Immune Characterization in Aneurysmal Subarachnoid Hemorrhage Reveals Distinct Monocytic Activation and Chemokine Patterns.

The pathophysiology of delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (aSAH) is incompletely understood. Intrathecal activation of inflammatory immune cells is suspected to play a major role for the induction of DCI. The aim of this study is to identify immune cell subsets and mediators involved in the pathogenesis of DCI. We prospectively collected blood and CSF from 25 patients with aSAH at early and late time points. We performed multicolor flow cytometry of peripheral blood and CSF, analyzing immune cell activation and pro-inflammatory cyto- and chemokines. In addition to the primary immune analysis, we retrospectively analyzed immune cell dynamics in the CSF of all our SAH patients. Our results show an increased monocyte infiltration secondary to aneurysm rupture in patients with DCI. Infiltrating monocytes are defined by a non-classical (CD14dim CD16+) phenotype at early stages. The infiltration is most likely triggered by the intrathecal immune activation. Here, high levels of pro-inflammatory chemokines, such as CXCL1, CXCL9, CXCL10, and CXCL11, are detected. The intrathecal cellular activation profile of monocytes was defined by upregulation of CD163 and CD86 on monocytes and a presumable later differentiation into antigen-presenting plasmacytoid dendritic cells (pDCs) and hemosiderophages. Peripheral immune activation was reflected by CD69 upregulation on T cells. Analysis of DCI prevalence, Hunt and Hess grade, and clinical outcome correlated with the degree of immune activation. We demonstrate that monocytes and T cells are activated intrathecally after aSAH and mediate a local inflammatory response which is presumably driven by chemokines. Our data shows that the distinct pattern of immune activation correlates with the prevalence of DCI, indicating a pathophysiological connection to the incidence of vasospasm.

Effect of local anesthesia with lidocaine on perioperative proinflammatory cytokine levels in plasma and cerebrospinal fluid in cerebral aneurysm patients: Study protocol for a randomized clinical trial.

BACKGROUND: Cerebral aneurysm surgery has significant mortality and morbidity rate. Inflammation plays a key role in the pathogenesis of intracranial aneurysms, their rupture, subarachnoid hemorrhage and neurologic complications. Proinflammatory cytokine level in blood and cerebrospinal fluid (CSF) is an indicator of inflammatory response. Cytokines contribute to secondary brain injury and can worsen the outcome of the treatment. Lidocaine is local anesthetic that can be applied in neurosurgery as regional anesthesia of the scalp and as topical anesthesia of the throat before direct laryngoscopy and endotracheal intubation. Besides analgesic, lidocaine has systemic anti-inflammatory and neuroprotective effect.Primary aim of this trial is to determine the influence of local anesthesia with lidocaine on the perioperative levels of pro-inflammatory cytokines interleukin-1ß, interleukin-6, and tumor necrosis factor-α in plasma and CSF in cerebral aneurysm patients. METHODS: We will conduct prospective randomized clinical trial among patients undergoing craniotomy and cerebral aneurysm clipping surgery in general anesthesia. Patients included in the trial will be randomly assigned to the lidocaine group (Group L) or to the control group (Group C). Patients in Group L, following general anesthesia induction, will receive topical anesthesia of the throat before endotracheal intubation and also regional anesthesia of the scalp before Mayfield frame placement, both done with lidocaine. Patients in Group C will have general anesthesia only without any lidocaine administration. The primary outcomes are concentrations of cytokines interleukin-1ß, interleukin-6 and tumor necrosis factor-α in plasma and CSF, measured at specific timepoints perioperatively. Secondary outcome is incidence of major neurological and infectious complications, as well as treatment outcome in both groups. DISCUSSION: Results of the trial could provide insight into influence of lidocaine on local and systemic inflammatory response in cerebrovascular surgery, and might improve future anesthesia practice and treatment outcome. TRIAL IS REGISTERED AT CLINICALTRIALS.GOV:: NCT03823482.

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.

Cell-Free Oxyhemoglobin in Cerebrospinal Fluid After Aneurysmal Subarachnoid Hemorrhage: Biomarker and Potential Therapeutic Target.

BACKGROUND: Aneurysmal subarachnoid hemorrhage (aSAH) is often complicated by the occurrence of delayed ischemic neurologic deficits (DIND), which impairs the clinical outcome of patients. The release of oxyhemoglobin (oxyHb) from lysing erythrocytes into cerebrospinal fluid (CSF) may critically contribute to the development of DIND. METHODS: Ventricular CSF of 18 high-grade (Fisher 3 and 4) aSAH patients was sampled daily from external ventricular drains between days 0 and 14 after bleeding. CSF was spectrophotometrically analyzed with precise quantification of cell-free oxyHb levels. RESULTS: OxyHb levels in CSF showed a delayed peak reaching the highest levels in the high-risk period for developing of DIND between days 3 and 14 after aneurysm rupture. Patients with DIND had a significantly higher cumulative oxyHb exposure within the first week after bleeding. CONCLUSIONS: OxyHb levels in CSF may be useful as a biomarker to predict DIND in aSAH patients. The contribution of oxyHb in CSF to the pathogenesis of DIND should be further investigated as a potential therapeutic target.

Early Dynamics of Interleukin-6 in Cerebrospinal Fluid after Aneurysmal Subarachnoid Hemorrhage.

BACKGROUND: Subarachnoid hemorrhage (SAH) is a severe condition associated with high mortality. Early brain injury (EBI) plays an important role in the pathophysiology of SAH, and inflammation is a major contributor to EBI. Inflammation is a widely studied topic in both experimental and clinical conditions; however, just a few clinical studies have focused primarily on the early inflammatory response after SAH, and detailed information about the association between the dynamics of early inflammatory response with main clinical characteristics is lacking. This study analyzes the early dynamics of inflammatory response after SAH and evaluates the possible associations between the markers of early inflammatory response and main clinical characteristics. PATIENTS AND METHODS: A total of 47 patients with a diagnosis of aneurysmal SAH within the last 24 hours were enrolled in the study. All treatments, including treatment of aneurysm (surgery/coiling) and implantation of a drainage system (external ventricular drainage/lumbar catheter), were conducted in the same way as in other patients with this diagnosis. Blood and cerebrospinal fluid (CSF) samples were collected three times a day for 4 days. The dynamics of proinflammatory cytokines were assessed, and associations between levels of the proinflammatory cytokines interleukin (IL)-6, IL-1ß, or tumor necrosis factor (TNF)α and main clinical characteristics were evaluated using linear mixed-effect models. RESULTS: The CSF levels of IL-6 were massively increased initially after SAH (up to 72 hours) with an additional increase in later phases (after 72 hours), but there was high variability in IL-6 levels. A significant association was noted between the Glasgow Outcome Scale score and both overall levels of IL-6 (p = 0.0095) and their dynamics (p = 0.0208); the effect of the Hunt and Hess scale was borderline (p = 0.0887). No association was found between IL-6 levels and Fisher grade, modality of treatment (surgery, coiling, no treatment), and later development of cerebral vasospasm. Plasmatic levels of IL-6 increased slightly, but no significant association was found. The levels of IL-1ß and TNFα were within the physiologic range in both CSF and plasma. CONCLUSIONS: Early dynamics of IL-6 in CSF are associated with a patient́s outcome. But it is difficult to use IL-6 alone for outcome prediction due to its high variability. The question is whether the dynamics of IL-6 could be used in combination with other early markers associated with brain injury. More detailed research is required to answer this question.

Increase of Soluble RAGE in Cerebrospinal Fluid following Subarachnoid Haemorrhage.

Receptors for advanced glycation end-products (RAGE) mediate the inflammatory reaction that follows aneurysmal subarachnoid haemorrhage. Soluble RAGE (sRAGE) may function as a decoy receptor. The significance of this endogenous anti-inflammatory mechanism in subarachnoid haemorrhage (SAH) remains unknown. The present study aims to analyse sRAGE levels in the cerebrospinal fluid (CSF) of SAH patients. sRAGE levels were assayed by ELISA kit in 47 CSF samples collected on post-SAH days 0-3, 5-7, and 10-14 from 27 SAH patients with acute hydrocephalus. CSF levels of sRAGE were compared with a control group and correlated with other monitored parameters. In the control group, the CSF contained only a trace amount of sRAGE. By contrast, the CSF of 20 SAH patients collected on post-SAH days 0-3 was found to contain statistically significant higher levels of sRAGE (mean concentration 3.91 pg/mL, p < 0.001). The most pronounced difference in CSF sRAGE levels between good and poor outcome patients was found on days 0-3 post-SAH but did not reach the significance threshold (p = 0.234). CSF sRAGE levels did not change significantly during hospitalisation (p = 0.868) and correlated poorly with treatment outcome, systemic inflammatory markers, and other monitored parameters. Our study revealed an early and constant increase of sRAGE level in the CSF of SAH patients.

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.

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.

[Diagnostic challenges of aneurysmal subarachnoid hemorrhage]. / Aneurysmaattinen lukinkalvonalainen verenvuoto--diagnoosi kiven alla ja kivi hukassa?

Diagostic approach to aneurysmal subarachnoid hemorrhage (aSAH) is based on computer tomography (CT) imaging, although a lumbar puncture and subsequent cerebrospinal fluid analysis is sometimes necessary. Identification of the ruptured aneurysm is done using angiography. Despite of modern imaging techniques, diagnostic definition of aSAH is still occasionally challenging. We describe three cases in which the diagnosis of aSAH has been delayed, in spite of positive imaging or lumbar puncture findings.

Association of Hemodynamic Factors With Intracranial Aneurysm Formation and Rupture: Systematic Review and Meta-analysis.

BACKGROUND: Recent evidence suggests a link between the magnitude and distribution of hemodynamic factors and the formation and rupture of intracranial aneurysms. However, there are many conflicting results. OBJECTIVE: To quantify the effect of hemodynamic factors on aneurysm formation and their association with ruptured aneurysms. METHODS: We performed a systematic review and meta-analysis through October 2014. Analysis of the effects of hemodynamic factors on aneurysm formation was performed by pooling the results of studies that compared geometrical models of intracranial aneurysms and "preaneurysm" models where the aneurysm was artificially removed. Furthermore, we calculated pooled standardized mean differences between ruptured and unruptured aneurysms to quantify the association of hemodynamic factors with ruptured aneurysms. Standard PRISMA guidelines were followed. RESULTS: The hemodynamic factors that showed high positive correlations with location of aneurysm formation were high wall shear stress (WSS) and high gradient oscillatory number, with pooled proportions of 78.8% and 85.7%, respectively. Positive correlations were largely seen in bifurcation aneurysms, whereas negative correlations were seen in sidewall aneurysms. Mean and normalized WSS were significantly lower and low shear area significantly higher in ruptured aneurysms. CONCLUSION: Pooled analyses of computational fluid dynamics models suggest that an increase in WSS and gradient oscillatory number may contribute to aneurysm formation, whereas low WSS is associated with ruptured aneurysms. The location of the aneurysm at the bifurcation or sidewall may influence the correlation of these hemodynamic factors.

Remote Multiple Intraparenchymal Hemorrhages Following Aneurysmal Clipping of the Anterior Communicating Artery: A Case Report and Literature Review.

Remote intraparenchymal hemorrhage after clipping of a ruptured aneurysm is rare. The pathogenesis is variable, and the therapeutic strategies remain controversial, because the natural history is unclear. Here we report a woman with subarachnoid hemorrhage (SAH), who had an aneurysm of the anterior communicating artery identified by computed tomography angiography (CTA). A 51-year-old women, who was in a good preoperative condition without movement disorders before operation, went on to exhibit left hemiparesis after aneurysmal clipping as she recovered from anesthesia in the operating room. CT images performed immediately after surgery showed that two intraparenchymal hemorrhages were present contralateral to the site of the operation. After conservative treatment, the patient recovered, but still displayed a movement disorder in the left limb. SAH induced-vasospasm, defective vascular autoregulation, excessive drainage of the cerebrospinal fluid, a change in the intracranial pressure after craniotomy, and brain shift may contribute to the pathogenesis of remote hemorrhage after surgery.

Search for Biomarkers of Intracranial Aneurysms: A Systematic Review.

INTRODUCTION: Intracranial aneurysms (IAs) remain a devastating clinical challenge, and the pathogenesis of IA formation and progression continues to be unclear. Biomarker analysis can help us understand IA development. The authors performed a systematic review of current literature on genetic and serum biomarkers for IAs in an attempt to identify diagnostic/prognostic factors for ruptured and unruptured aneurysms. METHODS: All relevant studies on PubMed that reported blood/cerebrospinal fluid (CSF) biomarkers and genes that regulate biomarker levels for IAs were assessed for whether the biomarkers/genes studied correlated with IA formation and rupture. RESULTS: Thirty-three studies were reviewed. IAs are associated with an increase in levels of immunologic markers, particularly complement C3 and C9, immunoglobulins IgG and IgM, M1/M2 macrophages, monocytes, and B and T lymphocytes; increase in blood and CSF levels of adhesion molecules; selectins found on vascular endothelium, platelets, and leukocytes; doubled ratios of elastase-to-alpha-1-antitrypsin as controls; elevated levels of neurofilament heavy chain SM135 and S-100 post rupture; and locus 19q13 with many candidate genes. CONCLUSION: Though the pathophysiology of the disease remains unclear, the current literature supports the role of inflammatory and cell adhesion molecules, enzymes and hormones that effect cerebral vasculature, and other cerebral proteins related to brain and vascular damage in both the formation and progression to rupture of IAs. Future investigations are needed to validate results from previous studies and identify new diagnostic/prognostic biomarkers of IAs.

Validation of cerebrospinal fluid findings in aneurysmal subarachnoid hemorrhage.

BACKGROUND: Recently proposed cutoff criteria for cerebrospinal fluid (CSF) analyses might safely exclude a diagnosis of aneurysmal subarachnoid hemorrhage (aSAH). OBJECTIVE: The objective of this study was to examine the sensitivity of a CSF red blood cell (RBC) count greater than 2000 × 10(6)/L (ie, 2000 RBCs per microliter) or the presence of visible CSF xanthochromia in identifying patients with aSAH. METHODS: We identified a retrospective case series of patients diagnosed with aSAH after lumbar puncture (LP) in an integrated health delivery system between January 2000 and June 2013 by chart review. All identified patients had at least 1 cerebral aneurysm that was treated with a neurosurgical or endovascular intervention during the index hospitalization. The lowest CSF RBC count was used for validation analysis. Cerebrospinal fluid color was determined by visual inspection. Xanthochromia was defined as pink, orange, or yellow pigmentation of CSF supernatant. RESULTS: Sixty-four patients met study inclusion criteria. Of these, 17 (33%) of 52 underwent LP within 12 hours of headache onset, and 49 (84%) of 58 exhibited CSF xanthochromia. The median CSF RBC count was 63250 × 10(6)/L. The sensitivity of a CSF RBC count of greater than 2000 × 10(6)/L in identifying aSAH was 96.9% (95% confidence interval, 89.3%-99.1%). Additional consideration of CSF xanthochromia resulted in a sensitivity of 100% (95% confidence interval, 94.3%-100%). CONCLUSIONS: All patients in this case series of patients with aSAH had either a CSF RBC count greater than 2000 × 10(6)/L or visible CSF xanthochromia, increasing the likelihood that this proposed cutoff strategy may safely identify patients who warrant further investigation for an aneurysmal cause of subarachnoid hemorrhage.

Microglia regulate blood clearance in subarachnoid hemorrhage by heme oxygenase-1.

Subarachnoid hemorrhage (SAH) carries a 50% mortality rate. The extravasated erythrocytes that surround the brain contain heme, which, when released from damaged red blood cells, functions as a potent danger molecule that induces sterile tissue injury and organ dysfunction. Free heme is metabolized by heme oxygenase (HO), resulting in the generation of carbon monoxide (CO), a bioactive gas with potent immunomodulatory capabilities. Here, using a murine model of SAH, we demonstrated that expression of the inducible HO isoform (HO-1, encoded by Hmox1) in microglia is necessary to attenuate neuronal cell death, vasospasm, impaired cognitive function, and clearance of cerebral blood burden. Initiation of CO inhalation after SAH rescued the absence of microglial HO-1 and reduced injury by enhancing erythrophagocytosis. Evaluation of correlative human data revealed that patients with SAH have markedly higher HO-1 activity in cerebrospinal fluid (CSF) compared with that in patients with unruptured cerebral aneurysms. Furthermore, cisternal hematoma volume correlated with HO-1 activity and cytokine expression in the CSF of these patients. Collectively, we found that microglial HO-1 and the generation of CO are essential for effective elimination of blood and heme after SAH that otherwise leads to neuronal injury and cognitive dysfunction. Administration of CO may have potential as a therapeutic modality in patients with ruptured cerebral aneurysms.

Intraventricular fibrinolysis with tissue plasminogen activator is associated with transient cerebrospinal fluid inflammation: a randomized controlled trial.

Locally administered tissue plasminogen activator (TPA) accelerates clearance of intraventricular hemorrhage (IVH), but its impact on neurologic outcomes remains unclear and preclinical research suggests it may have pro-inflammatory effects. We randomly allocated patients with ruptured cerebral aneurysms and IVH, treated with endovascular coiling and ventricular drainage, to receive either 2-mg intraventricular TPA or placebo every 12 hours. Cerebrospinal fluid (CSF) and serum cytokine and white blood cell (WBC) concentrations were measured before drug administration and daily for 72 hours. Cerebrospinal fluid D-dimer levels were assessed 6 and 12 hours after administration to quantify fibrinolysis. Six patients were randomized to each group. Patients treated with TPA developed higher CSF cytokine concentrations compared with placebo-treated patients (P<0.05 for tumor necrosis factor-α, interferon-γ, interleukin (IL)-1α, IL-1ß, IL-2, IL-4, and IL-6), as well as higher CSF WBC counts (P=0.03). Differences were greatest after 24 hours and decreased over 48 to 72 hours. The magnitude of the inflammatory response was significantly associated with peak CSF D-dimer concentration and extent of IVH clearance. We conclude that intraventricular TPA administration produces a transient local inflammatory response, the severity of which is strongly associated with the degree of fibrinolysis, suggesting it may be induced by release of hematoma breakdown products, rather than the drug itself.

Differentiation between traumatic tap and aneurysmal subarachnoid hemorrhage: prospective cohort study.

OBJECTIVES: To describe the findings in cerebrospinal fluid from patients with acute headache that could distinguish subarachnoid hemorrhage from the effects of a traumatic lumbar puncture. DESIGN: A substudy of a prospective multicenter cohort study. SETTING: 12 Canadian academic emergency departments, from November 2000 to December 2009. PARTICIPANTS: Alert patients aged over 15 with an acute non-traumatic headache who underwent lumbar puncture to rule out subarachnoid hemorrhage. MAIN OUTCOME MEASURE: Aneurysmal subarachnoid hemorrhage requiring intervention or resulting in death. RESULTS: Of the 1739 patients enrolled, 641 (36.9%) had abnormal results on cerebrospinal fluid analysis with >1 × 10(6)/L red blood cells in the final tube of cerebrospinal fluid and/or xanthochromia in one or more tubes. There were 15 (0.9%) patients with aneurysmal subarachnoid hemorrhage based on abnormal results of a lumbar puncture. The presence of fewer than 2000 × 10(6)/L red blood cells in addition to no xanthochromia excluded the diagnosis of aneurysmal subarachnoid hemorrhage, with a sensitivity of 100% (95% confidence interval 74.7% to 100%) and specificity of 91.2% (88.6% to 93.3%). CONCLUSION: No xanthochromia and red blood cell count <2000 × 10(6)/L reasonably excludes the diagnosis of aneurysmal subarachnoid hemorrhage. Most patients with acute headache who meet this cut off will need no further investigations and aneurysmal subarachnoid hemorrhage can be excluded as a cause of their headache.

Genetic markers in the EET metabolic pathway are associated with outcomes in patients with aneurysmal subarachnoid hemorrhage.

Preclinical studies show that epoxyeicosatrienoic acids (EETs) regulate cerebrovascular tone and protect against cerebral ischemia. We investigated the relationship between polymorphic genes involved in EET biosynthesis/metabolism, cytochrome P450 (CYP) eicosanoid levels, and outcomes in 363 patients with aneurysmal subarachnoid hemorrhage (aSAH). Epoxyeicosatrienoic acids and dihydroxyeicosatetraenoic acid (DHET) cerebrospinal fluid (CSF) levels, as well as acute outcomes defined by delayed cerebral ischemia (DCI) or clinical neurologic deterioration (CND), were assessed over 14 days. Long-term outcomes were defined by Modified Rankin Scale (MRS) at 3 and 12 months. CYP2C8*4 allele carriers had 44% and 36% lower mean EET and DHET CSF levels (P=0.003 and P=0.007) and were 2.2- and 2.5-fold more likely to develop DCI and CND (P=0.039 and P=0.041), respectively. EPHX2 55Arg, CYP2J2*7, CYP2C8*1B, and CYP2C8 g.36785A allele carriers had lower EET and DHET CSF levels. CYP2C8 g.25369T and CYP2C8 g.36755A allele carriers had higher EET levels. Patients with CYP2C8*2C and EPHX2 404del variants had worse long-term outcomes while those with EPHX2 287Gln, CYP2J2*7, and CYP2C9 g.816G variants had favorable outcomes. Epoxyeicosatrienoic acid levels were associated with Fisher grade and unfavorable 3-month outcomes. Dihydroxyeicosatetraenoic acids were not associated with outcomes. No associations passed Bonferroni multiple testing correction. These are the first clinical data demonstrating the association between the EET biosynthesis/metabolic pathway and the pathophysiology of aSAH.

Choice for the removal of bloody cerebrospinal fluid in postcoiling aneurysmal subarachnoid hemorrhage: external ventricular drainage or lumbar drainage?

AIM: External ventricular drainage (EVD) and lumbar drainage (LD) are the most widely used procedures for continued bloody cerebrospinal fluid drainage. Each has his own advantages and disadvantages. Here, we compared complications and clinical outcomes in patients with World Federation of Neurosurgical Societies (WFNS) grade III aneurysmal subarachnoid hemorrhage (aSAH) who underwent coil placement followed by EVD or LD. MATERIAL AND METHODS: In this prospective, controlled study, all patients with aSAH classified as WFNS grade III who underwent coil placement at our institution were divided randomly into 2 groups: the EVD group and the LD group. The ratios of intracerebral hemorrhage, vasospasm, infection, duration of catheter placement, hydrocephalus, and Glasgow outcome scale (GOS) after 2 months of onset were analyzed between the 2 groups. RESULTS: A total of 148 patients (mean age 56.8 years) were enrolled in this study. Seventy-six patients were assigned to the EVD group, and 72 patients were assigned to the LD group. The average time interval from stroke onset to surgery was 35.1 h. Compared with the EVD group, the LD group had a lower incidence of intracerebral hemorrhage, slightly higher rates of infection and hydrocephalus, and similar vasospasm and chronic hydrocephalus rates, durations of catheter placement, and GOS scores at 2 months after onset. CONCLUSION: In order to improve the clinical outcomes of patients with aSAH, we suggest that LD is better than EVD for patients with WFNS grade III aSAH who underwent coil placement.

Lipocalin-type prostaglandin D synthase scavenges biliverdin in the cerebrospinal fluid of patients with aneurysmal subarachnoid hemorrhage.

Lipocalin-type prostaglandin (PG) D synthase (L-PGDS) is the second major protein in human cerebrospinal fluid (CSF) and belongs to the lipocalin superfamily composed of various secretory lipophilic ligand transporter proteins. However, the endogenous ligand of L-PGDS has not yet been elucidated. In this study, we purified L-PGDS from the CSF of aneurysmal subarachnoid hemorrhage (SAH) patients. Lipocalin-type PG D synthase showed absorbance spectra with major peaks at 280 and 392 nm and a minor peak at around 660 nm. The absorbance at 392 nm of L-PGDS increased from 1 to 9 days and almost disappeared at 2 months after SAH, whereas the L-PGDS activity decreased from 1 to 7 days and recovered to normal at 2 months after SAH. These results indicate that some chromophore had accumulated in the CSF after SAH and bound to L-PGDS, thus inactivating it. Matrix assisted laser desorption ionization time-of-flight mass spectrometry of L-PGDS after digestion of it with endoproteinase Lys-C revealed that L-PGDS had covalently bound biliverdin, a by-product of heme breakdown. These results suggest that L-PGDS acted as a scavenger of biliverdin, which is a molecule not found in normal CSF. This is the first report of identification of a pathophysiologically important endogenous ligand for this lipocalin superfamily protein in humans.