Cerebrospinal fluid volume as an early radiological factor for clinical course prediction after aneurysmal subarachnoid hemorrhage. A pilot study.

BACKGROUND: The pathological mechanisms following aneurysmal subarachnoid hemorrhage (SAH) are poorly understood. Limited clinical evidence exists on the association between cerebrospinal fluid (CSF) volume and the risk of delayed cerebral ischemia (DCI) or cerebral vasospasm (CV). In this study, we raised the hypothesis that the amount of CSF or its ratio to hemorrhage blood volume, as determined from non-contrast Computed Tomography (NCCT) images taken on admission, could be a significant predictor for CV and DCI. METHODS: The pilot study included a retrospective analysis of NCCT scans of 49 SAH patients taken shortly after an aneurysm rupture (33 males, 16 females, mean age 56.4 ± 15 years). The SynthStrip and Slicer3D software tools were used to extract radiological factors - CSF, brain, and hemorrhage volumes from the NCCT images. The "pure" CSF volume (VCSF) was estimated in the range of [-15, 15] Hounsfield units (HU). RESULTS: VCSF was negatively associated with the risk of CV occurrence (p = 0.0049) and DCI (p = 0.0069), but was not associated with patients' outcomes. The hemorrhage volume (VSAH) was positively associated with an unfavorable outcome (p = 0.0032) but was not associated with CV/DCI. The ratio VSAH/VCSF was positively associated with, both, DCI (p = 0.031) and unfavorable outcome (p = 0.002). The CSF volume normalized by the brain volume showed the highest characteristics for DCI prediction (AUC = 0.791, sensitivity = 0.80, specificity = 0.812) and CV prediction (AUC = 0.769, sensitivity = 0.812, specificity = 0.70). CONCLUSION: It was demonstrated that "pure" CSF volume retrieved from the initial NCCT images of SAH patients (including CV, Non-CV, DCI, Non-DCI groups) is a more significant predictor of DCI and CV compared to other routinely used radiological biomarkers. VCSF could be used to predict clinical course as well as to personalize the management of SAH patients. Larger multicenter clinical trials should be performed to test the added value of the proposed methodology.

Interleukin 6 in cerebrospinal fluid is a biomarker for delayed cerebral ischemia (DCI) related infarctions after aneurysmal subarachnoid hemorrhage.

Interleukin 6 (IL-6) is a prominent proinflammatory cytokine and has been discussed as a potential biomarker for delayed cerebral ischemia (DCI) following aneurysmal subarachnoid hemorrhage. In the present study we have analyzed the time course of serum and cerebrospinal fluid (CSF) IL-6 levels in 82 patients with severe aneurysmal subarachnoid hemorrhage (SAH) requiring external ventricular drains in correlation to angiographic vasospasm, delayed cerebral ischemia, secondary infarctions and other clinical parameters. We observed much higher daily mean IL-6 levels (but also large interindividual variations) in the CSF than the serum of the patients with a peak between days 4 and 14 including a maximum on day 5 after SAH. Individual CSF peak levels correlated significantly with DCI (mean day 4-14 peak, DCI: 26,291 ± 24,159 pg/ml vs. no DCI: 16,184 ± 13,163 pg/ml; P = 0.023). Importantly, CSF IL-6 levels differed significantly between cases with DCI and infarctions and patients with DCI and no infarction (mean day 4-14 peak, DCI with infarction: 37,209 ± 26,951 pg/ml vs. DCI, no infarction: 15,123 ± 11,239 pg/ml; P = 0.003), while findings in the latter patient group were similar to cases with no vasospasm (mean day 4-14 peak, DCI, no infarction: 15,123 ± 11,239 vs. no DCI: 15,840 ± 12,979; P = 0.873). Together, these data support a potential role for elevated CSF IL-6 levels as a biomarker for DCI with infarction rather than for DCI in general. This fits well with a growing body of evidence linking neuroinflammation to ischemia and infarction, but (together with the large interindividual variations observed) limits the diagnostic usefulness of CSF IL-6 levels in SAH patients.

Changes in the cerebrospinal fluid lipid profile following subarachnoid hemorrhage in a closed cranium model: Correlations to cerebral vasospasm, neuronal cell death and Interleukin-6 synthesis. A pilot study.

BACKGROUND: Phospholipids and sphingolipids are cell membrane components, that participate in signaling events and regulate a wide variety of vital cellular processes. Sphingolipids are involved in ischemic stroke pathophysiology. Throughout cleavage of membrane sphingomyelin by sphingomyelinase in stroke patients, it results in increased Ceramide (Cer) levels in brain tissue. Different studies showed the evidence that sphingomyelinase with Cer production induces expression of interleukin (IL)-6 and have vasoconstrictive proprieties. With this study, we intend to evaluate cerebrospinal fluid (CSF) lipid profile changes in a rabbit closed cranium subarachnoid hemorrhage (SAH) model. METHODS: A total of 14 New Zealand white rabbits were randomly allocated either to SAH or sham group. In the first group SAH was induced by extracranial-intracranial shunting from the subclavian artery into the cisterna magna. Intracranial pressure (ICP) and arterial blood pressure were continuously monitored. Digital subtraction angiography of the basilar artery, CSF and blood samples were performed at day 0 pre SAH and on day 3 post SAH. The amount of IL-6 and various lipids in CSF were quantified using ELISA and Liquid Chromatography-Mass Spectrometry respectively. Cell death was detected in bilateral basal cortex, hippocampus (CA1 and CA3) using terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL). RESULTS: SAH Induction led to acute increase of ICP and increased delayed cerebral vasospasm (DCVS). At follow up CSF IL-6 levels showed a significant increase compared to baseline. Between baseline and follow up there were no significant differences in any of the measured CSF Lipids irrespective of subgroups. No relevant correlation was found between IL-6 and any of the sphingolipids. We found a correlation between baseline and follow up for the phospholipids phosphatidylethanolamine and phosphatidylcholine. CONCLUSIONS: Neuronal apoptosis, DCVS and IL-6 seems not to be related to changes in CSF lipid profiles except for PEA and PC in a rabbit closed cranium SAH model.

Propentdyopents as Heme Degradation Intermediates Constrict Mouse Cerebral Arterioles and Are Present in the Cerebrospinal Fluid of Patients With Subarachnoid Hemorrhage.

RATIONALE: Delayed ischemic neurological deficit is the most common cause of neurological impairment and unfavorable prognosis in patients with subarachnoid hemorrhage (SAH). Despite the existence of neuroimaging modalities that depict the onset of the accompanying cerebral vasospasm, preventive and therapeutic options are limited and fail to improve outcome owing to an insufficient pathomechanistic understanding of the delayed perfusion deficit. Previous studies have suggested that BOXes (bilirubin oxidation end products), originating from released heme surrounding ruptured blood vessels, are involved in arterial vasoconstriction. Recently, isolated intermediates of oxidative bilirubin degradation, known as PDPs (propentdyopents), have been considered as potential additional effectors in the development of arterial vasoconstriction. OBJECTIVE: To investigate whether PDPs and BOXes are present in hemorrhagic cerebrospinal fluid and involved in the vasoconstriction of cerebral arterioles. METHODS AND RESULTS: Via liquid chromatography/mass spectrometry, we measured increased PDP and BOX concentrations in cerebrospinal fluid of SAH patients compared with control subjects. Using differential interference contrast microscopy, we analyzed the vasoactivity of PDP isomers in vitro by monitoring the arteriolar diameter in mouse acute brain slices. We found an arteriolar constriction on application of PDPs in the concentration range that occurs in the cerebrospinal fluid of patients with SAH. By imaging arteriolar diameter changes using 2-photon microscopy in vivo, we demonstrated a short-onset vasoconstriction after intrathecal injection of either PDPs or BOXes. Using magnetic resonance imaging, we observed a long-term PDP-induced delay in cerebral perfusion. For all conditions, the arteriolar narrowing was dependent on functional big conductance potassium channels and was absent in big conductance potassium channels knockout mice. CONCLUSIONS: For the first time, we have quantified significantly higher concentrations of PDP and BOX isomers in the cerebrospinal fluid of patients with SAH compared to controls. The vasoconstrictive effect caused by PDPs in vitro and in vivo suggests a hitherto unrecognized pathway contributing to the pathogenesis of delayed ischemic deficit in patients with SAH.

Histidine-rich Glycoprotein Could Be an Early Predictor of Vasospasm after Aneurysmal Subarachnoid Hemorrhage.

Cerebral vasospasm (CVS) is a major contributor to the high morbidity and mortality of aneurysmal subarachnoid hemorrhage (aSAH) patients. We measured histidine-rich glycoprotein (HRG), a new biomarker of aSAH, in cerebrospinal fluid (CSF) to investigate whether HRG might be an early predictor of CVS. A total of seven controls and 14 aSAH patients (8 males, 6 females aged 53.4±15.4 years) were enrolled, and serial CSF and serum samples were taken. We allocated these samples to three phases (T1-T3) and measured HRG, interleukin (IL)-6, fibrinopeptide A (FpA), and 8-hydroxy-2'-deoxyguanosine (8OHdG) in the CSF, and the HRG in serum. We also examined the release of HRG in rat blood incubated in artificial CSF. In contrast to the other biomarkers examined, the change in the CSF HRG concentration was significantly different between the nonspasm and spasm groups (p<0.01). The rat blood/CSF model revealed a time course similar to that of the human CSF samples in the non-spasm group. HRG thus appears to have the potential to become an early predictor of CVS. In addition, the interaction of HRG with IL-6, FpA, and 8OHdG may form the pathology of CVS.

The rise of soluble platelet-derived growth factor receptor ß in CSF early after subarachnoid hemorrhage correlates with cerebral vasospasm.

Platelet-derived growth factor ß (PDGFß) has been proposed to contribute to the development of cerebral vasospasm (CVS) after subarachnoid hemorrhage (SAH), and soluble PDGFRß (sPDGFRß) is considered to be an inhibitor of PDGF signaling. We aimed at determining the sPDGFRß concentrations in the cerebrospinal fluid (CSF) of patients with aneurysmal SAH (aSAH) and analyzing the relationship between sPDGFRß level and CVS. CSF was sampled from 32 patients who suffered aSAH and five normal controls. Enzyme-linked immunosorbent assay was performed to determine the sPDGFRß concentrations in the CSF. Functional outcome was assessed using modified Rankin scale (mRS) at 6 months after aSAH. CVS was identified using transcranial Doppler or angio-CT or DSA. The cutoff of sPDGFRß for CVS was defined on the ROC curve. The concentrations of sPDGFRß following aSAH were both higher than those of normal controls on days 1-3 and 4-6, and peaked on days 7-9 post-SAH. The cutoff value of sPDGFRß level on days 1-3 for CVS was defined as 975.38 pg/ml according to the ROC curve (AUC = 0.680, p = 0.082). In addition, CSF sPDGFRß concentrations correlated with CVS (r = 0.416, p = 0.018), and multivariate analysis indicated that sPDGFRß level higher than 975.38 pg/ml on days 1-3 was an independent predictor of CVS (p = 0.001, OR = 19.22, 95% CI: 3.27-113.03), but not for unfavorable outcome after aSAH in the current study. CSF sPDGFRß level increases after aSAH and is higher in patients who developed CVS, and sPDGFRß level higher than 975.38 pg/ml on days 1-3 is a potential predictor for CVS after SAH.

A label-free cellulose SERS biosensor chip with improvement of nanoparticle-enhanced LSPR effects for early diagnosis of subarachnoid hemorrhage-induced complications.

It is very difficult to predict some complications after subarachnoid hemorrhage (SAH), despite rapid advances in medical science. Herein, we introduce a label-free cellulose surface-enhanced Raman spectroscopy (SERS) biosensor chip with pH-functionalized, gold nanoparticle (AuNP)-enhanced localized surface plasmon resonance (LSPR) effects for identification of SAH-induced cerebral vasospasm and hydrocephalus caused by cerebrospinal fluid (CSF). The SERS biosensor chip was implemented by the synthesis reaction of the AuNPs, which were charged positively through pH level adjustment, onto a negatively-charged cellulose substrate with ξ = -30.7 mV. The zeta potential, nanostructural properties, nanocrystallinity, and computational calculation-based electric field distributions of the cellulose-originated AuNPs were optimized to maximize LSPR phenomena and then characterized. Additionally, the performance of the SERS biosensor was compared under two representative excitation laser sources in the visible region (532 nm) and near-infrared region (785 nm). The Raman activities of our SERS biosensor chip were evaluated by trace small molecules (crystal violet, 2 µL), and the biosensor achieved an enhancement factor of 3.29 × 109 for the analytic concept with an excellent reproducibility of 8.5% relative standard deviation and a detection limit of 0.74 pM. Furthermore, the experimental results revealed that the five proposed SERS-based biomarkers could provide important information for identifying and predicting SAH-induced cerebral vasospasm and hydrocephalus complications (91.1% reliability and 19.3% reproducibility). Therefore, this facile and effective principle of our SERS biosensor chip may inspire the basis and strategies for the development of sensing platforms to predict critical complications in various neurosurgical diagnoses.

Seizures, CSF neurofilament light and tau in patients with subarachnoid haemorrhage.

OBJECTIVES: Patients with severe subarachnoid haemorrhage (SAH) often suffer from complications with delayed cerebral ischaemia (DCI) due to vasospasm that is difficult to identify by clinical examination. The purpose of this study was to monitor seizures and to measure cerebrospinal fluid (CSF) concentrations of neurofilament light (NFL) and tau, and to see whether they could be used for predicting preclinical DCI. METHODS: We prospectively studied 19 patients with aneurysmal SAH who underwent treatment with endovascular coiling. The patients were monitored with continuous EEG (cEEG) and received external ventricular drainage (EVD). CSF samples of neurofilament light (NLF) and total tau (T-tau) protein were collected at day 4 and day 10. Cox regression analysis was applied to evaluate whether seizures and protein biomarkers were associated with DCI and poor outcome. RESULTS: Seven patients developed DCI (37%), and 4 patients (21%) died within the first 2 months. Six patients (32%) had clinical seizures, and electrographic seizures were noted in one additional patient (4.5%). Increased tau ratio (proportion tau10/tau4) was significantly associated with DCI and hazard ratio [HR=1.33, 95% confidence interval (CI) 1.055-1.680. P = .016]. CONCLUSION: Acute symptomatic seizures are common in SAH, but their presence is not predictive of DCI. High values of the tau ratio in the CSF may be associated with development of DCI.

Long-Lasting Cerebral Vasospasm, Microthrombosis, Apoptosis and Paravascular Alterations Associated with Neurological Deficits in a Mouse Model of Subarachnoid Hemorrhage.

Subarachnoid hemorrhage (SAH) is a devastating disease with high mortality and morbidity. Long-term cognitive and sensorimotor deficits are serious complications following SAH but still not well explained and described in mouse preclinical models. The aim of our study is to characterize a well-mastered SAH murine model and to establish developing pathological mechanisms leading to cognitive and motor deficits, allowing identification of specific targets involved in these long-term troubles. We hereby demonstrate that the double blood injection model of SAH induced long-lasting large cerebral artery vasospasm (CVS), microthrombosis formation and cerebral brain damage including defect in potential paravascular diffusion. These neurobiological alterations appear to be associated with sensorimotor and cognitive dysfunctions mainly detected 10 days after the bleeding episode. In conclusion, this characterized model of SAH in mice, stressing prolonged neurobiological pathological mechanisms and associated sensitivomotor deficits, will constitute a validated preclinical model to better decipher the link between CVS, long-term cerebral apoptosis and cognitive disorders occurring during SAH and to allow investigating novel therapeutic approaches in transgenic mice.

Effect of Visible Light on Vasospasticity of Post-Subarachnoid Hemorrhage Cerebrospinal Fluid.

Background and Objective Cerebral vasospasm (CV) is a serious complication of subarachnoid hemorrhage (SAH) with high morbidity and mortality rates. The mechanism of CV has not been determined. There are many theories related to this unsolved issue, one of which supports CV as a two-stage phenomenon from a pathophysiologic perspective. The first stage consists of inhibition of neuronal nitric oxide synthase by oxyhemoglobin, which results in a decrease of nitric oxide (NO) production. The second stage consists of an increase in the levels of asymmetric dimethylarginine through bilirubin oxidation products (BOXes), which are oxidized by-products of hemoglobin metabolism. These in turn inhibit endothelial nitric oxide synthase (eNOS), which results in the blockage of the second NO production mechanism. BOXes are sensitive to visible light, as is their precursor bilirubin. The hypothesis of CV prevention using the photosensitivity of BOXes was tested in this study. Material and Methods Cerebrospinal fluid (CSF) obtained from two patients with SAH was divided in half and either exposed to a standard dose of visible light or not exposed to any light. The CSF was spectrophotometrically investigated and the concentration of BOXes was measured. A comparison between CSF samples exposed to light and not exposed to light was made. Using two groups of 16 rats each, the vasospastic effect of the CSF exposed and not exposed to light on arteries of the cortical surface was measured. The cortex was exposed using the cranial window. Results Spectrophotometric analysis revealed that the concentration of BOXes in the CSF decreased significantly after being exposed to visible light (p < 0.001). There was a significant difference of the vasospastic effect of CSF on exposed cortical arteries (p < 0.001). Conclusion The concentration of BOXes and the vasospastic effect of CSF taken from patients with SAH were significantly reduced after being exposed to visible light if compared with CSF not exposed to light.

Significance of routine cerebrospinal fluid analysis in subarachnoid hemorrhage.

BACKGROUND: The aim of this paper was to determine the diagnostic value of cerebrospinal fluid (CSF) analysis in the setting of aneurysmal subarachnoid hemorrhage (aSAH), hypothesizing that CSF analysis is only critical in confirming suspected infection and may be useful in predicting and/or detecting delayed cerebral ischemia (DCI). METHODS: Retrospective review of consecutive adult patients diagnosed with aSAH from 1/2000 to 12/2013 at Mayo Clinic, Rochester, MN, USA with cerebral aneurysm(s) identified by vascular imaging, and CSF drawn within 14 days of the date of hemorrhage. RESULTS: We identified 741 patients during the study period, 167 met inclusion criteria and 356 samples were collected. First Median CSF samples were taken 5 (4-8) days postbleed. Multiple samples were taken in 94 (54.5%) patients and the mean number of samples per patient was 2.1. Ventriculitis, confirmed by growth of organism from CSF culture was present in 2 (1.2%) patients and one patient (0.6%) developed meningitis. CSF WBC count remained elevated throughout the 14 days, even when corrected for red blood cell count (RBC). Peak CSF RBCs occurred 2-4 days post bleed, and then gradually normalized. Maximum CSF RBCs did not correlate with modified Fisher grades (P=0.422). Delayed cerebral ischemia (DCI) was present in 86 (51.5%) patients and there was no difference in the CSF profile of patients with DCI compared with those without. CONCLUSIONS: Routine CSF sampling for cell count and chemistry in the setting of temporary diversion following aSAH appears to have little clinical benefit beyond the evaluation for infection.

Interleukin 6 in the Cerebrospinal Fluid as a Biomarker for Onset of Vasospasm and Ventriculitis After Severe Subarachnoid Hemorrhage.

OBJECTIVE: The aim of the study was to investigate the diagnostic potential of interleukin 6 (IL-6) and other soluble biomarkers in serum and cerebrospinal fluid (CSF) for early diagnosis of cerebral vasospasm (cVSSAH) and external ventricular drain-associated ventriculitis (VCSAH) and to separate these conditions from aneurysmal subarachnoid hemorrhage (aSAH) without further complication (SAHw/o/c). METHODS: The concentrations of serum biomarkers and markers in the CSF were collected in 63 consecutive patients with aSAH and external ventricular drainage. Arithmetical means and standard deviations, area under the curve (AUC), cutoff values (C-OFF), sensitivity (SE), and specificity (SP) were calculated for markers and their correlation with SAHw/o/c, cVSSAH, and VCSAH. RESULTS: Clinical courses included 27 patients with cVSSAH, 17 with VCSAH, and 19 with SAHw/o/c. Mean ± standard deviationCSFIL-6 values were 7588 ± 4580 pg/mL at onset of VCSAH and 4102 ± 4970 pg/mL for cVSSAH and higher than 234 ± 239 pg/mL in SAHw/o/c (P < 0.001). CSFIL-6 showed excellent diagnostic potential for differing between VCSAH and SAHw/o/c (AUC, 1.00; C-OFF, 707; SE, 100%; SP, 100%), and a moderate diagnostic potential for differing VCSAH from cVSSAH (AUC, 0.757; C-OFF, 3100 pg/Ml; SE, 86.7%; SP, 70.6%). The concentration of CSFIL-6 within the cVSSAH group was significantly increased compared with SAHw/o/c (AUC, 0.937; C-OFF, 530 pg/mL; SE, 87.5%; SP, 91.7%). CONCLUSIONS: CSFIL-6 is increased after aSAH in patients with cVSSAH or VCSAH. Patients with a CSFIL-6 level higher than a C-OFF of 3100 pg/mL have an increased likelihood for VCSAH; patients with CSFIL-6 levels between 530 and 3100 pg/mL have an increased posttest probability for cVSSAH.

miRNA expression profiling of cerebrospinal fluid in patients with aneurysmal subarachnoid hemorrhage.

OBJECTIVE MicroRNAs (miRNAs) regulate gene expression and therefore play important roles in many physiological and pathological processes. The aim of this pilot study was to determine the feasibility of extraction and subsequent profiling of miRNA from CSF samples in a pilot population of aneurysmal subarachnoid hemorrhage patients and establish if there is a distinct CSF miRNA signature between patients who develop cerebral vasospasm and those who do not. METHODS CSF samples were taken at various time points during the clinical management of a subset of SAH patients (SAH patient samples without vasospasm, n = 10; SAH patient samples with vasospasm, n = 10). CSF obtained from 4 patients without SAH was also included in the analysis. The miRNA was subsequently isolated and purified and then analyzed on an nCounter instrument using the Human V2 and V3 miRNA assay kits. The data were imported into the nSolver software package for differential miRNA expression analysis. RESULTS From a total of 800 miRNAs that could be detected with each version of the miRNA assay kit, a total of 691 miRNAs were communal to both kits. There were 36 individual miRNAs that were differentially expressed (p < 0.01) based on group analyses, with a number of miRNAs showing significant changes in more than one group analysis. The changes largely reflected differences between non-SAH and SAH groups. These included miR-204-5p, miR-223-3p, miR-337-5p, miR-451a, miR-489, miR-508-3p, miR-514-3p, miR-516-5p, miR-548 m, miR-599, miR-937, miR-1224-3p, and miR-1301. However, a number of miRNAs did exclusively differ between the vasospasm and nonvasospasm SAH groups including miR-27a-3p, miR-516a-5p, miR-566, and miR-1197. CONCLUSIONS The findings indicate that temporal miRNA profiling can detect differences between CSF from aneurysmal SAH and non-SAH patients. Moreover, the miRNA profile of CSF samples from patients who develop cerebral vasopasm may be distinguishable from those who do not. These results provide a foundation for future research at identifying novel CSF biomarkers that might predispose to the development of cerebral vasospasm after SAH and therefore influence subsequent clinical management.

Massive Cerebrospinal Fluid Replacement Reduces Delayed Cerebral Vasospasm After Embolization of Aneurysmal Subarachnoid Hemorrhage.

BACKGROUND Delayed cerebral vasospasm (DCVS) following aneurismal subarachnoid hemorrhage (SAH) is a leading cause of poor prognosis and death in SAH patients. Effective management to reduce DCVS is needed. A prospective controlled trial was conducted to determine if massive cerebrospinal fluid (CSF) replacement (CR) could reduce DCVS occurrence and improve the clinical outcome after aneurysmal SAH treated with endovascular coiling. MATERIAL AND METHODS Patients treated with endovascular coiling after aneurysmal SAH were randomly divided into a control group receiving regular therapy alone (C group, n=42) and a CSF replacement group receiving an additional massive CSF replacement with saline (CR group, n=45). CSF examination, head CT, DCVS occurrence, cerebral infarction incidence, Glasgow Outcome Scale prognostic score, and 1-month mortality were recorded. RESULTS The occurrence of DCVS was 30.9% in the C group and 4.4% in the CR group (P<0.005). The cerebral infarction incidences in the C and CR groups were 19.0% and 2.2% (P<0.05), respectively, 1 month after the treatments. Mortality was not significantly different between the 2 groups during the follow-up period. CONCLUSIONS Massive CR after embolization surgery for aneurysmal SAH can significantly reduce DCVS occurrence and effectively improve the outcomes.

Elevated IL-6 and TNF-α Levels in Cerebrospinal Fluid of Subarachnoid Hemorrhage Patients.

The present study investigated the correlation between interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) levels in cerebrospinal fluid (CSF) and subarachnoid hemorrhage (SAH) progression. A meta-analysis was further conducted from pooled data to analyze the clinical value of IL-6 and TNF-α in SAH diagnosis. In our case-control study, a total of 57 SAH patients were assigned to two groups, CVS group (n = 27) and non-CVS group (n = 30), based on the presence of cerebral vasospasm (CVS). In addition, 65 healthy subjects were enrolled as controls. IL-6 and TNF-α levels in CSF were measured in all the study subjects by enzyme-linked immunosorbent assay (ELISA). For meta-analysis, an exhaustive literature search was conducted to identify relevant published articles and strict inclusion and exclusion criteria were applied to select studies for the present meta-analysis. Data extracted from these studies was analyzed using STATA 12.0 software. IL-6 and TNF-α levels in CSF of SAH patients were markedly higher than those of healthy controls (all P < 0.001). Further, CVS patients showed elevated IL-6 and TNF-α levels in CSF compared to non-CVS patients (all P < 0.001). The increase in IL-6 and TNF-α levels in CSF correlated with the increasing disease severity, based on Hunt-Hess grade, in SAH patients (all P < 0.05). Our meta-analysis also confirmed that IL-6 and TNF-α CSF levels were markedly higher in SAH patients compared to healthy controls (all P < 0.001). Ethnicity-stratified analysis showed that both IL-6 and TNF-α CSF levels were elevated in Asian SAH patients, compared to their healthy counterparts (all P < 0.05). The TNF-α CSF levels were significantly higher in Caucasian SAH patients (P < 0.001), but the IL-6 CSF levels showed no such differences compared to the healthy controls (P = 0.219). Subgroup analysis based on the presence of CVS showed that both IL-6 and TNF-α CSF levels were markedly higher in CVS patients than those in non-CVS patients (all P < 0.05). Our results provide strong evidence that IL-6 and TNF-α CSF levels are elevated in SAH patients and may participate in SAH development. Thus, these two cytokines could be important biomarkers for early diagnosis and disease monitoring in SAH patients.

[Reversible cerebral vasoconstriction syndrome. Challenge for diagnostics and intensive care therapy]. / Reversibles zerebrales Vasokonstriktionssyndrom. Herausforderung für Diagnostik und Intensivtherapie.

Reversible cerebral vasoconstriction syndrome (RCVS) is a disease of unclear incidence frequently affecting middle aged women and is usually associated with use of adrenergic or serotoninergic substances. The exclusion of relevant differential diagnoses, such as aneurysmal subarachnoid hemorrhage, primary cerebral angiitis, posterior reversible encephalopathy syndrome and carotid artery dissection is critical in terms of time and significance. Thunderclap headache as well as multiple and multilocular vasospasms with direct or indirect angiography without substantial findings in cerebrospinal fluid diagnostics are typical symptoms. The necessity for intensive care treatment is often justified by initial acute impairment of vital functions and possible development of cerebral or extracerebral complications. Because the exact pathophysiology remains unknown, a specific therapy does not exist. This poses significant challenges in intensive care medicine, which are illustrated on the basis of the case study presented.

Human tissue kallikrein ameliorates cerebral vasospasm in a rabbit model of subarachnoid hemorrhage.

OBJECTIVES: Cerebral vasospasm (CVS) and early brain injury are major causes of morbidity and mortality following subarachnoid hemorrhage (SAH). We investigated the efficiency of human tissue kallikrein (HTK) to prevent CVS in a rabbit model of SAH. METHODS: Forty-eight Japanese white rabbits were randomly divided into four groups (n = 12 each): control (sham-operated), SAH, SAH + phosphate-buffered saline (PBS, vehicle), and SAH + HTK. Basilar artery (BA) diameters were measured by three-dimensional computed tomography angiography at three time points. Endothelin-1 (ET-1) and nitric oxide (NO) levels in the cerebrospinal fluid (CSF) were assayed 24 h before and 5 and 7 days after SAH. After the last measurement, the animals were killed, and endothelial cell apoptosis was assessed. Bax and Bcl-2 levels in the BA were measured by western blotting. RESULTS: HTK was found to significantly reduce CVS following SAH in rabbits. Inverse changes were observed in ET-1 and NO levels in the CSF collected from the SAH group. HTK increased levels of NO, which has a vasodilatory effect, but did not affect levels of ET-1, which has a vasoconstrictive effect. CTA revealed that HTK treatment significantly increased BA diameter. Moreover, HTK treatment reduced the number of apoptotic cells following SAH, presumably by increasing and decreasing Bcl-2 and Bax expression, respectively. CONCLUSION: HTK ameliorated CVS and inhibited apoptosis in the BA in a rabbit model of SAH.

Haemoglobin scavenging after subarachnoid haemorrhage.

Rapid and effective clearance of cell-free haemoglobin after subarachnoid haemorrhage (SAH) is important to prevent vasospasm and neurotoxicity and improve long-term outcome. Haemoglobin is avidly bound by haptoglobin, and the complex is cleared by CD163 expressed on the membrane surface of macrophages. We studied the kinetics of haemoglobin and haptoglobin in cerebrospinal fluid after SAH. We show that haemoglobin levels rise gradually after SAH. Haptoglobin levels rise acutely with aneurysmal rupture as a result of injection of blood into the subarachnoid space. Although levels decline as haemoglobin scavenging occurs, complete depletion of haptoglobin does not occur and levels start rising again, indicating saturation of CD163 sites available for haptoglobin-haemoglobin clearance. In a preliminary neuropathological study we demonstrate that meningeal CD163 expression is upregulated after SAH, in keeping with a proinflammatory state. However, loss of CD163 occurs in meningeal areas with overlying blood compared with areas without overlying blood. Becauses ADAM17 is the enzyme responsible for shedding membrane-bound CD163, its inhibition may be a potential therapeutic strategy after SAH.

Time-dependent changes in cerebrospinal fluid metal ions following aneurysm subarachnoid hemorrhage and their association with cerebral vasospasm.

Aneurysm subarachnoid hemorrhage affects 10 in 100,000 people annually, 40 % of whom will develop neurological deficits from ischemic stroke caused by cerebral vasospasm. Currently, the underlying mechanisms are uncertain. Metal ions are important modulators of neuronal electrophysiological conduction and smooth muscle cell activity, thereby potentially contributing to vasospasm. We hypothesized that metal ion concentrations in the cerebrospinal fluid (CSF) after aneurysm rupture would change over time and be associated with vasospasm. To test this hypothesis, for 21 days, we collected CSF from patients with aneurysmal rupture and subjected it to spectrometry to detect metals. A repeated measures analysis was performed to analyze concentration changes over time. Six of the seven patients with aneurysmal rupture experienced vasospasm, all resolving by day 14. Changes in Fe²âº and Zn²âº concentrations in the CSF paralleled the incidence of vasospasm in this study population. Na²âº, Ca²âº, Mg²âº, and Cu²âº concentrations exhibited no statistically significant changes over time. In conclusion, Fe²âº concentration in the CSF was significantly elevated during days 7-10, whereas Zn²âº concentrations spiked shortly thereafter, during days 11-14. This suggests that Fe²âº may be related to the induction of vasospasm and Zn²âº may be a marker of early brain injury secondary to ischemic injury and inflammation.

Tenascin-C is a possible mediator between initial brain injury and vasospasm-related and -unrelated delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage.

INTRODUCTION: Tenascin-C (TNC), a matricellular protein, exerts diverse functions, including tissue remodeling and apoptosis, and is induced in cerebrospinal fluid (CSF) after aneurysmal subarachnoid hemorrhage (SAH). The purpose of this study was to examine the relationships among CSF TNC levels, initial brain injury, delayed cerebral ischemia (DCI), and vasospasm after SAH. METHODS: CSF TNC levels were measured in 30 patients with aneurysmal SAH of Fisher computed tomography (CT) group III who were treated microsurgically or endovascularly with CSF drainage within 24 h of SAH. Admission World Federation of Neurosurgical Societies (WFNS) grade was supposed to indicate the severity of initial brain injury. Cerebral vasospasm was defined as narrowed (≥ 25 %) cerebral arteries demonstrated by angiography. DCI was defined as any neurological deterioration presumed related to ischemia that persisted for ≥ 1 h. RESULTS: Higher CSF TNC levels were correlated with worse admission WFNS grades. Vasospasm was aggravated with higher TNC levels. DCI occurred regardless of the degree of vasospasm but was associated with TNC induction. Multivariate analyses showed that higher TNC levels and vasospasm were independent predictors of DCI occurrence. CONCLUSIONS: SAH (initial brain injury) that is more severe induces more TNC, which may cause the subsequent development of both vasospasm and vasospasm-unrelated secondary brain injury, leading to DCI.