Calcitonin-gene related peptide and cerebral vasospasm

The pathophysiology of arterial vasospasm following subarachnoid hemorrhage (SAH) is poorly understood and the contribution of endogenous neuropeptides has not been sufficiently elucidated. Recently, we detected an excessive release of vasoconstrictive neuropeptide Y (NPY) in SAH patients and identified a significant correlation of NPY cerebrospinal fluid (CSF) levels with vasospasm-related ischemia. Here, we present the results of an experimental study on the possible role of the potent endogenous vasodilator calcitonin-gene related peptide (CGRP) in the acute stage of SAH. Twelve consecutive patients with SAH were included. Seven patients had severe arterial vasospasm, confirmed by transcranial doppler-sonography (TCD). Prospectively, CSF was collected from day 1 to day 10 after onset of the SAH. The levels of CGRP were determined in a competitive enzyme immunoassay and were correlated with the clinical course and hemodynamic changes. A cohort of 29 patients without CNS disease served as a control. CGRP was significantly higher in SAH patients compared with the control group (p < 0.05). From day 1 to day 4, the CGRP levels in patients without vasospasm were significantly higher than the levels of CGRP in patients with vasospasm (p < 0.05). These patients did not develop cerebral ischemia. The significantly increased levels of the CGRP during the first days after onset of the SAH in the non-vasospasm group indicate a potential protective role of CGRP. CGRP may alleviate arterial vasoconstriction and thus protect the brain from vasospasm and subsequent ischemia.     

Cerebrospinal fluid membrane-bound tissue factor and myelin basic protein in the course of vasospasm after subarachnoid hemorrhage

Abstract

No marker that predicts accurately the time of occurrence of cerebral vasospasm due to subarachnoid hemorrhage (SAH) has been reported. In the present study, membrane-bound tissue factor (mTF) and myelin basic protein (MBP) concentrations in cerebrospinal fluid (CSF) were evaluated as a predictor of the time of occurrence of cerebral vasospasm. The mTF and MBP concentrations were measured in the CSF from 28 patients with SAH due to ruptured aneurysm. Serial assays were performed from day 4 to day 14 after SAH. CSF mTF and MBP concentrations from days 5 to 9 correlated with the volume of cerebral infarction due to vasospasm and outcome three months after SAH. From the serial assays, CSF mTF measurements predicted the time of occurrence and severity and irreversibility of symptoms due to vasospasm. In conclusion, CSF mTF is predictive of the occurrence and the recovery of cerebral vasospasm, while CSF MBP is only an indicator of severity of brain damage due to vasospasm. [Neurol Res 2001; 23: 715-720]     

Bilirubin production and oxidation in CSF of patients with cerebral vasospasm after subarachnoid hemorrhage.

Delayed cerebral vasospasm after subarachnoid hemorrhage (SAH) remains a significant cause of mortality and morbidity; however, the etiology is, as yet, unknown, despite intensive research efforts. Research in this laboratory indicates that bilirubin and oxidative stress may be responsible by leading to formation of bilirubin oxidation products (BOXes), so we investigated changes in bilirubin concentration and oxidative stress in vitro, and in cerebral spinal fluid (CSF) from SAH patients. Non-SAH CSF, a source of heme oxygenase I (HO-1), and blood were incubated, and in vitro bilirubin production measured. Cerebrospinal fluid from SAH patients was collected, categorized using stimulation of vascular smooth muscle metabolism in vitro, and information obtained regarding occurrence of vasospasm in the patients. Cerebral spinal fluid was analyzed for hemoglobin, total protein and bilirubin, BOXes, malonyldialdehyde and peroxidized lipids (indicators of an oxidizing environment), and HO-1 concentration. The formation of bilirubin in vitro requires that CSF is present, as well as whole, non-anti-coagulated blood. Bilirubin, BOXes, HO-1, and peroxidized lipid content were significantly higher in CSF from SAH patients with vasospasm, compared with nonvasospasm SAH CSF, and correlated with occurrence of vasospasm. We conclude that vasospasm may be more likely in patients with elevated BOXes. The conditions necessary for the formation of BOXes are indeed present in CSF from SAH patients with vasospasm, but not CSF from SAH patients without vasospasm.     

Cilostazol attenuates cerebral vasospasm after experimental subarachnoid hemorrhage

Abstract

Background and purpose: Cerebral vasospasm is a major cause of morbidity and mortality in patients with subarachnoid hemorrhage (SAH). Cilostazol, a selective inhibitor of phosphodiesterase 3, is a peripheral vasodilator, an anti-inflammatory, and causes antiplatelet aggregation. We investigated these effects on cerebral vasospasm after rat SAH.

Methods: Thirty-eight Sprague–Dawley rats were randomly divided into three groups: SAH + normal feed (SAH group; n=14), SAH + feed containing 0·1% cilostazol (cilostazol group; n=12) and sham-operated rats (sham group; n=12). The basilar arteries (BA) of all groups were analysed by measuring wall thickness, internal luminal perimeter and cross-sectional area on day 7. Immunohistochemical study with RM-4, an anti-rat macrophage/dendritic cells monoclonal antibody and ultrastructural study with transmission electron microscopy were performed.

Results: Although most animals in the SAH group presented with typical vasospasm, the means of inner perimeter and cross-section area of the BA in the cilostazol group were significantly greater than the SAH group (836 ± 134 μm versus 771 ± 125 μm and 39177 ± 15405 μm² versus 33098 ± 13871 μm², respectively). Wall thickness of the BA in the cilostazol group demonstrated significant decrease, compared with the SAH group (17·4 ± 2·3 versus 21·0 ± 2·7 μm). In immunohistological study, SAH induced an obvious increase in mean perivascular RM-4-positive cell count, whereas cilostazol significantly reduced it by 59%. Ultrastructural study depicted cilostazol markedly attenuating structural deterioration of the vascular wall due to SAH.

Conclusions: This work demonstrates that cilostazol attenuates cerebral vasospasm after SAH in rat, possibly in part due to the anti-inflammatory effect.     

蛛网膜下腔出血后脑血管痉挛与血管活性物质的关系

目的 探讨蛛网膜下腔出血后脑血管痉挛与血管活性物质的关系。方法 测定52例蛛网膜下腔出血患者血浆血栓素B_2(thromboxane B_2,TXB_2)、6-酮-前列环素F1α(6-keto-prostaglandin,6-Keto)及血浆和脑脊液中血管紧张素转化酶(angiotensin converting enzyme,ACE)活性,同时通过经颅多普勒超声检查法(transcranial Doppler nltrasonography,TCD)观察蛛网膜下腔出血后脑血管平均血流速度(Vm)的变化,并与正常对照组进行比较。结果 蛛网膜下腔出血患者血浆TXB_2水平高于对照组(P<0.01),6-Keto水平低于对照组(P<0.05或P<0.01);发病后血浆ACE活性无明显改变,但脑脊液中ACE活性高于对照组(P<0.01);大脑中动脉平均血流速度于蛛网膜下腔出血后第4～5d的变化最为显著(P<0.01)。结论 蛛网膜下腔出血后患者血浆TXB_2、6-Keto与脑脊液ACE水平均发生明显变化,结合TCD检测结果,推测蛛网膜下腔出血后脑血管痉挛与血管活性物质水平有关。     

Nonenzymatic derived lipid peroxide, 8-iso-PGF2α, participates in the pathogenesis of delayed cerebral vasospasm in a canine SAH model

Abstract

We studied whether 8-iso-PGF_2α, nonenzymatic arachidonyl peroxide, participated in the pathogenesis of delayed vasospasm using a canine subarachnoid hemorrhage (SAH) model. Fourteen adult mongrel dogs were divided into two groups, two-hemorrhage SAH group (n = 8) and control group (n = 6). The contents of 8-iso-PGF _2α in CSF, the basilar artery segment, and subarachnoid clot were measured by enzyme immunoassay kit. The CSF 8-iso-PGF_2α content on Day 7 in the SAH group was 67.9 ± 29.9 pg ml^-1 (n = 8), which was significantly higher than 27.1 ± 13.8 (n = 8) on Day 0 in the SAH group, and 33.2 ± 14.4 pg ml^-1 (n = 5) on Day 7 in the control group. The 8-iso-PGF_2α content in the basilar artery segment with spasm on Day 7 in the SAH group was 13.5 ± 1.9 pg mg^-1 wet weight (n = 8), significantly higher than 8.7 ± 1.9 (n = 6) in the control group. The 8-iso-PGF_2α content in subarachnoid clot was 1.7 ± 1.4 ng g^-1 wet weight (n = 8). Significant elevation of the 8-iso-PGF_2α contents in the CSF and the basilar artery segment occurred on Day 7 in the SAH group. The subarachnoid clot enclosed the basilar artery on Day 7, contained a considerable amount of 8-iso-PGF_2α. These results suggested that 8-iso-PGF_2α could play a crucial role in the pathogenesis of the delayed cerebral vasospasm. [Neurol Res 2002; 24: 301-306]     

Intracisternal administration of SB203580, a p38 mitogen-activated protein kinase inhibitor,attenuates cerebral vasospasm via inhibition of tumor-necrosis factor-α

Tumor-necrosis factor-α (TNF-α) is critical to the development of cerebral vasospasm after subarachnoid hemorrhage (SAH). Hence, therapeutic strategies targeting TNF-α can attenuate cerebral vasospasm. This study investigated the effects of SB203580, a p38 mitogen-activated protein kinase (MAPK) inhibitor, on TNF-α concentration in the cerebral arteries and the cerebrospinal fluid (CSF) after SAH and on subsequent cerebral vasospasm. Twenty-three rabbits were divided into four groups: (i) control (without SAH), (ii) SAH (SAH only), (iii) dimethylsulfoxide (DMSO, vehicle), and (iv) SB203580. The severity of vasospasm and the immunoreactivities of TNF-α and phosphorylated p38 MAPK in the brain vessels were determined in all animals, and the concentrations of TNF-α in the CSF were also assessed. Severe vasospasm was observed in the rabbits from the SAH and DMSO groups. SB203580 reversed vasospasm after SAH. Lower immunoreactivities of TNF-α and phosphorylated p38 MAPK were found in the basilar artery in the SB203580 group than in the DMSO group. The concentration of TNF-α in the CSF increased after SAH, but treatment with SB203080 after SAH suppressed this increase. Our data show that SB203580 reversed cerebral vasospasm by inhibiting the phosphorylation of p38 MAPK in the basilar artery and by suppressing the increase in TNF-α in the basilar artery and CSF after SAH. SB203580 could therefore potentially be used for the treatment of cerebral vasospasm after SAH.     

The expression of tissue factor and tissue factor pathway inhibitor in aortic smooth muscle cells is up-regulated in synthetic compared to contractile phenotype

Tissue factor (TF) and its specific inhibitor TF pathway inhibitor (TFPI) are produced by vascular smooth muscle cells (SMCs) in vitro and are increased in vivo in atherosclerotic compared to normal vessels. Besides local regulation of the hemostatic balance, this may be related to non-hemostatic TF/protease dependent functions such as SMC proliferation, adhesion and migration. The aim of the study was to compare the expression of both proteins between the contractile (normal adult) and synthetic (neo-intimal) SMC phenotypes. Primary cultures of SMCs isolated from rat thoracic aorta before and 10 days after balloon injury displayed stable characteristics of the contractile and synthetic phenotype, respectively. Synthetic SMCs expressed more TF mRNA than contractile SMCs, but released excess TF in the conditioned medium, so that the cell-associated TF activity measured by a factor Xa generating assay remained similar in the two subtypes. Accordingly, cell surface thrombogenicity measured under blood flow conditions was also similar. The production and release of functional TFPI was enhanced by a factor 3 to 6 (p < 0.01) in synthetic SMCs. A difference in the quantitative expression of TF and TFPI is a new distinctive feature of SMC phenotypes. Matrix-associated TFPI derived from synthetic SMCs may serve as an anchorage for their migration and regulate protease-activated processes during neo-intima formation.     

动脉瘤性蛛网膜下腔出血患者脑脊液中一氧化氮浓度的动态变化

目的探讨蛛网膜下腔出血后脑脊液中一氧化氮浓度的动态变化及其与脑血管痉挛的关系。方法采集57例动脉瘤性蛛网膜下腔出血(aSAH)患者脑脊液标本(采集时间为入院后即刻,出血后第3、5、7、10、14天),采用镉粒还原法检测脑脊液中NO浓度。结果出血后第3天脑脊液中NO浓度即有明显降低(P<0.05),在出血后第7～10天达到最低(P<0.01),而后逐渐升高。症状性脑血管痉挛患者NO浓度明显低于未痉挛者及无症状的脑血管痉挛患者。结论症状性脑血管痉挛的发生与脑脊液中NO浓度降低有一定相关性。     

Cerebrospinal fluid superoxide dismutase and serum malondialdehyde levels in patients with aneurysmal subarachnoid hemorrhage: preliminary results

Abstract

Objectives: Experimental studies provide evidence that oxidative damage plays a role in the development of vasospasm after aneurysmal subarachnoid hemorrhage (SAH) but data from human studies is still limited. The purpose of this study was to investigate the time course of cerebrospinal fluid (CSF) superoxide dismutase (SOD) and serum malondialdehyde (MDA) changes in patients with aneurysmal SAH.

Methods: SOD in CSF and MDA in the serum were detected on days 1–3, 5 and 7 after aneurysmal SAH in 21 patients, and the results were compared with 15 patients with hydrocephalus. The results were also compared with those of clinical parameters including the patient's outcome at 6 months.

Results: The mean CSF SOD levels were lower and serum MDA levels were higher than the controls. Patients with a high amount of blood within the cisterns had a trend to decreased SOD while increasing MDA levels.

Conclusion: These preliminary results suggest that the levels of antioxidants are decreased after the onset of SAH in the early period, possibly because of increased oxidative stress. Reactive oxygen-mediated oxidative damage may play an important role in inflammation after SAH.     

亚低温治疗对蛛网膜下腔出血继发性血管痉挛及脑脊液和血浆内皮素、降钙素基因相关肽的影响

目的 探讨亚低温治疗对蛛网膜下腔出血(SAH)继发性血管痉挛及脑脊液和血浆内皮素(ET)、降钙素基因相关肽(CGRP)水平的影响.方法 56例SAH患者随机分成亚低温组和对照组,两组在常规治疗的基础上,亚低温组增加局部亚低温治疗;检测两组入院时及治疗7 d、14 d脑脊液和血浆ET、CGRP水平,并比较两组脑血管痉挛的发病情况.结果 (1)脑脊液、血浆ET水平治疗7 d时亚低温组较对照组显著降低(均P＜0.05);14 d时差异更显著(均P＜0.01);两组CGRP水平治疗第7 d时降至最低,后渐升高,亚低温组较对照组变化幅度小,差异有统计学意义(P＜0.05～0.01).(2)亚低温组脑血管痉挛发病率为6.67%,较对照组的30.77%明显减少(P＜0.05).结论 亚低温治疗减少了SAH患者脑脊液和血浆中ET水平上升幅度及CGRP水平下降幅度,从而降低脑血管痉挛的发生率.     

High-Dose Simvastatin Is Effective in Preventing Cerebral Vasospasm after Aneurysmal Subarachnoid Hemorrhage: A Prospective Cohort Study in Korean Patients

ObjectiveThe goal of this study was to assess the effect of high-dose simvastatin on cerebral vasospasm and its clinical outcome after aneurysmal subarachnoid hemorrhage (SAH) in Korean patients.MethodsThis study was designed as a prospective observational cohort study. Its subjects were aneurysmal SAH patients who had undergone aneurysm clipping or coiling. They were assigned to 1 of 3 groups : the 20 mg, 40 mg, and 80 mg simvastatin groups. The primary end-point was the occurrence of symptomatic vasospasm. The clinical outcome was assessed with the modified Rankin Scale (mRS) score after 1 month and 3 months. The risk factors of the development of vasospasm were assessed by logistic regression analysis.ResultsNinety nine patients with aneurysmal SAH were treated and screened. They were sequentially assigned to the 20 mg (n=22), 40 mg (n=34), and 80 mg (n=31) simvastatin groups. Symptomatic vasospasm occurred in 36.4% of the 20 mg group, 8.8% of the 40 mg group, and 3.2% of the 80 mg group (p=0.003). The multiple logistic regression analysis showed that poor Hunt-Hess grades (OR=5.4 and 95% CI=1.09-26.62) and high-dose (80 mg) simvastatin (OR=0.09 and 95% CI=0.1-0.85) were independent factors of symptomatic vasospasm. The clinical outcomes did not show a significant difference among the three groups.ConclusionThis study demonstrated that 80 mg simvastatin treatment was effective in preventing cerebral vasospasm after aneurysmal SAH, but did not improve the clinical outcome in Korean 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

BackgroundPhospholipids 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.MethodsA 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).ResultsSAH 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.ConclusionsNeuronal 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.     

Neutrophil activation in acute human central nervous system injury

Abstract

Endothelial cell dysfunction may contribute to cerebral vasospasm and aggravation of ischemic brain damage following subarachnoid hemorrhage (SAH). It has been suggested that oxyhemoglobin derived from subarachnoid blood clots might be a prime candidate for cerebral vasospasm. In this study, cisternal bloody cerebrospinal fluid (bCSF) was collected from SAH patients four and seven days after aneurysmal rupture, and the effects of bCSF on the cell growth and intracellular calcium ion ([Ca²⁺]_i) dynamics were investigated in cultured human umbilical vein endothelial cells. CSF collected from patients undergoing other intracranial surgeries was used as a control. Pre-treatment with bCSF4 significantly facilitated cell proliferation and DNA synthesis in the cultured endothelial cells, and significantly enhanced histamine- induced [Ca²⁺]_i increase, while acute treatment of the bCSF elicited no [Ca²⁺]_i change. Pre-treatment with interleukin-1β showed a similar significant enhancement of the histamine-induced [Ca²⁺]_i response, while pre-treatment with high concentrations of serum or interleukin-6 did not change the [Ca²⁺]_i response. It is concluded that bCSF collected from SAH patients contains some substances which enhance endothelial cell proliferation and sensitivity to inflammatory mediator. [Neurol Res 2000; 22: 588-596]     

The Effect of Locally Administered Fibrinolytic Drugs Following Aneurysmal Subarachnoid Hemorrhage : A Meta-Analysis with Eight Randomized Controlled Studies

ObjectiveRapid dissolution of blood clots reduces vasospasm and hydrocephalus after subarachnoid hemorrhage (SAH), and locally administered fibrinolytic drugs (LAFDs) could facilitate the dissolution. However, the efficacy of LAFDs remains controversial. The aim of this meta-analysis was to determine the efficacy of LAFDs for vasospasm and hydrocephalus and in clinical outcomes. MethodsFrom PubMed, EMBASE, and Cochrane database, data were extracted by two authors. Meta-analysis was performed using a random effect model. Inclusion criteria were patients who had LAFDs with urokinase-type or recombinant tissue-plasminogen activator after SAH in comparison with medically untreated patients with fibrinolytic drugs. We only included randomized controlled trials (RCTs) in this analysis. The outcomes of interest were vasospasm, hydrocephalus, mortality, and 90-day unfavorable functional outcome. ResultsData from eight RCTs with 550 patients were included. Pooled-analysis revealed that the LAFDs were significantly associated with lower rates of vasospasm (LAFDs group vs. control group, 26.5% vs. 39.2%; odds ratio [OR], 0.48; 95% confidence interval [CI], 0.32–0.73); hydrocephalus (LAFDs group vs. control group, 26.0% vs. 31.6%; OR, 0.54; 95% CI, 0.32–0.91); and mortality (LAFDs group vs. control group, 10.5% vs. 15.7%; OR, 0.58; 95% CI, 0.34–0.99). The proportion of 90-day unfavorable outcomes was lower in the LAFDs group (LAFDs group vs. control group, 32.7% vs. 43.5%; OR, 0.55; 95% CI, 0.37–0.80). ConclusionThis meta-analysis with eight RCTs indicated that LAFDs were significantly associated with lower rates of vasospasm and hydrocephalus after SAH. Thus, LAFDs could consequently reduce mortality and improve clinical outcome after SAH.     

Endothelin and aneurysmal subarachnoid haemorrhage: a study of subarachnoid cisternal cerebrospinal fluid.

Endothelin (ET) is considered one of the most potent vasoconstrictor polypeptides; several experimental studies have suggested its possible role in the pathogenesis of arterial vasospasm after subarachnoid haemorrhage (SAH). Previously reported data on plasma and CSF levels of endothelin in patients with a diagnosis of SAH have been controversial. Cisternal endothelin CSF levels and the possibility that they could be related to vasospasm and other clinical patterns of SAH were investigated. CSF samples were obtained from 55 patients admitted after angiographic diagnosis of intracranial aneurysm. Levels of ET-1 and ET-3 were measured through radio-immunoassay technique. Twelve patients who had operations for unruptured aneurysms were considered control cases; 43 patients with SAH were classified according to: Hunt and Hess grading at admission, vasospasm grading, CT classification and timing of surgery. In all 55 patients ET-1 was measured, while positive levels of ET-3 were found only in 17 cases of 48. No linear correlation was found between cisternal CSF ET-1 levels when considering time of surgery, CT classification, Hunt and Hess grading at admission, and vasospasm grading. The results of ET-3 assay should be considered with great caution because of the low percentage of positive cases. Cisternal CSF levels of ET-1 and ET-3 are not directly related to the occurrence of arterial vasospasm after the aneurysm rupture, or to other major clinical patterns of SAH; however, ET-1 expression occurs either in paraphysiological (unruptured aneurysm) or in pathological conditions (SAH). It is suggested that ET may potentiate, or may be potentiated by, other factors playing a consistent pathophysiological role in the development of vasospasm.