Head injury outcome prediction in the emergency department: a role for protein S-100B?

Key Findings on Computed Tomography of the Head that Predict Death or the Need for Neurosurgical Intervention From Traumatic Brain Injury

BACKGROUND

Traumatic brain injury (TBI) requires rapid management to avoid secondary injury or death. This study evaluated if a simple schema for quickly interpreting CT head (CTH) imaging by trauma surgeons and trainees could be validated to predict need for neurosurgical intervention (NSI) or death from TBI within 24 hours.

METHODS

We retrospectively reviewed TBI patients presenting to our trauma center in 2020 with blunt mechanism and GCS ≤ 12. Primary independent variables were presence of 7 normal findings on CTH (CSF at foramen magnum, open fourth ventricle, CSF around quadrigeminal plate, CSF around cerebral peduncles, absence of midline shift, visible sulci/gyri, and gray-white differentiation). Trauma surgeons and trainees separately evaluated each patient's CTH, scoring findings as normal or abnormal. Primary outcome was NSI/death in 24 hours.

RESULTS

Our population consisted of 444 patients; 21.4% received NSI or died within 24 hours. By trainees' interpretation, 5.8% of patients without abnormal findings had NSI/death vs 52.0% of patients with ≥1 abnormality; attending interpretation was 8.7% and 54.9%, respectively (P < .001). Sulci/gyri effacement, midline shift, and cerebral peduncle effacement maximized sensitivity and specificity for predicting NSI/death. Considering pooled results, when ≥1 of those 3 findings was abnormal, sensitivity was 77.89%, specificity was 80.80%, positive predictive value was 52.48%, and negative predictive value was 93.07%.

DISCUSSION

Any single abnormality in this schema significantly predicted a large increase in NSI/death in 24 hours in TBI patients, and three particular findings were most predictive. This schema may help predict need for intervention and expedite management of moderate/severe TBI.

Neurodevelopmental outcomes in congenital heart disease: Usefulness of biomarkers of brain injury

INTRODUCTION

At present, neurodevelopmental abnormalities are the most frequent type of complication in school-aged children with congenital heart disease (CHD). We analysed the incidence of acute neurologic events (ANEs) in patients with operated CHD and the usefulness of neuromarkers for the prediction of neurodevelopment outcomes.

METHODS

Prospective observational study in infants with a prenatal diagnosis of CHD who underwent cardiac surgery in the first year of life. We assessed the following variables: (1) serum biomarkers of brain injury (S100B, neuron-specific enolase) in cord blood and preoperative blood samples; (2) clinical and laboratory data from the immediate postnatal and perioperative periods; (3) treatments and complications; (4) neurodevelopment (Bayley-III scale) at age 2 years.

RESULTS

the study included 84 infants with a prenatal diagnosis of CHD who underwent cardiac surgery in the first year of life. Seventeen had univentricular heart, 20 left ventricular outflow obstruction and 10 genetic syndromes. The postoperative mortality was 5.9% (5/84) and 10.7% (9/84) patients experienced ANEs. The mean overall Bayley-III scores were within the normal range, but 31% of patients had abnormal scores in the cognitive, motor or language domains. Patients with genetic syndromes, ANEs and univentricular heart had poorer neurodevelopmental outcomes. Elevation of S100B in the immediate postoperative period was associated with poorer scores.

CONCLUSIONS

children with a history of cardiac surgery for CHD in the first year of life are at risk of adverse neurodevelopmental outcomes. Patients with genetic syndromes, ANEs or univentricular heart had poorer outcomes. Postoperative ANEs may contribute to poorer outcomes. Elevation of S100B levels in the postoperative period was associated with poorer neurodevelopmental outcomes at 2 years. Studies with larger samples and longer follow-ups are needed to define the role of these biomarkers of brain injury in the prediction of neurodevelopmental outcomes in patients who undergo surgery for management of CHD.

Increased serum peripheral C-reactive protein is associated with reduced brain barriers permeability of TSPO radioligands in healthy volunteers and depressed patients: implications for inflammation and depression

The relationship between peripheral and central immunity and how these ultimately may cause depressed behaviour has been the focus of a number of imaging studies conducted with Positron Emission Tomography (PET). These studies aimed at testing the immune-mediated model of depression that proposes a direct effect of peripheral cytokines and immune cells on the brain to elicit a neuroinflammatory response via a leaky blood-brain barrier and ultimately depressive behaviour. However, studies conducted so far using PET radioligands targeting the neuroinflammatory marker 18 kDa translocator protein (TSPO) in patient cohorts with depression have demonstrated mild inflammatory brain status but no correlation between central and peripheral immunity. To gain a better insight into the relationship between heightened peripheral immunity and neuroinflammation, we estimated blood-to-brain and blood-to-CSF perfusion rates for two TSPO radiotracers collected in two separate studies, one large cross-sectional study of neuroinflammation in normal and depressed cohorts (N = 51 patients and N = 25 controls) and a second study where peripheral inflammation in N = 7 healthy controls was induced via subcutaneous injection of interferon (IFN)-α. In both studies we observed a consistent negative association between peripheral inflammation, measured with c-reactive protein P (CRP), and radiotracer perfusion into and from the brain parenchyma and CSF. Importantly, there was no association of this effect with the marker of BBB leakage S100β, that was unchanged. These results suggest a different model of peripheral-to-central immunity interaction whereas peripheral inflammation may cause a reduction in BBB permeability. This effect, on the long term, is likely to disrupt brain homeostasis and induce depressive behavioural symptoms.

PET imaging shows no changes in TSPO brain density after IFN-α immune challenge in healthy human volunteers

Depression is associated with peripheral inflammation, but its link with brain microglial activity remains unclear. In seven healthy males, we used repeated translocator protein-Positron Emission Tomography (TSPO-PET) dynamic scans with [11C]PBR28 to image brain microglial activation before and 24 h after the immune challenge interferon (IFN)-α. We also investigated the association between changes in peripheral inflammation, changes in microglial activity, and changes in mood. IFN-α administration decreased [11C]PBR28 PET tissue volume of distribution (Vt) across the brain (-20 ± 4%; t6 = 4.1, p = 0.01), but after correction for radioligand free-plasma fraction there were no longer any changes (+23 ± 31%; t = 0.1, p = 0.91). IFN-α increased serum IL-6 (1826 ± 513%, t6 = -7.5, p < 0.001), IL-7 (39 ± 12%, t6 = -3.6, p = 0.01), IL-10 (328 ± 48%, t6 = -12.8, p < 0.001), and IFN-γ (272 ± 64%, t6 = -7.0, p < 0.001) at 4-6 h, and increased serum TNF-α (49 ± 7.6%, t6 = -7.5, p < 0.001), IL-8 (39 ± 12%, t6 = -3.5, p = 0.013), and C-reactive protein (1320 ± 459%, t6 = -7.2, p < 0.001) at 24 h. IFN-α induced temporary mood changes and sickness symptoms after 4-6 h, measured as an increase in POMS-2 total mood score, confusion and fatigue, and a decrease in vigor and friendliness (all p ≤ 0.04). No association was found between changes in peripheral inflammation and changes in PET or mood measures. Our work suggests that brain TSPO-PET signal is highly dependent of inflammation-induced changes in ligand binding to plasma proteins. This limits its usefulness as a sensitive marker of neuroinflammation and consequently, data interpretation. Thus, our results can be interpreted as showing either that [11C]PBR28 is not sensitive enough under these conditions, or that there is simply no microglial activation in this model.

Correlation of serum S100B levels with brain magnetic resonance imaging abnormalities in children with status epilepticus

PURPOSE

To evaluate the association between elevated S100B levels with brain tissue damage seen in abnormalities of head magnetic resonance imaging (MRI; diffusion tensor imaging [DTI] sequence) in patients with status epilepticus (SE).

METHODS

An analytical observational study was conducted in children hospitalized at Dr Soetomo Hospital, Surabaya, from July to December 2016. The patients were divided into 2 groups: SE included all children with a history of SE; control included all children with febrile seizure. Blood samples of patients were drawn within 24 hours after admission. SE patients also underwent cranial MRI with additional DTI sequencing. The Mann-Whitney test and Spearman test were used for statistical analysis.

RESULTS

Fifty-three patients were enrolled the study. In the 24 children with SE who met the inclusion criteria, serum S100B and cranial MRI findings were assessed. Twenty-two children admitted with febrile seizures became the control group. Most patients were male (66.7%); the mean age was 35.8 months (standard deviation, 31.09). Mean S100B values of the SE group (3.430±0.141 μg/L) and the control group (2.998±0.572 μg/L) were significantly different (P<0.05). A significant difference was noted among each level of encephalopathy based on the cranial MRI results with serum S100B levels and the correlation was strongly positive with a coefficient value of 0.758 (P<0.001).

CONCLUSION

In SE patients, there is an increase of serum S100B levels within 24 hours after seizure, which has a strong positive correlation with brain damage seen in head MRI and DTI.

Prognostic Value of S-100β Protein for Prediction of Post-Concussion Symptoms after a Mild Traumatic Brain Injury: Systematic Review and Meta-Analysis

This systematic review and meta-analysis aimed to determine the prognostic value of S-100β protein to identify patients with post-concussion symptoms after a mild traumatic brain injury (mTBI). A search strategy was submitted to seven databases from their inception to October 2016. Individual patient data were requested. Cohort studies evaluating the association between S-100β protein level and post-concussion symptoms assessed at least seven days after the mTBI were considered. Outcomes were dichotomized as persistent (≥3 months) or early (≥7 days <3 months). Our search strategy yielded 23,298 citations of which 29 studies including between seven and 223 patients (n = 2505) were included. Post-concussion syndrome (PCS) (16 studies) and neuropsychological symptoms (9 studies) were the most frequently assessed outcomes. The odds of having persistent PCS (odds ratio [OR] 0.62, 95% confidence interval [CI]: 0.34-1.12, p = 0.11, I² 0% [n = five studies]) in patients with an elevated S-100β protein serum level were not significantly different from those of patients with normal values while the odds of having early PCS (OR 1.67, 95% CI: 0.98-2.85, p = 0.06, I² 38% [n = five studies]) were close to statistical significance. Similarly, having an elevated S-100β protein serum level was not associated with the odds of returning to work at six months (OR 2.31, 95% CI: 0.50-10.64, p = 0.28, I² 22% [n = two studies]). Overall risk of bias was considered moderate. Results suggest that the prognostic biomarker S-100β protein has a low clinical value to identify patients at risk of persistent post-concussion symptoms. Variability in injury to S-100ß protein sample time, mTBI populations, and outcomes assessed could potentially explain the lack of association and needs further evaluation.

Characteristics of patients included and enrolled in studies on the prognostic value of serum biomarkers for prediction of postconcussion symptoms following a mild traumatic brain injury: a systematic review

OBJECTIVE

Mild traumatic brain injury (mTBI) has been insufficiently researched, and its definition remains elusive. Investigators are confronted by heterogeneity in patients, mechanism of injury and outcomes. Findings are thus often limited in generalisability and clinical application. Serum protein biomarkers are increasingly assessed to enhance prognostication of outcomes, but their translation into clinical practice has yet to be achieved. A systematic review was performed to describe the adult populations included and enrolled in studies that evaluated the prognostic value of protein biomarkers to predict postconcussion symptoms following an mTBI.

DATA SOURCES

Searches of MEDLINE, Embase, CENTRAL, CINAHL, Web of Science, PsycBITE and PsycINFO up to October 2016.

DATA SELECTION AND EXTRACTION

Two reviewers independently screened for potentially eligible studies, extracted data and assessed the overall quality of evidence by outcome using the Grading of Recommendations Assessment, Development and Evaluation approach.

RESULTS

A total of 23 298 citations were obtained from which 166 manuscripts were reviewed. Thirty-six cohort studies (2812 patients) having enrolled between 7 and 311 patients (median 89) fulfilled our inclusion criteria. Most studies excluded patients based on advanced age (n=10 (28%)), neurological disorders (n=20 (56%)), psychiatric disorders (n=17 (47%)), substance abuse disorders (n=13 (36%)) or previous traumatic brain injury (n=10 (28%)). Twenty-one studies (58%) used at least two of these exclusion criteria. The pooled mean age of included patients was 39.3 (SD 4.6) years old (34 studies). The criteria used to define a mTBI were inconsistent. The most frequently reported outcome was postconcussion syndrome using the Rivermead Post-Concussion Symptoms Questionnaire (n=18 (50%)) with follow-ups ranging from 7 days to 5 years after the mTBI.

CONCLUSIONS

Most studies have recruited samples that are not representative and generalisable to the mTBI population. These exclusion criteria limit the potential use and translation of promising serum protein biomarkers to predict postconcussion symptoms.

Evaluation of S100B blood level as a biomarker to avoid computed tomography in patients with mild head trauma under antithrombotic medication

PURPOSE

The goal of this prospective study was to analyze the potential of S100B protein as a negative predictive marker for intracranial hemorrhage (ICH) after mild head trauma (MHT) in patient under antithrombotic medication.

METHODS

Patients under antithrombotic medication who had MHT were consecutively included in this study. S100B blood levels were determined from samples drawn within 6hours after injury and were analyzed with the results of head CT performed within the 24hours after injury. Sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) of S100B levels for the detection of ICH, with a cut-off set at 0.105μg/L, were calculated.

RESULTS

A total of 308 patients (151 men and 157 women) with a mean age of 79.1±10.5years (SD) were included in the analysis. CT was positive for the presence of ICH in 33 patients (10.7%; 95% CI: 7.5-14.7%). In the study population, S100B showed a sensitivity of 84.8% (95%CI: 68.1-94.9%), a specificity of 30.2% (95% CI: 24.8-36.0%), a NPV of 94.3% (95% CI: 87.2-98.1%), and a PPV of 12.7% (95% CI: 8.6-17.9%) for the diagnosis of ICH.

CONCLUSION

The results of this study suggest that a S100B serum level<0.105μg/L has a high NPV for ICH after mild head trauma in patients under antithrombotic medication.

The Insertion of Electrodes in the Brain for Electrophysiological Recording or Chronic Stimulation Is Not Associated With Any Biochemically Detectable Neuronal Injury

OBJECTIVE

The aim of this study was to evaluate the degree of brain tissue injury that could be potentially induced by the introduction of a) microrecording electrodes, b) macrostimulation electrodes, or c) chronic stimulation electrodes. We aimed to evaluate whether the use of five simultaneous microrecording tracks is associated with any brain injury not detectable by conventional imaging such as CT or MRI.

MATERIALS AND METHODS

The study included 61 patients who underwent surgery for implantation of 121 DBS leads. In all cases, five simultaneous tracts were utilized for microelectrode recordings. All patients underwent measurements of serum S-100b at specific time points as follows: a) prior to the operation, and b) intraoperatively at specific stages of the procedure: 1) after opening the burr hole, 2) after the insertion of microrecording electrodes, 3) during macrostimulation, 4) at the end of the operation, and 5) on the first postoperative day.

RESULTS

The levels of serum S-100B protein remained within the normal range during the entire period of investigation in all patients with the exception of two cases. In both patients, the procedure was complicated by intraparenchymal hemorrhage visible in neuro-imaging. The first patient developed a small intraparenchymal hemorrhage, visible on the postoperative MRI, with no neurological deficit. The second patient experienced a focal epileptic seizure after the insertion of the right DBS chronic lead and the postoperative CT scan revealed a right frontal lobe hemorrhage.

CONCLUSION

These results strongly indicate that the insertion of either multiple recording electrodes or the implantation of chronic electrodes in DBS does not increase the risk of brain hemorrhage or of other intracranial complications, and furthermore it does not cause any biochemically detectable brain tissue damage.

Postconcussion syndrome: a review

Postconcussion syndrome is as yet a poorly understood and controversial disorder. This article reviews a range of research considering the causes, symptoms, and possible interventions for postconcussion syndrome.

Prognostic value of circulating DNA levels in critically ill and trauma patients

The number of studies investigating circulating nucleic acids as potential biomarkers has increased in recent years. The detection of such biomarkers is a minimally invasive alternative for the diagnosis and prognosis of various clinical conditions. The value of circulating DNA levels as a predictive biomarker has been demonstrated in patients suffering from numerous acute pathologies that have a high risk of intensive care needs and in-hospital deaths. The mechanism by which circulating DNA levels increase in patients with these conditions remains unclear. In this review, we focused on the potential use of this biomarker for prognosis prediction in critically ill and trauma patients. The literature review was performed by searching MedLine using PubMed in the English language.

Outcome and Predicting Factor Following Severe Traumatic Brain Injury: A Retrospective Cross-Sectional Study

INTRODUCTION

Severe traumatic brain injury (TBI) is a major and challenging problem in critical care medicine.

AIM

To assess the outcome and predicting factor following severe TBI.

MATERIALS AND METHODS

This is a retrospective and cross-sectional study. Data were collected from two sections; one section consisting of a questionnaire answered by the patients and other section from the patient records. The instruments used included the Glasgow Outcome Scale (GOS), SF-36 and the Hospital Anxiety and Depression Scale (HAD).

RESULTS

The mortality rate of the patients was 46.2%. The quality of life (QOL) of the patients in most dimension were impaired and (58%) of patients had unfavourable QOL. About (37.5%) of patients with anxiety and (27.5%) had a depression. A significant correlation was found between age, GCS arrival, length of ICU stay, mechanical ventilation, VAP & ARDS and pupil reactivity with QOL, GOS, HAD-A and HAD-D (p<0.05, p< 0.001). GCS arrival a predicate factor for QOL and GOS (p <0.001, OR: 1.75, 1.94 respectively); length of ICU stay a predicate factor for QOL and GOS (p <0.05, OR : 1.11, 1.28 respectively); mechanical ventilation a predicate factor for GOS (p <0.001, OR : 1.78); ventilation associated pneumonia (VAP) & acute respiratory distress syndrome (ARDS) and pupil reactivity a predicate factor for GOS (p <0.05, OR : 1.36; p<0.001, OR: 1.94 respectively). The GCS arrival and ICU stay a predicate factor for HAD-A (p<0.05, OR: 1.73, 1.38 respectively).

CONCLUSION

With respect to results advanced in pre hospital, medical and surgical care for the decrease in mortality rates of Head trauma (HT), the use of trauma triage tools and strict enforcement of traffic rules are necessary.

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.

Evaluation of S100B in the diagnosis of suspected intracranial hemorrhage after minor head injury in patients who are receiving platelet aggregation inhibitors and in patients 65 years of age and older

OBJECT

Cranial CT (CCT) scans and hospital admission are increasingly performed to rule out intracranial hemorrhage in patients after minor head injury (MHI), particularly in older patients and in those receiving antiplatelet therapy. This leads to high radiation exposure and a growing financial burden. The aim of this study was to determine whether the astroglial-derived protein S100B that is released into blood can be used as a reliable negative predictive tool for intracranial bleeding in patients after MHI, when they are older than 65 years or being treated with antiplatelet drugs (low-dose aspirin, clopidogrel).

METHODS

The authors conducted a prospective observational study in 2 trauma hospitals. A total of 782 patients with MHI (Glasgow Coma Scale Score 13-15) who were on medication with platelet aggregation inhibitors (PAIs) or were age 65 years and older, independent of antiplatelet therapy, were included. Clinical examination, bloodwork, observation, and CCT were performed in the traumatology emergency departments. When necessary, patients were admitted and observation took place on the ward; in these patients, CCT was performed during their hospital stay. Patients with severe trauma, focal neurological deficits, posttraumatic seizures, anticoagulant therapy, alcohol intoxication, coagulation disorder, blood sampling more than 3 hours after trauma, and unknown time of the trauma were excluded from the study. The median age of the patients was 83 years, and 69% were female. Sensitivity, specificity, and positive and negative predictive values of S100B with reference to CCT findings were calculated. The cutoff of S100B was set at 0.105 μg/L.

RESULTS

Of the 782 patients, 50 (6.4%) had intracranial bleeding. One patient with positive results on CCT scan showed an S100B level below 0.105 μg/L. Of all patients, 33.1% were below the cutoff. S100B showed a sensitivity of 98.0% (CI 89.5%-99.7%), a negative predictive value of 99.6% (CI 97.9%-99.9%), a specificity of 35.3% (CI 31.9%- 38.8%), and a positive predictive value of 9.4% (CI 7.2%-12.2%).

CONCLUSIONS

Levels of S100B below 0.105 μg/L can accurately predict normal CCT findings after MHI in older patients and in those treated with PAIs. Combining conventional decision criteria with measurement of S100B can reduce the CCT scan and hospital admission rates by approximately 30%.

Immunohistochemical investigation of S100 and NSE in cases of traumatic brain injury and its application for survival time determination

The availability of markers able to provide insight into protein changes in the central nervous system after fatal traumatic brain injury (TBI) is limited. The present study reports on the semi-quantitative assessments of the immunopositive neuroglial cells (both astrocytes and oligodendrocytes) and neurons for S100 protein (S100), as well as neuronal specific enolase (NSE), in the cerebral cortex, hippocampus, and cerebellum with regard to survival time and cause of death. Brain tissues of 47 autopsy cases with TBI (survival times ranged between several minutes and 34 d) and 10 age- and gender-matched controls (natural deaths) were examined. TBI cases were grouped according to their survival time in acute death after brain injury (ABI, n = 25), subacute death after brain injury (SBI, n = 18) and delayed death after brain injury (DBI, n = 4). There were no significant changes in the percentages of S100-stained astrocytes between TBI and control cases. The percentages of S100-positive oligodendrocytes in the pericontusional zone (PCZ) in cases with SBI were significantly lower than in controls (p < 0.05) and in the ABI group (p < 0.05). In the hippocampus, S100-positive oligodendrocytes were significantly lower in cases with ABI and SBI (both, p < 0.05), compared with controls. It is of particular interest that there were also S100-positive neurons in the PCZ and hippocampus in TBI cases after more than 2 h survival but not in ABI cases or controls. The percentages of NSE-positive neurons in the hippocampus were likewise significantly lower in cases with ABI, compared with controls (p < 0.05) but increased in cases with SBI in PCZ (p < 0.05). In conclusion, the present findings emphasize that S100 and NSE-immunopositivity might be useful for detecting the cause and process of death due to TBI. Further, S100-positivity in neurons may be helpful to estimate the survival time of fatal injuries in legal medicine.

The Protective Effects of Sufentanil Pretreatment on Rat Brains under the State of Cardiopulmonary Bypass

This study aimed to observe the protective effects of sufentanil pretreatment on rat cerebral injury during cardiopulmonary bypass (CPB) and to explore the underlying mechanism. Twenty-four male adult Sprague Dawley (SD) rats were divided into 4 groups. Then, the rat CPB model was established. A 14G trocar was inserted into the atrium dextrum. For rats in S1 and S5 groups, sufentanil (1 µgKg(-1) and 5 µgKg(-1)) were applied before CPB process. After the operation, rat brain samples were harvested for measurement of the water content of the brains, total calcium in brain tissue and the level of serum S100β. Compared with the Sham group, the water content and the total calcium of the brain tissue, and the expression of S100β in serum were significantly increased in the CPB group (P<0.05). Compared with the CPB group, sufentanil treatment significantly reduced the water content of the brains, the total calcium and S100β expression (P<0.05). The blood pressure and heart rate were significantly decreased in groups CPB, S1, and S5 compared with Sham group during CPB. Compared with the Sham group, the levels of pH and blood lactate in other groups were decreased and increased, respectively, in the post-CPB period. During the CPB and post-CPB periods, the hematocrit levels were significantly down-regulated in groups CPB, S1, and S5 compared with Sham group. In conclusion, sufentanil pretreatment was effective in reducing the cerebral injury during CPB. Reduction in calcium overload may be a potential mechanism in such process.

Elevated cell-free plasma DNA level as an independent predictor of mortality in patients with severe traumatic brain injury

Trauma is the leading cause of death in individuals less than 45 years old worldwide, and up to 50% of trauma fatalities are because of brain injury. Prediction of outcome is one of the major problems associated with severe traumatic brain injury (TBI), and research efforts have focused on the investigation of biomarkers with prognostic value after TBI. Therefore, our aim was to investigate whether cell-free DNA concentrations correlated to short-term primary outcome (survival or death) and Glasgow Coma Scale (GCS) scores after severe TBI. A total of 188 patients with severe TBI were enrolled in this prospective study; outcome variables comprised survival and neurological assessment using the GCS at intensive care unit (ICU) discharge. Control blood samples were obtained from 25 healthy volunteers. Peripheral venous blood was collected at admission to the ICU. Plasma DNA was measured using a real-time quantitative polymerase chain reaction (PCR) assay for the β-globin gene. There was correlation between higher DNA levels and both fatal outcome and lower hospital admission GCS scores. Plasma DNA concentrations at the chosen cutoff point (≥171,381 kilogenomes-equivalents/L) predicted mortality with a specificity of 90% and a sensitivity of 43%. Logistic regression analysis showed that elevated plasma DNA levels were independently associated with death (p<0.001). In conclusion, high cell-free DNA concentration was a predictor of short-term mortality after severe TBI.

S-100β does not predict outcome after mild traumatic brain injury

OBJECTIVE

To determine the usefulness of S-100β, a marker for central nervous system damage, in the prediction of long-term outcomes after mild traumatic brain injury (MTBI) Hypothesis: Mid- and long-term outcomes of MTBI (i.e. 3, 6 and 12 months post-injury and return-to-work or school (RTWS)) may be predicted based on pre-injury and injury factors as well as S-100β.

METHODS

MTBI subjects without abnormal brain computed tomography requiring intervention, focal neurological deficits, seizures, amnesia > 24 hours and severe or multiple injuries were recruited at a level I trauma centre. Admission S-100β measurements and baseline Concussion Symptom Checklist were obtained. Symptoms and RTWS were re-assessed at follow-up visits (3-10 days and 3, 6 and 12 months). Outcomes included number of symptoms and RTWS at follow-up. Chi-square tests, linear and logistic regression models were used and p < 0.05 was considered statistically significant.

RESULTS

One hundred and fifty of 180 study subjects had S-100β results. Eleven per cent were unable to RTWS at 12 months. S-100β levels were not associated with post-concussive symptomatology at follow-up. In addition, no association was found between S-100β levels and RTWS.

CONCLUSION

Amongst MTBI patients, S-100β levels are not associated with prolonged post-concussive syndrome or the inability to RTWS.

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.

The role of markers of inflammation in traumatic brain injury

Within minutes of a traumatic impact, a robust inflammatory response is elicited in the injured brain. The complexity of this post-traumatic squeal involves a cellular component, comprising the activation of resident glial cells, microglia, and astrocytes, and the infiltration of blood leukocytes. The second component regards the secretion immune mediators, which can be divided into the following sub-groups: the archetypal pro-inflammatory cytokines (Interleukin-1, Tumor Necrosis Factor, Interleukin-6), the anti-inflammatory cytokines (IL-4, Interleukin-10, and TGF-beta), and the chemotactic cytokines or chemokines, which specifically drive the accumulation of parenchymal and peripheral immune cells in the injured brain region. Such mechanisms have been demonstrated in animal models, mostly in rodents, as well as in human brain. Whilst the humoral immune response is particularly pronounced in the acute phase following Traumatic brain injury (TBI), the activation of glial cells seems to be a rather prolonged effect lasting for several months. The complex interaction of cytokines and cell types installs a network of events, which subsequently intersect with adjacent pathological cascades including oxidative stress, excitotoxicity, or reparative events including angiogenesis, scarring, and neurogenesis. It is well accepted that neuroinflammation is responsible of beneficial and detrimental effects, contributing to secondary brain damage but also facilitating neurorepair. Although such mediators are clear markers of immune activation, to what extent cytokines can be defined as diagnostic factors reflecting brain injury or as predictors of long term outcome needs to be further substantiated. In clinical studies some groups reported a proportional cytokine production in either the cerebrospinal fluid or intraparenchymal tissue with initial brain damage, mortality, or poor outcome scores. However, the validity of cytokines as biomarkers is not broadly accepted. This review article will discuss the evidence from both clinical and laboratory studies exploring the validity of immune markers as a correlate to classification and outcome following TBI.

The potential utility of blood-derived biochemical markers as indicators of early clinical trends following severe traumatic brain injury

OBJECTIVE

Severe traumatic brain injury (TBI) is a dynamic neuropathologic process in which a substantial proportion of patients die within the first 48-hours. The assessment of injury severity and prognosis are of primary concern in the initial management of severe TBI. Supplemental testing that aids in the stratification of patients at high risk for deterioration may significantly improve posttraumatic management in the acute setting.

METHODS

This retrospective study assessed the utility of both single-marker and multimarker models as predictive indicators of acute clinical status after severe TBI. Forty-four patients who sustained severe TBI (admission Glasgow Coma Scale [GCS] score ≤ 8) were divided into two cohorts according to a dichotomized clinical outcome at 72 hours after admission: Poor status (death or GCS score ≤ 8) and improved status (GCS score improved to >8). Threshold values for clinical status prediction were calculated for serum S-100B, matrix metalloproteinase-9, and plasma D-dimer, upon admission and at 24 hours after TBI by the use of receiver operating characteristic analysis. Performance characteristics of these single-marker predictors were compared with those derived from a multimarker logistic regression analysis.

RESULTS

Biomarkers with the greatest predictive value for poor status at 72 hours included serum S-100B on admission, as well as plasma D-dimer and serum S-100B at 24 hours, for which, associations were strongly significant. Multimarker analysis indicated no substantial improvement in prediction accuracy over the best single predictors during this time frame.

CONCLUSION

In conjunction with other clinical, physical, and radiologic evidence, blood-derived biochemical markers may serve to enhance prediction of early clinical trends after severe TBI.

The role of markers of inflammation in traumatic brain injury

Within minutes of a traumatic impact, a robust inflammatory response is elicited in the injured brain. The complexity of this post-traumatic squeal involves a cellular component, comprising the activation of resident glial cells, microglia, and astrocytes, and the infiltration of blood leukocytes. The second component regards the secretion immune mediators, which can be divided into the following sub-groups: the archetypal pro-inflammatory cytokines (Interleukin-1, Tumor Necrosis Factor, Interleukin-6), the anti-inflammatory cytokines (IL-4, Interleukin-10, and TGF-beta), and the chemotactic cytokines or chemokines, which specifically drive the accumulation of parenchymal and peripheral immune cells in the injured brain region. Such mechanisms have been demonstrated in animal models, mostly in rodents, as well as in human brain. Whilst the humoral immune response is particularly pronounced in the acute phase following Traumatic brain injury (TBI), the activation of glial cells seems to be a rather prolonged effect lasting for several months. The complex interaction of cytokines and cell types installs a network of events, which subsequently intersect with adjacent pathological cascades including oxidative stress, excitotoxicity, or reparative events including angiogenesis, scarring, and neurogenesis. It is well accepted that neuroinflammation is responsible of beneficial and detrimental effects, contributing to secondary brain damage but also facilitating neurorepair. Although such mediators are clear markers of immune activation, to what extent cytokines can be defined as diagnostic factors reflecting brain injury or as predictors of long term outcome needs to be further substantiated. In clinical studies some groups reported a proportional cytokine production in either the cerebrospinal fluid or intraparenchymal tissue with initial brain damage, mortality, or poor outcome scores. However, the validity of cytokines as biomarkers is not broadly accepted. This review article will discuss the evidence from both clinical and laboratory studies exploring the validity of immune markers as a correlate to classification and outcome following TBI.

Neuron-specific enolase and S100BB as outcome predictors in severe diffuse axonal injury

BACKGROUND

Diffuse axonal injury (DAI) is a common type of traumatic brain injury, mostly associated with mild changes on computed tomography (CT) scan. Serum biomarkers might be used in the diagnosis and prognosis of this injury type. Our purpose was to determine temporal profile and predictive values of serum concentrations of protein S100BB and neuron-specific enolase (NSE) after DAI.

METHODS

Twenty-eight isolated severe DAI patients (Glasgow Coma Scale score ≤ 8) with normal CT were enrolled in the study. Serum levels of S100BB and NSE were determined at 6 hours, 24 hours, 48 hours, and 72 hours after injury, using enzyme-linked immunosorbent assay. Clinical outcome variables of DAI comprised survival at discharge and Glasgow Outcome scale (GOS) after 3 months and also 2 years.

RESULTS

S100BB concentration was maximum in 6 hours after injury (median = 280.75 ng/L) followed by a quick drop. Its value was significantly higher on third day in patients with unfavorable outcome (GOS score = 1-3) versus favorable outcome (GOS score = 4, 5) (p < 0.0001). The values of NSE had mild changes during 3 days; however, these measured values at 72 hours after trauma manifested higher in unfavorable outcome (p < 0.05).

CONCLUSIONS

Increased serum concentrations of NSE and S100BB within first 3 days after DAI are associated with poor outcome despite mild CT findings. S100BB level at 72 hours after injury can predict late outcome in DAI patients.

LEVEL OF EVIDENCE

Prognostic study, level III.

High S100B levels in cerebrospinal fluid and peripheral blood of patients with acute basal ganglial hemorrhage are associated with poor outcome

BACKGROUND

S100B is involved in brain injury. This study aimed to determine plasma and cerebral spinal fluid (CSF) levels of S100B in patients with spontaneous intracerebral hemorrhage (ICH), and to correlate S100B levels with Glasgow Coma Scale (GCS) scores, ICH volumes, presence of intraventricular hemorrhage (IVH), and survival rate, and to correlate CSF S100B levels with plasma S100B levels as well as CSF interleukin-1beta (IL-1β) levels.

METHODS

Ten patients with suspicion of subarachnoid hemorrhage and 38 patients with spontaneous basal ganglia hemorrhage were included in the study. Their plasma and CSF samples were collected. The concentrations of IL-1β in CSF and S100B in plasma and CSF were analyzed by enzyme-linked immunosorbent assay.

RESULTS

Plasma or CSF S100B levels in the ICH group were significantly higher than those in the control group (178.7±74.2 versus 63.2±23.0 pg/ml; P<0.001 or 158.1±70.9 versus 1.8±0.7 ng/ml; P<0.001). S100B levels were highly associated with GCS scores, ICH volumes, presence of IVH, and survival rate (all P<0.05). CSF S100B levels were highly associated with plasma S100B levels as well as CSF IL-1β levels (both P<0.01) in patients with ICH. A receiver operating characteristic curve identified CSF and plasma S100B cutoff levels that predicted 1-week mortality of patients with a high sensitivity and specificity. The areas under curves (AUCs) of GCS scores and ICH volumes were larger than those of CSF and plasma S100B levels, but the differences were not statistically significant (P>0.05).

CONCLUSION

High levels of S100B are present in the cerebrospinal fluid and peripheral blood of patients with ICH and may contribute to the inflammatory processes of ICH. The levels of CSF and plasma S100B after spontaneous onset of ICH seem to correlate with clinical outcome in these patients. Increases in peripheral S100B properly reflect brain injury, and plasma S100B level may serve as a useful clinical marker for evaluating the prognosis of ICH.

Slight and short-lasting increase of serum S-100B protein in extra-cranial trauma

OBJECTIVE

Serum S-100B protein is an established biochemical marker of traumatic brain injury. At the same time, the question of extra-cranial S-100B release has been raised. This study evaluates the post-traumatic and post-operative release kinetics of S-100B in 45 trauma victims without head injury.

METHOD

Serum S-100B protein was measured on admission and every 24 hours for 4 consecutive days.

RESULTS

Initial S-100B was slightly increased (median: 0.54 microg L-1) and correlated with the severity of extra-cranial trauma (p = 0.0004, Mann-Whitney test). Both severely (abdominal or chest trauma with or without bone fractures) and mildly (long bone fractures) injured showed a rapid decline of S-100B (< 0.2 microg L-1) around 72 hours post-trauma. Extra-cranial surgery caused a secondary increase of S-100B, especially in the mildly injured group (p = 0.004, Wilcoxon signed rank test).

CONCLUSIONS

Extra-cranial injury results in a mild elevation of serum S-100B protein that declines rapidly (1-3 days after injury).

Serum S100B protein in early management of patients after mild traumatic brain injury

BACKGROUND AND PURPOSE

Neuronal protein S100B assays are available now with a perspective of being an early screening tool for serious intracranial injury. The aim of the study was to correlate early S100B measurements and initial CCT findings in the patients sustaining mild traumatic brain injury (MTBI).

METHODS

The prospective study included patients of all ages with a history of MTBI. CCT scans and venous blood sampling for S100B analysis were performed within 6 h after injury. Levels of S100B above 0.1 ng/ml (S100B+) and any CCT detectable trauma-relevant intracranial lesions were considered positive (CCT+).

RESULTS

A series of 102 patients were involved in the study. CCT+ scans were present in eighteen (17.6%) and CCT- scans in 84 (82.4%) patients. There were 74 (72.5%) patients in S100B+ and 28 (27.5%) in S100B- group. Sensitivity of S100B assay attained 83.3% with a negative predictive value of 89.3%. Three patients from CCT+ group had negative plasma level of S100B. Two of them required surgical treatment.

DISCUSSION

S100B serum protein marker seems to be an unrealiable screening tool for determination of an intracranial injury risk group due to low sensitivity and negative predictive value seen from samples taken greater than 3 h after an MTBI.

[Can serum protein S100beta predict neurological deterioration after moderate or minor traumatic brain injury?]

INTRODUCTION

Patients with moderate traumatic brain injury (TBI) (Glasgow Coma Scale, GCS, 9-13) or minor TBI (GCS 14-15) are at risk for subsequent neurological deterioration. Serum protein S-100 is believed to reflect brain damage following TBI. In patients with normal or minor CT scan abnormalities on admission, we tested whether the determination of serum protein S-100 beta could predict secondary neurological deterioration.

METHODS

Sixty-seven patients with moderate or minor TBI were prospectively studied. Serum samples were collected on admission within 12 hours postinjury to measure serum protein S-100 levels. Neurological outcome was assessed up to seven days after trauma. Secondary neurological deterioration was defined as two points or more decrease from the initial GCS, or any treatment for neurological deterioration.

RESULTS

Nine patients had a secondary neurological deterioration after trauma. No differences in serum levels of protein S-100 were found between these patients and those without neurological aggravation (n=58 patients): 0.93 microg/l (0.14-4.85) vs 0.39 microg/l (0.04-6.40), respectively. The proportion of patients with abnormal levels of serum protein S-100 at admission according to two admitted cut-off levels (>0.1 and >0.5 microg/l) was comparable between the two groups of patients. Elevated serum levels of protein S-100 were found in patients with Injury Severity Score (ISS) of more than 16 (n=23 patients): 1.26 microg/l (0.14-6.40) vs 0.22 microg/l (0.04-6.20) in patients with ISS less than 16 (n=44 patients).

DISCUSSION

The dosage of serum protein S-100 on admission failed to predict patients at risk for neurological deterioration after minor or moderate TBI. Extracranial injuries can increase serum protein S-100 levels, then limiting the usefulness of this dosage in this clinical setting.

Predicting outcome after severe traumatic brain injury using the serum S100B biomarker: results using a single (24h) time-point

BACKGROUND AND OBJECTIVES

In recent years, biochemical markers have been employed to predict the outcome of patients with traumatic brain injury (TBI). In mild TBI, S100B has shown the most promise as a marker of outcome. The objective of this study in patients with severe TBI was to: show the range of serum S100B levels during the acute phase after trauma: determine if S100B has potential to discriminate favourable from unfavourable outcome in patients with similar brain injury severity scores and to establish an S100B 'cut-off' predictive for death.

METHODS

All patients with severe TBI, admitted to this neurointensive care unit within 24h of injury were eligible for inclusion in the study. One serum blood sample was obtained from each patient at the 24h post-injury time-point. S100B levels were measured using enzyme-linked immunosorbent assay. Injuries were coded using an internationally recognised injury severity scoring system (ISS). Three-month follow-up was undertaken with outcome assessed using the Glasgow outcome score (GOS).

RESULTS

One hundred patients were recruited. Serum S100B levels ranged from 0.08 to 12.62microgL(-1) S100B levels were significantly higher in patients with a GOS of 1 (death) 2 and 3 (unfavourable outcome) compared with those with GOS 4 and 5 (good recovery). In this study a cut-off point of 0.53microgL(-1) has sensitivity of >80% and specificity of 60% to predict unfavourable outcome and 49% to predict death.

CONCLUSION

In 100 patients studied with similar brain injury severity scores, serum S100B measured at the 24-h time-point after injury is significantly associated with outcome but a cut-off 0.53microgL(-1) does not have good prognostic performance.

Serum cleaved tau does not predict postconcussion syndrome after mild traumatic brain injury

OBJECTIVES

Our objective was to determine if the biomarker for axonal injury, serum cleaved tau (C-tau), predicts postconcussion syndrome (PCS) in adults after mild traumatic brain injury (mTBI).

METHODS

C-tau was measured from blood obtained in the emergency department. Outcome was assessed at 3 months post injury using the Rivermead Postconcussion Symptoms Questionnaire and Acute Medical Outcomes SF-36v2 Health Survey (SF-36).

RESULTS

Of 50 patients, there were 15 patients with detectable levels of C-tau, 10 patients with abnormal findings on initial head computed tomography (CT) and 22 patients with PCS. One-third of patients with detectable C-tau and 14.3% of patients without detectable C-tau had abnormal findings on head CT (P = .143). Serum C-tau was not detected more frequently in patients with PCS than those without, neither for all patients (P = .115) nor the subgroup with negative head CT (P = .253).

CONCLUSIONS

C-tau is a poor predictor of PCS after mTBI regardless of head CT result.

Reliability of S100B in predicting severity of central nervous system injury

S100B is a protein biomarker that reflects CNS injury. It can be measured in the CSF or serum with readily available immunoassay kits. The excellent sensitivity of S100B has enabled it to confirm the existence of subtle brain injury in patients with mild head trauma, strokes, and after successful resuscitation from cardiopulmonary arrest. The extent of S100B elevation has been found to be useful in predicting clinical outcome after brain injury. Elevations of S100B above certain threshold levels might be able to reliably predict brain death or mortality. A normal S100B level reliably predicts the absence of significant CNS injury. The specificity of S100B levels as a reflection of CNS injury is compromised by the findings that extra-cranial injuries can lead to elevations in the absence of brain injury. This potential problem can most likely be avoided by measuring serial S100B levels along with other biomarkers and carefully noting peripheral injuries. Serum markers GFAP and NSE are both more specific for CNS injury and have little to no extra-cranial sources. Sustained elevations of S100B over 24 h along with elevations of GFAP and NSE can more reliably predict the extent of brain injury and clinical outcomes. In the future, S100B measurements might reliably predict secondary brain injury and enable physicians to initiate therapeutic interventions in a timelier manner. S100B levels have been shown to rise hours to days before changes in ICP, neurological examinations, and neuroimaging tests. S100B levels may also be used to monitor the efficacy of treatments.

Protein S-100 and neuropsychological functioning following severe traumatic brain injury

PRIMARY OBJECTIVE

To examine the relationship between serum concentrations of protein S-100beta and neuropsychological functioning following severe traumatic brain injury.

DESIGN

Matched control group.

METHODS

Blood samples were taken within 12 hours of injury and then daily up to 7 days post-injury (n=23). Within 2 weeks of emerging from post-traumatic amnesia (PTA), participants completed a battery of neuropsychological measures. These results were compared with a matched sample of healthy controls.

RESULTS

Early measurement of S-100 not only reflected overall brain injury severity, but also related to neuropsychological deficits, with higher serum concentrations associated with poorer performance across most cognitive domains. PTA duration, measured by the Westmead PTA Scale, was found to be the strongest predictor of S-100 concentration (R2=0.59, p<0.001).

CONCLUSIONS

These findings show that measurement of serum protein S-100 may further aid in the identification of individuals with severe TBI who are likely to experience cognitive difficulties.

Role of Plasma DNA as a Predictive Marker of Fatal Outcome following Severe Head Injury in Males

The prediction of outcome is one of the major problems associated with traumatic brain injury. Recently, investigations have been performed on the potential use of circulating cell-free DNA in plasma for clinical diagnosis and prognosis of a variety of conditions. In this study, we investigated DNA plasma concentrations after severe traumatic brain injury (TBI) and its correlation with primary outcome. We studied 41 male victims of TBI, with isolated severe TBI or severe TBI with associated exracranial injuries. Control samples were obtained from 13 healthy male volunteers. Plasma DNA was measured by a real-time PCR assay for the beta-globin gene. The mean time for first sampling (study entry) was 11.7 +/- 5.2 h after injury; subsequent DNA determinations were performed 24 h after study entry. Mean plasma DNA concentrations were significantly increased in TBI patients (366,485 and 131,708 kilogenomes-equivalents/L, at study entry and 24 h later, respectively) compared with the control group (3031 kilogenomes-equivalents/L). Additionally, a significant correlation between higher plasma DNA concentrations, determined 24 h after study entry, and fatal outcome was observed. However, at second sampling, there was no significant correlation between plasma DNA concentrations and the presence of associated extracranial injuries. High plasma DNA concentrations at second sampling time predicted fatal outcome with a sensitivity of 67% and specificity of 76%, considering a cut-off value of 77,883 kilogenomes-equivalents/L. Thus, this study showed that severe TBI is associated with elevated DNA plasma levels and suggests that persistent DNA elevations correlate with mortality.

Five-year outcome after mild head injury: a prospective controlled study

OBJECTIVES

To study the prevalence of post-concussion symptoms (PCS) 5-7 years after mild head injury (MHI) and to investigate whether patients suffer from more symptoms than the normal population.

METHODS

We conducted a 5- to 7-year follow-up of patients (n = 89) with MHI. Post-concussion symptoms were quantified with the Rivermead Post Concussion Symptoms Questionnaire (RPQ) and health-related quality of life (HRQL) was measured with the EuroQol-5D (EQ-5D). We also quantified subjective general health state with the EuroQol Visual Analogue Scale (EQ-VAS). An age- and sex-matched, but otherwise randomly chosen control group of 89 persons was recruited from the National Population Registry for a cross-sectional comparison. Twenty-eight patients (30%) and 27 (30%) controls responded.

RESULTS

Patients reported significantly (P = 0.017) more PCS (median RPQ score 10, 95% CI 2-20) than controls (median 2, 95% CI 0-4). They also reported significantly (P = 0.008) lower HRQL (median EQ-5D score 0.866, 95% CI 0.796-1.000) than controls (1.000, 95% CI 1.000-1.000), but there was no difference between the groups in their subjective ratings of general health state.

CONCLUSIONS

Patients reported significantly more PCS and lower HRQL 5 to 7 years after MHI than age- and sex-matched controls from the normal population.

The prognostic value of serum S-100B protein in spontaneous subarachnoid haemorrhage

BACKGROUND

Despite the major progress in neurophysiological monitoring, there are still difficulties in the early identification and quantification of cerebral damage after a stroke. In this prospective study we examined the associations between serum S-100B protein, a serum marker of brain injury, and initial neurological-neuroimaging severity, secondary deterioration, external ventricular drainage (EVD: therapeutic intervention) and outcome in patients with subarachnoid haemorrhage (SAH).

METHOD

We recorded all pertinent clinical data of 52 patients with SAH and measured S-100B serum levels on admission and every 24 h for a maximum of 9 consecutive days. Mann-Whitney U-test and Kruskal Wallis analysis were employed to assess the association of S-100B levels with all variables of interest. Log-rank test was used to evaluate survival and Cox's proportional hazard regression analysis to define the significant predictors of survival rate.

FINDINGS

Admission S-100B was statistically significantly associated with initial neurological status, neuroimaging severity, and one-year outcome (p = 0.0002, 0.001, and 0.017, Kruskal Wallis analysis). Admission S-100B above 0.3 microg/L predicted unfavourable outcome (p < 0.0001, log rank test) and constituted an independent predictor of short-term survival (p = 0.035 Cox's proportional hazard regression analysis) with a hazard ratio of 2.2 (95% C.I.: 1.06-4.6) indicating a more than doubling of death probability. Secondary neurological deterioration associated with S-100B increase (p < 0.0001) and external ventricular drainage (EVD) with S-100B reduction (p = 0.003, Wilcoxon signed rank test).

CONCLUSIONS

Serum S-100B protein seems to be a useful biochemical indicator of neurological - neuroimaging severity, secondary deterioration, EVD (therapeutic intervention), and outcome in patients with SAH.

Role of serum S100B as a predictive marker of fatal outcome following isolated severe head injury or multitrauma in males

BACKGROUND

Severe traumatic brain injury (TBI) is associated with a 30%-70% mortality rate. S100B has been proposed as a biomarker for indicating outcome after TBI. Nevertheless, controversy has arisen concerning the predictive value of S100B for severe TBI in the context of multitrauma. Therefore, our aim was to determine whether S100B serum levels correlate with primary outcome following isolated severe TBI or multitrauma in males.

METHODS

Twenty-three consecutive male patients (age 18-65 years), victims of severe TBI [Glasgow Coma Scale (GCS) 3-8] (10 isolated TBI and 13 multitrauma with TBI) and a control group consisting of eight healthy volunteers were enrolled in this prospective study. Clinical outcome variables of severe TBI comprised: survival, time to intensive care unit (ICU) discharge, and neurological assessment [Glasgow Outcome Scale (GOS) at ICU discharge]. Venous blood samples were taken at admission in the ICU (study entry), 24 h later, and 7 days later. Serum S100B concentration was measured by an immunoluminometric assay.

RESULTS

At study entry (mean time 10.9 h after injury), mean S100B concentrations were significantly increased in the patient with TBI (1.448 microg/L) compared with the control group (0.037 microg/L) and patients with fatal outcome had higher mean S100B (2.10 microg/L) concentrations when compared with survivors (0.85 microg/L). In fact, there was a significant correlation between higher initial S100B concentrations and fatal outcome (Spearman's =0.485, p=0.019). However, there was no correlation between higher S100B concentrations and the presence of multitrauma. The specificity of S100B in predicting mortality according to the cut-off of 0.79 microg/L was 73% at study entry.

CONCLUSIONS

Increased serum S100B levels constitute a valid predictor of unfavourable outcome in severe TBI, regardless of the presence of associated multitrauma.

Cerebrospinal Fluid Biomarkers versus Glasgow Coma Scale and Glasgow Outcome Scale in Pediatric Traumatic Brain Injury: The Role of Young Age and Inflicted Injury

The Glasgow Coma Scale (GCS) and Glasgow Outcome Scale (GOS) are widely used clinical scoring systems to measure the severity of neurologic injury after traumatic brain injury (TBI), but have recognized limitations in infants and small children. Cerebrospinal fluid (CSF) concentrations of neuron-specific enolase (NSE) and S100B show promise as markers of brain injury. We hypothesized that the initial GCS and 6-month GOS scores would be inversely associated with CSF NSE and/or S100B concentrations after severe pediatric TBI. Using banked CSF obtained during ongoing studies of pediatric TBI, NSE and S100B were determined in CSF collected within 24 h of trauma from 88 infants and children with severe TBI (GCS < or = 8) versus 20 non-injured controls. Victims of inflicted (iTBI) and non-inflicted TBI (nTBI) showed similar (>10-fold) increases in both NSE and S100B versus control. Both markers showed overall significant, inverse correlation with GCS and GOS scores. In subgroup analysis, both markers correlated significantly with GCS and GOS scores only in older (>4 years) victims of nTBI; no correlation was found for patients < or =4 years old or victims of iTBI. While confirming the overall correlations between GCS/GOS score and CSF NSE and S100B seen in prior studies, we conclude that these clinical and CSF biomarkers of brain injury do not correlate in children < or =4 years of age and/or victims of iTBI. Although further, prospective study is warranted, these findings suggest important limitations in our current ability to assess injury severity in this important population.

Serum S-100B protein monitoring in patients with severe traumatic brain injury

OBJECTIVE

S-100B protein is a promising marker of injury severity and outcome after head injury. We examined the relationship between serum S-100B concentrations and injury severity, clinical course, survival, and treatment efficacy after severe traumatic brain injury (TBI).

DESIGN AND SETTING

Prospective observational study in a neurosurgical intensive care unit.

PATIENTS AND PARTICIPANTS

102 adult patients with severe TBI, admitted between June 2001 and November 2003 (30 months).

INTERVENTIONS

Serum S-100B levels were measured by immunoluminometric technique on admission and every 24 h thereafter for a maximum of 7 days.

MEASUREMENTS AND RESULTS

Initial S-100B levels were significantly related to pupillary status, computed tomography severity 1, and 1-month survival. Cox's proportional hazard regression analysis showed that initial S-100B was an independent predictor of 1-month survival, in the presence of dilated pupils, and with increased age. Subjects with initial levels above 1 microg/l had a nearly threefold increased probability of death within 1 month. Serum S-100B alteration indicated neurological improvement or deterioration. Finally, surgical treatment reduced S-100B levels.

CONCLUSIONS

Serum S-100B protein reflects injury severity and improves prediction of outcome after severe TBI. S-100B may also have a role in assessing the efficacy of treatment after severe TBI.