S-100B in serum and urine after traumatic head injury in children. ACTA ACUST UNITED AC. 2010;69:284-289. [PMID: 20734463 DOI: 10.1097/ta.0b013e3181ca060b]

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.

Features of urine S100B and its ability to rule out intracranial hemorrhage in patients with head trauma: a prospective trial

Purpose

Traumatic brain injury causes morbidity and mortality worldwide. S100B is the most documented emergency brain biomarker and its urine-assay might be advantageous because of easier sampling. The primary aim was to evaluate urine S100B’s ability to rule out intracranial hemorrhage. Secondary aims included S100B temporal pattern for 48 h post-trauma and chemical properties of urine that affect urine S100B.

Methods

Patients with head trauma were sampled for serum and urine S100B. Patients who were admitted for intracranial hemorrhage were sampled for 48 h to assess S100B-level, renal function, urine-pH, etc.

Results

The negative predictive value of serum S100B was 97.0% [95% confidence interval (CI) 89.5–99.2%] and that of urine S100B was 89.1% (95% CI 85.5–91.9%). The specificity of serum S100B was 34.4% (95% CI 27.7–41.6%) and that of urine was 67.1% (95% CI 59.4–74.1%). Urine-pH correlated strongly with urine S100B during the first 6-h post-trauma. Trend-analysis of receiver operator characteristics of S100B in serum, urine the arithmetic difference between serum and urine S100B showed the largest area under the curve for arithmetic difference, which had a negative predictive value of 93.1% (95% CI 89.1–95.8%) and a specificity of 71.8% (95% CI 64.4–78.4%).

Conclusion

This study cannot support ruling out intracranial hemorrhage with urine S100B. Urine-pH might affect urine S100B and merits further studies. Serum and urine S100B have poor concordance and interchangeability. The arithmetic difference had a slightly better area under the curve and can be worth exploring in certain subgroups.

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.

Detection of S-100β Protein in Plasma and Urine After a Mild Traumatic Brain Injury

This study assessed whether S-100β protein could be measured in urine when detectable in plasma after a mild traumatic brain injury (mTBI). Clinical data, plasma and urine samples were collected for the 46 adult patients prospectively enrolled in the emergency department (ED) of a Level 1 trauma center. S-100β protein concentrations were analysed using ELISA. S-100β protein was detectable in 91% and 71% of plasma and urine samples, but values were not correlated (r = 0.002). Urine sampling would have been a non-invasive procedure, but it does not appear to be useful in the ED during the acute phase after an mTBI.

Colonic electrical stimulation promotes colonic motility through regeneration of myenteric plexus neurons in slow transit constipation beagles

Slow transit constipation (STC) is a common disease characterized by markedly delayed colonic transit time as a result of colonic motility dysfunction. It is well established that STC is mostly caused by disorders of relevant nerves, especially the enteric nervous system (ENS). Colonic electrical stimulation (CES) has been regarded as a valuable alternative for the treatment of STC. However, little report focuses on the underlying nervous mechanism to normalize the delayed colonic emptying and relieve symptoms. In the present study, the therapeutic effect and the influence on ENS triggered by CES were investigated in STC beagles. The STC beagle model was established by oral administration of diphenoxylate/atropine and alosetron. Histopathology, electron microscopy, immunohistochemistry, Western blot analysis and immunofluorescence were used to evaluate the influence of pulse train CES on myenteric plexus neurons. After 5 weeks of treatment, CES could enhance the colonic electromyogram (EMG) signal to promote colonic motility, thereby improving the colonic content emptying of STC beagles. HE staining and transmission electron microscopy confirmed that CES could regenerate ganglia and synaptic vesicles in the myenteric plexus. Immunohistochemical staining showed that synaptophysin (SYP), protein gene product 9.5 (PGP9.5), cathepsin D (CAD) and S-100B in the colonic intramuscular layer were up-regulated by CES. Western blot analysis and immunofluorescence further proved that CES induced the protein expression of SYP and PGP9.5. Taken together, pulse train CES could induce the regeneration of myenteric plexus neurons, thereby promoting the colonic motility in STC beagles.

Biochemical changes in the injured brain

Brain metabolism is an energy intensive phenomenon involving a wide spectrum of chemical intermediaries. Various injury states have a detrimental effect on the biochemical processes involved in the homeostatic and electrophysiological properties of the brain. The biochemical markers of brain injury are a recent addition in the armamentarium of neuro-clinicians and are being increasingly used in the routine management of neuro-pathological entities such as traumatic brain injury, stroke, subarachnoid haemorrhage and intracranial space occupying lesions. These markers are increasingly being used in assessing severity as well as in predicting the prognostic course of neuro-pathological lesions. S-100 protein, neuron specific enolase, creatinine phosphokinase isoenzyme BB and myelin basic protein are some of the biochemical markers which have been proven to have prognostic and clinical value in the brain injury. While S-100, glial fibrillary acidic protein and ubiquitin C terminal hydrolase are early biomarkers of neuronal injury and have the potential to aid in clinical decision-making in the initial management of patients presenting with an acute neuronal crisis, the other biomarkers are of value in predicting long-term complications and prognosis in such patients. In recent times cerebral microdialysis has established itself as a novel way of monitoring brain tissue biochemical metabolites such as glucose, lactate, pyruvate, glutamate and glycerol while small non-coding RNAs have presented themselves as potential markers of brain injury for future.

Sports-related brain injuries: connecting pathology to diagnosis

Brain injuries are becoming increasingly common in athletes and represent an important diagnostic challenge. Early detection and management of brain injuries in sports are of utmost importance in preventing chronic neurological and psychiatric decline. These types of injuries incurred during sports are referred to as mild traumatic brain injuries, which represent a heterogeneous spectrum of disease. The most dramatic manifestation of chronic mild traumatic brain injuries is termed chronic traumatic encephalopathy, which is associated with profound neuropsychiatric deficits. Because chronic traumatic encephalopathy can only be diagnosed by postmortem examination, new diagnostic methodologies are needed for early detection and amelioration of disease burden. This review examines the pathology driving changes in athletes participating in high-impact sports and how this understanding can lead to innovations in neuroimaging and biomarker discovery.

Scandinavian guidelines for initial management of minor and moderate head trauma in children

BACKGROUND

The management of minor and moderate head trauma in children differs widely between countries. Presently, there are no existing guidelines for management of these children in Scandinavia. The purpose of this study was to produce new evidence-based guidelines for the initial management of head trauma in the paediatric population in Scandinavia. The primary aim was to detect all children in need of neurosurgical intervention. Detection of any traumatic intracranial injury on CT scan was an important secondary aim.

METHODS

General methodology according to the Appraisal of Guidelines for Research and Evaluation (AGREE) II and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was used. Systematic evidence-based review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology and based upon relevant clinical questions with respect to patient-important outcomes. Quality ratings of the included studies were performed using Quality Assessment of Diagnostic Accuracy Studies (QUADAS)-2 and Centre of Evidence Based Medicine (CEBM)-2 tools. Based upon the results, GRADE recommendations, a guideline, discharge instructions and in-hospital observation instructions were drafted. For elements with low evidence, a modified Delphi process was used for consensus, which included relevant clinical stakeholders.

RESULTS

The guidelines include criteria for selecting children for CT scans, in-hospital observation or early discharge, and suggestions for monitoring routines and discharge advice for children and guardians. The guidelines separate mild head trauma patients into high-, medium- and low-risk categories, favouring observation for mild, low-risk patients as an attempt to reduce CT scans in children.

CONCLUSIONS

We present new evidence and consensus based Scandinavian Neurotrauma Committee guidelines for initial management of minor and moderate head trauma in children. These guidelines should be validated before extensive clinical use and updated within four years due to rapid development of new diagnostic tools within paediatric neurotrauma.

Current status of fluid biomarkers in mild traumatic brain injury

Mild traumatic brain injury (mTBI) affects millions of people annually and is difficult to diagnose. Mild injury is insensitive to conventional imaging techniques and diagnoses are often made using subjective criteria such as self-reported symptoms. Many people who sustain a mTBI develop persistent post-concussive symptoms. Athletes and military personnel are at great risk for repeat injury which can result in second impact syndrome or chronic traumatic encephalopathy. An objective and quantifiable measure, such as a serum biomarker, is needed to aid in mTBI diagnosis, prognosis, return to play/duty assessments, and would further elucidate mTBI pathophysiology. The majority of TBI biomarker research focuses on severe TBI with few studies specific to mild injury. Most studies use a hypothesis-driven approach, screening biofluids for markers known to be associated with TBI pathophysiology. This approach has yielded limited success in identifying markers that can be used clinically, additional candidate biomarkers are needed. Innovative and unbiased methods such as proteomics, microRNA arrays, urinary screens, autoantibody identification and phage display would complement more traditional approaches to aid in the discovery of novel mTBI biomarkers.

Diagnostic performance of S100B protein serum measurement in detecting intracranial injury in children with mild head trauma

OBJECTIVE

To assess the accuracy of S100B serum level to detect intracranial injury in children with mild traumatic brain injury.

METHODS

A multicenter prospective cohort study was carried out in the paediatric emergency departments of three tertiary hospitals in Switzerland between January 2009 and December 2011. Participants included children aged <16 years with a mild traumatic brain injury (GCS ≥13) for whom a head CT was requested by the attending physician. Venous blood was obtained within 6 h of the trauma in all children for S100B measurement before a head CT was performed. As the S100B value was not available during the acute care period, the patient's management was not altered. The main measures were protein S100B value and the CT result.

RESULTS

20/73 (27.4%) included children had an intracranial injury detected on CT. S100B receiver operating characteristics area under the curve was 0.73 (95% CI 0.60 to 0.86). With a 0.14 µg/L cut-off point, S100B reached an excellent sensitivity of 95% (95% CI 77% to 100%) and 100% (95% CI 81% to 100%) in all children and in children aged >2 years, respectively. The specificity, however, was 34% (95% CI 27% to 36%) and 37% (95% CI 30% to 37%), respectively.

CONCLUSIONS

S100B has an excellent sensitivity but poor specificity. It is therefore an accurate tool to help rule out an intracranial injury but cannot be used as the sole marker owing to its specificity. Used with clinical decision rules, S100B may help to reduce the number of unnecessary CT scans.

Minor and repetitive head injury

Traumatic brain injury (TBI) is the leading cause of death and disability in the young, active population and expected to be the third leading cause of death in the whole world until 2020. The disease is frequently referred to as the silent epidemic, and many authors highlight the "unmet medical need" associated with TBI.The term traumatically evoked brain injury covers a heterogeneous group ranging from mild/minor/minimal to severe/non-salvageable damages. Severe TBI has long been recognized to be a major socioeconomical health-care issue as saving young lives and sometimes entirely restituting health with a timely intervention can indeed be extremely cost efficient.Recently it has been recognized that mild or minor TBI should be considered similarly important because of the magnitude of the patient population affected. Other reasons behind this recognition are the association of mild head injury with transient cognitive disturbances as well as long-term sequelae primarily linked to repeat (sport-related) injuries.The incidence of TBI in developed countries can be as high as 2-300/100,000 inhabitants; however, if we consider the injury pyramid, it turns out that severe and moderate TBI represents only 25-30 % of all cases, while the overwhelming majority of TBI cases consists of mild head injury. On top of that, or at the base of the pyramid, are the cases that never show up at the ER - the unreported injuries.Special attention is turned to mild TBI as in recent military conflicts it is recognized as "signature injury."This chapter aims to summarize the most important features of mild and repetitive traumatic brain injury providing definitions, stratifications, and triage options while also focusing on contemporary knowledge gathered by imaging and biomarker research.Mild traumatic brain injury is an enigmatic lesion; the classification, significance, and its consequences are all far less defined and explored than in more severe forms of brain injury.Understanding the pathobiology and pathomechanisms may aid a more targeted approach in triage as well as selection of cases with possible late complications while also identifying the target patient population where preventive measures and therapeutic tools should be applied in an attempt to avoid secondary brain injury and late complications.

The challenge of mild traumatic brain injury: role of biochemical markers in diagnosis of brain damage

During the past decade there has been an increasing recognition of the incidence of mild traumatic brain injury (mTBI) and a better understanding of the subtle neurological and cognitive deficits that may result from it. A substantial, albeit suboptimal, effort has been made to define diagnostic criteria for mTBI and improve diagnostic accuracy. Thus, biomarkers that can accurately and objectively detect brain injury after mTBI and, ideally, aid in clinical management are needed. In this review, we discuss the current research on serum biomarkers for mTBI including their rationale and diagnostic performances. Sensitive and specific biomarkers reflecting brain injury can provide important information regarding TBI pathophysiology and serve as candidate markers for predicting abnormal computed tomography findings and/or the development of residual deficits in patients who sustain an mTBI. We also outline the roles of biomarkers in settings of specific interest including pediatric TBI, sports concussions and military injuries, and provide perspectives on the validation of such markers for use in the clinic. Finally, emerging proteomics-based strategies for identifying novel markers will be discussed.

[Home falls in infants before walking acquisition]

Minor head trauma is frequent among infants and leads to numerous visits to emergency departments for neurological assessment to evaluate the value of cerebral CT scan with the risk for traumatic brain injuries (TBI).

OBJECTIVES

To analyze the epidemiological characteristics of nonwalking infants admitted after falling at home and to analyze associated factors for skull fractures and TBI.

PATIENTS AND METHODS

Between January 2007 and December 2011, all children aged 9 months or younger and admitted after a home fall to the pediatric emergency unit of a tertiary children's hospital were included. The data collected were age, sex, weight and height, body mass index; geographic origin, referral or direct admission, mode of transportation; month, day and time of admission; causes of the fall, alleged fall height, presence of an eyewitness, type of landing surface; Glasgow Coma Scale (GCS) score, application of the head trauma protocol, location and type of injuries, cerebral CT scan results, length of hospital stay, progression, and neglect or abuse situations.

RESULTS

DESCRIPTIVE ANALYSIS: within the study period, 1910 infants were included. Fifty-four percent of children were aged less than 6 months with a slight male prevalence (52%). Falls from parental bed and infant carriers accounted for the most frequent fall circumstances. GCS score on admission was equal to 14 or 15 in 99% of cases. A cerebral CT scan was performed in 34% of children and detected 104 skull fractures and 55 TBI. Infants aged less than 1 month had the highest rate of TBI (8.5%). Eleven percent of patients were hospitalized. A situation of abuse was identified in 51 infants (3%). UNIVARIATE ANALYSIS: Male children and infants aged less than 3 months had a higher risk of skull fractures (P = 0.03 and P = 0.0003, respectively). In the TBI group, children were younger (3.8 ± 2.6 months versus 5.4 ± 2.5 months, P < 0.0001), fell from a higher height (90.2 ± 29.5 cm versus 70.9 ± 28.7 cm, P < 0.0001), were more often admitted on a weekend or day off, and had more skull fractures (54% versus 6%, P < 0.001). MULTIVARIATE ANALYSIS: all variables showing P < 0.2 in the univariate analysis were entered into the model. In the final model, three variables continued to be associated with a risk of TBI: being referred by a physician (OR 4.6 [2.2-9.6], P < 0.0001), being younger than 3 months old (OR 3.1 [1.7-5.7], P = 0.0002), falling from a height greater than 90 cm (OR 3.1 [1.7-5.6], P = 0.0002).

COMMENTS

Before walking acquisition, children are particularly vulnerable and have the highest rate of TBI after a vertical fall. In this age group, the rate of abuse is also higher. Given this double risk, numerous cerebral CT scans are performed (35-40% of the target population). This protocol, however, leads to a low proportion of detected TBI (<10%) compared to the high number of CT scans and an additional risk of irradiation.

CONCLUSION

As no validated predictive score exists and pending the contribution of the S-100B protein assay, the identification of infants at high risk for TBI and justifying neuroimaging is based on the search for predisposing factors and circumstances.

Serum S100B Determination in the Management of Pediatric Mild Traumatic Brain Injury

BACKGROUND

The place of serum S100B measurement in mild traumatic brain injury (mTBI) management is still controversial. Our prospective study aimed to evaluate its utility in the largest child cohort described to date.

METHODS

Children younger than 16 years presenting at a pediatric emergency department within 3 h after TBI were enrolled prospectively for blood sampling to determine serum S100B concentrations. The following information was collected: TBI severity determined by using the Masters classification [1: minimal or Glasgow Coma Scale (GCS) 15, 2: mild or GCS 13–15, and 3: severe or GCS &lt;13]; whether hospitalized or not; good or bad clinical evolution (CE); whether cranial computed tomography (CCT) was prescribed; and related presence (CCT+) or absence (CCT−) of lesions.

RESULTS

For the 446 children enrolled, the median concentrations of S100B were 0.21, 0.31, and 0.44 μg/L in Masters groups 1, 2, and 3, respectively, with a statistically significant difference between these groups (P &lt; 0.05). In Masters group 2, 65 CCT scans were carried out. Measurement of S100B identified patients as CCT+ with 100% (95% CI 85–100) sensitivity and 33% (95% CI 20–50) specificity. Of the 424 children scored Masters 1 or 2, 21 presented “bad CE.” S100B identified bad CE patients with 100% (95% CI 84–100) sensitivity and 36% (95% CI 31–41) specificity. Of the 242 children hospitalized, 81 presented an S100B concentration within the reference interval.

CONCLUSIONS

Serum S100B determination during the first 3 h of management of children with mTBI has the potential to reduce the number of CCT scans, thereby avoiding unnecessary irradiation, and to save hospitalization costs.

Pediatric head trauma

Head injury in children accounts for a large number of emergency department visits and hospital admissions. Falls are the most common type of injury, followed by motor-vehicle-related accidents. In the present study, we discuss the evaluation, neuroimaging and management of children with head trauma. Furthermore, we present the specific characteristics of each type of pediatric head injury.