Serial measurement of S100B and NSE in pediatric traumatic brain injury

Neuromodulation technologies improve functional recovery after brain injury: From bench to bedside

Spontaneous recovery frequently proves maladaptive or insufficient because the plasticity of the injured adult mammalian central nervous system is limited. This limited plasticity serves as a primary barrier to functional recovery after brain injury. Neuromodulation technologies represent one of the fastest-growing fields in medicine. These techniques utilize electricity, magnetism, sound, and light to restore or optimize brain functions by promoting reorganization or long-term changes that support functional recovery in patients with brain injury. Therefore, this review aims to provide a comprehensive overview of the effects and underlying mechanisms of neuromodulation technologies in supporting motor function recovery after brain injury. Many of these technologies are widely used in clinical practice and show significant improvements in motor function across various types of brain injury. However, studies report negative findings, potentially due to variations in stimulation protocols, differences in observation periods, and the severity of functional impairments among participants across different clinical trials. Additionally, we observed that different neuromodulation techniques share remarkably similar mechanisms, including promoting neuroplasticity, enhancing neurotrophic factor release, improving cerebral blood flow, suppressing neuroinflammation, and providing neuroprotection. Finally, considering the advantages and disadvantages of various neuromodulation techniques, we propose that future development should focus on closed-loop neural circuit stimulation, personalized treatment, interdisciplinary collaboration, and precision stimulation.

Predictive role of neuron-specific enolase and S100-β in early neurological deterioration and unfavorable prognosis in patients with ischemic stroke

Background

We aimed to assess whether neuron-specific enolase (NSE) and S100-β levels are associated with early neurological deterioration (END) in patients with acute ischemic stroke (AIS).

Methods

We conducted a prospective study between March 2022 and October 2023 in 286 patients with AIS. Serum NSE and S100-β levels on admission and at 24 and 48 h after stroke onset were measured using electrochemiluminescence immunoassays. Outcomes included END events within 48 h of admission and unfavorable neurological outcomes at 3 months.

Results

Patients with END had higher serum NSE and S100-β levels. Patients with poor prognosis had higher serum NSE and S100-β levels. Serum NSE (on admission) was an independent biomarker for END in AIS patients and for unfavorable recovery at 3 months. In addition, serum S100-β was an independent biomarker of unfavorable recovery after 3 months in patients with AIS.

Conclusion

Serum NSE on admission and S100-β at 48 h of stroke onset may serve as biomarkers of short-term clinical outcome in patients with AIS. Elevated serum NSE and S100-β levels may be useful tools to predict prognosis in patients with AIS.

Serum exosomes miR-206 and miR-549a-3p as potential biomarkers of traumatic brain injury

Traumatic brain injury (TBI) is one of the leading causes of death and disability worldwide. However, effective diagnostic, therapeutic and prognostic biomarkers are still lacking. Our research group previously revealed through high-throughput sequencing that the serum exosomes miR-133a-3p, miR-206, and miR-549a-3p differ significantly in severe TBI (sTBI), mild or moderate TBI (mTBI), and control groups. However, convincing experimental evidence is lacking. To solve this problem, we used qPCR in this study to further verify the expression levels of serum exosomes miR-133a-3p, miR-206 and miR-549a-3p in TBI patients. The results showed that the serum exosomes miR-206 and miR-549a-3p showed good predictive value as biomarkers of TBI. In addition, in order to further verify whether serum exosomes miR-206 and miR-549a-3p can be used as potential biomarkers in patients with TBI and to understand the mechanism of their possible effects, we further determined the contents of SOD, BDNF, VEGF, VEGI, NSE and S100β in the serum of TBI patients. The results showed that, serum exosomes miR-206 and miR-549a-3p showed good correlation with BDNF, NSE and S100β. In conclusion, serum exosomes miR-206 and miR-549a-3p have the potential to serve as potential biomarkers in patients with TBI.

A biosensor for S100B detection based on PSS-MA-GoldMag-LFIA in early clinical diagnosis of brain damage

S100B is an essential biomarker in the early diagnosis and treatment monitoring of brain injury. However, the traditional clinical diagnostic assay for S100B detection requires a complex operation or large equipment, which limits its application for rapid point-of-care tests (POCT). This study aimed to establish a lateral-flow immunoassay (LFIA) strip test system for S100B determination. PSS-MA-GoldMag nanoparticles were conjugated with anti-S100B antibodies as probes. Using this antibody-nanoparticle composite, an LFIA system based on magnetic quantification was established for S100B detection. For the evaluation of the performance of this LFIA system in clinical practice, 216 clinical samples were assayed using the LFIA test system and a commercial ECLI kit. Using the LFIA system, reliable results could be obtained in 30 min with a detection limit of 0.05 ng mL-1. The coefficient of variation (CV) was <13.8% and <14.03% for intra- and inter-assay precision, respectively. The recoveries were between 95.1 and 107.3%. The relative deviation of the interference experiments was <10%. In the analysis of clinical samples, the result indicated that the sera level of S100B in the detection group did not correlate with gender (p = 0.564 > 0.05) or age (p = 0.083 > 0.05). There is a good correlation between the novel method and the Elecsys®, with a determination coefficient of R2 0.9566, p > 0.05. The Bland-Altman analysis between the two ways shows that the 95% confidence bands between the two methods in measuring S100B were -0.27 ng mL-1 to +0.29 ng mL-1 with a mean difference of +0.006 ng mL-1. These results indicated that the novel LFIA system could be a simple, rapid, convenient, and accurate method for S100B determination.

Evaluation of brain injury in goats naturally infected with Coenurus cerebralis; brain specific biomarkers, acute inflammation, and DNA oxidation

This investigate goals are to establish the utility of brain-specific biomarkers (GFAP and S100B) in vivo and to assess the brain damage in C. cerebralis-infected goats using histopathological and immunopathological methods. The animal material of the study consisted of 10 healthy and 20 Coenurus cerebralis infected female hair goats. Serum GFAP and S100B concentrations were measured to determine brain damage. Serum S100B (p < 0.037), GFAP (p < 0.012), urea (p < 0.045), GGT (p < 0.001) and ALT (p < 0.001) concentrations in the C.cerebralis group were significantly higher than the control group. There was no significant difference between the C.cerebralis group and the control group for hsTnI (p > 0.078), creatinine (p > 0.099) and CK-MB (p > 0.725). In the histopathological examination, pressure atrophy and related inflammatory changes were observed due to mechanical damage of the parasite. Immunohistochemical examinations revealed that the parasite stimulated inflammation with the expression of TNF-α and caused DNA damage with the expression of 8-OHdG. As a result, when the data collected for this study are assessed as a whole, it is thought that the use of brainspecific GFAP and S100B biomarkers may be beneficial in determining brain damage in naturally infected hair goats with C.cerebralis. Changes in the levels of brain-specific biomarkers contribute significantly to determining the prognosis of the disease in vivo. Measurement of GFAP and S100B concentrations from serum offers an important alternative to the CSF method.

Lipopolysaccharide impairs neurodevelopment and induces changes in astroglial reactivity, antioxidant defenses and bioenergetics in the cerebral cortex of neonatal rats

Neonates have an immature immune system, which increases their vulnerability to infectious agents and inflammatory insults. The administration of the immunostimulatory agent lipopolysaccharide (LPS) has been shown to induce the expression of pro-inflammatory cytokines and cause behavior alterations in rodents at different ages. However, the effects of LPS administration during the neonatal period and its consequences during immune system maturation remain to be elucidated. We showed here that a single intraperitoneal administration of LPS in rats on postnatal day (PND) 7 caused early and variable alterations in TNF-α, S100B and GFAP levels in the cerebral cortex, CSF and serum of the animals, indicating long-term induction of neuroinflammation and astroglial reactivity. However, on PND 21, only GFAP levels were increased by LPS. Additionally, LPS induced oxidative stress and altered energy metabolism enzymes in the cerebral cortex on PND 21, and caused neurodevelopment impairment over time. These data suggest that neuroinflammation induction during the neonatal period induces glial reactivity, oxidative stress and bioenergetic disruption that may lead to neurodevelopment impairment and cognitive deficit in adult life.

Platelet levels and age are determinants of survival after mild-moderate TBI: A prospective study in Spain

Introduction

Traumatic brain injury (TBI) is a very important reason for consultation in emergency departments.

Methods

A hospital cohort study with patients who attended a hospital emergency department between June 1, 2018 and December 31, 2020 due to TBI was studied. Clinical and sociodemographic variables were recorded. The levels of biomarkers and management variables were used. Qualitative variables were analyzed using Pearson's chi-square test, and quantitative variables using the Mann-Whitney U-test. Survival analyses were performed by fitting a multivariable Cox regression model for patient survival during the follow-up of the study in relation to the patient's characteristics upon admission to the emergency department.

Results

A total of 540 patients were included. The mean age was 83 years, and 53.9% of the patients were men. Overall, 112 patients (20.7%) died during the study follow-up. The mortality rate per 100 person-years was 14.33 (11.8-17.24), the most frequent mechanism being falls in the home, with none caused on public roads. The multivariable Cox proportional hazards model showed that survival after TBI was significantly associated with age, S100 levels, Charlson index, patient's institutionalized status, the place where the TBI occurred, and hemoglobin and platelet levels.

Discussion

The most common profile for a patient with a TBI was male and aged between 80 and 90 years. The combination of the variables age, Charlson index, place of TBI occurrence, and hemoglobin and platelet levels could offer early prediction of survival in our population independently of TBI severity. With the data obtained, a therapeutic algorithm could be established for patients suffering from mild TBI, allowing the patient to be supervised at home, avoiding futile referrals to emergency services.

The ratio of serum neuron-specific enolase level to admission glasgow coma scale score is associated with diffuse axonal injury in patients with moderate to severe traumatic brain injury

Background

Moderate to severe traumatic brain injury (TBI) is frequently accompanied by diffuse axonal injury (DAI). Considering the low sensitivity of computed tomography (CT) examination for microbleeds and axonal damage, identification of DAI is difficult using conventional diagnostic methods in the acute phase. Neuron-specific enolase (NSE) has been demonstrated to be increased in serum following various types of TBI and is already clinically/commercially available. We conjecture that serum NSE level to admission GCS score ratio (NGR) may be a useful indicator for the early diagnosis of DAI.

Methods

This study included 115 patients with moderate-to-severe TBI who underwent NSE measurements within 6 h after injury and brain magnetic resonance imaging (MRI) within 30 days. The positive and negative DAI groups were divided according to MRI findings.

Results

Among the 115 patients, 49 (42.6%) were classified into the DAI group and 66 (57.4%) patients into the non-DAI group by clinical MRI. The NGR of patients without DAI was found to be significantly lower than those of patients with DAI (p < 0.0001). NGR presented the largest Pearson r value (r = 0.755, 95% CI 0.664–0.824, p < 0.0001) and high diagnostic accuracy for DAI [area under the curve (AUC) = 0.9493; sensitivity, 90.91%; and specificity, 85.71%]. Patients with TBI presenting with higher NGR were more likely to suffer an unfavorable neurological outcome [6-month extended Glasgow Outcome Scale (GOSE) 1–4].

Conclusions

The NGR on admission could serve as an independent predictor of DAI with moderate-to-severe TBI.

Progress Toward a Multiomic Understanding of Traumatic Brain Injury: A Review

Traumatic brain injury (TBI) is not a single disease state but describes an array of conditions associated with insult or injury to the brain. While some individuals with TBI recover within a few days or months, others present with persistent symptoms that can cause disability, neuropsychological trauma, and even death. Understanding, diagnosing, and treating TBI is extremely complex for many reasons, including the variable biomechanics of head impact, differences in severity and location of injury, and individual patient characteristics. Because of these confounding factors, the development of reliable diagnostics and targeted treatments for brain injury remains elusive. We argue that the development of effective diagnostic and therapeutic strategies for TBI requires a deep understanding of human neurophysiology at the molecular level and that the framework of multiomics may provide some effective solutions for the diagnosis and treatment of this challenging condition. To this end, we present here a comprehensive review of TBI biomarker candidates from across the multiomic disciplines and compare them with known signatures associated with other neuropsychological conditions, including Alzheimer’s disease and Parkinson’s disease. We believe that this integrated view will facilitate a deeper understanding of the pathophysiology of TBI and its potential links to other neurological diseases.

Brain damage markers neuron-specific enolase (NSE) and S100B in serum in children with Lyme neuroborreliosis-detection and evaluation as prognostic biomarkers for clinical outcome

Lyme borreliosis (LB) is the most common tick-borne infection in Europe, with Lyme neuroborreliosis (LNB) its second most frequent clinical manifestation. Prognostic factors for clinical outcomes in LNB have not been identified. Elevated serum levels of the brain damage markers neuron-specific enolase (NSE) and S100 calcium-binding protein B (S100B) have been associated with poor clinical outcomes in other disorders of the central nervous system. The aim of this study is to assess NSE and S100B in serum as prognostic biomarkers for clinical outcomes in paediatric LNB patients. Children evaluated for LNB (n = 121) in Sweden were prospectively included during 2010–2014, serum samples were collected on admission, and all children underwent a 2-month follow-up. Patients with pleocytosis and anti-Borrelia antibodies in cerebrospinal fluid (CSF) were classified as having LNB (n = 61). Controls were age- and gender-matched non-LNB patients (n = 60). NSE was elevated in 38/61 (62%) LNB patients and in 31/60 (52%) controls. S100B was elevated in 3/60 (5%) LNB patients and 0/59 (0%) controls. NSE and S100B concentrations did not differ significantly when comparing LNB patients with controls. No differences were found in the concentrations when comparing the clinical recovery of LNB patients at the 2-month follow-up. NSE was detectable in the majority of LNB patients and controls, whereas S100B was detectable in only a few LNB patients and no controls. NSE and S100B in serum cannot be recommended as prognostic biomarkers for clinical outcomes in children with LNB.

Pediatric Traumatic Brain Injury: An Update on Preclinical Models, Clinical Biomarkers, and the Implications of Cerebrovascular Dysfunction

Traumatic brain injury (TBI) is a leading cause of pediatric morbidity and mortality. Recent studies suggest that children and adolescents have worse post-TBI outcomes and take longer to recover than adults. However, the pathophysiology and progression of TBI in the pediatric population are studied to a far lesser extent compared to the adult population. Common causes of TBI in children are falls, sports/recreation-related injuries, non-accidental trauma, and motor vehicle-related injuries. A fundamental understanding of TBI pathophysiology is crucial in preventing long-term brain injury sequelae. Animal models of TBI have played an essential role in addressing the knowledge gaps relating to pTBI pathophysiology. Moreover, a better understanding of clinical biomarkers is crucial to diagnose pTBI and accurately predict long-term outcomes. This review examines the current preclinical models of pTBI, the implications of pTBI on the brain's vasculature, and clinical pTBI biomarkers. Finally, we conclude the review by speculating on the emerging role of the gut-brain axis in pTBI pathophysiology.

Ultrasound Radiomics-Guided Iliac Fascia Block on Postoperative Cognitive Dysfunction in Elderly Patients Undergoing Hip Surgery

Objective. Elderly patients with hip surgery are prone to postoperative cognitive dysfunction (POCD), leading to health management difficulties. This study is aimed at investigating the effect of ultrasound radiomics-guided iliac fascia block on POCD. Methods. A total of 67 cases of patients who had undergone hip joint surgery were divided into a training set ( $n=47$ ) and a validation set (radiomics-guided group, $n=20$ ). The patients were intervened with ultrasound radiomics-guided iliac fascia block, and the maximum relevance minimum redundancy sifts out the image omics features obtained from 2D ultrasound images of patients. Another 20 patients undergone general anesthesia served as control. The incidence of POCD, the total amount of fentanyl, the visual analogue score (VAS) at different time points, and the levels of CRP and NSE in plasma were compared between the two groups. Results. The AUC on the training and validation sets were higher than 0.940. The incidence of POCD in the radiomics-guided and general anesthesia group was 5% and 30%, respectively ( $P=0.037$ ). Compared with the general anesthesia group, the dosage of fentanyl in the radiomics-guided was lower, the VAS score at 6 h, 1 d, and 2 d after operation was smaller, and the levels of CRP and NSE were lower (all $P<0.05$ ). Conclusions. For elderly patients with hip surgery, the ultrasound radiomics-guided iliac fascia block can reduce the incidence of POCD and improve the effect of nerve block.

Biomarkers of exposure and effect in the serum and urine of rats or workers exposed to 1-bromopropane

Extensively used in several industries in China as a cleaning agent, 1-bromopropane (1-BP) has significant adverse effects on the central nervous system. However, neither its mechanism of action nor sensitive biomarkers related to it have been determined thus far. In this study, animal experiments and occupational surveys were performed to explore the typical exposure and effect biomarkers of neurotoxicity induced by 1-BP. Male Wistar rats were exposed to 0, 500, or 1000 ppm of 1-BP followed by pathological and biomarker analyses. An epidemiological survey was conducted on 71 workers each from 1-BP exposed and control groups. Serum and urine samples were collected for biomarker testing. cNSE represents neuron-specific enolase (NSE) in the cerebral cortex, where as sNSE represents NSE in the serum; similar terminology applies to S-100β, and cyclooxygenase-2 (COX-2). In rats exposed to 1000 ppm 1-BP, pathological changes were observed in Purkinje cells, lumbar gray matter, and tibiofibular nerve, while levels of cNSE, cS-100β, cCOX-2, sS-100β, and sCOX-2 were significantly elevated at different time checkpoints. In the 500 ppm group, cCOX-2, sNSE, and sCOX-2 levels were significantly elevated at different time checkpoints. 1-BP and N-acetyl-S-(n-propyl)-L-cysteine (AcPrCys) were detected in rat urine, and there was a correlation between the level of sNSE or sCOX-2 and AcPrCys in the 500 ppm group. In the occupational epidemiological study, a significant correlation between AcPrCys and exposure concentration was also detected. The findings of this study indicated that AcPrCys was a sensitive exposure biomarker of 1-BP in rats as well as occupational populations.

Biomarkers in Moderate to Severe Pediatric Traumatic Brain Injury: A Review of the Literature

BACKGROUND

Despite decades of research, outcomes in pediatric traumatic brain injury (pTBI) remain highly variable. Brain biofluid-specific biomarkers from pTBI patients may allow us to diagnose and prognosticate earlier and with a greater degree of accuracy than conventional methods. This manuscript reviews the evidence surrounding current brain-specific biomarkers in pTBI and assesses the temporal relationship between the natural history of the traumatic brain injury (TBI) and measured biomarker levels.

METHODS

A literature search was conducted in the Ovid, PubMed, MEDLINE, and Cochrane databases seeking relevant publications. The study selection and screening process were documented in a Preferred Reporting Items for Systematic Reviews and Meta-Analyses flow diagram. Extraction forms included developmental stages of patients, type and biofluid source of biomarkers, brain injury type, and other relevant data.

RESULTS

The search strategy identified 443 articles, of which 150 examining the biomarkers of our interest were included. The references retrieved were examined thoroughly and discussed at length with a pediatric neurocritical care intensivist specializing in pTBI and a Ph.D. scientist with a high degree of involvement in TBI biomarker research, authoring a vast amount of literature in this field.

CONCLUSIONS

TBI biomarkers might serve as valuable tools in the diagnosis and prognosis of pTBI. However, while each biomarker has its advantages, they are not without limitations, and therefore, further research is critical in pTBI biomarkers.

GFAP and S100B: What You Always Wanted to Know and Never Dared to Ask

Traumatic brain injury (TBI) is a major global health issue, with outcomes spanning from intracranial bleeding, debilitating sequelae, and invalidity with consequences for individuals, families, and healthcare systems. Early diagnosis of TBI by testing peripheral fluids such as blood or saliva has been the focus of many research efforts, leading to FDA approval for a bench-top assay for blood GFAP and UCH-L1 and a plasma point-of-care test for GFAP. The biomarker S100B has been included in clinical guidelines for mTBI (mTBI) in Europe. Despite these successes, several unresolved issues have been recognized, including the robustness of prior data, the presence of biomarkers in tissues beyond the central nervous system, and the time course of biomarkers in peripheral body fluids. In this review article, we present some of these issues and provide a viewpoint derived from an analysis of existing literature. We focus on two astrocytic proteins, S100B and GFAP, the most commonly employed biomarkers used in mTBI. We also offer recommendations that may translate into a broader acceptance of these clinical tools.

Efficacy and safety of endovascular therapy versus surgical clipping for patients with unruptured middle cerebral artery bifurcation aneurysms

This study aims to evaluate the efficacy and safety of endovascular therapy versus neurosurgical clipping carried out for patients with unruptured middle cerebral artery bifurcation aneurysms (MCABAs). Patients diagnosed with MCABAs were enrolled in this prospective study according to the inclusion and exclusion standard. Enrolled patients were divided into a study group (endovascular therapy) and a control group (neurosurgical clipping), with 65 cases in each group. In terms of efficacy, we found that the proportion of Glasgow Outcome Scale (GOS) grade 1 after treatment in the study group was significantly higher than in the control group (p<0.001), while the proportion of GOS grades 2, 3, and 4 after treatment was significantly lower in the study group than in the control group (p<0.05). The postoperative brain injury indicators neuron-specific enolase and S100β in the study group were significantly lower than in the control group (p<0.001), and the postoperative life activity score of patients in the study group was significantly higher than in the control group (p<0.001). In terms of safety, the postoperative hospital stay of patients in the study group was significantly shorter than in the control group (p<0.001), and the incidence rate of postoperative pulmonary and intracranial infections in the study group was significantly lower than in the control group (p<0.05). Endovascular therapy for patients with unruptured MCABAs may be effective in improving outcomes and has better safety profile compared with neurosurgical clipping, but may increase the risk of postoperative recurrence.

Modeling Traumatic Brain Injury in Human Cerebral Organoids

Traumatic brain injury (TBI) is a head injury that disrupts the normal brain structure and function. TBI has been extensively studied using various in vitro and in vivo models. Most of the studies have been done with rodent models, which may respond differently to TBI than human nerve cells. Taking advantage of the recent development of cerebral organoids (COs) derived from human induced pluripotent stem cells (iPSCs), which resemble the architecture of specific human brain regions, here, we adapted the controlled cortical impact (CCI) model to induce TBI in human COs as a novel in vitro platform. To adapt the CCI procedure into COs, we have developed a phantom brain matrix, matching the mechanical characteristics of the brain, altogether with an empty mouse skull as a platform to allow the use of the stereotactic CCI equipment on COs. After the CCI procedure, COs were histologically prepared to evaluate neurons and astrocyte populations using the microtubule-associated protein 2 (MAP2) and the glial fibrillary acidic protein (GFAP). Moreover, a marker of metabolic response, the neuron-specific enolase (NSE), and cellular death using cleaved caspase 3 were also analyzed. Our results show that human COs recapitulate the primary pathological changes of TBI, including metabolic alterations related to neuronal damage, neuronal loss, and astrogliosis. This novel approach using human COs to model TBI in vitro holds great potential and opens new alternatives for understanding brain abnormalities produced by TBI, and for the development and testing of new therapeutic approaches.

Differential effect of ethanol intoxication on peripheral markers of cerebral injury in murine blunt traumatic brain injury

Background

Blood-based biomarkers have proven to be a reliable measure of the severity and outcome of traumatic brain injury (TBI) in both murine models and patients. In particular, neuron-specific enolase (NSE), neurofilament light (NFL) and S100 beta (S100B) have been investigated in the clinical setting post-injury. Ethanol intoxication (EI) remains a significant comorbidity in TBI, with 30–40% of patients having a positive blood alcohol concentration post-TBI. The effect of ethanol on blood-based biomarkers for the prognosis and diagnosis of TBI remains unclear. In this study, we investigated the effect of EI on NSE, NFL and S100B and their correlation with blood–brain barrier integrity in a murine model of TBI.

Methods

We used ultra-sensitive single-molecule array technology and enzyme-linked immunosorbent assay methods to measure NFL, NSE, S100B and claudin-5 concentrations in plasma 3 hours post-TBI.

Results

We showed that NFL, NSE and S100B were increased at 3 hours post-TBI. Interestingly, ethanol blood concentrations showed an inverse correlation with NSE but not with NFL or S100B. Claudin-5 levels were increased post-injury but no difference was detected compared to ethanol pretreatment. The increase in claudin-5 post-TBI was correlated with NFL but not with NSE or S100B.

Conclusions

Ethanol induces an effect on biomarker release in the bloodstream that is different from TBI not influenced by alcohol. This could be the basis of investigations into humans.

Serum biomarkers in severe paediatric traumatic brain injury-a narrative review

Severe traumatic brain injury continues to present complex management and prediction challenges for the clinician. While there is some evidence that better systems of care can improve outcome, multiple multi-centre randomised controlled trials of specific therapies have consistently failed to show benefit. In addition, clinicians are challenged in attempting to accurately predict which children will recover well and which children will have severe and persisting neurocognitive deficits. Traumatic brain injury is vastly heterogeneous and so it is not surprising that one therapy or approach, when applied to a mixed cohort of children in a clinical trial setting, has yielded disappointing results. Children with severe traumatic brain injury have vastly different brain injury pathologies of widely varying severity, in any number of anatomical locations at what may be disparate stages of brain development. This heterogeneity may also explain why clinicians are unable to accurately predict outcome. Biomarkers are objective molecular signatures of injury that are released following traumatic brain injury and may represent a way of unifying the heterogeneity of traumatic brain injury into a single biosignature. Biomarkers hold promise to diagnose brain injury severity, guide intervention selection for clinical trials, or provide vital prognostic information so that early intervention and rehabilitation can be planned much earlier in the course of a child's recovery. Serum S100B and serum NSE levels show promise as a diagnostic tool with biomarker levels significantly higher in children with severe TBI including children with inflicted and non-inflicted head injury. Serum S100B and serum NSE also show promise as a predictor of neurodevelopmental outcome. The role of biomarkers in traumatic brain injury is an evolving field with the potential for clinical application within the next few years.

S100B as a biomarker of blood-brain barrier disruption after thoracoabdominal aortic aneurysm repair: a secondary analysis from a prospective cohort study

PURPOSE

The objective of this study was to determine whether the magnitude of the peripheral inflammatory response to cardiovascular surgery is associated with increases in blood-brain barrier (BBB) permeability as reflected by changes in cerebrospinal fluid (CSF)/plasma S100B concentrations.

METHODS

We conducted a secondary analysis from a prospective cohort study of 35 patients undergoing elective thoracoabdominal aortic aneurysm repair with (n = 17) or without (n = 18) cardiopulmonary bypass (CPB). Plasma and CSF S100B, interleukin-6 (IL-6), and albumin concentrations were measured at baseline (C₀) and serially for up to five days.

RESULTS

Following CPB, the median [interquartile range] plasma S100B concentration increased from 58 [32-88] pg·mL^-1 at C₀ to a maximum concentration (C_max) of 1,131 [655-1,875] pg·mL^-1 over a median time (t_max) of 6.3 [5.9-7.0] hr. In the non-CPB group, the median plasma S100B increased to a lesser extent. There was a delayed increase in CSF S100B to a median C_max of 436 [406-922] pg·mL^-1 in the CPB group at a t_max of 23.7 [18.5-40.2] hr. In the non-CPB group, the CSF concentrations were similar at all time points. In the CPB group, we did not detect significant correlations between plasma and CSF S100B with plasma IL-6 [r = 0.52 (95% confidence interval [CI], -0.061 to 0.84)] and CSF IL-6 [r = 0.53 (95% CI, -0.073 to 0.85)] concentrations, respectively. Correlations of plasma or CSF S100B levels with BBB permeability were not significant.

CONCLUSION

The lack of parallel increases in plasma and CSF S100B following CPB indicates that S100B may not be a reliable biomarker for BBB disruption after thoracoabdominal aortic aneurysm repair employing CPB.

TRIAL REGISTRATION

www.clinicaltrials.gov (NCT00878371); registered 7 April 2009.

Longitudinal Course of Traumatic Brain Injury Biomarkers for the Prediction of Clinical Outcomes: A Review

Protein biomarkers are often measured at hospital presentation to diagnose traumatic brain injury (TBI) and predict patient outcomes. However, a biomarker measurement at this single time point is no more accurate at predicting patient outcomes than less invasive and more cost-effective methods. Here, we review evidence that TBI biomarkers provide greater prognostic value when measured repeatedly over time, such that a trajectory of biomarker concentrations can be evaluated. PubMed, Google Scholar, and Cochrane Central Register were searched to identify studies from the last decade in which established TBI biomarkers had been measured at more than one time point following acute TBI, and which related their findings to patient outcomes. Twenty-two studies were identified, 18 of which focused on adults and 4 of which focused on children. Three general biomarker trajectories were identified: persistently high, persistently low, and reversal of decreasing concentrations. Downtrend reversal was highly specific to predicting poor patient outcomes. Four studies demonstrated that biomarker trajectories can be affected by therapeutic interventions. Additional studies demonstrated that biomarkers measured at a later time point offered superior prognostic value than a single measurement obtained at initial hospital presentation. Among other details, longitudinal biomarker trajectory assessments may identify ongoing injury and predict patient deterioration before clinical symptoms develop and thus help guide therapeutic interventions.

A blood biomarker and clinical correlation cohort study protocol to diagnose sports-related concussion and monitor recovery in elite rugby

Introduction

In professional rugby, sports-related concussion (SRC) remains the most frequent time loss injury. Therefore, accurately diagnosing SRC and monitoring player recovery, through a multi-modal assessment process, is critical to SRC management. In this protocol study, we aim to assess SRC over multiple time points post-injury to determine the value of multi-modal assessments to monitor player recovery. This is of significance to minimise premature return-to-play and, ultimately, to reduce the long-term effects associated with SRC. The study will also establish the logistics of implementing such a study in a professional setting to monitor a player's SRC recovery.

Methods and analysis

All players from the participating professional rugby club within the Irish Rugby Football Union are invited to participate in the current study. Player assessment includes head injury assessment (HIA), neuropsychometric assessment (ImPACT), targeted biomarker analysis and untargeted biomarker analysis. Baseline HIA, ImPACT, and blood draws are performed prior to the start of playing season. During the baseline tests, player's complete consent forms and an SRC history questionnaire. Subsequently, any participant that enters the HIA process over the playing season due to a suspected SRC will be clinically assessed (HIA and ImPACT) and their blood will be drawn within 3 days of injury, 6 days post-injury, and 13 days post-injury.

Ethics and dissemination

Ethical approval was attained from the Science and Engineering Research Ethics Committee, University of Limerick (Approval Code: 2018_06_11_S&E). On completion of the study, further manuscripts will be published to present the results of the tests and their ability to measure player recovery from SRC.

Trial registration number

NCT04485494.

Traumatic brain injury biomarkers in pediatric patients: a systematic review

Traumatic brain injury (TBI) is the main cause of pediatric trauma death and disability worldwide. Recent studies have sought to identify biomarkers of TBI for the purpose of assessing functional outcomes. The aim of this systematic review was to evaluate the utility of TBI biomarkers in the pediatric population by summarizing recent findings in the medical literature. A total of 303 articles were retrieved from our search. An initial screening to remove duplicate studies yielded 162 articles. After excluding all articles that did not meet the inclusion criteria, 56 studies were gathered. Among the 56 studies, 36 analyzed serum biomarkers; 11, neuroimaging biomarkers; and 9, cerebrospinal fluid (CSF) biomarkers. Most studies assessed biomarkers in the serum, reflecting the feasibility of obtaining blood samples compared to obtaining CSF or performing neuroimaging. S100B was the most studied serum biomarker in TBI, followed by SNE and UCH-L1, whereas in CSF analysis, there was no unanimity. Among the different neuroimaging techniques employed, diffusion tensor imaging (DTI) was the most common, seemingly holding diagnostic power in the pediatric TBI clinical setting. The number of cross-sectional studies was similar to the number of longitudinal studies. Our data suggest that S100B measurement has high sensitivity and great promise in diagnosing pediatric TBI, ideally when associated with head CT examination and clinical decision protocols. Further large-scale longitudinal studies addressing TBI biomarkers in children are required to establish more accurate diagnostic protocols and prognostic tools.

DAMPs and RAGE Pathophysiology at the Acute Phase of Brain Injury: An Overview

Early or primary injury due to brain aggression, such as mechanical trauma, hemorrhage or is-chemia, triggers the release of damage-associated molecular patterns (DAMPs) in the extracellular space. Some DAMPs, such as S100B, participate in the regulation of cell growth and survival but may also trigger cellular damage as their concentration increases in the extracellular space. When DAMPs bind to pattern-recognition receptors, such as the receptor of advanced glycation end-products (RAGE), they lead to non-infectious inflammation that will contribute to necrotic cell clearance but may also worsen brain injury. In this narrative review, we describe the role and ki-netics of DAMPs and RAGE at the acute phase of brain injury. We searched the MEDLINE database for “DAMPs” or “RAGE” or “S100B” and “traumatic brain injury” or “subarachnoid hemorrhage” or “stroke”. We selected original articles reporting data on acute brain injury pathophysiology, from which we describe DAMPs release and clearance upon acute brain injury, and the implication of RAGE in the development of brain injury. We will also discuss the clinical strategies that emerge from this overview in terms of biomarkers and therapeutic perspectives

Laboratory Markers in the Management of Pediatric Polytrauma: Current Role and Areas of Future Research

Severe trauma is the most common cause of mortality in children and is associated with a high socioeconomic burden. The most frequently injured organs in children are the head and thorax, followed by the extremities and by abdominal injuries. The efficient and early assessment and management of these injuries is essential to improve patients' outcome. Physical examination as well as imaging techniques like ultrasound, X-ray and computer tomography are crucial for a valid early diagnosis. Furthermore, laboratory analyses constitute additional helpful tools for the detection and monitoring of pediatric injuries. Specific inflammatory markers correlate with post-traumatic complications, including the development of multiple organ failure. Other laboratory parameters, including lactate concentration, coagulation parameters and markers of organ injury, represent further clinical tools to identify trauma-induced disorders. In this review, we outline and evaluate specific biomarkers for inflammation, acid-base balance, blood coagulation and organ damage following pediatric polytrauma. The early use of relevant laboratory markers may assist decision making on imaging tools, thus contributing to minimize radiation-induced long-term consequences, while improving the outcome of children with multiple trauma.

Severe Traumatic Brain Injury (TBI) Modulates the Kinetic Profile of the Inflammatory Response of Markers for Neuronal Damage

The inflammatory response plays an important role in the pathophysiology of multiple injuries. This study examines the effects of severe trauma and inflammatory response on markers of neuronal damage. A retrospective analysis of prospectively collected data in 445 trauma patients (Injury Severity Score (ISS) ≥ 16) is provided. Levels of neuronal biomarkers (calcium-binding Protein B (S100b), Enolase2 (NSE), glial fibrillary acidic protein (GFAP)) and Interleukins (IL-6, IL-10) in severely injured patients (with polytrauma (PT)) without traumatic brain injury (TBI) or with severe TBI (PT+TBI) and patients with isolated TBI (isTBI) were measured upon arrival until day 5. S100b, NSE, GFAP levels showed a time-dependent decrease in all cohorts. Their expression was higher after multiple injuries (p = 0.038) comparing isTBI. Positive correlation of marker level after concomitant TBI and isTBI (p = 0.001) was noted, while marker expression after PT appears to be independent. Highest levels of IL-6 and -10 were associated to PT und lowest to isTBI (p < 0.001). In all groups pro-inflammatory response (IL-6/-10 ratio) peaked on day 2 and at a lower level on day 4. Severe TBI modulates kinetic profile of inflammatory response by reducing interleukin expression following trauma. Potential markers for neuronal damage have a limited diagnostic value after severe trauma because undifferentiated increase.

A Meta-Analysis of Neuron-Specific Enolase Levels in Cerebrospinal Fluid and Serum in Children With Epilepsy

Background: Studies suggest that neuron-specific enolase (NSE) levels in the cerebrospinal fluid (CSF) and serum play an important role in childhood epilepsy. However, these investigations remain controversial due to inconsistent clinical results. The present study aimed to quantitatively summarize and assess whether CSF and serum NSE levels are associated with epilepsy in children. Methods : A systematic search of the Harvard Hollis+, Clinicaltrials, Open Gray, China National Knowledge Infrastructure, and Wanfang databases was performed. Studies investigating NSE and epilepsy were identified and retrieved. Original studies with data overlapping those from other investigations and those lacking the necessary data were excluded. The included studies were extracted and synthesized, and data were analyzed using a random-effects model in R Studio and Comprehensive Meta-Analysis version 3 (Biostat, Englewood, NJ, USA). Results: Random-effects meta-analysis of 26 studies, including 1,360 patients, and 1,256 healthy control, revealed that childhood epilepsy exhibited meaningfully increased CSF and serum levels of NSE compared with controls [Hedges' g = 1.962 (95% confidence interval, 1.413-2.512); P < 0.001]. No single study meaningfully influenced the overall association between CSF and serum levels of NSE and epilepsy after sensitivity analysis. Subgroup analyses according to sample source and assay type revealed a significant association between NSE levels and epilepsy. Stratified analysis confirmed that NSE levels were significantly correlated with the severity of neurological compromise. Metaregression analyses revealed that sample size, mean age, and sex may contribute to effect-size reductions; however, sample source, assay type, and country did not moderate effect size. Funnel plots constructed using the trim-and-fill method confirmed that the outcome of the meta-analysis could not be due to publication bias. Conclusion: The results demonstrated that childhood epilepsy exhibits significantly elevated levels of NSE in the CSF and serum, thus strengthening the association between increased NSE levels and epilepsy.

Neurofilament Heavy Chain and Tau Protein Are Not Elevated in Cerebrospinal Fluid of Adult Patients with Spinal Muscular Atrophy during Loading with Nusinersen

Nusinersen is the first approved drug for the treatment of spinal muscular atrophy (SMA). Treatment of SMA with nusinersen is based on a fixed dosing regimen. For other motoneuron diseases, such as amyotrophic lateral sclerosis (ALS), biomarkers are available for clinical diagnostics; however, no such biomarkers have yet been found for SMA. Serum and cerebrospinal fluid (CSF) samples of 11 patients with adult SMA type 3 were prospectively collected and analyzed during loading with nusinersen. Neurofilament heavy chain, tau protein, S100B protein, and neuron-specific enolase were investigated as potential biomarkers of motor neuron destruction. No significant pathological alterations in levels of neurofilament heavy chain, tau protein, or S100B protein were detected in the CSF or blood samples under baseline conditions or during loading with nusinersen. Neuron-specific enolase was marginally elevated in CSF and blood samples without significant alteration during treatment. In a mixed cohort of adult patients with SMA type 3, neurofilament heavy chain, tau protein, S100B protein, and neuron-specific enolase do not serve as potential biomarkers during the loading phase of nusinersen. The slow progression rate of SMA type 3 may not lead to detectable elevation of levels of these common markers of axonal degradation.

Toward development of clinically translatable diagnostic and prognostic metrics of traumatic brain injury using animal models: A review and a look forward

Traumatic brain injury is a leading cause of cognitive and behavioral deficits in children in the US each year. There is an increasing interest in both clinical and pre-clinical studies to discover biomarkers to accurately diagnose traumatic brain injury (TBI), predict its outcomes, and monitor its progression especially in the developing brain. In humans, the heterogeneity of TBI in terms of clinical presentation, injury causation, and mechanism has contributed to the many challenges associated with finding unifying diagnosis, treatment, and management practices. In addition, findings from adult human research may have little application to pediatric TBI, as age and maturation levels affect the injury biomechanics and neurophysiological consequences of injury. Animal models of TBI are vital to address the variability and heterogeneity of TBI seen in human by isolating the causation and mechanism of injury in reproducible manner. However, a gap between the pre-clinical findings and clinical applications remains in TBI research today. To take a step toward bridging this gap, we reviewed several potential TBI tools such as biofluid biomarkers, electroencephalography (EEG), actigraphy, eye responses, and balance that have been explored in both clinical and pre-clinical studies and have shown potential diagnostic, prognostic, or monitoring utility for TBI. Each of these tools measures specific deficits following TBI, is easily accessible, non/minimally invasive, and is potentially highly translatable between animals and human outcomes because they involve effort-independent and non-verbal tasks. Especially conspicuous is the fact that these biomarkers and techniques can be tailored for infants and toddlers. However, translation of preclinical outcomes to clinical applications of these tools necessitates addressing several challenges. Among the challenges are the heterogeneity of clinical TBI, age dependency of some of the biomarkers, different brain structure, life span, and possible variation between temporal profiles of biomarkers in human and animals. Conducting parallel clinical and pre-clinical research, in addition to the integration of findings across species from several pre-clinical models to generate a spectrum of TBI mechanisms and severities is a path toward overcoming some of these challenges. This effort is possible through large scale collaborative research and data sharing across multiple centers. In addition, TBI causes dynamic deficits in multiple domains, and thus, a panel of biomarkers combining these measures to consider different deficits is more promising than a single biomarker for TBI. In this review, each of these tools are presented along with the clinical and pre-clinical findings, advantages, challenges and prospects of translating the pre-clinical knowledge into the human clinical setting.

The pig as a preclinical traumatic brain injury model: current models, functional outcome measures, and translational detection strategies

Traumatic brain injury (TBI) is a major contributor of long-term disability and a leading cause of death worldwide. A series of secondary injury cascades can contribute to cell death, tissue loss, and ultimately to the development of functional impairments. However, there are currently no effective therapeutic interventions that improve brain outcomes following TBI. As a result, a number of experimental TBI models have been developed to recapitulate TBI injury mechanisms and to test the efficacy of potential therapeutics. The pig model has recently come to the forefront as the pig brain is closer in size, structure, and composition to the human brain compared to traditional rodent models, making it an ideal large animal model to study TBI pathophysiology and functional outcomes. This review will focus on the shared characteristics between humans and pigs that make them ideal for modeling TBI and will review the three most common pig TBI models-the diffuse axonal injury, the controlled cortical impact, and the fluid percussion models. It will also review current advances in functional outcome assessment measures and other non-invasive, translational TBI detection and measurement tools like biomarker analysis and magnetic resonance imaging. The use of pigs as TBI models and the continued development and improvement of translational assessment modalities have made significant contributions to unraveling the complex cascade of TBI sequela and provide an important means to study potential clinically relevant therapeutic interventions.