Delayed intracerebral hemorrhage after ventriculoperitoneal shunt insertion. Case report and literature review

We present another case of delayed intracerebral hemorrhage after a ventriculoperitoneal (VP) shunting procedure. In this case, a right occipital intraparenchymal hematoma and associated intraventricular hemorrhage occurred six days after the operation for hydrocephalus secondary to subarachnoid hemorrhage in a 64 year old woman. It is a rare complication of VP shunting, with few cases reported previously in the literature. The presumed mechanism is the erosion of a cerebral blood vessel secondary to a close contact with the ventricular catheter; bleeding disorder, vascular malformation, head trauma or brain tumor were excluded in this patient.     

蛛网膜下腔出血后脑血管痉挛实验研究

目的　在兔蛛网膜下腔出血 (SAH)模型上 ,尝试建立经颅多普勒超声 (TCD)及血管造影 ,监测椎基动脉脑血管痉挛 (CVS)的新方法。方法　兔枕大池一次性注血 ,同时行逆行颈总动脉插管椎基动脉造影及开骨窗TCD监测。结果　逆行性脑血管造影能清晰显示椎基底动脉系统 ,注血前后血管直径差异明显 (P <0 .0 5 ) ,平均血流速度注血后明显增快 ,但中、重度痉挛之间基底动脉血流速度变化无明显差异。结论　一侧颈总动脉逆行插管椎基动脉造影 ,操作简便 ,结果可靠。采取开骨窗以提高TCD超声频率的方法 ,可获得兔基底动脉稳定的频谱图并易于重复。     

蛛网膜下腔出血后脑血管痉挛的研究进展

脑血管痉挛被认为是动脉瘤性蛛网膜下腔出血后迟发性脑缺血的主要原因,其发病机制尚不明确,且治疗效果不佳。最近的研究表明蛛网膜下腔出血后脑血管痉挛受多因素影响,包括脑血管功能失调、氧化应激、皮层去极化、免疫反应等,现就蛛网膜下腔出血后脑血管痉挛的可能发病机制及防治进展进行综述。     

Cerebral vasospasm after subarachnoid hemorrhage: the emerging revolution

Cerebral vasospasm is the classic cause of delayed neurological deterioration after aneurysmal subarachnoid hemorrhage, leading to cerebral ischemia and infarction, and thus to poor outcome and occasionally death. Advances in diagnosis and treatment-principally the use of nimodipine, intensive care management, hemodynamic manipulations and endovascular neuroradiology procedures-have improved the prospects for these patients, but outcomes remain disappointing. Recent clinical trials have demonstrated marked prevention of vasospasm with the endothelin receptor antagonist clazosentan, yet patient outcome was not improved. This Review considers possible explanations for this result and proposes alternative causes of neurological deterioration and poor outcome after subarachnoid hemorrhage, including delayed effects of global cerebral ischemia, thromboembolism, microcirculatory dysfunction and cortical spreading depression.     

盐酸戊乙奎醚蛛网膜下腔出血给药缓解脑血管痉挛

背景与目的: 胆碱受体阻断剂具有抗炎、拮抗氧自由基诱导的细胞应激打击、保护缺血损伤等非胆碱受体阻断的药理作用,还可以缓解蛛网膜下腔出血(SAH)后脑血管痉挛(CVS)和脑损伤[1-3],但以往的胆碱受体阻断剂因其某些不良反应限制了此类药在SAH方面的相关研究和应用。盐酸戊乙奎醚（Penehycldine Hydrochloride Injection,PHC）是我国自主研发的新型胆碱受体阻断剂,能弥补前述不足。本实验旨在动物模型中研究新型抗胆碱药PHC处理后,是否能改善SAH后损伤发挥其保护作用及不同用药方式效果比较。 盐酸戊乙奎醚是中国自主研发的新型胆碱受体阻断剂,给蛛网膜下腔出血动物模型肌注和枕大池注射盐酸戊乙奎醚,可缓解兔基底动脉痉挛,枕大池给药效果更好,且明显降低脑脊液中神经元特异性烯醇化酶和S-100β蛋白的表达。对蛛网膜下腔出血兔海马CA1区存活神经元数量、超氧化物歧化酶活性和丙二醛含量没有影响。提示盐酸戊乙奎醚对蛛网膜下腔出血的治疗作用与氧化应激无关,枕大池注射给药疗效可能更好。结果:在光镜下观察,药物治疗的两个组基底动脉痉挛有所缓解。术前检测的一般情况观察资料在各组间没有差异。与SAH和SAH+vehicle组相比,SAH+CM组的CC值明显降低,并有统计学差异(P＜0.05)。与SAH 和 SAH+Vehicle组相比, SAH+IM 和 SAH+CM组脑脊液NSE、S-100β浓度降低明显,有统计学差异(P＜0.05)。在SAH,SAH+IM,SAH+Vehicle,SAH+CM各组间,SOD活性、MDA含量、CA1区存活神经元数无统计学差异。 结论：盐酸戊乙奎醚能缓解动物模型蛛网膜下腔出血后的脑血管痉挛及保护脑细胞的损伤,并且局部给药有更好的疗效。 关键词：蛛网膜下腔出血;脑血管痉挛;盐酸戊乙奎醚;脑损伤     

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.     

Cerebral vasospasm after subarachnoid hemorrhage: An update

Symptomatic vasospasm, or delayed cerebral ischemia associated with arteriographic evidence of arterial constriction, is currently the most important cause of morbidity after acute subarachnoid hemorrhage. The development of vasospasm is directly correlated with the presence of thick blood clots in the basal subarachnoid cisterns, which can be detected by an early computed tomographic scan. Symptomatic vasospasm usually develops between 4 and 12 days after subarachnoid hemorrhage. The onset is gradual, occurring over hours or days. There is typically a gradual deterioration of the level of consciousness, accompanied by focal neurological deficits that are determined by the arterial territories involved. Hyponatremia frequently occurs and may exacerbate the symptoms. The patients are usually volume depleted, and therefore many authorities now treat them with replenishment and expansion of their intravascular volume with colloid and blood. Volume expansion, together with elevation of the systemic blood pressure and reduction of the intracranial pressure when elevated, constitute the only currently available effective therapy for symptomatic vasospasm. The cause of vasospasm remains obscure. Mechanisms of smooth muscle cell contraction and relaxation and experimental efforts to elucidate the nature of vasospasm are reviewed.     

Diffusion- and perfusion-weighted imaging in vasospasm after subarachnoid hemorrhage

BACKGROUND AND PURPOSE: Better measures of cerebral tissue perfusion and earlier detection of ischemic injury are needed to guide therapy in subarachnoid hemorrhage (SAH) patients with vasospasm. We sought to identify tissue ischemia and early ischemic injury with combined diffusion-weighted (DW) and hemodynamically weighted (HW) MRI in patients with vasospasm after SAH. METHODS: Combined DW and HW imaging was used to study 6 patients with clinical and angiographic vasospasm, 1 patient without clinical signs of vasospasm but with severe angiographic vasospasm, and 1 patient without angiographic spasm. Analysis of the passage of an intravenous contrast bolus through brain was used to construct multislice maps of relative cerebral blood volume (rCBV), relative cerebral blood flow (rCBF), and tissue mean transit time (tMTT). We hypothesize that large HW imaging (HWI) abnormalities would be present in treated patients at the time they develop neurological deficit due to vasospasm without matching DW imaging (DWI) abnormalities. RESULTS: Small, sometimes multiple, ischemic lesions on DWI were seen encircled by a large area of decreased rCBF and increased tMTT in all patients with symptomatic vasospasm. Decreases in rCBV were not prominent. MRI hemodynamic abnormalities occurred in regions supplied by vessels with angiographic vasospasm or in their watershed territories. All patients with neurological deficit showed an area of abnormal tMTT much larger than the area of DWI abnormality. MRI images were normal in the asymptomatic patient with angiographic vasospasm and the patient with normal angiogram and no clinical signs of vasospasm. CONCLUSIONS: We conclude that DW/HW MRI in symptomatic vasospasm can detect widespread changes in tissue hemodynamics that encircle early foci of ischemic injury. With additional study, the technique could become a useful tool in the clinical management of patients with SAH.     

Novel mechanism of endothelin-1-induced vasospasm after subarachnoid hemorrhage.

Cerebral vasospasm is a major cause of morbidity and mortality after aneurysmal subarachnoid hemorrhage (SAH). It is a sustained constriction of the cerebral arteries that can be reduced by endothelin (ET) receptor antagonists. Voltage-gated Ca(2+) channel antagonists such as nimodipine are relatively less effective. Endothelin-1 is not increased enough after SAH to directly cause the constriction, so we sought alternate mechanisms by which ET-1 might mediate vasospasm. Vasospasm was created in dogs, and the smooth muscle cells were studied molecularly, electrophysiologically, and by isometric tension. During vasospasm, ET-1, 10 nmol/L, induced a nonselective cation current carried by Ca(2+) in 64% of cells compared with in only 7% of control cells. Nimodipine and 2-aminoethoxydiphenylborate (a specific antagonist of store-operated channels) had no effect, whereas SKF96365 (a nonspecific antagonist of nonselective cation channels) decreased this current in vasospastic smooth muscle cells. Transient receptor potential (TRP) proteins may mediate entry of Ca(2+) through nonselective cationic pathways. We tested their role by incubating smooth muscle cells with anti-TRPC1 or TRPC4, both of which blocked ET-1-induced currents in SAH cells. Anti-TRPC5 had no effect. Anti-TRPC1 also inhibited ET-1 contraction of SAH arteries in vitro. Quantitative polymerase chain reaction and Western blotting of seven TRPC isoforms found increased expression of TRPC4 and a novel splice variant of TRPC1 and increased protein expression of TRPC4 and TRPC1. Taken together, the results support a novel mechanism whereby ET-1 significantly increases Ca(2+) influx mediated by TRPC1 and TRPC4 or their heteromers in smooth muscle cells, which promotes development of vasospasm after SAH.     

甲基强的松龙对兔实验性脑血管痉挛的作用

目的探讨大剂量甲基强的松龙对蛛网膜下腔出血(SAH)后脑血管痉挛(CVS)的作用。方法将24只雄性新西兰白兔随机分成2组:SAH对照组和SAH 大剂量甲基强的松龙(MP,18mg/kg)治疗组。通过枕大池二次注血法构建SAH模型,观察MP对脑基底动脉的影响。应用酶联免疫生化技术检测各组兔基底动脉血管平滑肌细胞膜蛋白激酶C(PKC)活性。结果经脑血管造影证实该剂量甲基强的松龙明显减轻实验性脑血管痉挛的严重程度,与对照组相比,PKC活性在大剂量甲基强的松龙治疗组没有明显提高。结论大剂量甲基强的松龙能够明显减轻脑血管痉挛程度,通过抑制血管平滑肌细胞来防治脑血管痉挛的发生发展。     

Angiographic vasospasm and release of platelet thromboxane after subarachnoid hemorrhage

We studied adenosine diphosphate-induced platelet aggregation and the associated release of thromboxane B2 in 49 patients with subarachnoid hemorrhage in relation to angiographic vasospasm. Postoperative cerebral angiography was performed less than or equal to 3 (median 1) days after surgery for an aneurysm 5-14 days after subarachnoid hemorrhage. Correspondingly, one sample from each patient was taken within 24 hours either before or after angiography. The occurrence of severe as well as diffuse, moderate, or severe angiographic vasospasm was associated with the presence of delayed cerebral ischemia (p less than 0.05). Patients with diffuse angiographic vasospasm had significantly higher (p less than 0.05) values for thromboxane B2 release than the others, even after adjustment by the clinical grades on admission and before surgery, the timing of surgery, the time from subarachnoid hemorrhage to angiography and blood sampling, and nimodipine therapy. Severe and diffuse angiographic vasospasm were also associated with poor outcome at 1 year (p less than 0.05). Our results suggest that augmented release of platelet thromboxane may be involved in the pathogenesis of vasospasm in large cerebral arteries.     

甲基强的松龙对兔实验性脑血管痉挛的作用

目的探讨大剂量甲基强的松龙对蛛网膜下腔出血（SAH）后脑血管痉挛（CVS）的作用。方法将24只雄性新西兰白兔随机分成2组：SAH对照组和SAH＋大剂量甲基强的松龙（MP，18mg／kg）治疗组。通过枕大池二次注血法构建SAH模型，观察MP对脑基底动脉的影响。应用酶联免疫生化技术检测各组兔基底动脉血管平滑肌细胞膜蛋白激酶C（PKC）活性。结果经脑血管造影证实该剂量甲基强的松龙明显减轻实验性脑血管痉挛的严重程度，与对照组相比，PKC活性在大剂量甲基强的松龙治疗组没有明显提高。结论大剂量甲基强的松龙能够明显减轻脑血管痉挛程度，通过抑制血管平滑肌细胞来防治脑血管痉挛的发生发展。     

Trapidil对蛛网膜下腔出血后脑血管痉挛作用的实验研究

目的 探讨蛛网膜下腔出血（SAH）后脑血管痉挛的发生机制及其可能的治疗方法。方法 利用家兔枕大池内注血构建SAH模型，观察血小板衍生生长因子（PDGF）拮抗剂trapidil对脑基底动脉的影响。结果 脑基底动脉于SAH后48h明显变细；静脉或动脉内持续灌注trapidil 15min（1．5mg／min）后，数字减影脑血管造影（DSA）显示痉挛血管已明显扩张变粗，30min时达高峰。结论 PDGF可能参与脑血管痉挛发生的病理过程，PDGF拮抗剂trapidil可有效缓解实验性SAH后脑血管痉挛，有望成为脑血管痉挛的治疗药物。     

动脉瘤性蛛网膜下腔出血后脑血管痉挛危险因素的分析

目的 探讨动脉瘤性蛛网膜下腔出血后脑血管痉挛的危险因素.方法 回顾性分析93例动脉瘤性蛛网膜下腔出血患者的临床资料,研究脑血管痉挛的危险因素.结果 93例动脉瘤性蛛网膜下腔出血患者中共有28例患者(30.1％)发生脑血管痉挛.Hunt-Hess分级≥Ⅲ级血管痉挛发生率明显高于Hunt-Hess分级Ⅰ-Ⅱ级,差异有统计学意义(P＜0.01);Fisher分级≥Ⅲ级血管痉挛发生率明显高于Fisher分级Ⅰ-Ⅱ级,差异有统计学意义(P＜0.01);白细胞计数＞ 15×109的患者脑血管痉挛发生率(41.9％,18/43)明显升高(P＜0.05).结论 Hunt-Hess分级≥Ⅲ级、Fisher分级≥Ⅲ级、白细胞计数增高是蛛网膜下腔出血后脑血管痉挛的危险因素.