Severe head injury in children: impact of risk factors on outcome

EASIX is an effective marker in predicting mortality of traumatic brain injury patients

BACKGROUND

The Endothelial Activation and Stress Index (EASIX) is a novel marker of endothelial injury and correlates with survival of various patients. The endothelial dysfunction plays an important role on the pathophysiological process of traumatic brain injury (TBI). This study was designed to explore the prognostic value of EASIX on TBI patients.

METHODS

358 TBI patients hospitalized in the West China hospital between October 2018 and October 2022 were enrolled for this study. The EASIX was calculated based on the formula: lactate dehydrogenase (U/L) × creatinine (mg/dL)/platelets (109 cells/L). The univariate and multivariate logistic regression with forward method was performed to explore the association between EASIX and mortality. A prognostic model was developed combining significant risk factors in the multivariate logistic regression. The receiver operating characteristic (ROC) curve was used to compare the predictive accuracy of the EASIX and the developed model.

RESULTS

The 30-day mortality of enrolled 358 TBI patients was 51.1%. Non-survivors had higher EASIX than survivors (p < 0.001). The multivariate logistic regression confirmed seven risk factors for mortality of TBI including injury mechanism (p = 0.010), GCS (p < 0.001), glucose (p < 0.001), EASIX (p = 0.017), subdural hematoma (p = 0.012), coagulopathy (p = 0.001). The AUC of EASIX, SOFA, GCS was 0.747, 0.748 and 0.774, respectively. The AUC of developed predictive model was 0.874 with the sensitivity of 0.913 and specificity of 0.686.

CONCLUSIONS

The EASIX is a reliable marker for predicting mortality of TBI patients. The predictive model incorporating EASIX is helpful for clinicians to evaluate the mortality risk of TBI patients.

A multicenter observational study on outcomes of moderate and severe pediatric traumatic brain injuries-time to reappraise thresholds for treatment

PURPOSE

Children with moderate traumatic brain injury (modTBI) (Glasgow Coma Scale (GCS) 9-13) may benefit from better stratification. We aimed to compare neurocritical care utilization and functional outcomes between children with high GCS modTBI (hmodTBI, GCS 11-13), low GCS modTBI (lmodTBI, GCS 9-10), and severe TBI (sTBI, GCS ≤ 8). We hypothesized that patients with lmodTBI have higher neurocritical care needs and worse outcomes than patients with hmodTBI and are similar to patients with sTBI.

METHODS

Prospective observational study from June 2018 to October 2022 in 28 pediatric intensive care units (PICU) in Asia, South America, and Europe. We included children (age < 18 years) with modTBI and sTBI admitted to PICU and measured functional outcomes at 3 months using the Glasgow Outcome Scale-Extended Pediatric Revision (GOS-E Peds, scale 1-8, 1 = upper good recovery, 8 = death).

RESULTS

We analyzed 409 patients: 98 (24%) and 311 (76%) with modTBI and sTBI, respectively. Patients with lmodTBI (vs. hmodTBI) were more likely to have invasive ICP monitoring (32.3% vs. 4.5%, p < 0.001), longer PICU stay (days, median [IQR]; 5.00 [4.00, 9.75] vs 4.00 [2.00, 5.00], p = 0.007), and longer hospital stay (days, median [IQR]: 13.00 [8.00, 17.00] vs. 8.00 [5.00, 12, 25], p = 0.015). Median GOS-E Peds scores were significantly different (hmodTBI (1.00 [1.00, 3.00]), lmodTBI (3.00 [IQR 2.00, 5.75]), and sTBI (5.00 [IQR 1.00, 6.00]) (p < 0.001)). After adjusting for age, sex, presence of polytrauma and cerebral edema, lmodTBI, and sTBI remained significantly associated with higher GOS-E scores (adjusted coefficient (standard error): 1.24 (0.52), p = 0.018, and 1.27 (0.33), p < 0.001, respectively) compared with hmodTBI.

CONCLUSIONS

Children with lmodTBI have higher rates of neurocritical care utilization and worse functional outcomes than those with hmodTBI but better than those with sTBI. Children with lmodTBI may benefit from guideline-based management similar to what is implemented in children with sTBI. This work was performed in hospitals within the PACCMAN and LARed networks. No reprints will be ordered.

Synergistic effects of auraptene and 17-β estradiol on traumatic brain injury treatment: oxidant/antioxidant status, inflammatory cytokines and pathology

OBJECTIVE

Despite significant advances that have been made in the treatment of traumatic brain injury (TBI), it remains a global health issue. This study aimed to investigate the synergistic effects of 17-β estradiol (E2) and auraptene (AUR) on TBI treatment.

METHODS

In total, 70 adult male Wistar rats were divided randomly into ten main groups: Sham, TBI, TBI + DMSO, TBI + AUR (4 mg/kg), TBI + AUR (8 mg/kg), TBI + AUR (25 mg/kg), TBI + E2 group, TBI + AUR (4 mg/kg) + E2 group, TBI + AUR (8 mg/kg) + E2 group and TBI + AUR (25 mg/kg) + E2 group. Diffuse TBI was caused by the Marmarou process in male rats. The brain's tissues were harvested to check the parameters of oxidative stress and levels of inflammatory cytokine.

RESULTS

The finding revealed that TBI induced a significant increase in brain edema, pro-inflammatory cytokines and oxidant levels [MDA and NO], and also a decrease in the brain's antioxidant biomarkers [GPx, SOD]. We also found that E2 and AUR (25 mg/kg) significantly preserved the levels of these biomarkers. The combination of AUR concentrations and E2 showed that this treatment efficiently preserved the levels of these biomarkers. Furthermore, the combination of E2 and AUR (25 mg/kg) c could cause the most effective synergistic interaction.

CONCLUSION

AUR could act synergistically with E2 to treat brain injury complications.

Initial CT Imaging Predicts Mortality in Severe Traumatic Brain Injuries in Pediatric Population-A Systematic Review and Meta-Analysis

The purpose of this systematic review was to analyze evidence based on existing studies on the ability of initial CT imaging to predict mortality in severe traumatic brain injuries (TBIs) in pediatric patients. An experienced librarian searched for all existing studies based on the inclusion and exclusion criteria. The studies were screened by two blinded reviewers. Of the 3277 studies included in the search, data on prevalence of imaging findings and mortality rate could only be extracted from 22 studies. A few of those studies had patient-specific data relating specific imaging findings to outcome, allowing the data analysis, calculation of the area under the curve (AUC) and receiver operating characteristic (ROC), and generation of a forest plot for each finding. The data were extracted to calculate the sensitivity (SN), specificity (SP), positive predictive value (PPV), negative predicted value (NPV), AUC, and ROC for extradural hematoma (EDH), subdural hematoma (SDH), traumatic subarachnoid hemorrhage (tSAH), skull fractures, and edema. There were a total of 2219 patients, 747 females and 1461 males. Of the total, 564 patients died and 1651 survived; 293 patients had SDH, 76 had EDH, 347 had tSAH, 244 had skull fractures, and 416 had edema. The studies included had high bias and lower grade of evidence. Out of the different CT scan findings, brain edema had the highest SN, PPV, NPV, and AUC. EDH had the highest SP to predict in-hospital mortality.

The Influence of Serious Extracranial Injury on In-Hospital Mortality in Children with Severe Traumatic Brain Injury

(1) Background: Severe traumatic brain injury (sTBI) is the leading cause of death in children. Serious extracranial injury (SEI) commonly coexists with sTBI after the high impact of trauma. Limited studies evaluate the influence of SEI on the prognosis of pediatric sTBI. We aimed to analyze SEI’s clinical characteristics and initial presentations and evaluate if SEI is predictive of higher in-hospital mortality in these sTBI children. (2) Methods: In this 11-year-observational cohort study, a total of 148 severe sTBI children were enrolled. We collected patients’ initial data in the emergency department, including gender, age, mechanism of injury, coexisting SEI, motor components of the Glasgow Coma Scale (mGCS) score, body temperature, blood pressure, blood glucose level, initial prothrombin time, and intracranial Rotterdam computed tomography (CT) score of the first brain CT scan, as potential mortality predictors. (3) Results: Compared to sTBI children without SEI, children with SEI were older and more presented with initial hypotension and hypothermia; the initial lab showed more prolonged prothrombin time and a higher in-hospital mortality rate. Multivariate analysis showed that motor components of mGCS, fixed pupil reaction, prolonged prothrombin time, and higher Rotterdam CT score were independent predictors of in-hospital mortality in sTBI children. SEI was not an independent predictor of mortality. (4) Conclusions: sTBI children with SEI had significantly higher in-hospital mortality than those without. SEI was not an independent predictor of mortality in our study. Brain injury intensity and its presentations, including lower mGCS, fixed pupil reaction, higher Rotterdam CT score, and severe injury-induced systemic response, presented as initial prolonged prothrombin time, were independent predictors of in-hospital mortality in these sTBI children.

Pediatric severe traumatic brain injury mortality prediction determined with machine learning-based modeling

INTRODUCTION

Severe traumatic brain injury (sTBI) is a leading cause of mortality in children. As clinical prognostication is important in guiding optimal care and decision making, our goal was to create a highly discriminative sTBI outcome prediction model for mortality.

METHODS

Machine learning and advanced analytics were applied to the patient admission variables obtained from a comprehensive pediatric sTBI database. Demographic and clinical data, head CT imaging abnormalities and blood biochemical data from 196 children and adolescents admitted to a tertiary pediatric intensive care unit (PICU) with sTBI were integrated using feature ranking by way of a forest of randomized decision trees, and a model was generated from a reduced number of admission variables with maximal ability to discriminate outcome.

RESULTS

In total, 36 admission variables were analyzed using feature ranking with variable weighting to determine their predictive importance for mortality following sTBI. Reduction analysis utilizing Borata feature selection resulted in a parsimonious six-variable model with a mortality classification accuracy of 82%. The final admission variables that predicted mortality were: partial thromboplastin time (22%); motor Glasgow Coma Scale (21%); serum glucose (16%); fixed pupil(s) (16%); platelet count (13%) and creatinine (12%). Using only these six admission variables, a t-distributed stochastic nearest neighbor embedding algorithm plot demonstrated visual separation of sTBI patients that lived or died, with high mortality predictive ability of this model on the validation dataset (AUC = 0.90) which was confirmed with a conventional area-under-the-curve statistical approach on the total dataset (AUC = 0.91; P < 0.001).

CONCLUSIONS

Machine learning-based modeling identified the most clinically important prognostic factors resulting in a pragmatic, high performing prognostic tool for pediatric sTBI with excellent discriminative ability to predict mortality risk with 82% classification accuracy (AUC = 0.90). After external multicenter validation, our prognostic model might help to guide treatment decisions, aggressiveness of therapy and prepare family members and caregivers for timely end-of-life discussions and decision making.

LEVEL OF EVIDENCE

III; Prognostic.

Predictors of In-Hospital Mortality for Road Traffic Accident-Related Severe Traumatic Brain Injury

(1) Background: Road traffic accidents (RTAs) are the leading cause of pediatric traumatic brain injury (TBI) and are associated with high mortality. Few studies have focused on RTA-related pediatric TBI. We conducted this study to analyze the clinical characteristics of RTA-related TBI in children and to identify early predictors of in-hospital mortality in children with severe TBI. (2) Methods: In this 15-year observational cohort study, a total of 618 children with RTA-related TBI were enrolled. We collected the patients' clinical characteristics at the initial presentations in the emergency department (ED), including gender, age, types of road user, the motor components of the Glasgow Coma Scale (mGCS) score, body temperature, blood pressure, blood glucose level, initial prothrombin time, and the intracranial computed tomography (CT) Rotterdam score, as potential mortality predictors. (3) Results: Compared with children exhibiting mild/moderate RTA-related TBI, those with severe RTA-related TBI were older and had a higher mortality rate (p < 0.001). The in-hospital mortality rate for severe RTA-related TBI children was 15.6%. Compared to children who survived, those who died in hospital had a higher incidence of presenting with hypothermia (p = 0.011), a lower mGCS score (p < 0.001), a longer initial prothrombin time (p < 0.013), hyperglycemia (p = 0.017), and a higher Rotterdam CT score (p < 0.001). Multivariate analyses showed that the mGCS score (adjusted odds ratio (OR): 2.00, 95% CI: 1.28-3.14, p = 0.002) and the Rotterdam CT score (adjusted OR: 2.58, 95% CI: 1.31-5.06, p = 0.006) were independent predictors of in-hospital mortality. (4) Conclusions: Children with RTA-related severe TBI had a high mortality rate. Patients who initially presented with hypothermia, a lower mGCS score, a prolonged prothrombin time, hyperglycemia, and a higher Rotterdam CT score in brain CT analyses were associated with in-hospital mortality. The mGCS and the Rotterdam CT scores were predictive of in-hospital mortality independently.

Patient Characteristics and Clinical and Intraoperative Variables Affecting Outcome in Pediatric Traumatic Brain Injury

Background Pediatric traumatic brain injury (TBI) has distinctive pathophysiology and characteristics that differ from adults. These can be attributed to age-related anatomical and physiological differences and distinct patterns of injuries seen in children. Our aim was to identify the patient characteristics, clinical variables during intensive care and intraoperative management associated with poor functional outcome in a cohort of pediatric TBI patients.

Methods Retrospective chart review of pediatric TBI patients admitted to neurotrauma intensive care unit (NICU) over a period of 1 year.

Results A total of 105 children (< 12 years) with head injury were admitted in the NICU during the study period. The most common mechanism of injury was fall in 78% cases. Fifty-four patients (51.4%) presented with a severe head injury (Glasgow coma scale [GCS] ≤ 8), while 31 (29.5%) and 20 (19.1%) had a mild and moderate head injury. The most common finding was skull fractures (59%), contusions (36.2%), and subdural hematoma (SDH) (30.4%). Forty nine patients (46.7%) required surgical management. The median duration of anesthesia was 205 (interquartile range [IQR] 65, 375) minutes, and median blood loss during the surgery was 16.7 mL/kg body weight with 41% requiring intraoperative blood transfusions. Median duration of ICU and hospital stay was 5 (IQR 1, 47) and 8 (IQR 1, 123) days, respectively. GOS at discharge ≤ 3 representing poor outcome was present in 35 patients (33.3%). Mortality was seen in 15 (14.3%) patients. Multivariate analysis identified postresuscitation GCS ≤ 8 on admission as independent predictor of mortality, and postresuscitation GCS ≤ 8 on admission and NICU stay of > 7 days as independent predictor of poor outcome.

Conclusion Despite advances in neurointensive care, mortality and morbidity remains high in pediatric head trauma and is mainly dependent on postresuscitation GCS and NICU stay of more than 7 days. Multidimensional approach is required for its prevention and management.

Management of Cerebral Edema, Brain Compression, and Intracranial Pressure

PURPOSE OF REVIEW

This article reviews the pathophysiology and management of cerebral edema, brain compression, and elevated intracranial pressure (ICP). It also provides a brief introduction to the concept of the glymphatic system and select cellular contributors to cerebral edema.

RECENT FINDINGS

Cerebral edema and brain compression should be treated in a tiered approach after the patient demonstrates a symptomatic indication to start treatment. All patients with acute brain injury should be treated with standard measures to optimize intracranial compliance and minimize risk of ICP elevation. When ICP monitors are used, therapies should target maintaining ICP at 22 mm Hg or less. Evidence exists that serial clinical examination and neuroimaging may be a reasonable alternative to ICP monitoring; however, clinical trials in progress may demonstrate advantages to advanced monitoring techniques. Early decompressive craniectomy and hypothermia are not neuroprotective in traumatic brain injury and should be reserved for situations refractory to initial medical interventions. Medical therapies that acutely lower plasma osmolality may lead to neurologic deterioration from osmotic cerebral edema, and patients with acute brain injury and renal or liver failure are at elevated risk.

SUMMARY

A tiered approach to the management of cerebral edema and brain compression can reduce secondary brain injury when implemented according to core physiologic principles. However, our knowledge of the pathophysiology of acute brain injury is incomplete, and the conceptual framework underlying decades of clinical management may need to be revised in response to currently evolving discoveries regarding the pathophysiology of acute brain injury.

Electroosmosis Based Novel Treatment Approach for Cerebral Edema

OBJECTIVE

Cerebral edema characterized as an abnormal accumulation of interstitial fluid has not been treated effectively. We propose a novel edema treatment approach to drive edematous fluid out of the brain by direct current utilizing brain tissue's electroosmotic property.

METHODS

A finite element (FE) head model is developed and employed to assess the feasibility of the approach. First, the capacity of the model for electric field prediction is validated against human experiments. Second, two electrode configurations (S and D-montage) are designed to evaluate the distribution of the electric field, electroosmotic flow (EOF), current density, and temperature across the brain under an applied direct current.

RESULTS

The S-montage is shown to induce an average EOF velocity of 7e-4 mm/s underneath the anode by a voltage of 15 V, and the D-montage induces a velocity of 9e-4 mm/s by a voltage of 5 V. Meanwhile, the brain temperature in both configurations is below 38 °C, which is within the safety range. Further, the magnitude of EOF is proportional to the electric field, and the EOF direction follows the current flow from anode to cathode. The EOF velocity in the white matter is significantly higher than that in the gray matter under the anode where the fluid is to be drawn out.

CONCLUSION

The proposed electroosmosis based approach allows alleviating brain edema within the critical time window by direct current.

SIGNIFICANCE

The approach may be further developed as a new treatment solely or as a complement to existing conventional treatments of edema.

Estrogen Attenuates Traumatic Brain Injury by Inhibiting the Activation of Microglia and Astrocyte-Mediated Neuroinflammatory Responses

Traumatic brain injury (TBI), which leads to high mortality and morbidity, is a prominent public health problem worldwide. Neuroinflammation involving microglia and astrocyte activation has been demonstrated to play critical role in the secondary injury induced by TBI. A1 astrocytes, which are induced by activated microglia, can directly kill neurons by secreting neurotoxic complement C3. Estrogen has been proved to possess neuroprotective effects, but the effect and underlying mechanism of estrogen on TBI-induced neuroinflammatory injury remain largely unclear. In this study, we constructed an adult male mouse model of TBI and immediately after injury treated the mice with 17β-estradiol (E2) (100 μg/kg, once every day via intraperitoneal injection) for 3 days. We found that E2 treatment significantly alleviated TBI-induced neurological deficits, neuronal injuries, and brain edema and significantly inhibited Iba1 and GFAP expression, which are markers of microglia and astrocyte activation, respectively. E2 treatment also significantly inhibited TLR4 and NF-κB protein expression, and significantly reduced the expression of the proinflammatory factors IL-1β, IL-6, and TNF-α. Moreover, E2 treatment significantly decreased the number of complement C3d/GFAP-positive cells and complement C3d protein expression. Taking these results together, we concluded that E2 treatment dramatically alleviates TBI neuroinflammatory injury by inhibiting TLR4/NF-κB pathway-mediated microglia and astrocyte activation and neuroinflammation and reducing A1-phenotype neurotoxic astrocyte activation. Our findings indicate that E2 treatment may be a potential therapy strategy for TBI-induced neuroinflammation injury.

Endothelial Regulation by Exogenous Annexin A1 in Inflammatory Response and BBB Integrity Following Traumatic Brain Injury

Background and Target

Following brain trauma, blood–brain barrier (BBB) disruption and inflammatory response are critical pathological steps contributing to secondary injury, leading to high mortality and morbidity. Both pathologies are closely associated with endothelial remodeling. In the present study, we concentrated on annexin A1 (ANXA1) as a novel regulator of endothelial function after traumatic brain injury.

Methods

After establishing controlled cortical impact (CCI) model in male mice, human recombinant ANXA1 (rANXA1) was administered intravenously, followed by assessments of BBB integrity, brain edema, inflammatory response, and neurological deficits.

Result

Animals treated with rANXA1 (1 μg/kg) at 1 h after CCI exhibited optimal BBB protection including alleviated BBB disruption and brain edema, as well as endothelial junction proteins loss. The infiltrated neutrophils and inflammatory cytokines were suppressed by rANXA1, consistent with decreased adhesive and transmigrating molecules from isolated microvessels. Moreover, rANXA1 attenuated the neurological deficits induced by CCI. We further found that the Ras homolog gene family member A (RhoA) inhibition has similar effect as rANXA1 in ameliorating brain injuries after CCI, whereas rANXA1 suppressed CCI-induced RhoA activation.

Conclusion

Our findings suggest that the endothelial remodeling by exogenous rANXA1 corrects BBB disruption and inflammatory response through RhoA inhibition, hence improving functional outcomes in CCI mice.

Bloodletting Puncture at Hand Twelve Jing-Well Points Relieves Brain Edema after Severe Traumatic Brain Injury in Rats via Inhibiting MAPK Signaling Pathway

OBJECTIVE

To investigate whether blood-brain barrier (BBB) served a key role in the edema-relief effect of bloodletting puncture at hand twelve Jing-well points (HTWP) in traumatic brain injury (TBI) and the potential molecular signaling pathways.

METHODS

Adult male Sprague-Dawley rats were assigned to the sham-operated (sham), TBI, and bloodletting puncture (bloodletting) groups (n=24 per group) using a randomized number table. The TBI model rats were induced by cortical contusion and then bloodletting puncture were performed at HTWP twice a day for 2 days. The neurological function and cerebral edema were evaluated by modified neurological severity score (mNSS), cerebral water content, magnetic resonance imaging and hematoxylin and eosin staining. Cerebral blood flow was measured by laser speckles. The protein levels of aquaporin 4 (AQP4), matrix metalloproteinases 9 (MMP9) and mitogen-activated protein kinase pathway (MAPK) signaling were detected by immunofluorescence staining and Western blot.

RESULTS

Compared with TBI group, bloodletting puncture improved neurological function at 24 and 48 h, alleviated cerebral edema at 48 h, and reduced the permeability of BBB induced by TBI (all P<0.05). The AQP4 and MMP9 which would disrupt the integrity of BBB were downregulated by bloodletting puncture (P<0.05 or P<0.01). In addition, the extracellular signal-regulated kinase (ERK) and p38 signaling pathways were inhibited by bloodletting puncture (P<0.05).

CONCLUSIONS

Bloodletting puncture at HTWP might play a significant role in protecting BBB through regulating the expressions of MMP9 and AQP4 as well as corresponding regulatory upstream ERK and p38 signaling pathways. Therefore, bloodletting puncture at HTWP may be a promising therapeutic strategy for TBI-induced cerebral edema.

Predictors of In-Hospital Mortality for School-Aged Children with Severe Traumatic Brain Injury

Traumatic brain injury (TBI) is the leading cause of mortality in children. There are few studies focused on school-aged children with TBI. We conducted this study to identify the early predictors of in-hospital mortality in school-aged children with severe TBI. In this 10 year observational cohort study, a total of 550 children aged 7-18 years with TBI were enrolled. Compared with mild/moderate TBI, children with severe TBI were older; more commonly had injury mechanisms of traffic accidents; and more neuroimage findings of subarachnoid hemorrhage (SAH), subdural hemorrhage (SDH), parenchymal hemorrhage, cerebral edema, and less epidural hemorrhage (EDH). The in-hospital mortality rate of children with severe TBI in our study was 23%. Multivariate analysis showed that falls, being struck by objects, motor component of Glasgow coma scale (mGCS), early coagulopathy, and SAH were independent predictors of in-hospital mortality. We concluded that school-aged children with severe TBI had a high mortality rate. Clinical characteristics including injury mechanisms of falls and being struck, a lower initial mGCS, early coagulopathy, and SAH are predictive of in-hospital mortality.

Cerebral Edema in Traumatic Brain Injury: a Historical Framework for Current Therapy

PURPOSE OF REVIEW

The purposes of this narrative review are to (1) summarize a contemporary view of cerebral edema pathophysiology, (2) present a synopsis of current management strategies in the context of their historical roots (many of which date back multiple centuries), and (3) discuss contributions of key molecular pathways to overlapping edema endophenotypes. This may facilitate identification of important therapeutic targets.

RECENT FINDINGS

Cerebral edema and resultant intracranial hypertension are major contributors to morbidity and mortality following traumatic brain injury. Although Starling forces are physical drivers of edema based on differences in intravascular vs extracellular hydrostatic and oncotic pressures, the molecular pathophysiology underlying cerebral edema is complex and remains incompletely understood. Current management protocols are guided by intracranial pressure measurements, an imperfect proxy for cerebral edema. These include decompressive craniectomy, external ventricular drainage, hyperosmolar therapy, hypothermia, and sedation. Results of contemporary clinical trials assessing these treatments are summarized, with an emphasis on the gap between intermediate measures of edema and meaningful clinical outcomes. This is followed by a brief statement summarizing the most recent guidelines from the Brain Trauma Foundation (4th edition). While many molecular mechanisms and networks contributing to cerebral edema after TBI are still being elucidated, we highlight some promising molecular mechanism-based targets based on recent research including SUR1-TRPM4, NKCC1, AQP4, and AVP1.

SUMMARY

This review outlines the origins of our understanding of cerebral edema, chronicles the history behind many current treatment approaches, and discusses promising molecular mechanism-based targeted treatments.

Cerebral edema and liver disease: Classic perspectives and contemporary hypotheses on mechanism

Liver disease is a growing public health concern. Hepatic encephalopathy, the syndrome of brain dysfunction secondary to liver disease, is a frequent complication of both acute and chronic liver disease and cerebral edema (CE) is a key feature. While altered ammonia metabolism is a key contributor to hepatic encephalopathy and CE in liver disease, there is a growing appreciation that additional mechanisms contribute to CE. In this review we will begin by presenting three classic perspectives that form a foundation for a discussion of CE in liver disease: 1) CE is unique to acute liver failure, 2) CE in liver disease is only cytotoxic, and 3) CE in liver disease is primarily an osmotically mediated consequence of ammonia and glutamine metabolism. We will present each classic perspective along with more recent observations that call in to question that classic perspective. After highlighting these areas of debate, we will explore the leading contemporary mechanisms hypothesized to contribute to CE during liver disease.

Pattern and Outcome of Pediatric Traumatic Brain Injury at Hawassa University Comprehensive Specialized Hospital, Southern Ethiopia: Observational Cross-Sectional Study

BACKGROUND

Traumatic brain injury (TBI) is the most common cause of death/disability in children. The Glasgow coma scale and other parameters are used for treatment/follow-up of TBI. Childhood TBI data are scarce from sub-Saharan Africa. The study aimed to determine the pattern and predictors of the TBI outcome in Southern Ethiopia.

METHODS

An observational cross-sectional study was conducted from September 2017 to September 2018 at Hawassa University Hospital. Structured questionnaires were used for data collection. Significant associations were declared at a P value of <0.05.

RESULTS

There were 4,258 emergency room (ER) visits during the study period, and TBI contributed to 317 (7.4%) cases. The mean age of study subjects was 7.66 ± 3.88 years. Boys, predominantly above 5 years of age, comprise 218 (68.8%) of the study subjects with a male to female ratio of 2.2 : 1. Pedestrian road traffic accidents (RTA), 120 (37.9%), and falls, 104 (32.8%), were the commonest causes of TBI. Mild, moderate, and severe TBI were documented in 231 (72.9%), 61 (19.2%), and 25 (7.9%) of cases, respectively. Most of the TBI cases presented within 24 hrs of injury, 258 (81.4%). Recovery with no neurologic deficit, 267 (84.2%); focal neurologic deficit, 30 (9.5%); depressed mentation, 10 (3.2%); and death, 10 (3.2%), were documented. Signs of increased intracranial pressure (ICP) at admission [AOR: 1.415 (95% CI: 1.4058-9.557)], severe TBI [AOR: 2.553 (95% CI: 1.965-4.524)], presence of hyperglycemia [AOR: 2.318 (95% CI: 1.873-7.874)], and presence of contusion, diffuse axonal injury (DAI), or intracranial bleeding on the head computed tomography (CT) scan [AOR: 2.45 (95% CI: 1.811-7.952)] predicted poor TBI outcome.

CONCLUSION

TBI contributed to 7.4% of pediatric ER visits. Pedestrian RTA and falls, early presentation (<24 hours of injury), and mild form of TBI among boys were the most common documented patterns. ICP, hyperglycemia, severe TBI, and presence of contusion, DAI, or intracranial bleeding on head CT predicted poor outcome. Strategies to ensure road safety and to prevent falls and animal-related injuries and TBI follow-up for ICP and glycemic controls are recommended.

Role of Sulfonylurea Receptor 1 and Glibenclamide in Traumatic Brain Injury: A Review of the Evidence

Cerebral edema and contusion expansion are major determinants of morbidity and mortality after TBI. Current treatment options are reactive, suboptimal and associated with significant side effects. First discovered in models of focal cerebral ischemia, there is increasing evidence that the sulfonylurea receptor 1 (SUR1)-Transient receptor potential melastatin 4 (TRPM4) channel plays a key role in these critical secondary injury processes after TBI. Targeted SUR1-TRPM4 channel inhibition with glibenclamide has been shown to reduce edema and progression of hemorrhage, particularly in preclinical models of contusional TBI. Results from small clinical trials evaluating glibenclamide in TBI have been encouraging. A Phase-2 study evaluating the safety and efficacy of intravenous glibenclamide (BIIB093) in brain contusion is actively enrolling subjects. In this comprehensive narrative review, we summarize the molecular basis of SUR1-TRPM4 related pathology and discuss TBI-specific expression patterns, biomarker potential, genetic variation, preclinical experiments, and clinical studies evaluating the utility of treatment with glibenclamide in this disease.

The Effect of Candesartan Alone and Its Combination With Estrogen on Post-traumatic Brain Injury Outcomes in Female Rats

Aim: The aim of this study was to evaluate the effect of candesartan (angiotensin II type I receptor blocker) alone and its combination with estrogen on the changes in brain edema, intracranial pressure (ICP), and cerebral perfusion pressure (CPP) following diffuse traumatic brain injury (TBI) in female rats.

Methods: TBI was induced in ovariectomized female rats using Marmarou's method. The treatment groups received low-dose (LC) and high-dose (HC) candesartan, estrogen (E2), a combination of estrogen vehicle and candesartan vehicle (oil + vehicle), or a combination of estrogen with low-dose (E2 + LC), or with high-dose (E2 + HC) candesartan. ICP and CPP were measured before and several times after TBI, and the brain water content (brain edema) was measured 24 h after TBI.

Results: After the TBI, brain edema and ICP in the estrogen group were lower than in the vehicle and TBI groups. Brain edema and ICP in the HC group were lower than in the vehicle group after TBI. Although there was no significant difference in brain edema and ICP between the LC and vehicle groups, significant differences in these variables were observed when the E2 + LC and E2 + HC groups were compared with the oil + vehicle group after TBI. A significant increase in CPP was observed in the estrogen group 4 and 24 h post-TBI, while this increase was found in the HC and E2 + LC groups 24 h post-TBI.

Conclusions: A low dose of candesartan did not exert a protective effect on TBI outcomes, but such an effect did appear after combination with estrogen. This finding suggests that interaction between low-dose candesartan and estrogen improves TBI-induced consequences.

Acute Kahweol Treatment Attenuates Traumatic Brain Injury Neuroinflammation and Functional Deficits

Traumatic brain injury (TBI) affects millions worldwide with devastating long-term effects on health and cognition. Emerging data suggest that targeting the immune response may offer promising strategies to alleviate TBI outcomes; kahweol, an anti-inflammatory diterpene that remains in unfiltered coffee, has been shown to be beneficial in neuronal recovery. Here, we examined whether kahweol could alleviate brain trauma-induced injury in a mouse model of TBI and its underlying mechanisms. TBI was induced by controlled cortical impact (CCI) and various doses of kahweol were intraperitoneally administered following injury. Contusion volume, brain edema, neurobehavioral deficits, and protein expression and activity were evaluated in both short-term and long-term recovery. We found that kahweol treatments significantly reduced secondary brain injury and improved neurobehavioral outcomes in TBI mice. These changes were accompanied by the attenuation of proinflammatory cytokine secretion, decreased microglia/macrophage activation, and reduction of neutrophil and leukocyte infiltration. In addition, continuous kahweol treatment further improved short-term TBI outcomes compared to single-dosage. Collectively, our data showed that kahweol protects against TBI by reducing immune responses and may serve as a potential therapeutic intervention for TBI patients.

Sex Differences in Animal Models of Traumatic Brain Injury

Traumatic brain injury (TBI) is highly prevalent and there is currently no adequate treatment. Understanding the underlying mechanisms governing TBI and recovery remains an elusive goal. The heterogeneous nature of injury and individual's response to injury have made understanding risk and susceptibility to TBI of great importance. Epidemiologic studies have provided evidence of sex-dependent differences following TBI. However, preclinical models of injury have largely focused on adult male animals. Here, we review 50 studies that have investigated TBI in both sexes using animal models. Results from these studies are highly variable and model dependent, but largely show females to have a protective advantage in behavioral outcomes and pathology following TBI. Further research of both sexes using newer models that better recapitulate mild and repetitive TBI is needed to characterize the nature of sex-dependent injury and recovery, and ultimately identifies targets for enhanced recovery.

Correlation between cerebral co-oximetry (rSO2) and outcomes in traumatic brain injury cases: A prospective, observational study

BACKGROUND

Traumatic brain injury (TBI) is known to be an important reason for the increase in disabilities and deaths worldwide. Studies have demonstrated that brain tissue oxygen (PO2) monitoring reduces mortality significantly but is a invasive method of monitoring. Therefore, there is a need to monitor cerebral ischemia in TBI by noninvasive methods. The study aims to correlate cerebral co-oximetry and possible outcomes in patients with TBI.

METHODS

The study included 78 patients with TBI admitted in intensive care unit (ICU) with glascow coma scale (GCS) of 8 or less than 8. Near-infrared spectroscopy monitor is applied to the patients immediately after admission to ICU; readings are noted every 4 hours up to first 48 hours, and outcomes studied as survival or neurological deficit are noted at 28 days.

RESULTS

A total of 12 (15.4%) deaths were seen in this study. Survived patients were further divided into good recovery 33 (42.3%), moderate disability 21(26.9%), major disability 8 (10.3%), and persistent vegetative state 4 (5.1%). The rSO2 values in surviving patients were ranging from mean of 60.74% (standard deviation [SD] 4.38) to a mean of 64.98% (SD 5.01), and the mean rSO2 values in patients who died were ranging from a mean of 52.17% (SD 4.11) to a mean of 37.17% (SD 12.48). Lower rSO2 values were correlating significantly with worse neurological outcome or death by using two independent sample t-test (p < 0.001).

CONCLUSION

Cerebral co-oximetry is a simple noninvasive method for predicting the outcomes in TBI and can be used to guide the management of these patients.

Clinical Characteristics and Predictors of Poor Hospital Discharge Outcome for Young Children with Abusive Head Trauma

Children with abusive head trauma tend to have worse outcomes than children with accidental head trauma. However, current predictors of poor outcomes for children with abusive head trauma are still limited. We aim to use clinical data to identify early predictors of poor outcome at discharge in children with abusive head trauma. In the 10-year observational retrospective cohort study, children aged between zero and four years with abusive or accidental head trauma were recruited. Multivariate logistic regression models were applied to evaluate factors associated with poor prognosis in children with abusive head trauma. The primary outcome was mortality or a Glasgow Coma Scale (GCS) motor component score of less than 6 at discharge. A total of 292 head trauma children were included. Among them, 59 children had abusive head trauma. In comparison to children with accidental head trauma, children with abusive head trauma were younger, had more severe head injuries, and experienced a higher frequency of post-traumatic seizures. Their radiologic findings showed common presence of subdural hemorrhage, cerebral edema, and less epidural hemorrhage. They were more in need of neurosurgical intervention. In the multivariate analysis for predictors of poor outcome in children with abusive head trauma, initial GCS ≤ 5 (versus GCS > 5 with the adjusted odds ratio (OR) = 25.7, 95% confidence interval (CI) = 1.5⁻432.8, p = 0.024) and older age (per year with the adjusted OR = 3.3, 95% CI = 1.2⁻9.5, p = 0.024) were independently associated with poor outcome. These findings demonstrate the characteristic clinical differences between children with abusive and accidental head trauma. Initial GCS ≤ 5 and older age are predictive of poor outcome at discharge in children with abusive head trauma.

Bilaterally Absent Pupillary Responses: Not Always a Bad Sign

Pupillary responses are a simple test commonly used as a predictor of outcome after severe brain injury. It is also common for clinicians to associate bilaterally absent pupillary responses with very poor prognosis. We report a series of cases of severely brain injured children with bilaterally absent pupillary responses who had favourable outcomes. From a group of 89 patients with brain injury, 32 had bilaterally absent pupillary responses and six (four with traumatic brain injury and two with infective brain injury) subsequently had favourable outcomes. This represents 18.8% of patients and should be a reminder to clinicians that the clinical sign of bilaterally absent pupillary responses is not always associated with a hopeless outcome.

Prediction of Poor Prognosis After Severe Head Injury in Children Using Logistic Regression

OBJECTIVES

Head trauma is one of the main causes of death in childhood and often leaves severe disability with serious neurological damage. Appropriate treatment must be provided immediately to improve outcomes. This study was performed to identify factors associated with a poor prognosis at an early stage of severe head injury in children.

METHODS

The subjects were registered in the Japan Neurotrauma Data Bank. They were 119 children (mean age, 8 years; male, 67.2%) with severe head injury registered during a period of 4 years (from July 1, 2004 to June 30, 2006 and from July 1, 2009 to June 30, 2011). Univariate and multivariate analyses were performed to examine relationships among factors and outcome 6 months after discharge. Logistic regression analysis was performed to develop models for poor prognosis and death.

RESULTS

Outcome was evaluated based on the Glasgow Outcome Scale: 73 children (61.3%) had good recovery, 11 (9.2%) had moderate disability, 8 (6.7%) had severe disability, 4 (3.3%) were in a vegetative state, and 23 (19.3%) had died. Four factors were identified as predictors of a poor prognosis: serum glucose level greater than or equal to 200 mg/dL, Glasgow Coma Scale score on admission less than or equal to 5, presence of mydriasis, and presence of traumatic subarachnoid hemorrhage. Three factors were identified as predictors of death: serum glucose level greater than or equal to 200 mg/dL, Glasgow Coma Scale score on admission less than or equal to 5, and presence of mydriasis.

CONCLUSIONS

Using these predictors, subsequent exacerbation may be predicted just after arrival at the hospital and appropriate treatment can be provided immediately.

A Precision Medicine Approach to Cerebral Edema and Intracranial Hypertension after Severe Traumatic Brain Injury: Quo Vadis?

PURPOSE OF REVIEW

Standard clinical protocols for treating cerebral edema and intracranial hypertension after severe TBI have remained remarkably similar over decades. Cerebral edema and intracranial hypertension are treated interchangeably when in fact intracranial pressure (ICP) is a proxy for cerebral edema but also other processes such as extent of mass lesions, hydrocephalus, or cerebral blood volume. A complex interplay of multiple molecular mechanisms results in cerebral edema after severe TBI, and these are not measured or targeted by current clinically available tools. Addressing these underpinnings may be key to preventing or treating cerebral edema and improving outcome after severe TBI.

RECENT FINDINGS

This review begins by outlining basic principles underlying the relationship between edema and ICP including the Monro-Kellie doctrine and concepts of intracranial compliance/elastance. There is a subsequent brief discussion of current guidelines for ICP monitoring/management. We then focus most of the review on an evolving precision medicine approach towards cerebral edema and intracranial hypertension after TBI. Personalization of invasive neuromonitoring parameters including ICP waveform analysis, pulse amplitude, pressure reactivity, and longitudinal trajectories are presented. This is followed by a discussion of cerebral edema subtypes (continuum of ionic/cytotoxic/vasogenic edema and progressive secondary hemorrhage). Mechanisms of potential molecular contributors to cerebral edema after TBI are reviewed. For each target, we present findings from preclinical models, and evaluate their clinical utility as biomarkers and therapeutic targets for cerebral edema reduction. This selection represents promising candidates with evidence from different research groups, overlap/inter-relatedness with other pathways, and clinical/translational potential. We outline an evolving precision medicine and translational approach towards cerebral edema and intracranial hypertension after severe TBI.

Glibenclamide Produces Region-Dependent Effects on Cerebral Edema in a Combined Injury Model of Traumatic Brain Injury and Hemorrhagic Shock in Mice

Cerebral edema is critical to morbidity/mortality in traumatic brain injury (TBI) and is worsened by hypotension. Glibenclamide may reduce cerebral edema by inhibiting sulfonylurea receptor-1 (Sur1); its effect on diffuse cerebral edema exacerbated by hypotension/resuscitation is unknown. We aimed to determine if glibenclamide improves pericontusional and/or diffuse edema in controlled cortical impact (CCI) (5m/sec, 1 mm depth) plus hemorrhagic shock (HS) (35 min), and compare its effects in CCI alone. C57BL/6 mice were divided into five groups (n = 10/group): naïve, CCI+vehicle, CCI+glibenclamide, CCI+HS+vehicle, and CCI+HS+glibenclamide. Intravenous glibenclamide (10 min post-injury) was followed by a subcutaneous infusion for 24 h. Brain edema in injured and contralateral hemispheres was subsequently quantified (wet-dry weight). This protocol brain water (BW) = 80.4% vehicle vs. 78.3% naïve, p < 0.01) but was not reduced by glibenclamide (I%BW = 80.4%). Ipsilateral edema also developed in CCI alone (I%BW = 80.2% vehicle vs. 78.3% naïve, p < 0.01); again unaffected by glibenclamide (I%BW = 80.5%). Contralateral (C) %BW in CCI+HS was increased in vehicle (78.6%) versus naive (78.3%, p = 0.02) but unchanged in CCI (78.3%). At 24 h, glibenclamide treatment in CCI+HS eliminated contralateral cerebral edema (C%BW = 78.3%) with no difference versus naïve. By 72 h, contralateral cerebral edema had resolved (C%BW = 78.5 ± 0.09% vehicle vs. 78.3 ± 0.05% naïve). Glibenclamide decreased 24 h contralateral cerebral edema in CCI+HS. This beneficial effect merits additional exploration in the important setting of TBI with polytrauma, shock, and resuscitation. Contralateral edema did not develop in CCI alone. Surprisingly, 24 h of glibenclamide treatment failed to decrease ipsilateral edema in either model. Interspecies dosing differences versus prior studies may play an important role in these findings. Mechanisms underlying brain edema may differ regionally, with pericontusional/osmolar swelling refractory to glibenclamide but diffuse edema (via Sur1) from combined injury and/or resuscitation responsive to this therapy. TBI phenotype may mandate precision medicine approaches to treat brain edema.

Pathophysiology and treatment of cerebral edema in traumatic brain injury

Cerebral edema (CE) and resultant intracranial hypertension are associated with unfavorable prognosis in traumatic brain injury (TBI). CE is a leading cause of in-hospital mortality, occurring in >60% of patients with mass lesions, and ∼15% of those with normal initial computed tomography scans. After treatment of mass lesions in severe TBI, an important focus of acute neurocritical care is evaluating and managing the secondary injury process of CE and resultant intracranial hypertension. This review focuses on a contemporary understanding of various pathophysiologic pathways contributing to CE, with a subsequent description of potential targeted therapies. There is a discussion of identified cellular/cytotoxic contributors to CE, as well as mechanisms that influence blood-brain-barrier (BBB) disruption/vasogenic edema, with the caveat that this distinction may be somewhat artificial since molecular processes contributing to these pathways are interrelated. While an exhaustive discussion of all pathways with putative contributions to CE is beyond the scope of this review, the roles of some key contributors are highlighted, and references are provided for further details. Potential future molecular targets for treating CE are presented based on pathophysiologic mechanisms. We thus aim to provide a translational synopsis of present and future strategies targeting CE after TBI in the context of a paradigm shift towards precision medicine. This article is part of the Special Issue entitled "Novel Treatments for Traumatic Brain Injury".

Noninvasive monitoring of brain edema after hypoxia in newborn piglets

BackgroundDevelopment of cerebral edema after brain injury carries a high risk for brain damage and death. The present study tests the ability of a noninvasive cerebral edema monitoring system that uses near-infrared spectroscopy (NIRS) with water as the chromophore of interest to detect brain edema following hypoxia.MethodsVentilated piglets were exposed to hypoxia for 1 h, and then returned to normal oxygen levels for 4 h. An NIRS sensor was placed on the animal's head at baseline, and changes in light attenuation were converted to changes in H₂O. Cerebral water content and aquaporin-4 protein (AQP4) expression were measured.ResultsThe system detected changes in NIRS-derived water signal as early as 2 h after hypoxia, and provided fivefold signal amplification, representing a 10% increase in brain water content and a sixfold increase in AQP4, 4 h after hypoxia. Changes in water signal correlated well with changes in cerebral water content (R=0.74) and AQP4 expression (R=0.97) in the piglet brain.ConclusionThe data show that NIRS can detect cerebral edema early in the injury process, thus providing an opportunity to initiate therapy at an earlier and more effective time-point after an insult than is available with current technology.

Transcranial Ultrasound Stimulation Improves Long-Term Functional Outcomes and Protects Against Brain Damage in Traumatic Brain Injury

The purpose of this study was to assess the long-term treatment efficacy of low-intensity pulsed ultrasound (LIPUS) on functional outcomes, brain edema, and the possible involvement of reactions in mice following traumatic brain injury (TBI). Mice subjected to controlled cortical impact injury received LIPUS treatment daily for a period of 4 weeks. The effects of LIPUS on edema were detected by MR imaging in the mouse brain at 148 days following TBI. Long-term functional outcomes of LIPUS stimulation were evaluated by behavioral analyses. One-way or two-way analysis of variance and Student's t test were used for statistical analyses, with a significant level of .05. Up to post-injury day 148, treatment with LIPUS significantly improved functional outcomes (all p < 0.05). LIPUS also significantly attenuated brain edema and neuronal death at day 148 after TBI (all p < 0.05). Furthermore, LIPUS reduced MMP9 activity, neutrophil infiltration, and microglial activation at day 1 or day 4 following TBI (all p < 0.05). Meanwhile, LIPUS increased the Bcl-2/Bax ratio and enhanced the phosphorylation of Bad and FOXO-1 at day 1 or day 4 following TBI (all p < 0.05). Almost 5 months of follow-up showed that the treatment efficacy of post-injury LIPUS stimulation on reduced brain edema and improved functional outcomes persisted over time after TBI. The neuroprotective effects of LIPUS are associated with a reduction of early inflammatory events and inhibition of apoptotic progression.

Low-intensity pulsed ultrasound improves behavioral and histological outcomes after experimental traumatic brain injury

The purpose of this study was to investigate the neuroprotective effects of low-intensity pulsed ultrasound (LIPUS) on behavioral and histological outcomes in a mouse model of traumatic brain injury (TBI). Mice subjected to controlled cortical impact injury were treated with LIPUS in the injured region daily for a period of 4 weeks. The effects of LIPUS on edema were observed by MR imaging in the mouse brain at 1 and 4 days following TBI. Brain water content, blood-brain barrier permeability, histology analysis, and behavioral studies were performed to assess the effects of LIPUS. Two-way analysis of variance and Student t test were used for statistical analyses, with a significant level of 0.05. Treatment with LIPUS significantly attenuated brain edema, blood-brain barrier permeability, and neuronal degeneration beginning at day 1. Compared with the TBI group, LIPUS also significantly improved functional recovery and reduced contusion volumes up to post-injury day 28. Post-injury LIPUS treatment reduced brain edema and improved behavioral and histological outcomes following TBI. The neuroprotective effects of LIPUS may be a promising new technique for treating TBI.

Efficacy of decompressive craniectomy in the management of intracranial pressure in severe traumatic brain injury

Traumatic brain injury (TBI) is a common cause of permanent disability for which clinical management remains suboptimal. Elevated intracranial pressure (ICP) is a common sequela following TBI leading to death and permanent disability if not properly managed. While clinicians often employ stepwise acute care algorithms to reduce ICP, a number of patients will fail medical management and may be considered for surgical decompression. Decompressive craniectomy (DC) involves removing a component of the bony skull to allow cerebral tissue expansion in order to reduce ICP. However, the impact of DC, which is performed in the setting of neurological instability, ongoing secondary injury, and patient resuscitation, has been challenging to study and outcomes are not well understood. This review summarizes historical and recent studies to elucidate indications for DC and the nuances, risks and complications in its application. The pathophysiology driving ICP elevation, and the corresponding medical interventions for their temporization and treatment, are thoroughly described. The current state of DC - including appropriate injury classification, surgical techniques, concurrent medical therapies, mortality and functional outcomes - is presented. We also report on the recent updates from large randomized controlled trials in severe TBI (Decompressive Craniectomy [DECRA] and Randomized Evaluation of Surgery with Craniectomy for Uncontrollable Elevation of ICP [RESCUEicp]), and recommendations for early DC to treat refractory ICP elevations in malignant middle cerebral artery syndrome. Limitations for DC, such as the equipoise between immediate reduction in ICP and clinically meaningful functional outcomes, are discussed in support of future investigations.

The Role of Substance P in Secondary Pathophysiology after Traumatic Brain Injury

It has recently been shown that substance P (SP) plays a major role in the secondary injury process following traumatic brain injury (TBI), particularly with respect to neuroinflammation, increased blood–brain barrier (BBB) permeability, and edema formation. Edema formation is associated with the development of increased intracranial pressure (ICP) that has been widely associated with increased mortality and morbidity after neurotrauma. However, a pharmacological intervention to specifically reduce ICP is yet to be developed, with current interventions limited to osmotic therapy rather than addressing the cause of increased ICP. Given that previous publications have shown that SP, NK1 receptor antagonists reduce edema after TBI, more recent studies have examined whether these compounds might also reduce ICP and improve brain oxygenation after TBI. We discuss the results of these studies, which demonstrate that NK1 antagonists reduce posttraumatic ICP to near normal levels within 4 h of drug administration, as well as restoring brain oxygenation to near normal levels in the same time frame. The improvements in these parameters occurred in association with an improvement in BBB integrity to serum proteins, suggesting that SP-mediated increases in vascular permeability significantly contribute to the development of increased ICP after acute brain injury. NK1 antagonists may therefore provide a novel, mechanistically targeted approach to the management of increased ICP.

Vascular impairment as a pathological mechanism underlying long-lasting cognitive dysfunction after pediatric traumatic brain injury

Traumatic brain injury (TBI) is the leading cause of death and disability in children. Indeed, the acute mechanical injury often evolves to a chronic brain disorder with long-term cognitive, emotional and social dysfunction even in the case of mild TBI. Contrary to the commonly held idea that children show better recovery from injuries than adults, pediatric TBI patients actually have worse outcome than adults for the same injury severity. Acute trauma to the young brain likely interferes with the fine-tuned developmental processes and may give rise to long-lasting consequences on brain's function. This review will focus on cerebrovascular dysfunction as an important early event that may lead to long-term phenotypic changes in the brain after pediatric TBI. These, in turn may be associated with accelerated brain aging and cognitive dysfunction. Finally, since no effective treatments are currently available, understanding the unique pathophysiological mechanisms of pediatric TBI is crucial for the development of new therapeutic options.

Sulfonylurea Receptor-1: A Novel Biomarker for Cerebral Edema in Severe Traumatic Brain Injury

OBJECTIVES

Cerebral edema is a key poor prognosticator in traumatic brain injury. There are no biomarkers identifying patients at-risk, or guiding mechanistically-precise therapies. Sulfonylurea receptor-1-transient receptor potential cation channel M4 is upregulated only after brain injury, causing edema in animal studies. We hypothesized that sulfonylurea receptor-1 is measurable in human cerebrospinal fluid after severe traumatic brain injury and is an informative biomarker of edema and outcome.

DESIGN

A total of 119 cerebrospinal fluid samples were collected from 28 severe traumatic brain injury patients. Samples were retrieved at 12, 24, 48, 72 hours and before external ventricular drain removal. Fifteen control samples were obtained from patients with normal pressure hydrocephalus. Sulfonylurea receptor- 1 was quantified by enzyme-linked immunosorbent assay. Outcomes included CT edema, intracranial pressure measurements, therapies targeting edema, and 3-month Glasgow Outcome Scale score.

MAIN RESULTS

Sulfonylurea receptor-1 was present in all severe traumatic brain injury patients (mean = 3.54 ± 3.39 ng/mL, peak = 7.13 ± 6.09 ng/mL) but undetectable in all controls (p < 0.001). Mean and peak sulfonylurea receptor-1 was higher in patients with CT edema (4.96 ± 1.13 ng/mL vs 2.10 ± 0.34 ng/mL; p = 0.023). There was a temporal delay between peak sulfonylurea receptor-1 and peak intracranial pressure in 91.7% of patients with intracranial hypertension. There was no association between mean/peak sulfonylurea receptor-1 and mean/peak intracranial pressure, proportion of intracranial pressure greater than 20 mm Hg, use of edema-directed therapies, decompressive craniotomy, or 3-month Glasgow Outcome Scale. However, decreasing sulfonylurea receptor-1 trajectories between 48 and 72 hours were significantly associated with improved cerebral edema and clinical outcome. Area under the multivariate model receiver operating characteristic curve was 0.881.

CONCLUSIONS

This is the first report quantifying human cerebrospinal fluid sulfonylurea receptor-1. Sulfonylurea receptor-1 was detected in severe traumatic brain injury, absent in controls, correlated with CT-edema and preceded peak intracranial pressure. Sulfonylurea receptor-1 trajectories between 48 and 72 hours were associated with outcome. Because a therapy inhibiting sulfonylurea receptor-1 is available, assessing cerebrospinal fluid sulfonylurea receptor-1 in larger studies is warranted to evaluate our exploratory findings regarding its diagnostic, and monitoring utility, as well as its potential to guide targeted therapies in traumatic brain injury and other diseases involving cerebral edema.

Objective triage in the disaster setting: will children and expecting mothers be treated like others?

The study of disaster triage is made difficult by the complex emotional response of potentially lifesaving intervention that a triage officer must make basing decisions on a succinct and efficient algorithm. A survey of triage professionals in international settings was designed to identify possible emotionally led bias that affects objective decision making in identifying victims most likely to benefit from immediate life support intervention. This survey suggests a lack of correlation between triage priority and predictable clinical outcomes as predicted by the Revised Trauma Score tool. Among the subjects, it was observed that a pediatric victim is uniformly overtriaged when compared to less injured victims.

Controllable permeability of blood-brain barrier and reduced brain injury through low-intensity pulsed ultrasound stimulation

It has been shown that the blood-brain barrier (BBB) can be locally disrupted by focused ultrasound (FUS) in the presence of microbubbles (MB) while sustaining little damage to the brain tissue. Thus, the safety issue associated with FUS-induced BBB disruption (BBBD) needs to be investigated for future clinical applications. This study demonstrated the neuroprotective effects induced by low-intensity pulsed ultrasound (LIPUS) against brain injury in the sonicated brain. Rats subjected to a BBB disruption injury received LIPUS exposure for 5 min after FUS/MB application. Measurements of BBB permeability, brain water content, and histological analysis were then carried out to evaluate the effects of LIPUS. The permeability and time window of FUS-induced BBBD can be effectively modulated with LIPUS. LIPUS also significantly reduced brain edema, neuronal death, and apoptosis in the sonicated brain. Our results show that brain injury in the FUS-induced BBBD model could be ameliorated by LIPUS and that LIPUS may be proposed as a novel treatment modality for controllable release of drugs into the brain.

Spectrum and outcome of traumatic brain injury in children <15 years: A tertiary level experience in India

BACKGROUND

Though, traumatic brain injury (TBI) has been documented as the single most common cause of morbidity and mortality in infancy and childhood, the exact incidence is unavailable in India. Moreover, modes of injury, mechanisms of damage, and management differ significantly from that of an adult.

AIMS AND OBJECTIVES

To analyze the epidemiological factors, the spectrum of TBI, modes of injury, types of injury, and the outcome in the children <15 years with TBI.

MATERIALS AND METHODS

This is a retrospective study from August 2012 to May 2013 at Department of Neurosurgery, S.C.B. Medical College, Cuttack, Odisha, India. All the pertinent details from case records of hundred and forty-seven children <15 years with TBI were analyzed. Follow-up was done for 6 months at outpatients department.

RESULTS

Age wise, incidence and severity of TBI is more common in 10-15 years. Males outnumber females with a male: female ratio 2.19:1. Overall, road traffic accident (RTA) is the commonest mode of injury. Assault is not uncommon (7.48% cases). Falls is common in <5 years while RTA is common in 5-15 years. The extradural hematoma was the most common injury pattern; however, surgical consideration was maximal for fracture skull. Overall mortality was 7.48%. Diffuse axonal injury has the maximum individual potential for mortality. We noticed excellent recovery in 68.7%, disabilities in 17.68%, and persistent vegetative state in 5.45% cases.

CONCLUSION

TBI in children carries good outcome, if resuscitated and referred early to a neurotrauma center, and managed subsequently on an individualized basis with a well-organized team approach. Severe TBI in children has a poor outcome.

Subarachnoid hemorrhage prevalence and its association with short-term outcome in pediatric severe traumatic brain injury

BACKGROUND

Subarachnoid hemorrhage (SAH) is an independent prognostic indicator of outcome in adult severe traumatic brain injury (sTBI). There is a paucity of investigations on SAH in pediatric sTBI. The goal of this study was to determine in pediatric sTBI patients SAH prevalence, associated factors, and its relationship to short-term outcome.

METHODS

We retrospectively analyzed 171 sTBI patients (pre-sedation GCS ≤8 and head MAIS ≥4) who underwent CT head imaging within the first 24 h of hospital admission. Data were analyzed with both univariate and multivariate techniques.

RESULTS

SAH was found in 42 % of sTBI patients (n = 71/171), and it was more frequently associated with skull fractures, cerebral edema, diffuse axonal injury, contusion, and intraventricular hemorrhage (p < 0.05). Patients with SAH had higher Injury Severity Scores (p = 0.032) and a greater frequency of fixed pupil(s) on admission (p = 0.001). There were no significant differences in etiologies between sTBI patients with and without SAH. Worse disposition occurred in sTBI patients with SAH, including increased mortality (p = 0.009), increased episodes of central diabetes insipidus (p = 0.002), greater infection rates (p = 0.002), and fewer ventilator-free days (p = 0.001). In sTBI survivors, SAH was associated with increased lengths of stay (p < 0.001) and a higher level of care required on discharge (p = 0.004). Despite evidence that SAH is linked to poorer outcomes on univariate analyses, multivariate analysis failed to demonstrate an independent association between SAH and mortality (p = 0.969).

CONCLUSION

SAH was present in almost half of pediatric sTBI patients, and it was indicative of TBI severity and a higher level of care on discharge. SAH in pediatric patients was not independently associated with increased risk of mortality.

Preservation of the blood brain barrier and cortical neuronal tissue by liraglutide, a long acting glucagon-like-1 analogue, after experimental traumatic brain injury

Cerebral edema is a common complication following moderate and severe traumatic brain injury (TBI), and a significant risk factor for development of neuronal death and deterioration of neurological outcome. To this date, medical approaches that effectively alleviate cerebral edema and neuronal death after TBI are not available. Glucagon-like peptide-1 (GLP-1) has anti-inflammatory properties on cerebral endothelium and exerts neuroprotective effects. Here, we investigated the effects of GLP-1 on secondary injury after moderate and severe TBI. Male Sprague Dawley rats were subjected either to TBI by Controlled Cortical Impact (CCI) or sham surgery. After surgery, vehicle or a GLP-1 analogue, Liraglutide, were administered subcutaneously twice daily for two days. Treatment with Liraglutide (200 μg/kg) significantly reduced cerebral edema in pericontusional regions and improved sensorimotor function 48 hours after CCI. The integrity of the blood-brain barrier was markedly preserved in Liraglutide treated animals, as determined by cerebral extravasation of Evans blue conjugated albumin. Furthermore, Liraglutide reduced cortical tissue loss, but did not affect tissue loss and delayed neuronal death in the thalamus on day 7 post injury. Together, our data suggest that the GLP-1 pathway might be a promising target in the therapy of cerebral edema and cortical neuronal injury after moderate and severe TBI.

Severe Pediatric Head Injury During the Iraq and Afghanistan Conflicts

BACKGROUND:

Much has been written about injuries sustained by US and coalition soldiers during the Global War on Terrorism campaigns. However, injuries to civilians, including children, have been less well documented.

OBJECTIVE:

To describe the epidemiologic features and outcomes associated with isolated severe head injury in children during Operations Enduring Freedom and Iraqi Freedom (OEF and OIF).

METHODS:

A retrospective review of children (&lt;18 years old) in the Joint Theater Trauma Registry with isolated head injury (defined as an Abbreviated Injury Score Severity Code &gt;3) and treated at a US combat support hospital in Iraq or Afghanistan (2004–2012). The primary outcome was in-hospital mortality.

RESULTS:

We identified 647 children with severe isolated head injuries: 337 from OEF, 268 from OIF, and 42 nontheater specific. Most were boys (76%; median age = 8 years). Penetrating injuries were most common (60.6%). Overall, 330 (51%) children underwent a craniotomy/craniectomy; 156 (24.1%) succumbed to their injuries. Admission Glasgow Coma Score was predictive of survival among the entire cohort and each of the individual conflicts. Male sex also significantly increased the odds of survival for the entire group and OEF, but not for OIF. Closed-head injury improved the predictive ability of our model but did not reach statistical significance as an independent factor.

CONCLUSION:

This is the largest study of combat-related isolated head injuries in children. Admission Glasgow Coma Score and male sex were found to be predictive of survival. Assets to comprehensively care for the pediatric patient should be established early in future conflicts.

Epidemiology and treatment outcome of head injury in children: A prospective study

Summary:

Head injury in children is a major concern all over the world. The increasing level of poverty in the world is exposing more children to trauma situations. The future consequences of trauma in these children are enormous, hence prevention they say, is better than cure.

Aim of the Study:

The study was designed to determine the etiological pattern, age group affectation and treatment outcome in children managed for head injury in our center.

Methods:

It was a prospective, descriptive and cross-sectional study of children with head injuries managed in our center from July 2010 to December 2013. Data were collected using structured proforma that was part of our prospective Data Bank approved by our hospital Research and Ethics Committee. Data were collected in accident and emergency unit, Intensive Care Unit, wards and out-patient clinic. The data was analyzed using Epi Info 7 software.

Results:

Total of 76 children managed by the unit and followed-up to a minimum of 3 months qualified for the study. There were 42 males. The age ranged from 7 months to 18 years with a mean of 8.66 years. There were 30 adolescent/teenagers. Road traffic accident formed 63.15%. Pedestrian accident was more among preschool and school children. Thirty-seven patients had mild head injury. Sixty-six patients were managed conservatively. The commonest posttraumatic effect was seizure (15.79%). Good functional outcome (≥4) was seen in 92.1%. Mode of accident and severity of injury affected the outcome.

Conclusions:

The etiologies of traumatic brain injury, from our study, were age dependent with falls commonest in toddlers and pedestrian accident commonest in pre-school and school ages. The outcome of treatment was related to severity of injury.

Factors associated with hemispheric hypodensity after subdural hematoma following abusive head trauma in children

Abusive head trauma (AHT) is a unique form of pediatric TBI with increased mortality and neurologic sequelae. Hemispheric hypodensity (HH) in association with subdural blood after AHT has been described. Though risk factors for HH are not understood, we hypothesized that risk factors could be identified. We retrospectively enrolled children under 5 years with TBI secondary to AHT (child advocacy diagnosis) who had undergone initial and interval brain imaging. Records were interrogated for prearrival and in-hospital physiologic and radiographic findings. HH was determined by a blinded observer. Twenty-four children were enrolled and 13 developed HH. HH was not significantly associated with age, initial Glascow Coma Scale, or mortality. Pediatric Intensity Level of Therapy (PILOT) scores (p=0.01) and daily maximal intracranial pressure (ICPmax; p=0.037) were higher in HH. Hypoxia, hypotension, cardiopulmonary arrest, need for blood transfusion, and daily blood glucoses tended to be greater in HH. Whereas all children with HH had acute subdural hematoma (SBH), many children without HH also had subdural blood; the presence of skull fracture was more likely in the children who did not develop HH (p=0.04), but no other intracranial radiographic pattern of injury was associated with HH. Surgical intervention did not appear to protect against development of HH. A variety of insults associated with ischemia, including intracranial hypertension, ICP-directed therapies, hypoxia, hypotension, and cardiac arrest, occurred in the children who developed HH. Given the morbidity and mortality of this condition, larger studies to identify mechanisms leading to the development of HH and mitigating clinical approaches are warranted.

Outcome of patients with traumatic head injury in infants: An institutional experience at level 1 trauma center

Background:

Traumatic head injury is a common cause of mortality and acquired disability in infants and children. However, patterns and outcome of head injury in infants are different from other age groups.

Aims and Objectives:

Aim of our study was to find out epidemiological factors, characteristics of injury, and outcome in infants with traumatic brain injury.

Materials and Methods:

This is a retrospective study from March 2009 through Feb 2012, at JPNATC, AIIMS, New Delhi. The clinical records of all patients, admitted with head injury were evaluated. Twenty-nine infants with traumatic brain injury were followed up and outcome was analyzed.

Results:

Twenty-nine infants with traumatic brain injury were included in the study. Of these 17 (59%) were boys and 12 (41%) were girls. Fall from height was recorded in 27 (93%) patients and road traffic accident was the mode of injury in 2 (7%). Mild head injury (GCS 14-15) was found in 18 (62%) patients, moderate in 4 (14%) patients (GCS 9-13), severe (GCS 3-8) in 7 (24%) patients. SDH was the most common injury in 8 (27%) patients. Out of these 4 (14%) were immediately operated, 25 (86%) were managed conservatively. Overall mortality was 11% (3 patients). Glasgow Outcome Scale was 5 in 20 (69%) patients and 3 (10.3%) patients each had GOS 3 or 4.

Conclusion:

Infants suffered significant brain injury due to fall. Traumatic brain injury in infants generally carries good outcome. Severe head injury was observed to be a predictor of poor outcome.

Accidental head trauma during care activities in the first year of life: a neurosurgical comparative study

OBJECTIVES

This study aims to describe clinical-epidemiological data regarding accidental fall injuries occurring during homecare activities among children up to 1 year of age and to compare their outcomes according to the type of trauma.

METHODS

We searched four different hospital databases on head injuries from 1999 to 2009. Patients recorded under the descriptors "accidental fall" and "home-related" in the subtext were selected. Patients were classified into two groups: those who flipped over and fell from a changing table (n = 253) and those who fell from the bed sustaining a direct impact from the floor (n = 483).

RESULTS

There was no difference between both groups with respect to age, gender, and Glasgow Coma Scale score. However, children who suffered injuries after an accidental fall from the changing table were more likely to require surgery (26/483 vs. 57/253, p < 0.0001), had a mean longer length of stay (LOS, 4 vs. 1 day), and a higher incidence of depressed skull fractures (12/483 vs. 24/253, p < 0.0001). Children with a direct impact from the floor after falling off the bed were expected to suffer from simple linear skull fractures, while those who flipped over the changing table were more likely to present facial, soft tissue, or skeletal injuries.

CONCLUSIONS

Children who flipped over a changing table during their homecare activities were more likely to require surgery, showed a higher morbidity, and showed a longer LOS than those who fell down from the bed. These results probably reflect the different impact energy according to each injury mechanism.

Effect of melatonin on intracranial pressure and brain edema following traumatic brain injury: role of oxidative stresses

BACKGROUND AND AIMS

Traumatic brain injury (TBI) is one of the main causes of brain edema and increased intracranial pressure (ICP). In the clinic it is essential to limit the development of ICP after TBI. In the present study, the effects of melatonin on these parameters at different time points and alterations of oxidant factors as one of the probable involved mechanisms have been evaluated.

METHODS

Albino N-Mary rats were divided into five groups of sham, TBI, TBI + vehicle, TBI + Mel5 and TBI + Mel20. Brain injury was induced by Marmarou method. Melatonin was injected i.p. at 1, 24, 48 and 72 h after brain trauma. Brain water and Evans blue dye contents as well as oxidant/antioxidant factors were measured 72 h after TBI. ICP and neurological scores were determined at -1, 1, 24, 48 and 72 h post-TBI.

RESULTS

Brain water and Evans blue dye contents in melatonin-treated groups decreased as compared to the TBI + vehicle group (p <0.001). Veterinary coma scale (VCS) at 24, 48 and 72 h after TBI showed a significant increase in melatonin groups (TBI + Mel5: p <0.01 and TBI + Mel20: p <0.001) in comparison to the TBI + vehicle group. ICP at 24, 48 and 72 h after TBI decreased in melatonin groups as compared to the TBI + vehicle group (p <0.001). Superoxide dismutase and glutathione peroxidase activities showed a significant increase, whereas malondialdehyde level in these groups was significantly lower in melatonin groups in comparison to the TBI + vehicle group (p <0.001).

CONCLUSION

Melatonin decreases brain edema, BBB permeability and ICP, but increases VCS after TBI. These effects are probably due to inhibition of oxidative stress.