Name: intracranial pressure monitoring in nontraumatic intraventricular hemorrhage rodent model
Uploaded: 2022-02-08T14:45:00
Description: Watch this Scientific Journal Video about Intracranial Pressure Monitoring In Nontraumatic Intraventricular Hemorrhage Rodent Model at JoVE.com

这项工作由NINDS资助：K08NS105914

所有研究方法和动物护理/维护均按照加州大学戴维斯分校的机构指南进行。加州大学戴维斯分校的机构动物护理和使用委员会（IACUC）批准了所有动物使用方案和实验程序（IACUC协议#21874）。
1. 动物饲养
<ol><li>获得8-10个月大的Sprague-Dawley大鼠。在任何实验程序之前，将大鼠饲养在动物饲养室中，并在随意进食和水的12小时光照/黑暗循环后，在笼子中允许至少1周?...

<ol>
	<li>Gates, P. C., Barnett, H. J. M., Vinters, H. V., Simonsen, R. L., Siu, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Primary+intraventricular+hemorrhage+in+adults.">Primary intraventricular hemorrhage in adults.</a> Stroke. 17, 872-877 (1986).</li><li>Strajle, J., Garton, H. J. L., Maher, C. O., Muraszko, K., Keep, R. F., Xi, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanisms+of+hydrocephalus+after+neonatal+and+adult+intraventricular+hemorrhage.">Mechanisms of hydrocephalus after neonatal and adult intraventricular hemorrhage.</a> Translational Stroke Research. 3, 25-38 (2012).</li><li>Murao, K., Rossi, C., Cordonnier, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intracerebral+hemorrhage+and+cognitive+decline.">Intracerebral hemorrhage and cognitive decline.</a> Revue Neurologique. 169, 772-778 (2013).</li><li>Al-Khindi, T., Macdonald, R. L., Schweizer, T. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cognitive+and+functional+outcome+after+aneurysmal+subarachnoid+hemorrhage.">Cognitive and functional outcome after aneurysmal subarachnoid hemorrhage.</a> Stroke. 41, 519-536 (2010).</li><li>Kreiter, K. T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Predictors+of+cognitive+dysfunction+after+subarachnoid+hemorrhage.">Predictors of cognitive dysfunction after subarachnoid hemorrhage.</a> Stroke. 33, 200-208 (2002).</li><li>Zanaty, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intraventricular+extension+of+an+aneurysmal+subarachnoid+hemorrhage+is+an+independent+predictor+of+a+worse+functional+outcome.">Intraventricular extension of an aneurysmal subarachnoid hemorrhage is an independent predictor of a worse functional outcome.</a> Clinical Neurology and Neurosurgery. 170, 67-72 (2018).</li><li>Gabrielian, L., Willshire, L. W., Helps, S. C., vanden Heuvel, C., Mathias, J., Vink, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intracranial+pressure+changes+following+traumatic+brain+injury+in+rats:+lack+of+significant+change+in+the+absence+of+mass+lesions+or+hypoxia.">Intracranial pressure changes following traumatic brain injury in rats: lack of significant change in the absence of mass lesions or hypoxia.</a> Journal of Neurotrauma. 28, 2103-2111 (2011).</li><li>Kolar, M., Nohejlova, K., Duska, F., Mares, J., Pachl, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Changes+of+cortical+perfusion+in+the+early+phase+of+subarachnoid+bleeding+in+a+rat+model+and+the+role+of+intracranial+hypertension.">Changes of cortical perfusion in the early phase of subarachnoid bleeding in a rat model and the role of intracranial hypertension.</a> Physiological Research. 66, 545-551 (2017).</li><li>Ariesen, M. J., Claus, S. P., Rinkel, G. J. E., Algra, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Risk+factors+for+intracerebral+hemorrhage+in+the+general+population.+A+systematic+review.">Risk factors for intracerebral hemorrhage in the general population. A systematic review.</a> Stroke. 34, 2060-2066 (2003).</li><li>MacLellan, C. L., Paquette, R., Colbourne, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+critical+appraisal+of+experimental+intracerebral+hemorrhage+research.">A critical appraisal of experimental intracerebral hemorrhage research.</a> Journal of Cerebral Blood Flow &amp; Metabolism. 32, 612-627 (2012).</li><li>Hartman, R., Lekic, T., Rojas, H., Tang, J., Zhang, J. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Assessing+functional+outcomes+following+intracerebral+hemorrhage+in+rats.">Assessing functional outcomes following intracerebral hemorrhage in rats.</a> Brain Research. 1280, 148-157 (2009).</li></ol>

本研究调查了在非创伤性IVH大鼠模型中测量ICP，MAP和CPP的机制。记录以下组的结果：假，VH 200μL和载体对照（人工脑脊液脑室内注射）动物。选择该实验设计来研究如何在IVH注射期间监测ICP，因为我们假设ICP的峰值可能导致更显着的继发性脑损伤，从而导致IVH动物模型中的记忆缺陷。因此，本研究的目标是建立一个IVH动物模型，客观监测非创伤性IVH后的ICP，MAP和CPP，以便我们可以在未来的实验中?...

脑室内出血（IVH）是颅内出血（ICH）的一种，是一种毁灭性的疾病，具有很高的死亡率和发病率。IVH的特征是血液制品在颅内脑室内的积聚。孤立性脑室内出血不常见，通常发生在成人1.它可能与高血压出血、颅内动脉瘤破裂或其他血管畸形、肿瘤或创伤有关1.IVH导致继发性脑损伤以及脑积水的发展2。IVH的幸存者在受伤后通常会留下明显的功能，记忆和认知障碍。据报道，这些长期认知和记忆缺陷在高达44%的非物质文化遗产3幸存者中。在蛛网膜下腔出血（SAH）中，另一种类型的ICH中，众所周知，大约一半的幸存者会有记忆缺陷，对于那些除了SAH之外还有IVH的患者，结果往往明显更差4，5，6。
IVH后记忆功能障碍的潜在机制仍有待阐明。利用具有功能和记忆功能障碍的非创伤性IVH动物模型进行体内研究对于发现此类患者的潜在治疗靶点至关重要。IVH后记忆和功能障碍更严重的动物模型将是研究这些变化的最佳方法。资深作者的实验室也一直在专门研究高颅内压（ICP）在IVH大鼠模型中记忆缺陷发展中的作用。因此，在IVH期间精确测量ICP的方法对于研究非常重要。在本文中，我们报告了在IVH大鼠模型中精确测量ICP的方法。虽然ICP监测以前已用于创伤性ICH和蛛网膜下腔出血动物模型，但自发性IVH啮齿动物模型中的ICP监测并不像文献中常见报道的那样7，8。因此，本文提出的实验设计包括三组Sprague Dawley大鼠：假手术、标准200μl脑室内出血和载体对照。IVH组采用自体脑室内注射血液模型。对于载体对照动物，使用无菌乳酸林格氏溶液的心室内注射。术中记录ICPs、平均动脉压（MAP）和脑灌注压（CPP），结果在此报告。

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>0.25% bupivacaine</td>
			<td>Hospira, Inc.</td>
			<td>409115901</td>
			<td></td>
		</tr>
		<tr>
			<td>1 mL syringe</td>
			<td>Covetrus</td>
			<td>60734</td>
			<td></td>
		</tr>
		<tr>
			<td>10% providine iodine solution</td>
			<td>Aplicare</td>
			<td>MSD093947</td>
			<td></td>
		</tr>
		<tr>
			<td>20 mL syringe</td>
			<td>Covidien</td>
			<td>8881520657</td>
			<td></td>
		</tr>
		<tr>
			<td>22 G needles</td>
			<td>Becton Dickinson</td>
			<td>305155</td>
			<td></td>
		</tr>
		<tr>
			<td>28 G intraventricular needles</td>
			<td>P technologies</td>
			<td>8IC313ISPCXC</td>
			<td>C313I/SPC 28-Gneedles to fit 22-G guide cannula with 6 mm projection</td>
		</tr>
		<tr>
			<td>3-0 silk suture</td>
			<td>Henry Schein, Inc.</td>
			<td>SP116</td>
			<td></td>
		</tr>
		<tr>
			<td>3-way-stopcock</td>
			<td>Merti Medical Systems</td>
			<td>M3SNC</td>
			<td></td>
		</tr>
		<tr>
			<td>4% paraformaldehyde</td>
			<td>Fisher Chemical</td>
			<td>30525-89-4</td>
			<td></td>
		</tr>
		<tr>
			<td>AnyMaze software</td>
			<td>Any-Maze behavioral tracking software</td>
			<td></td>
			<td>Stoelting CO, USA</td>
		</tr>
		<tr>
			<td>Artificial ointment</td>
			<td>Covetrus</td>
			<td>48272</td>
			<td></td>
		</tr>
		<tr>
			<td>Blood collection vials with EDTA</td>
			<td>Becton Dickinson</td>
			<td>367856</td>
			<td></td>
		</tr>
		<tr>
			<td>Bone wax</td>
			<td>CP Medical, Inc.</td>
			<td>CPB31A</td>
			<td></td>
		</tr>
		<tr>
			<td>Carprofen</td>
			<td>Zoetis, Inc.</td>
			<td>54771-8507-1</td>
			<td></td>
		</tr>
		<tr>
			<td>Centrifuge</td>
			<td>Beckman</td>
			<td>BE-GS6R</td>
			<td>Model GS-6R</td>
		</tr>
		<tr>
			<td>Cotton tip applicators</td>
			<td>Covetrus</td>
			<td>71214</td>
			<td></td>
		</tr>
		<tr>
			<td>Drill</td>
			<td>Dremel</td>
			<td>1600A011JA</td>
			<td></td>
		</tr>
		<tr>
			<td>Fiberoptic pressure sensors with readout units</td>
			<td>Opsens Medical</td>
			<td>OPP-M200-X-80SC- 2.0PTFE-XN-100PIT-P1 and LIS-P1-N-62SC</td>
			<td>Opp-M200 packaged pressure sensors with LifeSens system</td>
		</tr>
		<tr>
			<td>Forceps</td>
			<td></td>
			<td>11923-13, 11064-07</td>
			<td></td>
		</tr>
		<tr>
			<td>Gauze</td>
			<td>Covetrus</td>
			<td>71043</td>
			<td></td>
		</tr>
		<tr>
			<td>Guillotine</td>
			<td>World Precision Instruments</td>
			<td>51330</td>
			<td></td>
		</tr>
		<tr>
			<td>Heating pad with rectal thermometer</td>
			<td>CWE, Inc.</td>
			<td>08-13000 ,08-13014</td>
			<td>TC1000 Temperature controller</td>
		</tr>
		<tr>
			<td>Hemostats</td>
			<td></td>
			<td>&#160;13013-14,&#160; 13008-12</td>
			<td></td>
		</tr>
		<tr>
			<td>Isoflurane</td>
			<td>Covetrus</td>
			<td>29405</td>
			<td></td>
		</tr>
		<tr>
			<td>Lactated ringers</td>
			<td>Baxter Healthcare Corp.</td>
			<td>Y345583</td>
			<td></td>
		</tr>
		<tr>
			<td>Laryngoscope</td>
			<td>American Diagnostic Corporation</td>
			<td>4080</td>
			<td></td>
		</tr>
		<tr>
			<td>Metal clip</td>
			<td>Fine Scientic Tools</td>
			<td>18056-14</td>
			<td></td>
		</tr>
		<tr>
			<td>Micro scissors</td>
			<td>Fine Scientic Tools</td>
			<td>15007-08</td>
			<td></td>
		</tr>
		<tr>
			<td>Microscope</td>
			<td>Leica</td>
			<td>model L2</td>
			<td></td>
		</tr>
		<tr>
			<td>Needle driver</td>
			<td></td>
			<td>12003-15</td>
			<td></td>
		</tr>
		<tr>
			<td>Polyethylene tubing</td>
			<td>Thermo Fisher Scientific</td>
			<td>14-170-12B</td>
			<td>PE-50 tubing</td>
		</tr>
		<tr>
			<td>Rats</td>
			<td>Envigo</td>
			<td></td>
			<td>Sprague Dawley rats 8&#8211;10 months old</td>
		</tr>
		<tr>
			<td>Scalpel</td>
			<td></td>
			<td>&#160;10010-00</td>
			<td></td>
		</tr>
		<tr>
			<td>Scissors</td>
			<td></td>
			<td>14090-11</td>
			<td></td>
		</tr>
		<tr>
			<td>Stereotaxic instrument</td>
			<td>Kopf instruments</td>
			<td></td>
			<td>Model 940 with ear bars</td>
		</tr>
		<tr>
			<td>Syringe pump</td>
			<td>KD Scientific</td>
			<td>780100</td>
			<td>Model 100 series</td>
		</tr>
		<tr>
			<td>Touhy Borst</td>
			<td>Abbott</td>
			<td>23242</td>
			<td></td>
		</tr>
		<tr>
			<td>Ventilator</td>
			<td>Harvard rodent ventilator</td>
			<td>55-0000</td>
			<td>Model 683</td>
		</tr>
	</tbody>
</table>

intracranial pressure monitoring in nontraumatic intraventricular hemorrhage rodent model

脑室内出血的幸存者通常留下明显的长期记忆障碍;因此，利用脑室内出血动物模型进行研究至关重要。在这项研究中，我们寻找了测量大鼠非创伤性脑室内出血期间颅内压、平均动脉压和脑灌注压的方法。实验设计包括三个Sprague Dawley组：假，标准200μl脑室内出血和载体对照组。通过引入实质内光纤压力传感器，在所有组中都获得了精确的颅内压测量值。根据颅内压和平均动脉压值的知识计算脑灌注压。正如预期的那样，脑室内出血组和载体对照组在脑室内注射自体血和人工脑脊液时，颅内压均分别升高，随后脑灌注压下降。增加实质内光纤压力传感器有利于监测精确的颅内压变化。

颅内、平均动脉和脑灌注压 在所有动物的术中监测ICP和MAP（图1）。大鼠年龄为8-10个月大，平均体重为495±17克。还收集了实时ICP图（图2）。排除假手术组，IVH和载体对照组在脑室内注射期间ICP显着增加（图3）。与车辆对照组（36.5 mmHg）相比，IVH组（43 mmHg）的ICP峰值更高。然后，在这些动物组中，ICP在脑室?...

Watch this Scientific Journal Video about Intracranial Pressure Monitoring In Nontraumatic Intraventricular Hemorrhage Rodent Model at JoVE.com

Intracranial Pressure Monitoring In Nontraumatic Intraventricular Hemorrhage Rodent Model

监测非创伤性脑室内出血啮齿动物模型中的颅内压在目前的文献中并不常见。在本文中，我们展示了一种在大鼠动物模型中测量脑室内出血期间颅内压、平均动脉压和脑灌注压的技术。

非创伤性脑室内出血啮齿动物模型中的颅内压监测

Survivors of intraventricular hemorrhage are often left with significant long-term memory impairment; thus, research utilizing intraventricular hemorrhage ...

该方案描述了一种测量啮齿动物非创伤性脑室内出血后颅内压、平均动脉压和脑灌注压的方法。通过分别插入大鼠皮层和股动脉的光纤传感器，可以准确可靠地测量颅内压和平均动脉压。当脑室内出血患者需要有创颅内压监测时，此处描述的技术已转化为临床环境。本研究的目标是建立一个IVH动物模型，客观监测脑室内IVH后的ICP，MAP和CCP，以便作者可以在未来的实验中进一步应用，重点关注IVH诱导的ICP对后续记忆功能障碍的影响。主要困难可能包括精度，因为光纤传感器很小。股动脉夹层也可能对某些人构成挑战，特别是那些未用于显微外科技能的人。麻醉大鼠后，插入直肠温度计以连续监测温度。在手术前夹住头部和股骨区域的头发，并用三种Betadine和70%酒精的交替磨砂膏准备皮肤。通过暂时将大鼠从呼吸机中取出并用连接到 10 毫升注射器的 PE-50 管吸出分泌物来吸出任何积聚的呼吸道分泌物。用无菌人工泪液眼膏保护眼睛。在头皮切口之前，将局部布比卡因注射到皮肤和皮下组织中。将大鼠置于立体定向框架上的俯卧位置并用耳杆固定。用 15 刀片手术刀沿中线切开 1.5 厘米的头皮切口。用纱布轻轻按压止血。使用无菌棉尖涂抹器，将骨膜与颅骨分开，直到可见前臼标志。使用立体定位并标记前胝骨，并在前胝侧 1.4 毫米和后侧负 0.9 毫米处标记出两个双侧毛刺孔的位置。使用手持式钻头，在左右半球创建这两个小的颅毛孔。用无菌乳酸林格氏溶液冲洗任何多余的骨屑。在右半球，将 22 号导引套管放置在毛刺孔水平，将 28 号针穿过套管插入右侧心室深处，以产生脑室内出血。将光纤压力传感器连接到读数单元。打开读数单元，并确保所选单位以毫米汞柱为单位。然后，通过将传感器尖端浸入装有乳酸林格氏溶液的小烧杯中来启动传感器，直到读数单元读出零并可以使用。在左半球，将压力传感器轻轻插入皮层两到三毫米的深度，以实时监测ICP。插入ICP监视器后，转动大鼠的下躯干，以便于进入左大腿和腹股沟区域。无菌制备和局部布比卡因给药后，用 15 刀片手术刀在后肢上做一个 1.5 厘米的皮肤切口。用止血器浅表解剖左股动脉，然后在显微镜下用细尖的镊子解剖更深的层。识别深蓝色股静脉以帮助定位邻近动脉。使用 3-0 丝线绑住股动脉远端，并在股动脉近端放置一个临时金属夹。将第二个光纤压力传感器连接到已经启动的读数单元。将压力传感器插入PE-50管中，PE-50管插入Tuohy Borst，然后关闭。将 Tuohy Borst 连接到三通旋塞阀，一端连接到 1 毫米注射器，另一端连接到带有 PE-50 管的 22 号针头。在显微镜下，用微型剪刀进行两毫米的股动脉切开术，并用连接到其余装置的PE-50管插管。使用一毫米注射器吸出 500 微升血液，然后转动三向旋塞阀，让压力传感器读取 MAP。将连接到PE-50管的28号脑室内针头与IVH动物的吸血和载体对照动物的乳酸林格氏一起启动。然后将该针插入引导套管至右侧心室深处。使用每分钟100微升的速度，通过用拇指泵送1毫米注射器，将血液或200微升无菌乳酸林格氏溶液注射到右侧心室。监测和记录 ICP、动脉血压和直肠温度。监控并记录注射后的 ICP 和 MAP 值。完成脑室内注射后，取出插入股动脉的装有压力传感器的PE-50管，并将临时夹子敷在股动脉上以防止出血。使用 3-0 丝线绑住股动脉的近端部分，并使用 3-0 丝线以中断方式关闭股动脉切口。在ICP监视器中用心室内针移除引导套管。用骨蜡密封毛刺孔。并用3-0丝线中断关闭颅切口。在切口处应用局部布比卡因，每公斤卡洛芬注射0.5毫克。在动物恢复足够的意识以维持胸骨卧位之前，不要让它们无人看管。让大鼠在手术后在监督下完全康复，并在康复后将它们送回家中的笼子，并免费获得食物和水。排除假手术组，IVH和载体对照组脑室内注射期间ICP显著增加。与车辆控制相比，IVH组的ICP更高。然后，在这些动物组中，ICP在脑室内注射后五分钟内迅速下降并恢复正常。观察到MAP在整个过程中保持相似，而CPP在脑室内注射血液或乳酸林格氏溶液时减少。手术的重要步骤包括正确定位和钻孔和股动脉切开术。应严格遵守上述步骤，以确保传感器准确读取压力变化。

Research

JoVE Journal

Neuroscience

Autologous Blood Injection to Model Spontaneous Intracerebral Hemorrhage in Mice

自体血液的注入模型小鼠自发性脑出血

Investigation of the pathophysiology of injury after intracerebral
hemorrhage (ICH) requires a reproducible animal model.  While ICH
accounts for 10-15% ...

科研

神经科学

Direct Intraventricular Delivery of Drugs to the Rodent Central Nervous System

啮齿动物的中枢神经系统药物直接脑室交货

Due to an inability to cross the blood brain barrier, certain drugs need to be directly delivered into the central nervous system (CNS). Our lab focuses ...

Long-term Continuous EEG Monitoring in Small Rodent Models of Human Disease Using the Epoch Wireless Transmitter System

在人类疾病中使用大纪元无线传输系统的小型啮齿动物模型的长期连续监测脑电图

Many progressive neurologic diseases in humans, such as epilepsy, require pre-clinical animal models that slowly develop the disease in order to test ...

A Volumetric Method for Quantification of Cerebral Vasospasm in a Murine Model of Subarachnoid Hemorrhage

小鼠蛛网膜下腔出血模型脑血管痉挛量化的容积法

Subarachnoid hemorrhage (SAH) is a subtype of hemorrhagic stroke. Cerebral vasospasm that occurs in the aftermath of the bleeding is an important factor ...

Minimally Invasive Endoscopic Intracerebral Hemorrhage Evacuation

微创内窥镜内腹出血疏散

Intracerebral hemorrhage (ICH) is a subtype of stroke with high mortality and poor functional outcomes, largely because there are no evidence-based ...

Intracranial Pharmacotherapy and Pain Assays in Rodents

颅内药物治疗和啮齿动物疼痛检测

Pain is a salient sensory experience with affective and cognitive dimensions. However, central mechanisms for pain remain poorly understood, hindering the ...

Brain Death Induction in Mice Using Intra-Arterial Blood Pressure Monitoring and Ventilation via Tracheostomy

使用动脉内血压监测和通气通过气管切除术的小鼠脑死亡诱导

While both living donation and donation after circulatory death provide alternative opportunities for organ transplantation, donation after donor brain ...

Translaminar Autonomous System Model for the Modulation of Intraocular and Intracranial Pressure in Human Donor Posterior Segments

用于调节人类供体后段眼内压和颅内压的跨层自主系统模型

There is a current unmet need for a new preclinical human model that can target disease etiology ex vivo using intracranial pressure (ICP) and intraocular ...

Double Direct Injection of Blood into the Cisterna Magna as a Model of Subarachnoid Hemorrhage

双直接注射血液到西斯特纳麦格作为苏巴拉奇内德出血的模型

Among strokes, subarachnoid hemorrhage (SAH) consecutive to the rupture of a cerebral arterial aneurysm represents 5-9% but is responsible for about 30% ...

Analysis of Cerebral Vasospasm in a Murine Model of Subarachnoid Hemorrhage with High Frequency Transcranial Duplex Ultrasound

高频颅内双体超声波的苏巴拉赫诺德出血的穆林模型脑血管痉挛分析

Cerebral vasospasm that occurs in the weeks after subarachnoid hemorrhage, a type of hemorrhagic stroke, contributes to delayed cerebral ischemia. A ...