Brain biomarkers and pre-injury cognition are associated with long-term cognitive outcome in children with traumatic brain injury

Acute Fluid Biomarkers for Diagnosis and Prognosis in Children with Mild Traumatic Brain Injury: A Systematic Review

BACKGROUND AND OBJECTIVE

Fluid biomarkers have the potential to improve the accuracy of diagnosis and prognosis in children with mild traumatic brain injury. Our primary objective was to assess the diagnostic and prognostic utility of acute blood and fluid biomarkers in children with mild traumatic brain injury.

METHODS

We performed a systematic review of the published literature in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology. Fluid biomarker studies assessing pediatric mild traumatic brain injury diagnosis or prognosis were included if blood or fluids were sampled within 24 h of injury.

RESULTS

Thirty-two studies involving 4743 patients were included comprising 25 diagnostic studies and ten prognostic studies with three studies assessing both diagnosis and prognosis. Sixteen of the 25 diagnostic studies reported the area under the receiver operating characteristic curve (AUC) for predicting abnormal computed tomography scans of the head; S100 calcium binding protein B (S100B, N = 6 studies, AUC range 0.67-1.00), glial fibrillary acidic protein (N = 5, AUC range 0.41-0.85), ubiquitin C-terminal hydrolase (N = 3, AUC 0.59 and 0.83), neuron specific enolase (N = 1, AUC 0.99), total tau (N = 1, AUC 0.65), and interleukin-6 (N = 1, AUC 0.61). In four of the ten prognostic studies, increased acute serum S100B levels, tumor necrosis factor-α, or interleukin-8 were associated with post-concussive symptoms or fatigue from 3 to 12 months post-injury.

CONCLUSIONS

The largest amount of evidence supported the potential use of S100B, glial fibrillary acidic protein, and UCH-L1, but there was mixed accuracy for diagnosis and prognostication for all biomarkers in pediatric mTBI.

Potential Biomarkers in Experimental Animal Models for Traumatic Brain Injury

Traumatic brain injury (TBI) is a complex and multifaceted disorder that has become a significant public health concern worldwide due to its contribution to mortality and morbidity. This condition encompasses a spectrum of injuries, including axonal damage, contusions, edema, and hemorrhage. Unfortunately, specific effective therapeutic interventions to improve patient outcomes following TBI are currently lacking. Various experimental animal models have been developed to mimic TBI and evaluate potential therapeutic agents to address this issue. These models are designed to recapitulate different biomarkers and mechanisms involved in TBI. However, due to the heterogeneous nature of clinical TBI, no single experimental animal model can effectively mimic all aspects of human TBI. Accurate emulation of clinical TBI mechanisms is also tricky due to ethical considerations. Therefore, the continued study of TBI mechanisms and biomarkers, of the duration and severity of brain injury, treatment strategies, and animal model optimization is necessary. This review focuses on the pathophysiology of TBI, available experimental TBI animal models, and the range of biomarkers and detection methods for TBI. Overall, this review highlights the need for further research to improve patient outcomes and reduce the global burden of TBI.

Medial prefrontal cortex oxytocin mitigates epilepsy and cognitive impairments induced by traumatic brain injury through reducing neuroinflammation in mice

Traumatic brain injury (TBI) is a major risk factor to develop epilepsy and cognitive impairments. Neuropeptide oxytocin has been previously evidenced to produce antiepileptic effects. However, the involvement of central oxytocin in TBI-induced epileptic status and cognitive dysfunctions is not fully elucidated. In this study, we aim to investigate the role of oxytocin on a TBI model followed by seizure induction to clarify whether the epilepsy and cognitive deficits could be mitigated by oxytocin. TBI was established by weight drop and epileptic behaviors were induced by pentylenetetrazole (PTZ) injection in mice. Moreover, oxytocin was microinjected into the medial prefrontal cortex (mPFC) to observe the effects on the epilepsy and cognition. The blood-brain barrier (BBB) function and the neuroinflammation were measured by Evans Blue staining and enzyme-linked immunosorbent assays, respectively. Mice exposed to TBI demonstrate increased vulnerability to PTZ-mediated seizures and cognitive disturbances with a decrease in peripheral and brain oxytocin levels. Additionally, TBI reduces oxytocin, disrupts the BBB permeability and triggers neuroinflammation in mPFC in PTZ-treated mice. Intra-mPFC oxytocin simultaneously mitigates epilepsy and cognitive impairments. Finally, oxytocin restores BBB integrity and reduces mPFC inflammation in PTZ-treated TBI mice. These findings showed that intra-mPFC oxytocin suppressed the seizure vulnerability and cognitive deficits in TBI mice. The normalization of BBB integrity and inhibition of neuroinflammation may be involved in the antiepileptic and cognition-improved effects of oxytocin, suggesting that targeting inflammatory procedure in mPFC may decrease the risk to develop epilepsy and cognitive impairments in individuals previously experienced TBI.

Hyperbaric oxygen therapy in children with post-concussion syndrome improves cognitive and behavioral function: a randomized controlled trial

Persistent post-concussion syndrome (PPCS) is a common and significant morbidity among children following traumatic brain injury (TBI) and the evidence for effective PPCS treatments remains limited. Recent studies have shown the beneficial effects of hyperbaric oxygen therapy (HBOT) in PPCS adult patients. This randomized, sham-control, double blind trial evaluated the effect of hyperbaric oxygen therapy (HBOT) on children (age 8–15) suffering from PPCS from mild-moderate TBI events six months to 10 years prior. Twenty-five children were randomized to receive 60 daily sessions of HBOT (n = 15) or sham (n = 10) treatments. Following HBOT, there was a significant increase in cognitive function including the general cognitive score (d = 0.598, p = 0.01), memory (d = 0.480, p = 0.02), executive function (d = 0.739, p = 0.003), PPCS symptoms including emotional score (p = 0.04, d = – 0.676), behavioral symptoms including hyperactivity (d = 0.244, p = 0.03), global executive composite score (d = 0.528, p = 0.001), planning/organizing score (d = 1.09, p = 0.007). Clinical outcomes correlated with significant improvements in brain MRI microstructural changes in the insula, supramarginal, lingual, inferior frontal and fusiform gyri. The study suggests that HBOT improves both cognitive and behavioral function, PPCS symptoms, and quality of life in pediatric PPCS patients at the chronic stage, even years after injury. Additional data is needed to optimize the protocol and to characterize the children who can benefit the most.

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.

Executive function, repetitive behaviour and restricted interests in neurodevelopmental disorders

BACKGROUND

Individuals with genetic syndromes show unique profiles of repetitive behaviours and restricted interests (RRBs). The executive dysfunction account of RRBs suggests that in autistic (AUT) individuals executive function impairments underpin RRBs, but not communication and social interaction autistic characteristics.

AIMS

To 1) describe profiles of behavioural manifestations of executive function (EF behaviours) and 2) explore the relationship between EF behaviours and autistic traits across individuals with Cornelia de Lange (CdLS), fragile X (FXS) and Rubinstein-Taybi syndromes (RTS), and AUT individuals.

METHOD

Carers completed the Behavior Rating Inventory of Executive Function - Preschool Version and the Social Communication Questionnaire. Data reporting on 25 individuals with CdLS (Mage = 18.60, SD = 8.94), 25 with FXS (Mage = 18.48, SD = 8.80), 25 with RTS (Mage = 18.60, SD = 8.65) and 25 AUT individuals (Mage = 18.52, SD = 8.65) matched on chronological age and adaptive ability were included in analyses.

RESULTS

All groups showed impairments across EF behaviours compared to two-to-three-year-old typically developing normative samples with no differences between groups. Different EF behaviours predicted RRBs in the syndrome groups with no associations found in the AUT group.

CONCLUSIONS

Syndrome related differences should be considered when developing targeted interventions that focus on EF behaviours and/or RRBs in these groups.

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.

Serum Biomarkers of Regeneration and Plasticity are Associated with Functional Outcome in Pediatric Neurocritical Illness: An Exploratory Study

BACKGROUND/OBJECTIVE

Pediatric neurocritical care survivorship is frequently accompanied by functional impairments. Lack of prognostic biomarkers is a barrier to early identification and management of impairment. We explored the association between blood biomarkers and functional impairment in children with acute acquired brain injury.

METHODS

This study is a secondary analysis of a randomized control trial evaluating early versus usual care rehabilitation in the pediatric intensive care unit (PICU). Forty-four children (17 [39%] female, median age 11 [interquartile range 6-13] years) with acute acquired brain injury admitted to the PICU were studied. A single center obtained serum samples on admission days 0, 1, 3, 5, and the day closest to hospital discharge. Biomarkers relevant to brain injury (neuron specific enolase [NSE], S100b), inflammation (interleukin [IL-6], C-reactive protein), and regeneration (brain-derived neurotrophic factor [BDNF], vascular endothelial growth factor [VEGF]) were collected. Biomarkers were analyzed using a Luminex® bioassay. Functional status scale (FSS) scores were abstracted from the medical record. New functional impairment was defined as a (worse) FSS score at hospital discharge compared to pre-PICU (baseline). Individual biomarker fluorescence index (FI) values for each sample collection day were correlated with new functional impairment using Spearman rank correlation coefficient (ρ). Trends in repeated measures of biomarker FI over time were explored graphically, and the association between repeated measures of biomarker FI and new functional impairment was analyzed using covariate adjusted linear mixed-effect models.

RESULTS

Functional impairment was inversely correlated with markers of regeneration and plasticity including BDNF at day 3 (ρ =  - 0.404, p = .015), day 5 (ρ =  - 0.549, p = 0.005) and hospital discharge (ρ =  - 0.420, p = 0.026) and VEGF at day 1 (ρ =  - 0.282, p = 0.008) and hospital discharge (ρ =  - 0.378, p = 0.047), such that lower levels of both markers at each time point were associated with greater impairment. Similarly, repeated measures of BDNF and VEGF were inversely correlated with new functional impairment (B =  - 0.001, p = 0.001 and B =  - 0.001, p = 0.003, respectively). NSE, a biomarker of acute brain injury, showed a positive correlation between day 0 levels and new functional impairment (ρ = 0.320, p = 0.044).

CONCLUSIONS

Blood-based biomarkers of regeneration and plasticity may hold prognostic utility for functional impairment among pediatric patients with neurocritical illness and warrant further investigation.

Magnetic Resonance Imaging Findings Are Associated with Long-Term Global Neurological Function or Death after Traumatic Brain Injury in Critically Ill Children

The identification of children with traumatic brain injury (TBI) who are at risk of death or poor global neurological functional outcome remains a challenge. Magnetic resonance imaging (MRI) can detect several brain pathologies that are a result of TBI; however, the types and locations of pathology that are the most predictive remain to be determined. Forty-two critically ill children with TBI were recruited prospectively from pediatric intensive care units at five Canadian children's hospitals. Pathologies detected on subacute phase MRIs included cerebral hematoma, herniation, cerebral laceration, cerebral edema, midline shift, and the presence and location of cerebral contusion or diffuse axonal injury (DAI) in 28 regions of interest were assessed. Global functional outcome or death more than 12 months post-injury was assessed using the Pediatric Cerebral Performance Category score. Linear modeling was employed to evaluate the utility of an MRI composite score for predicting long-term global neurological function or death after injury, and nonlinear Random Forest modeling was used to identify which MRI features have the most predictive utility. A linear predictive model of favorable versus unfavorable long-term outcomes was significantly improved when an MRI composite score was added to clinical variables. Nonlinear Random Forest modeling identified five MRI variables as stable predictors of poor outcomes: presence of herniation, DAI in the parietal lobe, DAI in the subcortical white matter, DAI in the posterior corpus callosum, and cerebral contusion in the anterior temporal lobe. Clinical MRI has prognostic value to identify children with TBI at risk of long-term unfavorable outcomes.

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.

Interleukin-8 Predicts Fatigue at 12 Months Post-Injury in Children with Traumatic Brain Injury

Despite many children experiencing fatigue after childhood brain injury, little is known about the predictors of this complaint. To date, traditional indices of traumatic brain injury (TBI) severity have not predicted reliably persisting fatigue (up to three years post-injury). This study aimed to establish whether persisting fatigue is predicted by serum biomarker concentrations in child TBI. We examined whether acute serum biomarker expression would improve prediction models of 12-month fatigue based on injury severity. Blood samples were collected from 87 children (1-17 years at injury) sustaining mild to severe TBI (Glasgow Coma Scale [GCS] range 3-15; mean 12.43; classified as mild TBI [n = 50, 57%] vs. moderate/severe TBI [n = 37, 43%]), and presenting to the emergency departments (ED) and pediatric intensive care units (PICU) at one of three tertiary pediatric hospitals (Royal Children's Hospital (RCH); Hospital for Sick Children (HSC), Toronto; St Justine Children's Hospital (SJH), Montreal). Six serum biomarker concentrations were measured within 24 h of injury (interleukin-6, interleukin-8 [IL-8], soluble vascular cell adhesion molecule [SVCAM], S100 calcium binding protein B [S100B], neuron specific enolase [NSE], and soluble neural cell adhesion molecule [sNCAM]). Fatigue at 12 months post-injury was measured using the Pediatric Quality of Life Inventory Multidimensional Fatigue Scale (parent report), classified as present/absent using previously derived cut-points. At 12 months post-injury, 22% of participants experienced fatigue. A model including IL-8 was the best serum biomarker for estimating the probability of children experiencing fatigue at 12 months post-injury. The IL-8 also significantly improved predictive models of fatigue based on severity.

Latent Class Analysis to Classify Injury Severity in Pediatric Traumatic Brain Injury

Heterogeneity of injury severity among children with traumatic brain injury (TBI) classified by the Glasgow Coma Scale (GCS) makes comparisons across research cohorts, enrollment in clinical trials, and clinical predictions of outcomes difficult. The present study uses latent class analysis (LCA) to distinguish severity subgroups from a prospective cohort of 433 children 2.5-15 years of age with TBI who were recruited from two level 1 pediatric trauma centers. Indicator variables available within 48 h post-injury including emergency department (ED) GCS, hospital motor GCS, Abbreviated Injury Score (AIS), Rotterdam Score, hypotension in the ED, and pre-hospital loss of consciousness, intubation, seizures, and sedation were evaluated to define subgroups. To understand whether latent class subgroups were predictive of clinically meaningful outcomes, the Pediatric Injury Functional Outcome Scale (PIFOS) at 6 and 12 months, and the Behavior Rating Inventory of Executive Function at 12 months, were compared across subgroups. Then, outcomes were examined by GCS (primary) and AIS (secondary) classification alone to assess whether LCA provided improved outcome prediction. LCA identified four distinct increasing severity subgroups (1-4). Unlike GCS classification, mean outcome differences on PIFOS at 6 months showed decreasing function across classes. PIFOS differences relative to the lowest latent class (LC1) were: LC2 2.27 (0.83, 3.72), LC3 3.99 (1.88, 6.10), and LC4 11.2 (7.04, 15.4). Differences in 12 month outcomes were seen between the most and least severely injured groups. Differences in outcomes in relation to AIS were restricted to the most and less severely injured at both time points. This study distinguished four latent classes that are clinically meaningful, distinguished a more homogenous severe injury group, and separated children by 6-month functional outcomes better than GCS alone. Systematic reporting of these variables would allow comparisons across research cohorts, potentially improve clinical predictions, and increase sensitivity to treatment effects in clinical trials.

Ability of the PILOT score to predict 6-month functional outcome in pediatric patients with moderate-severe traumatic brain injury

PURPOSE

To assess the Pediatric Intensity Level of Therapy (PILOT) score alone and in combination with Emergency Department (ED) GCS and Rotterdam score of initial head CT to predict functional outcomes in children with traumatic brain injury (TBI).

METHODS

Children (n=108) aged 31months-15years with moderate to severe TBI were prospectively enrolled at two sites. The ability of PILOT, ED GCS, and Rotterdam scores to predict the 6-month Pediatric Injury Functional Outcome Scale (PIFOS) was evaluated using multivariable regression models with enrollment site, age, and sex as covariates.

RESULTS

PILOT total (sum) score was more predictive of PIFOS (R²=0.23) compared to mean (R² = 0.20) or peak daily PILOT scores (R²=0.11). PILOT total score predicted PIFOS better than ED GCS (R²=0.01) or Rotterdam score (R²=0.06) and was similar to PILOT, ED GCS, and Rotterdam score combined. PILOT total score performed better in patients with intracranial pressure monitors (n=30, R²=0.28, slope=0.30) than without (n=78, R²=0.09, slope=0.36).

CONCLUSIONS

The PILOT score correlated moderately with functional outcome following TBI and outperformed other common predictors. PILOT may be a useful predictor or moderator of functional outcomes.

LEVEL OF EVIDENCE

Prognosis study, Level II.

Cumulative Influence of Inflammatory Response Genetic Variation on Long-Term Neurobehavioral Outcomes after Pediatric Traumatic Brain Injury Relative to Orthopedic Injury: An Exploratory Polygenic Risk Score

The addition of genetic factors to prognostic models of neurobehavioral recovery following pediatric traumatic brain injury (TBI) may account for unexplained heterogeneity in outcomes. The present study examined the cumulative influence of candidate genes involved in the inflammatory response on long-term neurobehavioral recovery in children with early childhood TBI relative to children with orthopedic injuries (OI). Participants were drawn from a prospective, longitudinal study evaluating outcomes of children who sustained TBI (n = 67) or OI (n = 68) between the ages of 3 and 7 years. Parents completed ratings of child executive function and behavior at an average of 6.8 years after injury. Exploratory unweighted and weighted polygenic risk scores (PRS) were constructed from single nucleotide polymorphisms (SNPs) across candidate inflammatory response genes (i.e., angiotensin converting enzyme [ACE], brain-derived neurotrophic factor [BDNF], interleukin-1 receptor antagonist [IL1RN], and 5'-ectonucleotidase [NT5E]) that showed nominal (p ≤ 0.20) associations with outcomes in the TBI group. Linear regression models tested the PRS × injury group (TBI vs. OI) interaction term and post-hoc analyses examined the effect of PRS within each injury group. Higher inflammatory response PRS were associated with more executive dysfunction and behavior problems in children with TBI but not in children with OI. The cumulative influence of inflammatory response genes as measured by PRS explained additional variance in long-term neurobehavioral outcomes, over and above well-established predictors and single candidate SNPs tested individually. The results suggest that some of the unexplained heterogeneity in long-term neurobehavioral outcomes following pediatric TBI may be attributable to a child's genetic predisposition to a greater or lesser inflammatory response to TBI.

Functional outcome after severe childhood traumatic brain injury: Results of the TGE prospective longitudinal study

BACKGROUND

Childhood severe traumatic brain injury (TBI) is a leading cause of long-lasting acquired disability, but little is known about functional outcome.

OBJECTIVE

We aimed to 1) study clinical recovery and functional outcome over 24 months after severe childhood TBI, 2) identify early sociodemographic and severity factors influencing outcome, and 3) examine the clinical utility of the Pediatric Injury Functional Outcome Scale (PIFOS) to assess functional outcome.

METHODS

Children (0-15 years) consecutively admitted in a trauma centre after accidental severe TBI over 3 years were included in a prospective longitudinal study (Traumatisme Grave de l'Enfant cohort). We measured clinical/neurological recovery, functional status (Pediatric Injury Functional Outcome Scale, [PIFOS]), overall disability (pediatric Glasgow Outcome Scale [GOS-Peds]) as well as intellectual ability (Wechsler scales) and educational outcome (mainstream school vs special education) of survivors at 1, 3, 12 and 24 months post-injury.

RESULTS

For 45 children (aged 3 to 15 years at injury), functional impairments were severe within the first 3 months. Despite the initial rapid clinical recovery and significant improvement over the first year, substantial alterations persisted for most children at 12 months post-TBI, with no significant improvement up to 2 years. Up to 80% of children still had moderate or severe overall disability (GOS-Peds) at 24 months. The severity of functional impairments (PIFOS) at 12 and 24 months was mostly related to socio-emotional, cognitive and physical impairments, and was significantly correlated with clinical/neurological deficits and cognitive (intellectual, executive) and behavioural disorders. Initial TBI severity was the main prognostic factor associated with functional status over the first 2 years post-injury.

CONCLUSIONS

Our results confirm the significant impact of severe childhood TBI on short- and medium-term functional outcomes and overall disability. All patients should benefit from systematic follow-up. The PIFOS appeared to be an accurate and reliable tool to assess functional impairment evolution and clinically meaningful outcomes over the first 2 years post-injury.

Early predictors of perinatal brain damage: the role of neurobiomarkers

The early detection of perinatal brain damage in preterm and term newborns (i.e. intraventricular hemorrhage, periventricular leukomalacia and perinatal asphyxia) still constitute an unsolved issue. To date, despite technological improvement in standard perinatal monitoring procedures, decreasing the incidence of perinatal mortality, the perinatal morbidity pattern has a flat trend. Against this background, the measurement of brain constituents could be particularly useful in the early detection of cases at risk for short-/long-term brain injury. On this scenario, the main European and US international health-care institutions promoted perinatal clinical and experimental neuroprotection research projects aimed at validating and including a panel of biomarkers in the clinical guidelines. Although this is a promising attempt, there are several limitations that do not allow biomarkers to be included in standard monitoring procedures. The main limitations are: (i) the heterogeneity of neurological complications in the perinatal period, (ii) the small cohort sizes, (iii) the lack of multicenter investigations, (iv) the different techniques for neurobiomarkers assessment, (iv) the lack of consensus for the validation of assays in biological fluids such as urine and saliva, and (v), the lack of reference curves according to measurement technique and biological fluid. In the present review we offer an up-to-date overview of the most promising developments in the use of biomarkers in the perinatal period such as calcium binding proteins (S100B protein), vasoactive agents (adrenomedullin), brain biomarkers (activin A, neuron specific enolase, glial fibrillary acidic protein, ubiquitin carboxyl-terminal hydrolase-L1) and oxidative stress markers.

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.

Best Practices for Obtaining Genomic Consent in Pediatric Traumatic Brain Injury Research

BACKGROUND

Precision health relies on large sample sizes to ensure adequate power, generalizability, and replicability; however, a critical first step to any study is the successful recruitment of participants.

OBJECTIVES

This study seeks to explore how the enrollment strategies used in a parent study contributed to the high consent rates, establish current best practices that can be used in future studies, and identify additional factors that contribute to consent into pediatric traumatic brain injury biobanks.

METHODS

Retrospective secondary analysis of data from a parent study with high consent rates was examined to explore factors affecting consent into biobanking studies.

RESULTS

Of the 76 subjects who were approached, met the eligibility criteria, and reviewed the consent form, only 16 (21.1%) declined to participate. The consented group (n = 60) represents 64.5% of those who met the eligibility criteria upon initial screening (n = 93) and 78.9% of those with confirmed eligibility (n = 76). Analysis of screening data suggested there were no major barriers to consenting individuals into this pediatric traumatic brain injury biobank.

DISCUSSION

There were no demographic or research-related characteristics that significantly explained enrollment. Ethically, to obtain true informed consent, parents need to understand only their child's diagnosis, prognosis, and medical care, as well as the purpose of the proposed research and its risks and benefits. Researchers need to implement best practices, including a comprehensive review of census data to identify eligible participants to approach, a prescreening protocol, and effective consenting process to obtain informed consent so that precision care initiatives can be pursued.

Derivation of a Three Biomarker Panel to Improve Diagnosis in Patients with Mild Traumatic Brain Injury

Background

Nearly 5 million emergency department (ED) visits for head injury occur each year in the United States, of which <10% of patients show abnormal computed tomography (CT) findings. CT negative patients frequently suffer protracted somatic, behavioral, and neurocognitive dysfunction. Our goal was to evaluate biomarkers to identify mild TBI (mTBI) in patients with suspected head injury.

Methods

An observational ED study of head-injured and control patients was conducted at Johns Hopkins University (HeadSMART). Head CT was obtained (ACEP criteria) in patients with Glasgow Coma Scale scores of 13–15 and aged 18–80. Three candidate biomarker proteins, neurogranin (NRGN), neuron-specific enolase (NSE), and metallothionein 3 (MT3), were evaluated by immunoassay (samples <24 h from injury). American Congress of Rehabilitation Medicine (ACRM) criteria were used for diagnosis of mTBI patients for model building. Univariate analysis, logistic regression, and random forest (RF) algorithms were used for data analysis in R. Overall, 662 patients were studied. Statistical models were built using 328 healthy controls and 179 mTBI patients.

Results

Median time from injury was 5.9 h (IQR, 4.0; range 0.8–24 h). mTBI patients had elevated NSE, but decreased MT3 versus controls (p < 0.01 for each). NRGN was also elevated but within 2–6 h after injury. In the derivation set, the best model to distinguish mTBI from healthy controls used three markers, age, and sex as covariates (C-statistic = 0.91, sensitivity 98%, specificity 72%). Panel test accuracy was validated with the 155 remaining ACRM+ mTBI patients. Applying the RF model to the ACRM+ mTBI validation set resulted in 78% correctly classified as mTBI (119/153). CT positive and CT negative validation subsets were 91% and 75% correctly classified. In samples taken <2 h from injury, 100% (10/10) samples classified correctly, indicating that hyperacute testing is possible with these biomarker assays. The model accuracy varied from 72–100% overall, and had greater accuracy with increasing severity, as shown by comparing CT+ with CT− (91% versus 75%), and Injury Severity Score ≥16 versus <16 (88% versus 72%, respectively). Objective blood tests, detecting NRGN, NSE, and MT3, can be used to identify mTBI, irrespective of neuroimaging findings.