Diffusion-perfusion MR evaluation and spectroscopy before and after surgical therapy for intracerebral hemorrhage

Introduction: Advanced magnetic resonance imaging (MRI) techniques provide metabolic/hemodynamic information that is useful in the diagnosis of ischemic stroke. To date, however, their application in intracerebral hemorrhage (ICH) has been limited. We postulate that these MRI techniques may help define mechanisms of secondary damage and assess effects of therapeutic interventions in perihematoma tissue after ICH. Methods: A 44-year-old woman presented with severe headache resulting from a right temporal ICH. After developing neurological deterioration 5 days after the bleed, the patient underwent evacuation of the hematoma. Specimen pathology suggested the presence of a small vascular malformation. Diffusion- and perfusion-weighted imaging as well as proton magnetic resonance spectroscopic imaging (¹H-MRSI) investigations to assess perihematoma brain tissue metabolic and circulatory profiles were performed before and after hematoma evacuation. Results: Pre-operative results showed mild oligemia posterior to the hematoma, increased average diffusion coefficient (DAV), and normal perihematoma N-acetyl-aspartate (NAA) concentration on ¹H-MRSI. This profile was interpreted as inconsistent with ischemia (as defined by reduced DAV and NAA) but compatible with perihematoma inflammation (as defined by elevated DAV and lactate signal). Postsurgical MRI investigations showed near normalization of the perfusion deficit. Conclusion: We postulate that mass effect produced by the hematoma, and perhaps inflammation, can induce perilesional reduced cerebral perfusion in a reversible manner.     

脑出血大鼠急性期血浆及脑匀浆神经肽Y活性的变化

目的　观察大鼠脑出血急性期血浆及脑匀浆中神经肽 Y (NPY)活性的动态变化 ,探讨 NPY在脑出血脑损害中的作用。方法　 Wistar大鼠 70只 ,随机抽签法分为脑出血组及假手术对照组 ,每组各 35只 ;每组再按出血前及出血后 0 .5、6、12、2 4、4 8和 72 h分为 7个亚组 ,每亚组 5只。分别于各时间点测定血浆和血肿周边脑组织 NPY含量 ,并观察血肿病灶区的组织形态学病理改变。结果　脑出血后 6 h血浆和血肿周边脑组织 NPY的含量开始同步升高 ,并于 2 4 h达峰值 ,4 8h开始回落 ,但至 72 h时 NPY的含量仍显著高于出血前 (P<0 .0 5或 P<0 .0 1)。光镜和电镜下脑组织也发生相应的病理损害。结论　 NPY可能参与了脑出血的病理生理过程。     

鼠脑出血后海马内皮素-1变化与脑出血继发性损伤

目的:研究脑出血后脑内内皮素(ET-1)表达与脑出血灶周围组织水肿之间的关系。方法:采用脑内注射胶原酶建立大鼠脑出血模型,SD大鼠30只单纯随机分为注射胶原酶4,24,48,72h组及假手术组,通过免疫组化、彩色病理图像分析系统及干湿法观察脑出血后海马ET-1表达和脑出血灶周围脑组织水含量。结果:给大鼠尾壳核注射胶原酶0.5IU,4h后即可见直径约2.5mm的血肿,脑水含量即明显升高,24h达高峰;与此同时脑出血后4h海马CA1犤(37.6±7.3)个/切片犦、CA3区犤(41.3±3.7)个/切片犦的阳性细胞数较假手术组犤(18.3±4.0),(27.1±4.3)个/切片犦明显增加,24h犤(75.8±6.6),(88.4±9.6)个/切片犦最为显著,阳性细胞数及平均截面积除72h组外,明显高于对照组,均有统计学的显著性意义(t=2.306～5×106,P<0.01或P<0.05),72h后阳性细胞数已逐渐接近正常。结论:大鼠脑出血后脑内ET-1过度表达可能是血肿周围存在水肿和继发性缺血的重要因素之一。     

Perihematoma cerebral blood flow is unaffected by statin use in acute intracerebral hemorrhage patients

Statin therapy has been associated with improved cerebral blood flow (CBF) and decreased perihematoma edema in animal models of intracerebral hemorrhage (ICH). We aimed to assess the relationship between statin use and cerebral hemodynamics in ICH patients. A post hoc analysis of 73 ICH patients enrolled in the Intracerebral Hemorrhage Acutely Decreasing Arterial Pressure Trial (ICH ADAPT). Patients presenting <24 hours from ICH onset were randomized to a systolic blood pressure target <150 or <180 mm Hg with computed tomography perfusion imaging 2 hours after randomization. Cerebral blood flow maps were calculated. Hematoma and edema volumes were measured planimetrically. Regression models were used to assess the relationship between statin use, perihematoma edema and cerebral hemodynamics. Fourteen patients (19%) were taking statins at the time of ICH. Statin-treated patients had similar median (IQR Q25 to 75) hematoma volumes (21.1 (9.5 to 38.3) mL versus 14.5 (5.6 to 27.7) mL, P=0.25), but larger median (IQR Q25 to 75) perihematoma edema volumes (2.9 (1.7 to 9.0) mL versus 2.2 (0.8 to 3.5) mL, P=0.02) compared with nontreated patients. Perihematoma and ipsilateral hemispheric CBF were similar in both groups. A multivariate linear regression model revealed that statin use and hematoma volumes were independent predictors of acute edema volumes. Statin use does not affect CBF in ICH patients. Statin use, along with hematoma volume, are independently associated with increased perihematoma edema volume.     

Perihematomal edema: Implications for intracerebral hemorrhage research and therapeutic advances

In humans, perihematomal edema (PHE) is considered to be a radiological marker of secondary injury following intracerebral hemorrhage (ICH). There is also evidence that PHE might contribute to poor outcome in ICH patients. Given the rising interest in secondary injury after ICH as a therapeutic target, PHE is becoming increasingly used as a proof-of-concept surrogate measure to assess the potential efficacy of various therapeutic interventions in clinical trials. We review the pathophysiology of PHE and its evolution, its prognostic significance and relationship to clinical outcomes, and variabilities in its detection and measurement methodologies to determine the advantages versus shortcomings of using PHE as a translational target or radiological marker to examine the efficacy of interventions aiming to mitigate secondary injury in ICH.     

高血压脑出血血肿周围水肿的危险因素分析

目的探讨高血压脑出血血肿周围水肿的独立危险因素。方法回顾性分析符合纳入条件的36例高血压脑出血患者的临床资料。其中发生血肿周围水肿扩大者17例,未发生血肿周围水肿扩大者19例。对患者的一般资料、术前搬运、发病到手术间隔时间、血压、高血压病程、出血量、出血位置、血肿侧别、血肿形状等可能影响血肿周围水肿的因素进行单因素分析。对单因素分析有统计学意义的结果(血压,出血位置,术前搬运)建立Logistic回归模型,分析血肿周围水肿的独立危险因素。结果 Logistic回归分析结果显示,高血压病程(P=0.007)和血肿形状(P=0.008)与血肿周围水肿密切相关;而血压、出血位置以及术前搬运等无统计学意义。结论较长的高血压病程以及不规则的血肿形状可能是高血压脑出血血肿周围水肿的危险因素。     

脑出血患者血肿周围组织病理及超微结构变化的动态观察

背景五年来,人们已经在动物脑内对脑出血血肿周围的病理改变进行了一些研究,然而很少人对脑出血后血肿周围的病理和超微结构进行评估。因此,本研究的目的是观察脑出血患者血肿周围组织普通病理及超微结构的动态变化。方法对30例脑出血患者采取非功能区漏斗式入颅,在入颅路径过程必须切除的脑组织中,把远离血肿的脑组织作为对照组(发病12h以内),靠近血肿旁1cm脑组织作为实验组。按发病到手术的时间将实验组分为6h以内组6例,6~12h组7例,12~24h组5例,24~48h组3例,48~72h组3例,3~4d组3例,5d组2例,8d组1例。应用光镜和电镜观察脑组织普通病理及超微结构的动态变化。结果对照组脑组织形态和结构基本正常。实验组6h以内脑组织有轻微损伤。6h以后脑组织损伤逐渐加重。24~48h损伤达高峰,光镜显示脑细胞和纤维水肿明显,细胞形态不完整,核固缩,炎性细胞浸润明显;电镜显示神经元细胞核变空染色质聚集,线粒体肿胀,嵴变短或消失,核糖体减少,次级溶酶体增加,细胞变空,细胞膜不完整,胶质细胞核固缩。72h以后损伤逐渐好转,5d时损伤与6~12h组相似,8d时基本好转,与6h以内组基本接近。结论脑出血后血肿周围脑组织继发性损伤早期就有病理改变,损伤高峰在24~72h,与一般脑出血临床神经功能损害的变化规律基本一致,可能与血肿周围组织的继续发性损伤有关。     

脑出血患者血肿周围组织炎性反应与细胞凋亡的相关性研究

目的探讨脑出血患者血肿周围组织炎性反应与细胞凋亡的关系。方法对30例手术的脑出血患者于血肿旁约1cm处取少许脑组织作为试验组，按发病到手术的时间将试验组分为〈6h（6例）、6～12h（7例）、12～24h（5例）、24～72h（6例）、〉72h（6例）。从前两组中选7例患者于手术入颅路径上远隔血肿处取少许脑组织作为对照组。应用苏木素-伊红（HE）染色、免疫组化染色、末端脱氧核苷酸转移酶介导的dUTP缺口末端标记法（TUNEL）、逆转录-聚合酶链反应（RT—PCR）分别观察组织病理、炎性细胞浸润和小胶质细胞增生、凋亡细胞、促凋亡基因（Bax）、抗凋亡基因（Bcl-X）的变化情况。结果光镜观察显示：对照组和试验组6h内脑组织基本正常，试验组6～12h损伤较轻，12～24h损伤较重，24～48h损伤严重，以后逐渐好转，8d时与对照组相似。免疫组化显示：中性粒细胞、淋巴细胞、巨噬细胞浸润从6～12h逐渐明显，12～24h达高峰（P均〈0．01），小胶质细胞增生从24～72h开始，72h以后明显增强（P均〈0．01）；凋亡细胞、Bax蛋白表达从6～12h开始增加，12～24h达高峰（P〈0．05或P〈O．01）。Bcl—X蛋白及其mRNA表达从12～72h有增加的趋势，但差异无显著性。RT—PCR显示：Bax mRNA表达与免疫组化结果相似；相关分析显示：中性粒细胞、淋巴细胞、巨噬细胞浸润和小胶质细胞增生与凋亡细胞、Bax蛋白和BaxmRNA表达呈显著正相关（P〈0．05或P〈0．01）．与Bcl—X蛋白及其mRNA表达无相关性（P均〉0．05）。结论脑出血后血肿周围组织的炎性反应与细胞凋亡关系密切，并与组织病理损伤相一致。     

脑出血患者血肿周围组织补体激活与炎性反应的相关性研究

目的研究脑出血患者血肿周围组织补体激活与炎性反应的关系。方法对30例脑出血患者(实验组)在手术时于血肿旁约1cm处取少许脑组织,按发病到手术的时间将实验组分为<6h组(6例),6~12h组(7例),12~24h组(5例),24~72h组(6例),>72h组(6例)。从前2组中选7例患者(对照组)在手术入颅路径上远离血肿处取少许脑组织。应用免疫组化染色,逆转录-聚合酶链反应(RT-PCR)分别观察补体C3和补体抑制剂(Clusterin)的表达与炎性细胞的浸润、胶质细胞增生、炎性细胞因子的表达情况。结果与对照组相比,脑出血患者C3表达高峰在12~72h(P<0.05~0.01),Clusterin表达于12~72h有增高趋势,但无统计学意义;炎性细胞浸润从6~12h逐渐明显,12~72h达高峰(P<0.05~0.01);小胶质细胞、星形胶质细胞于24~72h后增生明显(均P<0.01);肿瘤坏死因子-α(TNF-α)表达于12~72h达高峰(P<0.05~0.01),后逐渐降低。RT-PCR显示:TNF-αmRNA的表达与蛋白表达基本一致;白细胞介素(IL)-1β(IL-1β)和IL-6mRNA表达于12~72h达峰值(均P<0.01)。相关因素分析显示:C3表达与炎性细胞浸润和胶质细胞增生及与细胞因子表达呈显著正相关(r=0.42~0.80;P<0.05~0.01),而Clusterin与上述表达无相关性。结论脑出血患者血肿周围组织补体激活与炎性反应有密切关系。     

大鼠脑出血血肿周围半暗带及其时间窗的探讨

缺血半暗带的概念最早由Astrup于1977年提出。其主要特征为缺血性、可逆性、存在的时限性即时间窗。本文旨在探讨脑出血血肿周边脑组织随着出血时间的不同是否存在着类似脑梗死病理变化的半暗带,并进一步探讨其时间窗。