The prognostic value of NSE and S100B from serum and cerebrospinal fluid in patients with spontaneous subarachnoid hemorrhage

Usability of serum inter-α-trypsin inhibitor heavy chain 4 as a biomarker for assessing severity and predicting functional outcome after human aneurysmal subarachnoid hemorrhage: A prospective observational cohort study at a single institution

BACKGROUND

Inter-α-trypsin inhibitor heavy chain 4 (ITIH4) may harbor anti-inflammatory activities. We sought to discern the predictive significance of serum ITIH4 for delayed cerebral ischemia (DCI) and clinical outcomes of human aneurysmal subarachnoid hemorrhage (aSAH).

METHODS

At a single institution, we performed a prospective and observational cohort study of 148 patients with aSAH and 52 healthy controls. Poststroke six-month extended Glasgow Outcome Scale (GOSE) score of 1-4 was designated as a poor prognosis. Prognosis associations were verified using multivariate analysis.

RESULTS

As compared to controls, patients had significantly declined serum ITIH4 concentrations from admission until day 10, with the lowest concentrations at days 1-3 after stroke. Serum ITIH4 concentrations, which were substantially decreased with the increasing Hunt-Hess scores or modified Fisher scores, were independently correlated with the two scores. Moreover, serum ITIH4 concentrations, which were markedly elevated in the order of GOSE scores from 1 to 8, together with Hunt-Hess scores and modified Fisher scores were independently related to GOSE scores and poor prognosis. However, serum ITIH4 concentrations were not independently predictive of DCI. Prediction model of poor prognosis integrating the preceding three variables were delineated using the nomogram, were verified under the calibration curve, and displayed high discriminatory efficiencies under the receiver operating characteristic curve.

CONCLUSIONS

A significant decline of serum ITIH4 concentrations during the early phase after aSAH was closely related to severity and poor prognosis, assuming that serum ITIH4 may represent a promising prognostic biomarker of aSAH.

Cerebrospinal Fluid and Serum Biomarker Insights in Aneurysmal Subarachnoid Haemorrhage: Navigating the Brain-Heart Interrelationship for Improved Patient Outcomes

The pathophysiological mechanisms underlying severe cardiac dysfunction after aneurysmal subarachnoid haemorrhage (aSAH) remain poorly understood. In the present study, we focused on two categories of contributing factors describing the brain-heart relationship. The first group includes brain-specific cerebrospinal fluid (CSF) and serum biomarkers, as well as cardiac-specific biomarkers. The secondary category encompasses parameters associated with cerebral autoregulation and the autonomic nervous system. A group of 15 aSAH patients were included in the analysis. Severe cardiac complications were diagnosed in seven (47%) of patients. In the whole population, a significant correlation was observed between CSF S100 calcium-binding protein B (S100B) and brain natriuretic peptide (BNP) (rS = 0.62; p = 0.040). Additionally, we identified a significant correlation between CSF neuron-specific enolase (NSE) with cardiac troponin I (rS = 0.57; p = 0.025) and BNP (rS = 0.66; p = 0.029), as well as between CSF tau protein and BNP (rS = 0.78; p = 0.039). Patients experiencing severe cardiac complications exhibited notably higher levels of serum tau protein at day 1 (0.21 ± 0.23 [ng/mL]) compared to those without severe cardiac complications (0.03 ± 0.04 [ng/mL]); p = 0.009. Impaired cerebral autoregulation was noted in patients both with and without severe cardiac complications. Elevated serum NSE at day 1 was related to impaired cerebral autoregulation (rS = 0.90; p = 0.037). On the first day, a substantial, reciprocal correlation between heart rate variability low-to-high frequency ratio (HRV LF/HF) and both GFAP (rS = -0.83; p = 0.004) and S100B (rS = -0.83; p = 0.004) was observed. Cardiac and brain-specific biomarkers hold the potential to assist clinicians in providing timely insights into cardiac complications, and therefore they contribute to the prognosis of outcomes.

Systemic Inflammation after Aneurysmal Subarachnoid Hemorrhage

Aneurysmal subarachnoid hemorrhage (aSAH) is one of the most severe neurological disorders, with a high mortality rate and severe disabling functional sequelae. Systemic inflammation following hemorrhagic stroke may play an important role in mediating intracranial and extracranial tissue damage. Previous studies showed that various systemic inflammatory biomarkers might be useful in predicting clinical outcomes. Anti-inflammatory treatment might be a promising therapeutic approach for improving the prognosis of patients with aSAH. This review summarizes the complicated interactions between the nervous system and the immune system.

Serum protein S-100B as a novel biomarker of diagnosis and prognosis of childhood epilepsy

Background

Elevated levels of S-100B in serum are increasingly considered a potential biochemical marker of nervous system damage. To our knowledge, limited number of research studies have tested the serum S-100B protein levels in children with epilepsy. The objective of our study is to measure the serum levels of S-100B protein in pediatric cases with epilepsy.

Results

The mean serum concentration of S-100B protein was 0.135 ± 0.014 mg/L in the patient group and 0.082 ± 0.018 mg/L in the control group. The patients showed significantly high S-100B protein levels compared with healthy controls (P < 0.001).

Conclusion

Our data suggest that increased S-100B protein levels in the serum potentially indicate neuronal damage in the brains of children with epilepsy.

Serum S100B correlates with health-related quality of life and functional outcome in patients at 1 year after aneurysmal subarachnoid haemorrhage

Background

Early, objective prognostication after aneurysmal subarachnoid haemorrhage (aSAH) is difficult. A biochemical marker would be desirable. Correlation has been found between levels of the protein S100 beta (S100B) and outcome after aSAH. Timing and clinical usefulness are under investigation.

Methods

Eighty-nine patients admitted within 48 h of aSAH were included. Modified ranking scale (mRS), EuroQoL health-related quality of life measure (EQ-5D_index) and EuroQoL visual analogue scale (EQ-VAS) values were evaluated after 1 year. S100B was measured in blood samples collected at admission and up to day 10.

Results

S100B correlated significantly with EQ-5D_index and mRS, but not EQ-VAS at 1 year after aSAH. A receiver operating characteristic analysis for peak S100B values (area under the curve 0.898, 95% confidence interval 0.828–0.968, p < 0.0001), with a cutoff of 0.4 μg/l, yielded 95.3% specificity and 68% sensitivity for predicting unfavourable outcome. Dichotomized S100B (> 0.4 μg/l vs ≤ 0.4 μg/l), age and Hunt and Hess grading scale score (HH) were associated with unfavourable mRS outcome in univariate logistic regression analysis. Dichotomized S100B was the only variable independently correlated with unfavourable mRS outcome in a multivariate logistic regression analysis.

Conclusions

For the first time, S100B was shown to correlate with mRS and health-related quality of life at 1 year after aSAH. Peak S100B can be used as a prognostic factor for unfavourable outcome measured as dichotomized mRS after aSAH. A peak value cutoff of 0.4 μg/l is suggested. Ethical approval no: 2013/366-31, 4th of February 2014.

Brain Biomarkers in Patients with COVID-19 and Neurological Manifestations: A Narrative Review

Acute hyperinflammatory response (cytokine storm) and immunosuppression are responsible for critical illness in patients infected with coronavirus disease 2019 (COVID-19). It is a serious public health crisis that has affected millions of people worldwide. The main clinical manifestations are mostly by respiratory tract involvement and have been extensively researched. Increasing numbers of evidence from emerging studies point out the possibility of neurological involvement by COVID-19 highlighting the need for developing technology to diagnose, manage, and treat brain injury in such patients. Here, we aimed to discuss the rationale for the use of an emerging spectrum of blood biomarkers to guide future diagnostic strategies to mitigate brain injury-associated morbidity and mortality risks in COVID-19 patients, their use in clinical practice, and prediction of neurological outcomes.

Effect of remote ischemic preconditioning on cerebral vasospasm, biomarkers of cerebral ischemia, and functional outcomes in aneurysmal subarachnoid hemorrhage (ERVAS): A randomized controlled pilot trial

BACKGROUND:

Cerebral vasospasm can complicate aneurysmal subarachnoid hemorrhage (aSAH), contributing to cerebral ischemia. We explored the role of remote ischemic preconditioning (RIPC) in reducing cerebral vasospasm and ischemia and improving outcomes after aSAH.

MATERIALS AND METHODS:

Patients with ruptured cerebral aneurysm undergoing surgical clipping and meeting the trial criteria were randomized to true RIPC (n = 13) (inflating upper extremity blood pressure cuff thrice to 30 mmHg above systolic pressure for 5 min) or sham RIPC (n = 12) (inflating blood pressure cuff thrice to 30 mmHg for 5 min) after ethical approval. A blinded observer assessed outcome measures-cerebral vasospasm and biomarkers of cerebral ischemia. We also evaluated the feasibility and safety of RIPC in aSAH and Glasgow Outcome Scale-Extended (GOSE).

RESULTS:

Angiographic vasospasm was seen in 9/13 (69%) patients; 1/4 patients (25%) in true RIPC group, and 8/9 patients (89%) in sham RIPC group (P = 0.05). Vasospasm on transcranial Doppler study was diagnosed in 5/25 (20%) patients and 1/13 patients (7.7%) in true RIPC and 4/12 patients (33.3%) in sham RIPC group, (P = 0.16). There was no difference in S100B and neuron-specific enolase (NSE) levels over various time-points within groups (P = 0.32 and 0.49 for S100B, P = 0.66 and 0.17 for NSE in true and sham groups, respectively) and between groups (P = 0.56 for S100B and P = 0.31 for NSE). Higher GOSE scores were observed with true RIPC (P = 0.009) unlike sham RIPC (P = 0.847) over 6-month follow-up with significant between group difference (P = 0.003). No side effects were seen with RIPC.

CONCLUSIONS:

RIPC is feasible and safe in patients with aSAH and results in a lower incidence of vasospasm and better functional outcome.

Implication of cerebral astrocytes in major depression: A review of fine neuroanatomical evidence in humans

Postmortem investigations have implicated astrocytes in many neurological and psychiatric conditions. Multiple brain regions from individuals with major depressive disorder (MDD) have lower expression levels of astrocyte markers and lower densities of astrocytes labeled for these markers, suggesting a loss of astrocytes in this mental illness. This paper reviews the general properties of human astrocytes, the methods to study them, and the postmortem evidence for astrocyte pathology in MDD. When comparing astrocyte density and morphometry studies, astrocytes are more abundant and smaller in human subcortical than cortical brain regions, and immunohistochemical labeling for the astrocyte markers glial fibrillary acidic protein (GFAP) and vimentin (VIM) reveals fewer than 15% of all astrocytes that are present in cortical and subcortical regions, as revealed using other staining techniques. By combining astrocyte densities and morphometry, a model was made to illustrate that domain organization is mostly limited to GFAP-IR astrocytes. Using these markers and others, alterations of astrocyte densities appear more widespread than those for astrocyte morphologies throughout the brain of individuals having died with MDD. This review suggests how reduced astrocyte densities may relate to the association of depressive episodes in MDD with elevated S100 beta (S100B) cerebrospinal fluid serum levels. Finally, a potassium imbalance theory is proposed that integrates the reduced astrocyte densities generated from postmortem studies with a hypothesis for the antidepressant effects of ketamine generated from rodent studies.

Biomarkers of Neurological Outcome After Aneurysmal Subarachnoid Hemorrhage as Early Predictors at Discharge from an Intensive Care Unit

Background

Subarachnoid bleeding is associated with brain injuries and ranges from almost negligible to acute and life threatening. The main objectives were to study changes in brain-specific biomarker levels in patients after an aneurysmal subarachnoid hemorrhage (aSAH) in relation to early clinical findings, severity scores, and intensive care unit (ICU) outcome. Analysis was done to identify specific biomarkers as predictors of a bad outcome in the acute treatment phase.

Methods

Analysis was performed for the proteins of neurofilament, neuron-specific enolase (NSE), microtubule-associated protein tau (MAPT), and for the proteins of glial cells, S100B, and glial fibrillary acidic protein (GFAP). Outcomes were assessed at discharge from the ICU and analyzed based on the grade in the Glasgow Outcome Scale (GOS). Patients were classified into two groups: with a good outcome (Group 1: GOS IV–V, n = 24) and with a bad outcome (Group 2: GOS I–III, n = 31). Blood samples were taken upon admission to the ICU and afterward daily for up to 6 days.

Results

In Group 1, the level of S100B (1.0, 0.9, 0.7, 2.0, 1.0, 0.3 ng/mL) and NSE (1.5, 2.0, 1.6, 1.2, 16.6, 2.2 ng/mL) was significantly lower than in Group 2 (S100B: 4.7, 4.8, 4.4, 4.5, 6.6, 6.8 ng/mL; NSE: 4.0, 4.1, 4.3, 3.8, 4.4, 2.5 1.1 ng/mL) on day 1–6, respectively. MAPT was significantly lower only on the first and second day (83.2 ± 25.1, 132.7 ± 88.1 pg/mL in Group 1 vs. 625.0 ± 250.7, 616.4 ± 391.6 pg/mL in Group 2). GFAP was elevated in both groups from day 1 to 6. In the ROC analysis, S100B showed the highest ability to predict bad ICU outcome of the four biomarkers measured on admission [area under the curve (AUC) 0.81; 95% CI 0.67–0.94, p < 0.001]. NSE and MAPT also had significant predictive value (AUC 0.71; 95% CI 0.54–0.87, p = 0.01; AUC 0.74; 95% CI 0.55–0.92, p = 0.01, respectively). A strong negative correlation between the GOS and S100B and the GOS and NSE was recorded on days 1–5, and between the GOS and MAPT on day 1.

Conclusion

Our findings provide evidence that brain biomarkers such as S100B, NSE, GFAP, and MAPT increase significantly in patients following aSAH. There is a direct relationship between the neurological outcome in the acute treatment phase and the levels of S100B, NSE, and MAPT. The detection of brain-specific biomarkers in conjunction with clinical data may constitute a valuable diagnostic and prognostic tool in the early phase of aSAH treatment.

Biomarkers in traumatic brain injury: new concepts

Traumatic brain injury is a multifaceted condition that encompasses a spectrum of injuries: contusions, axonal injuries in specific brain regions, edema, and hemorrhage. Brain injury determines a broad clinical and disability spectrum due to the implication of various cellular pathways, genetic phenotypes, and environmental factors. It is challenging to predict patient outcomes, to appropriately evaluate the patients, to determine a suitable treatment strategy and rehabilitation program, and to communicate with patient relatives. Biomarkers detected from body fluids are potential evaluation tools for traumatic brain injury patients. These may serve as internal indicators of cerebral damage, delivering valuable information about the dynamic cellular, biochemical, and molecular environments. The diagnostic and prognostic value of biomarkers tested both in animal models of traumatic brain injury is still under question, despite a considerable scientific literature. Recent publications emphasize that a more realistic approach involves combining multiple types of biomarkers with other investigative tools (imaging, outcome scales, and genetic polymorphisms). Additionally, there is increasing interest in the use of biomarkers as tools for treatment monitoring and as surrogate outcome variables to facilitate the design of distinct randomized controlled trials. This review highlights the latest available evidence regarding biomarkers in adults after traumatic brain injury and discusses new approaches in the evaluation of this patient group.

Biomarkers Facilitate the Assessment of Prognosis in Critically Ill Patients with Primary Brain Injury: A Cohort Study

Primary injuries to the brain are common causes of hospitalization of patients in intensive care units (ICU). The Acute Physiology and Chronic Health Evaluation (APACHE) II scoring system is widely used for prognostication among critically ill subjects. Biomarkers help to monitor the severity of neurological status. This study aimed to identify the best biomarker, along with APACHE II score, in mortality prediction among patients admitted to the ICU with the primary brain injury. This cohort study covered 58 patients. APACHE II scores were assessed 24 h post ICU admission. The concentrations of six biomarkers were determined, including the C-reactive protein (CRP), the S100 calcium-binding protein B (S100B), neuron-specific enolase (NSE), neutrophil gelatinase-associated lipocalin (NGAL), matrix metalloproteinase 9 (MMP-9), and tissue inhibitor of metalloproteinase 1 (TIMP-1), using commercially available ELISA kits. The biomarkers were specifically chosen for this study due to their established connection to the pathophysiology of brain injury. In-hospital mortality was the outcome. Median APACHE II was 18 (IQR 13–22). Mortality reached 40%. Median concentrations of the CRP, NGAL, S100B, and NSE were significantly higher in deceased patients. S100B (AUC = 0.854), NGAL (AUC = 0.833), NSE (AUC = 0.777), and APACHE II (AUC = 0.766) were the best independent predictors of mortality. Combination of APACHE II with S100B, NSE, NGAL, and CRP increased the diagnostic accuracy of mortality prediction. MMP and TIMP-1 were impractical in prognostication, even after adjustment for APACHE II score. S100B protein and NSE seem to be the best predictors of compromised outcome among critically ill patients with primary brain injuries and should be assessed along with the APACHE II calculation after ICU admission.

Serum myelin basic protein as a marker of brain injury in aneurysmal subarachnoid haemorrhage

Background

Myelin basic protein (MBP) is the second most abundant protein in central nervous system myelin. Since the 1980s, it has been regarded as a marker of brain tissue injury in both trauma and disease. There have been no recent reports regarding MBP in aneurysmal subarachnoid haemorrhage (SAH).

Methods

One hundred four SAH patients with ruptured aneurysms underwent endovascular treatment within 24 h of rupture, and 156 blood samples were collected: 104 on days 0–3, 32 on days 4–6 and 20 on days 9–12 post-SAH. MBP levels were assayed using ELISA and compared with the clinical status on admission, laboratory results, imaging findings and treatment outcome at 3 months.

Results

MBP levels on days 0–3 post-SAH were significantly higher among poor outcome patients (p < 0.001), non-survivors (p = 0.005), patients who underwent intracranial intervention (p < 0.001) and patients with intracerebral haemorrhage (ICH; p < 0.001). On days 4–6 post-SAH, significantly higher levels were found following intracranial intervention (p = 0.009) and ICH (p = 0.039). There was clinically relevant correlation between MBP levels on days 0–3 post-SAH and 3-month Glasgow Outcome Scale (cc = − 0.42) and also ICH volume (cc = 0.48). All patients who made a full recovery had MBP levels below detection limit on days 0–3 post-SAH. Following endovascular aneurysm occlusion, there was no increase in MBP in 86 of the 104 patients investigated (83%).

Conclusions

The concentration of MBP in peripheral blood after intracranial aneurysm rupture reflects the severity of the brain tissue injury (due to surgery or ICH) and correlates with the treatment outcome. Endovascular aneurysm occlusion was not followed by a rise in MBP in most cases, suggesting the safety of this technique.

[The possibility of using neuron-specific enolase as a biomarker in the acute period of stroke]

The article presents a review of the literature on neuron-specific enolase (NSE) as a biomarker of stroke. It is shown that NSE does not allow differentiation of the ischemic and hemorrhagic process in stroke, but is suitable for determining the extent of brain tissue destruction both in the first hours of stroke and in the dynamics. The HSE analysis can be useful for monitoring the course of the disease, control of the dynamics of the pathological process, including when the size of the lesion increases, for evaluating the effectiveness of therapy and as a prognostic biomarker.

Assessment of neuron-specific enolase, S100B and malondialdehyde levels in serum and vitreous of patients with proliferative diabetic retinopathy

PURPOSE

To assess the vitreous and serum levels of neuron-specific enolase (NSE), S100B and malondialdehyde (MDA) in proliferative diabetic retinopathy (PDR) cases and investigate the correlation between preoperative and postoperative anatomical and clinical features.

MATERIALS AND METHODS

The study group included patients who had pars plana vitrectomy (PPV) for PDR. The control group included non-diabetic individuals who underwent PPV surgery for vitreoretinal interface disorders. Samples of serum were taken from all participants preoperatively, while vitreous samples were taken during the PPV. Vitreous and serum levels of NSE, S100B and MDA were measured, and comparisons were made between the groups.

RESULTS

The study group consisted of 56 eyes of 56 cases with PDR. The control group consisted of 20 eyes of 20 cases. The concentrations of vitreous NSE, S100B and MDA were significantly higher than the control group (p < 0.0001, p < 0.05, p < 0.001, respectively). Serum levels were statistically different for NSE and S100B (p < 0.05).

CONCLUSION

Our results clearly show that vitreous levels of S100B, NSE and MDA and serum concentrations of NSE and S100B increased significantly in patients with PDR. The findings may possibly indicate neurodegeneration and oxidative stress; therefore, these markers may have a diagnostic value in patients with PDR.

Is Admission Lipoprotein-Associated Phospholipase A2 a Novel Predictor of Vasospasm and Outcome in Patients With Aneurysmal Subarachnoid Hemorrhage?

BACKGROUND

The relationships between lipoprotein-associated phospholipase A2 (Lp-PLA2) level, vasospasm, and clinical outcome of patients with aneurysmal subarachnoid hemorrhage (aSAH) are still unclear.

OBJECTIVE

To identify the associations between admission Lp-PLA2 and vasospasm following subarachnoid hemorrhage and the clinical outcome of aSAH.

METHODS

A total of 103 aSAH patients who had Lp-PLA2 level obtained within 24 h postbleeding were included. The relationships between Lp-PLA2 level, vasospasm, and clinical outcome were analyzed.

RESULTS

Vasospasm was observed in 52 patients (50.49%). Patients with vasospasm had significantly higher Lp-PLA2 level than those without (P &lt; .001). Both modified Fisher grade (P = .014) and Lp-PLA2 level (P &lt; .001) were significant predictors associated with vasospasm. The Z test revealed that power of Lp-PLA2 was significantly higher than that of modified Fisher grade in predicting vasospasm (Z = 2.499, P = .012). At 6-mo follow-up, 44 patients (42.72%) had unfavorable outcome and 36 patients (34.95%) died. The World Federation of Neurosurgical Societies (WFNS) grade and Lp-PLA2 level were both significant predictors associated with 6-mo unfavorable outcome and mortality (all P &lt; .001). The predictive values of Lp-PLA2 for unfavorable outcome and mortality at 6-mo tended to be lower than those of the WFNS grade, but the differences were not statistically significant (P = .366 and 0.115, respectively). Poor-grade patients having Lp-PLA2 &gt; 200 μg/L had significantly worse 6-mo survival rate than poor-grade patients having Lp-PLA2 ≤ 200 μg/L (P = .001).

CONCLUSION

The Lp-PLA2 might be useful as a novel predictor in aSAH patients. A total of 30 poor-grade patients; those with elevated Lp-PLA2 level have higher risk of 6-mo mortality compared to those without.

Role of Damage Associated Molecular Pattern Molecules (DAMPs) in Aneurysmal Subarachnoid Hemorrhage (aSAH)

Aneurysmal subarachnoid hemorrhage (aSAH) represents only a small portion of all strokes, but accounts for almost half of the deaths caused by stroke worldwide. Neurosurgical clipping and endovascular coiling can successfully obliterate the bleeding aneurysms, but ensuing complications such as cerebral vasospasm, acute and chronic hydrocephalus, seizures, cortical spreading depression, delayed ischemic neurological deficits, and delayed cerebral ischemia lead to poor clinical outcomes. The mechanisms leading to these complications are complex and poorly understood. Early brain injury resulting from transient global ischemia can release molecules that may be critical to initiate and sustain inflammatory response. Hence, the events during early brain injury can influence the occurrence of delayed brain injury. Since the damage associated molecular pattern molecules (DAMPs) might be the initiators of inflammation in the pathophysiology of aSAH, so the aim of this review is to highlight their role in the context of aSAH from diagnostic, prognostic, therapeutic, and drug therapy monitoring perspectives. DAMPs represent a diverse and a heterogenous group of molecules derived from different compartments of cells upon injury. Here, we have reviewed the most important DAMPs molecules including high mobility group box-1 (HMGB1), S100B, hemoglobin and its derivatives, extracellular matrix components, IL-1α, IL-33, and mitochondrial DNA in the context of aSAH and their role in post-aSAH complications and clinical outcome after aSAH.

S100B, NSE and MMP-9 fail to predict neurologic outcome while elevated S100B associates with milder initial clinical presentation after aneurysmal subarachnoid hemorrhage

OBJECTIVE

Despite advances in the treatment of aneurysmal subarachnoid hemorrhage (aSAH) one-year mortality remains approximately 50%. Making an accurate prognosis at the early phase of the disease is notoriously difficult. A clinically reliable biomarker that could be used for better prediction of prognosis and/or as a surrogate for developing complications after aSAH is still lacking. In this study, we evaluated the prognostic values of three promising biomarkers, i.e. S100B, NSE, and MMP-9 in aSAH.

METHODS

In this prospective population-based study, S100B, NSE, and MMP-9 levels were measured in 47 aSAH patients for up to five days. Blood samples were taken at 0, 12 and 24 h after the admission to the intensive care unit (ICU) and daily after that until the patient was transferred from the ICU. The patients' neurological outcome was evaluated with the modified Rankin Scale (mRS) at six months after aSAH.

RESULTS

Biomarker-levels measured during the first 24 h were not associated with neurological outcome. S100B levels during the first 24 h were elevated in patients with a non-severe initial clinical presentation. Otherwise, there was no association between selected clinical variables and the early biomarker levels. In 22 patients, whose ICU follow-up lasted for up to five days, the total release of biomarkers was not associated with the neurological outcome.

CONCLUSIONS

None of the measured biomarkers were associated with the neurological outcome evaluated at six months after aSAH. Elevated levels of S100B in patients with non-severe initial presentation suggest an adaptive role of this biomarker in aSAH. Based on our findings it is not advisable to use these biomarkers to guide clinical decision-making in patients with aSAH.

Vascular diseases and bleedings

Diseases of the central nervous system that are caused by an underlying vascular pathology typically result in either hemorrhage or ischemia. Most prominent entities include spontaneous subarachnoid hemorrhage, spontaneous intracerebral hemorrhage, and ischemic stroke. For anatomic reasons, cerebrospinal fluid (CSF) qualifies as body fluid for the exploration of biomarkers in these disorders. Even though in subarachnoid hemorrhage a few CSF parameters have been established for routine diagnostic purposes, there is still an unmet need and broad interest in the identification of molecules that would allow further insight into disease mechanisms and supplement patients' medical care. This chapter provides an overview on what is presently known about CSF biomarkers in spontaneous subarachnoid hemorrhage, spontaneous intracerebral hemorrhage, and ischemic stroke. We recapitulate current evidence on established diagnostic tests, discuss the role of various CSF molecules in the pathophysiology of these diseases, and illuminate their potential use in future clinical practice. Furthermore, we address methodologic aspects as well as shortcomings of research in this field.

Prognostic Value of Early S100 Calcium Binding Protein B and Neuron-Specific Enolase in Patients with Poor-Grade Aneurysmal Subarachnoid Hemorrhage: A Pilot Study

BACKGROUND

This prospective study was undertaken to investigate the value of early S100 calcium binding protein B (S100B) and neuron-specific enolase (NSE) in prognosticating outcome in patients with poor-grade aneurysmal subarachnoid hemorrhage and to develop a statistical model and cutoff values for clinical practice.

METHODS

Between 2012 and 2014, patients with poor-grade subarachnoid hemorrhage (Hunt and Hess grade 3-5) who were admitted within 24 hours after hemorrhage were prospectively enrolled. Serum NSE and S100B levels were assayed once daily during the first 3 days after hemorrhage. Patient characteristics, Glasgow Coma Scale score, Hunt and Hess grade, and Fisher grade at admission were recorded. Glasgow Outcome Scale (GOS) score was obtained at 6 months and dichotomized as poor (score 1-3) or good (score 4-5). Logistic regression and receiver operating characteristic curve were used to assess the value of S100B and NSE in predicting outcome, and cutoff values were calculated using conditional interference trees.

RESULTS

The study included 52 patients. Hunt and Hess grade was 3 in 23 patients, 4 in 15 patients, and 5 in 14 patients. S100B range was 0.07-5.62 μg/L (mean 0.87 μg/L ± 1.06). NSE range was 5.7-94.2 μg/L (mean 16.1 μg/L ± 10.5). At 6-month follow-up, 23 patients (44.2%) had a poor outcome, and 29 patients (55.8%) had a good outcome. Both S100B at day 1 (P = 0.004; cutoff 0.202 μg/L) and NSE at day 1 (P = 0.047; cutoff 9.4 μg/L) predicted good outcome with a specificity of 100%. The specificity of mean S100B in detecting patients with poor outcome reached 100% (P = 0.003) when combined with mean NSE levels.

CONCLUSIONS

S100B and NSE measured during the first 3 days after hemorrhage showed, separately and combined, a significant predictive value in prognosticating clinical outcome in patients with poor-grade subarachnoid hemorrhage. A multicenter study with a large patient cohort is necessary to validate the above-mentioned cutoff values for clinical practice.

Serial blood lactate measurements and its prognostic significance in intensive care unit management of aneurysmal subarachnoid hemorrhage patients

PURPOSE

This study assesses the behavior of serial blood lactate measurements during intensive care unit (ICU) stay to identify prognostic factors of unfavorable neurological outcomes (UO) in patients with aneurysmal subarachnoid hemorrhage (SAH).

METHODS

We retrospectively reviewed all patients who were consecutively hospitalized with SAH between 2009 and 2016. Arterial blood lactate levels were routinely obtained on admission and every 6h in the ICU. Univariate/multivariate analyses were performed to identify independent predictors of UO (modified Rankin scale of 3-6 upon hospital discharge).

RESULTS

There were 145 patients with 46% of UO. Initially, increased lactate levels reached maximum levels during the first 24h and then decreased to within the normal range. Then, the levels slightly increased again to within the normal range for the next 24h, especially in UO. On multiple regression analysis, lactate levels measured at 24h, and 48h after admission were strong predictors of UO. Lactate level measured at 48h after admission demonstrated the greatest accuracy and the highest specificity (area under the curve, 0.716; sensitivity, 40%; specificity, 92.1%).

CONCLUSIONS

The lactate level at 48h after admission was the most accurate predictor of UO with a high specificity in SAH patients.

A review of the clinical utility of serum S100B protein levels in the assessment of traumatic brain injury

Background

In order to improve injury assessment of brain injuries, protein markers of pathophysiological processes and tissue fate have been introduced in the clinic. The most studied protein “biomarker” of cerebral damage in traumatic brain injury (TBI) is the protein S100B. The aim of this narrative review is to thoroughly analyze the properties and capabilities of this biomarker with focus on clinical utility in the assessment of patients suffering from TBI.

Results

S100B has successfully been implemented in the clinic regionally (1) to screen mild TBI patients evaluating the need to perform a head computerized tomography, (2) to predict outcome in moderate-to-severe TBI patients, (3) to detect secondary injury development in brain-injured patients and (4) to evaluate treatment efficacy. The potential opportunities and pitfalls of S100B in the different areas usually refer to its specificity and sensitivity to detect and assess intracranial injury.

Conclusion

Given some shortcomings that should be realized, S100B can be used as a versatile screening, monitoring and prediction tool in the management of TBI patients.

A review of the clinical utility of serum S100B protein levels in the assessment of traumatic brain injury

BACKGROUND

In order to improve injury assessment of brain injuries, protein markers of pathophysiological processes and tissue fate have been introduced in the clinic. The most studied protein "biomarker" of cerebral damage in traumatic brain injury (TBI) is the protein S100B. The aim of this narrative review is to thoroughly analyze the properties and capabilities of this biomarker with focus on clinical utility in the assessment of patients suffering from TBI.

RESULTS

S100B has successfully been implemented in the clinic regionally (1) to screen mild TBI patients evaluating the need to perform a head computerized tomography, (2) to predict outcome in moderate-to-severe TBI patients, (3) to detect secondary injury development in brain-injured patients and (4) to evaluate treatment efficacy. The potential opportunities and pitfalls of S100B in the different areas usually refer to its specificity and sensitivity to detect and assess intracranial injury.

CONCLUSION

Given some shortcomings that should be realized, S100B can be used as a versatile screening, monitoring and prediction tool in the management of TBI patients.

The Relationship Between Serum Neuron-Specific Enolase Levels and Severity of Bleeding and Functional Outcomes in Patients With Nontraumatic Subarachnoid Hemorrhage

BACKGROUND

The value of neuron-specific enolase (NSE) in predicting clinical outcomes has been investigated in a variety of neurological disorders.

OBJECTIVE

To investigate the associations of serum NSE with severity of bleeding and functional outcomes in patients with subarachnoid hemorrhage (SAH).

METHODS

We retrospectively reviewed the records of patients with SAH from June 2008 to June 2012. The severity of SAH bleeding at admission was measured radiographically with the Fisher scale and clinically with the Glasgow Coma Scale, Hunt and Hess grade, and World Federation of Neurologic Surgeons scale. Outcomes were assessed with the modified Rankin Scale at discharge.

RESULTS

We identified 309 patients with nontraumatic SAH, and 71 had NSE testing. Median age was 54 years (range, 23-87 years), and 44% were male. In multivariable analysis, increased NSE was associated with a poorer Hunt and Hess grade (P = .003), World Federation of Neurologic Surgeons scale score (P < .001), and Glasgow Coma Scale score (P = .003) and worse outcomes (modified Rankin Scale at discharge; P = .001). There was no significant association between NSE level and Fisher grade (P = .81) in multivariable analysis.

CONCLUSION

We found a significant association between higher NSE levels and poorer clinical presentations and worse outcomes. Although it is still early for any relevant clinical conclusions, our results suggest that NSE holds promise as a tool for screening patients at increased risk of poor outcomes after SAH.

S100B raises the alert in subarachnoid hemorrhage

Subarachnoid hemorrhage (SAH) is a devastating disease with high mortality and mobility, the novel therapeutic strategies of which are essentially required. The calcium binding protein S100B has emerged as a brain injury biomarker that is implicated in pathogenic process of SAH. S100B is mainly expressed in astrocytes of the central nervous system and functions through initiating intracellular signaling or via interacting with cell surface receptor, such as the receptor of advanced glycation end products. The biological roles of S100B in neurons have been closely associated with its concentrations, resulting in either neuroprotection or neurotoxicity. The levels of S100B in the blood have been suggested as a biomarker to predict the progress or the prognosis of SAH. The role of S100B in the development of cerebral vasospasm and brain damage may result from the induction of oxidative stress and neuroinflammation after SAH. To get further insight into mechanisms underlying the role of S100B in SAH based on this review might help us to find novel therapeutic targets for SAH.

Prognostic value of the S100B protein in newly diagnosed and recurrent glioma patients: a serial analysis

The S100B protein is associated with brain damage and a breached blood–brain barrier. A previous pilot study showed that high serum levels of S100B are associated with shorter survival in glioma patients. The aim of our study was to assess the prognostic value in terms of survival and longitudinal dynamics of serum S100B for patients with newly diagnosed and recurrent glioma. We obtained blood samples from patients with newly diagnosed and recurrent glioma before the start (baseline) and at fixed time-points during temozolomide chemotherapy. S100B-data were dichotomized according to the upper limit of the reference value of 0.1 μg/L. Overall survival (OS) was estimated with Kaplan–Meier curves and groups were compared with the log rank analysis. To correct for potential confounders a Cox regression analysis was used. We included 86 patients with newly-diagnosed and 27 patients with recurrent glioma. Most patients in both groups had baseline serum levels within normal limits. In the newly diagnosed patients we found no significant difference in OS between the group of patients with S100B levels >0.1 μg/L at baseline compared to those with <0.1 μg/L. In the patients with recurrent glioma we found a significantly shorter OS for patients with raised levels. In both groups, S100B values did not change significantly throughout the course of the disease. Serum S100B levels do not seem to have prognostic value in newly diagnosed glioma patients. In recurrent glioma patients S100B might be of value in terms of prognostication of survival.

Association between S100B Levels and Long-Term Outcome after Aneurysmal Subarachnoid Hemorrhage: Systematic Review and Pooled Analysis

S100 calcium binding protein B (S100B), a well-studied marker for neurologic injury, has been suggested as a candidate for predicting outcome after subarachnoid hemorrhage. We performed a pooled analysis summarizing the associations between S100B protein in serum and cerebrospinal fluid (CSF) with radiographic vasospasm, delayed ischemic neurologic deficit (DIND), delayed cerebral infarction, and Glasgow Outcome Scale (GOS) outcome. A literature search using PubMed, the Cochrane Library, and the EMBASE databases was performed to identify relevant studies published up to May 2015. The weighted Stouffer's Z method was used to perform a pooled analysis of outcome measures with greater than three studies. A total of 13 studies were included in this review. Higher serum S100B level was found to be associated with cerebral infarction as diagnosed by CT (padj = 3.1 x 10(-4)) and worse GOS outcome (padj = 5.5 x 10(-11)). There was no association found between serum and CSF S100B with radiographic vasospasm or DIND. S100B is a potential prognostic marker for aSAH outcome.

Early and persistent high level of PS 100β is associated with increased poor neurological outcome in patients with SAH: is there a PS 100β threshold for SAH prognosis?

BACKGROUND

Protein S100β (PS100 β) and neuron specific enolase (NSE) have been described as biological markers of neuronal damage. The purpose of our study was to assess the prognosis thresholds of these biomarkers in subarachnoid aneurysmal hemorrhage (SAH).

METHODS

Forty eight patients admitted following SAH were treated by endovascular coiling. Initial neurologic severity was assessed using the World Federation Neurologic Surgeons (WFNS), Fisher grades, initial Glasgow coma scale (GCS) and SAPS II. PS100β and NSE plasma concentration were measured daily within the first week. The primary endpoint of the study was the 6-month Glasgow Outcome Score (GOS) dichotomized as poor (GOS 1-3) or good (GOS 4-5).

RESULTS

A poor outcome at 6-months was associated with significant higher levels of S100β value from day 1 to day 7, whereas NSE values were significantly higher from day 5 to day 7. Best threshold value, for prognosis, was obtained at day 5 for PS100β >0.13 μg/L (specificity 0.95 95% confidence interval (CI) 0.74-1; sensitivity 0.83 95% CI 0.65-0.93) and day 7 for NSE >14.5 μg/L (specificity 0.90 95% CI 0.67-0.98); sensitivity (0.69 95% CI 0.51-0.83)). After multivariate logistic analysis, only PS100β at day 5 and SAPS II enabled to predict neurological outcome at 6 months (p<0.05).

CONCLUSION

PS100β >0.13 μg/L at day 5 is an independent predicting factor of poor neurological outcome at 6 months following SAH. This result could support the use of this biomarker at the acute phase of SAH to help physician determine the prognosis.

Intracerebroventricular application of S100B selectively impairs pial arteriolar dilating function in rats

S100B is an astrocyte-derived protein that can act through the receptor for advanced glycation endproducts (RAGE) to mediate either "trophic" or "toxic" responses. Its levels increase in many neurological conditions with associated microvascular dysregulation, such as subarachnoid hemorrhage (SAH) and traumatic brain injury. The role of S100B in the pathogenesis of microvasculopathy has not been addressed. This study was designed to examine whether S100B alters pial arteriolar vasodilating function. Rats were randomized to receive (1) artificial cerebrospinal fluid (aCSF), (2) exogenous S100B, and (3) exogenous S100B+the decoy soluble RAGE (sRAGE). S100B was infused intracerebroventricularly (icv) using an osmotic pump and its levels in the CSF were adjusted to achieve a concentration similar to what we observed in SAH. After 48 h of continuous icv infusion, a cranial window/intravital microscopy was applied to animals for evaluation of pial arteriolar dilating responses to sciatic nerve stimulation (SNS), hypercapnia, and topical suffusion of vasodilators including acetylcholine (ACh), s-nitroso-N-acetyl penicillamine (SNAP), or adenosine (ADO). Pial arteriolar dilating responses were calculated as the percentage change of arteriolar diameter in relation to baseline. The continuous S100B infusion for 48 h was associated with reduced responses to the neuronal-dependent vasodilator SNS (p<0.05) and the endothelial-dependent vasodilator ACh (p<0.05), compared to controls. The inhibitory effects of S100B were prevented by sRAGE. On the other hand, S100B did not alter the responses elicited by vascular smooth muscle cell-dependent vasodilators, namely hypercapnia, SNAP, or ADO. These findings indicate that S100B regulates neuronal and endothelial dependent cerebral arteriolar dilation and suggest that this phenomenon is mediated through RAGE-associated pathways.

Biomarkers of Brain Damage: S100B and NSE Concentrations in Cerebrospinal Fluid--A Normative Study

NSE and S100B belong among the so-called structural proteins of the central nervous system (CNS). Lately, this group of structural proteins has been profusely used as specific biomarkers of CNS tissue damage. So far, the majority of the research papers have focused predominantly on the concentrations of these proteins in blood in relation to CNS damage of various origins. Considering the close anatomic and functional relationship between the brain or spinal cord and cerebrospinal fluid (CSF), in case of a CNS injury, a rapid and pronounced increase of the concentrations of structural proteins specifically in CSF takes place. This study inquires into the physiological concentrations of NSE and S100B proteins in CSF, carried out on a sufficiently large group of 601 patients. The detected values can be used for determination of a normal reference range in CSF in a clinical laboratory diagnostics.

Secondary peaks of S100B in serum relate to subsequent radiological pathology in traumatic brain injury

INTRODUCTION

Patients suffering from severe traumatic brain injury (TBI) often develop secondary brain lesions that may worsen outcome. S100B, a biomarker of brain damage, has been shown to increase in response to secondary cerebral deterioration. The aim of this study was to analyze the occurrence of secondary increases in serum levels of S100B and their relation to potential subsequent radiological pathology present on CT/MRI-scans.

METHODS

Retrospective study from a trauma level 1 hospital, neuro-intensive care unit. 250 patients suffering from TBI were included. Inclusion required a minimum of two radiological examinations and at least three serum samples of S100B, with at least one >48 h after trauma.

RESULTS

Secondary pathological findings on CT/MRI, present in 39 % (n = 98) of the patients, were highly correlated to secondary increases of ≥0.05 μg/L S100B (P < 0.0001, pseudo-R (2) 0.532). Significance remained also after adjusting for known important TBI predictors. In addition, secondary radiological findings were significantly correlated to outcome (Glasgow Outcome Score, GOS) in uni-(P < 0.0001, pseudo-R (2) 0.111) and multivariate analysis. The sensitivity and specificity of detecting later secondary radiological findings was investigated at three S100B cut-off levels: 0.05, 0.1, and 0.5 μg/L. A secondary increase of ≥0.05 μg/L had higher sensitivity (80 %) but lower specificity (89 %), compared with a secondary increase of ≥0.5 μg/L (16 % sensitivity, 98 % specificity), to detect secondary radiological findings.

CONCLUSIONS

Secondary increases in serum levels of S100B, even as low as ≥0.05 μg/L, beyond 48 h after TBI are strongly correlated to the development of clinically significant secondary radiological findings.

Effects of intravenous infusion of hydrogen-rich fluid combined with intra-cisternal infusion of magnesium sulfate in severe aneurysmal subarachnoid hemorrhage: study protocol for a randomized controlled trial

Background

The failures of recent studies intended to prevent cerebral vasospasm have moved the focus of research into delayed cerebral ischemia away from cerebral artery constriction towards other mechanisms. Recent accumulating evidence has suggested that early brain injury is also involved in the development of delayed cerebral ischemia, and that hydrogen can prevent early brain injury. Therefore, we have established a combination therapy of intravenous hydrogen infusion and intra-cisternal magnesium sulfate infusion for the treatment of both early brain injury and cerebral vasospasm. The present randomized controlled clinical trial is designed to investigate the effects of this novel therapeutic strategy on the occurrence of cerebral vasospasm, delayed cerebral ischemia, and clinical outcomes after high-grade subarachnoid hemorrhage.

Methods

This study is a randomized, double-blind, placebo-controlled design to be conducted in two hospitals. A total of 450 patients with high-grade subarachnoid hemorrhage will be randomized to one of three arms: (i) Mg + H₂ group, (ii) Mg group, and (iii) control group. Patients who are assigned to the Mg + H₂ group will receive intra-cisternal magnesium sulfate infusion (2.5 mmol/L) at 20 mL/h for 14 days and intravenous hydrogen-rich fluid infusion (200 mL) twice a day for 14 days. Patients who are assigned to the Mg group will receive intra-cisternal magnesium sulfate infusion (2.5 mmol/L) at 20 mL/h for 14 days and intravenous normal glucose-electrolyte solution (200 mL) without added hydrogen twice a day for 14 days. Patients who are assigned to the control group will receive intra-cisternal Ringer solution without magnesium sulfate at 20 mL/h for 14 days and intravenous normal glucose-electrolyte solution (200 mL) without added hydrogen twice a day for 14 days. Primary outcome measures will be occurrence of delayed cerebral ischemia and cerebral vasospasm. Secondary outcome measures will be modified Rankin scale score at 3, 6, and 12 months and biochemical markers.

Discussion

The present protocol for a randomized, placebo-controlled study of intravenous hydrogen therapy with intra-cisternal magnesium infusion is expected to establish the efficacy and safety of this therapeutic strategy.

Trial registration

UMIN-CTR: UMIN000014696

Lack of association of S100β and neuron-specific enolase with mortality in critically ill patients

OBJECTIVE

To evaluate the relationship between brain damage biomarkers and mortality in the intensive care unit (ICU).

METHODS

The sample comprised 70 patients admitted to an ICU. Blood samples were collected from all patients on ICU admission, and levels of S100β and neuron-specific enolase (NSE) were determined by ELISA.

RESULTS

Acute Physiologic and Chronic Health Evaluation (APACHE II) score was associated with mortality, but NSE and S100β were not associated with this outcome. In contrast, S100β levels were significantly higher in delirious and non-delirious patients who required mechanical ventilation during ICU stay.

CONCLUSION

Levels of brain biomarkers at the time of ICU admission did not predict mortality in critically ill patients.

Biomarkers and acute brain injuries: interest and limits

For patients presenting with acute brain injury (such as traumatic brain injury, subarachnoid haemorrhage and stroke), the diagnosis and identification of intracerebral lesions and evaluation of the severity, prognosis and treatment efficacy can be challenging. The complexity and heterogeneity of lesions after brain injury are most probably responsible for this difficulty. Patients with apparently comparable brain lesions on imaging may have different neurological outcomes or responses to therapy. In recent years, plasmatic and cerebrospinal fluid biomarkers have emerged as possible tools to distinguish between the different pathophysiological processes. This review aims to summarise the plasmatic and cerebrospinal fluid biomarkers evaluated in subarachnoid haemorrhage, traumatic brain injury and stroke, and to clarify their related interests and limits for diagnosis and prognosis. For subarachnoid haemorrhage, particular interest has been focused on the biomarkers used to predict vasospasm and cerebral ischaemia. The efficacy of biomarkers in predicting the severity and outcome of traumatic brain injury has been stressed. The very early diagnostic performance of biomarkers and their ability to discriminate ischaemic from haemorrhagic stroke were studied.

Biomarkers as outcome predictors in subarachnoid hemorrhage--a systematic review

CONTEXT

Subarachnoid hemorrhage (SAH) has a high fatality rate and many suffer from delayed neurological deficits. Biomarkers may aid in the identification of high-risk patients, guide treatment/management and improve outcome.

OBJECTIVE

The aim of this review was to summarize biomarkers of SAH associated with outcome.

METHODS

An electronic database query was completed, including an additional review of reference lists to include all potential human studies.

RESULTS

A total of 298 articles were identified; 112 were reviewed; 55 studies were included.

CONCLUSION

This review details biomarkers of SAH that correlate with outcome. It provides the basis for research investigating their possible translation into the management of SAH patients.

Identification of novel biomarkers of brain damage in patients with hemorrhagic stroke by integrating bioinformatics and mass spectrometry-based proteomics

Hemorrhagic stroke (HS) is a significant cause of mortality that requires rapid diagnosis and prompt medical attention. A time-efficient diagnostic test to assist in the early classification of patients with stroke would be of great value. The aims here were to (a) select "brain-specific" proteins using a bioinformatics approach, (b) develop selected reaction monitoring (SRM) assays for candidate proteins, and (c) quantify these proteins in cerebrospinal fluid (CSF). "The Human Protein Atlas" and the "Peptide Atlas" were used to select proteins specifically and abundantly expressed in brain tissue, excluding high-abundance plasma proteins. Protein extracts from brain tissue were used for SRM assay development of proteins of interest. The levels of 68 "brain-specific" proteins were measured by SRM in 36 age-matched patients, including individuals with HS (n = 15), ischemic stroke (n = 11), and controls (n = 10). Additionally, S100B was measured using an electrochemoluminometric immunoassay. CSF levels of S100B and eight of the "brain-specific" proteins (NSE, GFAP, α-Inx, MBP, MT3, NFM, β-Syn, and γ-Syn) were increased in a subset of samples from HS patients, especially in those individuals with intraventricular hemorrhage and poor outcome. Seven of these proteins (S100B, NSE, GFAP, α-Inx, MBP, NFM, and β-Syn) showed significant differences between patients with and without brain hemorrhage. Novel biomarkers of brain injury (α-Inx, NFM, and β-Syn) were identified in the CSF of patients with HS. Investigating the role of these proteins in blood with more sensitive methods is warranted.

Can S100B Predict Cerebral Vasospasms in Patients Suffering from Subarachnoid Hemorrhage?

Background: Protein S100B has proven to be a useful biomarker for cerebral damages. Increased levels of serum and cerebrospinal fluid (CSF) S100B have been shown in patients suffering subarachnoid hemorrhage (SAH), severe head injury and stroke. In patients with SAH, the course of S100B levels has been correlated with neurological deficits and outcome. Cerebral vasospasm is a major contributor to morbidity and mortality. The primary aim of this study was to investigate the potential of S100B protein as a predictor of cerebral vasospasm in patients with severe SAH.

Materials and Methods: Patients with SAH, Fisher grade 3 and 4, were included in the study. Five samples of CSF and serum S100B were collected from each patient. The first sample (baseline sample) was drawn within the first 3 days following ictus and the following four samples, once a day on days 5–8, with day of ictus defined as day 1. Clinical suspicion of cerebral vasospasm confirmed by computed tomography angiography was used to diagnose cerebral vasospasm.

Results: A total of 18 patients were included. Five patients (28%) developed cerebral vasospasm, two (11%) developed ventriculitis. There were no significant differences between S100B for those with and without vasospasm. Serum S100B levels in patients with vasospasm were slightly lower within the first 5 days following ictus, compared to patients without vasospasm. Two out of five patients had elevated and increasing serum S100B prior to vasospasm. Only one showed a peak level of S100B 1 day before vasospasm could be diagnosed. Due to the low number of patients in the study, statistical significance could not be reached.

Conclusion: Neither serum nor CSF S100B can be used as predictor of cerebral vasospasm in patients suffering from SAH.

CSF and Serum Biomarkers Focusing on Cerebral Vasospasm and Ischemia after Subarachnoid Hemorrhage

Delayed cerebral vasospasm (CVS) and delayed cerebral ischemia (DCI) remain severe complications after subarachnoid hemorrhage (SAH). Although focal changes in cerebral metabolism indicating ischemia are detectable by microdialysis, routinely used biomarkers are missing. We therefore sought to evaluate a panel of possible global markers in serum and cerebrospinal fluid (CSF) of patients after SAH. CSF and serum of SAH patients were analyzed retrospectively. In CSF, levels of inhibitory, excitatory, and structural amino acids were detected by high-performance liquid chromatography (HPLC). In serum, neuron-specific enolase (NSE) and S100B level were measured and examined in conjunction with CVS and DCI. CVS was detected by arteriography, and ischemic lesions were assessed by computed tomography (CT) scans. All CSF amino acids were altered after SAH. CSF glutamate, glutamine, glycine, and histidine were significantly correlated with arteriographic CVS. CSF glutamate and serum S100B were significantly correlated with ischemic events after SAH; however, NSE did not correlate neither with ischemia nor with vasospasm. Glutamate, glutamine, glycine, and histidine might be used in CSF as markers for CVS. Glutamate also indicates ischemia. Serum S100B, but not NSE, is a suitable marker for ischemia. These results need to be validated in larger prospective cohorts.

Protein S100B in Traumatic Brain Injury

Protein S100B is a small calcium-binding protein expressed in astroglial cells in the central nervous system. Its concentration increases in cerebrospinal fluid and blood after traumatic brain injury. There are several commercially available methods for analyzing serum S100B. The clinical use of serum S100B is mainly in minor head injury, as a complement to existing guidelines in order to help clinicians to determine who could safely be discharged without a previous CT scan. S100B in severe TBI is still being studied as a marker for secondary neurological complications, but has not yet had an impact in this specific area. Recent research on the clinical use of S100B in pediatric TBI has shown promising results, and the introduction of S100B in minor head injuries could have even greater impact than for adults. However, more research needs to be done before a biomarker can be clinically used in pediatric TBI.