level of Therapy scale used to quantify treatment of elevated intracranial pressure. Secondary measures included the Pediatric Logistic Organ Dysfunction score and days of intracranial pressure monitoring as a surrogate for length of neurointensive care. A repeated-measure mixed model with marginal linear predictions identified a significant reduction in the Pediatric Intensity Level of Therapy score beginning at 24 hours posttreatment through week 1 (p < 0.05). This divergence was also reflected in the Pediatric Logistic Organ Dysfunction score following the first week. The duration of intracranial pressure monitoring was 8.2 ± 1.3 days in the treated group and 15.6 ± 3.5 days (p = 0.03) in the time-matched control group.

CONCLUSIONS

IV autologous bone marrow-derived mononuclear cell therapy is associated with lower treatment intensity required to manage intracranial pressure, associated severity of organ injury, and duration of neurointensive care following severe traumatic brain injury. This may corroborate preclinical data that autologous bone marrow-derived mononuclear cell therapy attenuates the effects of inflammation in the early post-traumatic brain injury period.

Preschool children with head injury: comparing injury severity measures and clinical care

The purpose of this study was to compare child, hospital course, and discharge characteristics by admitting unit, injury type, head Abbreviated Injury Scale (AIS), and Glasgow Coma Scale (GCS), and test congruence of AIS and GCS categories. Chart data were collected from seven hospitals on 183 preschool children with head injury (90 admitted to PICU, 93 to general care unit). Injury events included falls (n = 89, 49%), hit by car (n = 35, 19%), motor vehicle crashes (n = 26, 14%), bicycle crashes (n = 12, 7%), and blunt traumas (n = 21, 11%). Most children (68%) had head injuries only, 20% had other fractures, 5% had organ damage, and 7% had all three. Injury severity was measured by head AIS and GCS scores. Treatments and procedures included tubes/lines, blood/blood products, and medications. Children with head injuries only had fewer hospital days, less severe head injuries, and near normal GCS scores. They were less likely to have tubes/lines and medications. Children were discharged with medications (61%) and medical equipment (14%). Five children were discharged to long-term care facilities, and five were discharged to rehabilitation facilities. Concordance of head AIS and GCS categories occurred for only 50 (28%) children. Although the GCS is the gold standard for identifying changes in neurological status, it was not as helpful in representing hospital care. Head AIS injury categories clustered children in more homogeneous groups and better represented hospital care. Head AIS categories are better indicators of injury severity and care provided than GCS. Head injury AIS score may be an important addition to GCS for guiding care.

Effect of cell therapy on metabolite content in brain structures of children with consequences of severe brain injury: 1H magnetic resonance spectroscopy study

The effect of intravenous injection of human umbilical cord blood cells on the levels of N-acetylaspartate, creatine and phosphocreatine, choline-containing compounds, glutamine and glutamate, and myoinositol in morphologically intact areas of the cortex, white matter, and hippocampus of children with consequences of traumatic brain injury was studied by single voxel 1H magnetic resonance spectroscopy. It was shown that cell therapy increases the content of N-acetylaspartate, a marker of functional integrity of neurons, in the white matter and in the cortex at the boundary between the frontotemporal and parietal lobes and reduces neurological deficit.

Re-orientation of clinical research in traumatic brain injury: report of an international workshop on comparative effectiveness research

During the National Neurotrauma Symposium 2010, the DG Research of the European Commission and the National Institutes of Health/National Institute of Neurological Disorders and Stroke (NIH/NINDS) organized a workshop on comparative effectiveness research (CER) in traumatic brain injury (TBI). This workshop reviewed existing approaches to improve outcomes of TBI patients. It had two main outcomes: First, it initiated a process of re-orientation of clinical research in TBI. Second, it provided ideas for a potential collaboration between the European Commission and the NIH/NINDS to stimulate research in TBI. Advances in provision of care for TBI patients have resulted from observational studies, guideline development, and meta-analyses of individual patient data. In contrast, randomized controlled trials have not led to any identifiable major advances. Rigorous protocols and tightly selected populations constrain generalizability. The workshop addressed additional research approaches, summarized the greatest unmet needs, and highlighted priorities for future research. The collection of high-quality clinical databases, associated with systems biology and CER, offers substantial opportunities. Systems biology aims to identify multiple factors contributing to a disease and addresses complex interactions. Effectiveness research aims to measure benefits and risks of systems of care and interventions in ordinary settings and broader populations. These approaches have great potential for TBI research. Although not new, they still need to be introduced to and accepted by TBI researchers as instruments for clinical research. As with therapeutic targets in individual patient management, so it is with research tools: one size does not fit all.

Sensorimotor behavioral tests for use in a juvenile rat model of traumatic brain injury: assessment of sex differences

Modeling juvenile traumatic brain injury (TBI) in rodents presents several unique challenges compared to adult TBI, one of which is selecting appropriate sensorimotor behavioral tasks that enable the assessment of the extent of injury and recovery over time in developing animals. To address this challenge, we performed a comparison of common sensorimotor tests in Long-Evans rats of various sizes and developmental stages (postnatal days 16-45, 35-190 g). Tests were compared and selected for their developmental appropriateness, scalability for growth, pre-training requirements, and throughput capability. Sex differences in response to TBI were also assessed. Grid walk, automated gait analysis, rotarod, beam walk, spontaneous forelimb elevation test, and measurement of motor activity using the force-plate actometer were evaluated. Grid walk, gait analysis, and rotarod failed to meet one or more of the evaluation criteria. Beam walk, spontaneous forelimb elevation test, and measurement of motor activity using the force-plate actometer satisfied all criteria and were capable of detecting motor abnormalities in rats subjected to controlled cortical impact on postnatal day 17. No sex differences were detected in the acute effects of TBI or functional recovery during the 28 days after injury using these tests. This demonstrates the utility of these tests for the evaluation of sensorimotor function in studies using rat models of pediatric TBI, and suggests that pre-pubertal males and females respond similarly to TBI with respect to sensorimotor outcomes.

[Infusion therapy for neonates, infants and children]

Intravenous administration of fluids, electrolytes and glucose are the most common interventions in hospitalized pediatric patients. Parenteral fluid administration can be life-saving, however, if used incorrectly it also carries substantial risks. Perioperatively, adequate hydration, prevention of electrolyte imbalances and maintenance of normoglycemia are the main goals of parenteral fluid therapy. Conceptionally, the distinction between maintenance requirements, deficits and ongoing loss is helpful. Although the pathophysiological basis for parenteral fluid therapy was clarified in the first half of the 20th century, some aspects still remain controversial. In newborn infants, rational parenteral fluid therapy must take into account large insensible fluid losses, adaptive changes of renal function in the first days of life and the fact that neonates do not tolerate prolonged periods of fasting. In older infants the occurrence of iatrogenic hyponatremia with the use of hypotonic solutions has led to a critical reappraisal of the validity of the Holliday-Segar method for calculating maintenance fluid requirements in the postoperative period. Pragmatically, only isotonic solutions should be used in clinical situations which are known to be associated with increases in antidiuretic hormone (ADH) secretion. In this context, it is important to realize that in contrast to lactated Ringer's solution, the use of normal saline can lead to hyperchloremic acidosis in a dose-dependent fashion. Although there is no convincing evidence that colloids are better than crystalloids, there are clinical situations where the use of the more expensive colloids seems justified. It may be reasonable to choose a solution for fluid replacement which has a composition comparable to the composition of the fluid which must be replaced. Although hypertonic saline can reduce an elevated intracranial pressure, this therapy cannot be recommended as a routine procedure because there is currently no evidence that this intervention improves long-term outcome in pediatric patients with traumatic brain injury.

Autologous Bone Marrow Mononuclear Cell Therapy for Severe Traumatic Brain Injury in Children

BACKGROUND:

Severe traumatic brain injury (TBI) in children is associated with substantial long-term morbidity and mortality. Currently, there are no successful neuroprotective/neuroreparative treatments for TBI. Numerous preclinical studies suggest that bone marrow-derived mononuclear cells (BMMNCs), their derivative cells (marrow stromal cells), or similar cells (umbilical cord blood cells) offer neuroprotection.

OBJECTIVE:

To determine whether autologous BMMNCs are a safe treatment for severe TBI in children.

METHODS:

Ten children aged 5 to 14 years with a postresuscitation Glasgow Coma Scale of 5 to 8 were treated with 6 × 106 autologous BMMNCs/kg body weight delivered intravenously within 48 hours after TBI. To determine the safety of the procedure, systemic and cerebral hemodynamics were monitored during bone marrow harvest; infusion-related toxicity was determined by pediatric logistic organ dysfunction (PELOD) scores, hepatic enzymes, Murray lung injury scores, and renal function. Conventional magnetic resonance imaging (cMRI) data were obtained at 1 and 6 months postinjury, as were neuropsychological and functional outcome measures.

RESULTS:

All patients survived. There were no episodes of harvest-related depression of systemic or cerebral hemodynamics. There was no detectable infusion-related toxicity as determined by PELOD score, hepatic enzymes, Murray lung injury scores, or renal function. cMRI imaging comparing gray matter, white matter, and CSF volumes showed no reduction from 1 to 6 months postinjury. Dichotomized Glasgow Outcome Score at 6 months showed 70% with good outcomes and 30% with moderate to severe disability.

CONCLUSION:

Bone marrow harvest and intravenous mononuclear cell infusion as treatment for severe TBI in children is logistically feasible and safe.

Traumatic brain injury: preferred methods and targets for resuscitation

PURPOSE OF REVIEW

Severe traumatic brain injury (TBI) is the most common cause of death and disability in pediatric trauma. This review looks at the strategies to treat TBI in a temporal fashion. We examine the targets for resuscitation from field triage to definitive care in the pediatric ICU.

RECENT FINDINGS

Guidelines for the management of pediatric TBI exist. The themes of contemporary clinical research have been compliance with these guidelines and refinement of treatment recommendations developing a more sophisticated understanding of the pathophysiology of the injured brain. In the field, the aim has been to achieve routine compliance with the resuscitation goals. In the hospital, efforts have been directed at improving our ability to monitor the injured brain, developing techniques that limit brain swelling, and customizing brain perfusion.

SUMMARY

As our understanding of pediatric TBI evolves, the ambition is that age-specific and perhaps individual brain injury strategies based upon feedback from continuous monitors will be defined. In addition, vogue methods such as hypothermia, hypertonic saline, and aggressive surgical decompression may prove to impact brain swelling and outcomes.

Progenitor cell therapy for traumatic brain injury: effect of serum osmolarity on cell viability and cytokine production

INTRODUCTION

The potential translation of mesenchymal stem cell (MSC) therapy into a multimodal protocol for traumatic brain injury requires evaluation of viability and cytokine production in a hyperosmolar environment. Optimization of MSC therapy requires delivery to the target area without significant loss of cellular function or viability. No model evaluating the potential efficacy of MSC therapy at varying osmolarities currently exists.

METHODS

Rat MSCs were characterized with flow cytometric immunophenotyping. MSCs (passage 3) were placed in culture with multipotent adult progenitor cell media at varying osmolarities (250, 270, 290, 310, 330, 350 and 370 mOsm) potentially found with hypertonic saline infusion. After culture for 24 h, cellular viability was measured using flow cytometry (n = 6). Next, brain tissue supernatant was harvested from both normal rat brains and injured brains 6 h after cortical injury. Subsequently, MSCs were placed in culture with multipotent adult progenitor cell media +/- 20% normal brain or injured brain supernatant (at the aforementioned osmolarities) and allowed to remain in culture for 24 h (n = 11). At this point, media supernatant cytokine levels were measured using a multiplex cytokine assay system.

RESULTS

MSCs showed no clinically significant difference in viability at 24 h. MSCs cultured with 20% injured brain supernatant showed an decrease in proinflammatory cytokine production (IL-1alpha and IL-1beta) with increasing osmolarity. No difference in anti-inflammatory cytokine production (IL-4 and IL-10) was observed.

CONCLUSION

Progenitor cell therapy for traumatic brain injury may require survival and activity in a hyperosmolar environment. Culture of MSCs in such conditions shows no clinically significant effect on cell viability. In addition, MSC efficacy could potentially be enhanced via a decrease in proinflammatory cytokine production. Overall, a multimodal traumatic brain injury treatment protocol based upon MSC infusion and hypertonic saline therapy would not negatively affect progenitor cell efficacy and could be considered for multicenter clinical trials.