【作者】 刘勇；

【导师】 赵钢；

【作者基本信息】 第四军医大学 ， 神经病学（专业学位）， 2014， 硕士

【摘要】 研究背景：近年来，脑梗死发病年龄逐渐呈现出年轻化趋势，中青年脑梗死发病原因、其危险因素及发病的内在机制是近年来研究的焦点。在脑的供血动脉发生严重狭窄或闭塞时，脑的侧支循环建立可以通过增加脑血流量来防止脑缺血的发生，脑侧支循环网络的建立和发展对缺血性脑血管病的预防和治疗具有极其重要的作用。小血管梗死是一个非常复杂的现象，它的内在机制更是近年来研究的热点。目前大多数的研究主要探讨的是大血管的梗死的临床特点、影响因素和治疗方法，而对于一些不明原因的脑梗死，例如大脑中动脉慢性闭塞后发生的脑梗死的研究却比较少见，对中青年小血管梗死的研究则更少，这对于脑梗死机制的阐明和小血管梗死临床针对性治疗造成极大的限制。本研究的患者都是单侧大脑中动脉M1段慢性闭塞的患者，他们之中新发小血管梗死的患者的比例很高，由此可以对小血管梗死的特点进行研究。同时，这部分患者的侧支循环建立与其小血管梗死之间有怎样的关系？以往关于脑血管传统危险因素与侧支循环之间的关系的结论存在的不一致性，那么对于单侧大脑中动脉M1段慢性闭塞的患者其危险因素又和侧支循环的建立有怎样的关系？这是本研究要探索的问题。研究目的：探讨中青年单侧大脑中动脉起始段（M1段）慢性闭塞后新发脑梗死患者的侧支循环与脑梗死的关系，脑血管危险因素与脑梗死的关系，以及脑血管危险因素对中青年单侧大脑中动脉起始段（M1段）慢性闭塞患者侧支循环建立的影响。研究方法:分析2009年7月—2013年6月就诊于我院神经内科的90例单纯M1段慢性闭塞患者的临床资料，其中男48例，女42例，平均（44.6±9.7）岁，并将其分为新发脑梗死组和无脑梗死组两组，有新发梗死灶者50例，无脑梗死灶者40例。并对其脑梗死发病情况、脑血管危险因素情况、及其侧支循环建立的情况，以及它们之间的相互关系进行分析。研究结果:1.90例M1段慢性闭塞患者年龄分布趋势为50~59岁组最多，占37.8%，20~29岁组最少，占8.9%。有无脑梗死两组患者年龄分布差异无统计学意义，χ2=4.394，P>0.05。2.高血脂、糖尿病、吸烟、高血压、高同型半胱氨酸血症等危险因素与是否发生脑梗死无显著相关性。3.大脑中动脉慢性闭塞患者侧支血流分级与其是否有脑梗死呈显著的负相关（r=-0.76，p<0.01），新发脑梗死组侧支血流分级（采用ASITN/SIR的血流分级系统评估）1、2级占84%，而无脑梗死组1、2级只占10%，3、4级占90%，高于有脑梗死者，侧支血流分级与脑梗死发生呈负相关，γs=-0.76，P<0.01。4.有无脑血管危险因素两组的侧支开放程度1级（前交通动脉和后交通动脉）、2级（眼动脉逆流和软脑膜侧支）和3级（新生血管）是否开放的差异均无统计学意义（P均＞0.05）。Spearman相关分析显示，侧支开放程度1级是否开放与年龄、发生高血压、高血脂、糖尿病、吸烟呈正相关，与高同型半胱氨酸血症呈负相关，但差异均无统计学意义（P均＞0.05）；侧支开放程度2级是否开放与年龄、发生高血压、吸烟、高同型半胱氨酸血症呈负相关，与高血脂、糖尿病呈正相关，但差异均无统计学意义（P均＞0.05）；侧支开放程度3级是否开放与高血压、高血脂、糖尿病、吸烟呈正相关，与年龄、同型半胱氨酸血症呈负相关，但差异均无统计学意义（P均＞0.05）。5.侧支血流分级与高血压、同型半胱氨酸血症、吸烟之间的相关为负相关，而侧支血流分级与高血脂、糖尿病之间的相关为正相关，但差异均无统计学意义（P均＞0.05）。只有糖尿病与侧支血流之间的相关在统计学上显著。结论:1.本研究未显示脑血管病的传统危险因素与脑梗死发生，以及脑血管病的传统危险因素与侧支循环开放程度和侧支血流分级具有相关性。2.MCA-M1段慢性闭塞使得侧支循环有充分时间建立，其侧支循环的血流分级起到重要作用，血流分级越高越不容易发生脑梗死。3.本研究结果从侧面支持大脑中动脉慢性闭塞后，如果血管神经网络建立不充分，动脉的上游神经血管单元灌注阻力则会增加，从而会减少下游神经血管单元的灌注，使其供血不完全而导致梗死，可能是发生此类梗死重要的机制之一。4.本研究结果显示，侧支血流分级是侧支循环评估指标中一个较为敏感和有效的指标，未来关于侧支循环的研究要充分考虑侧支随时间的动态变化的特点，且有必要将其纳入重要的研究指标，来探索侧支循环的形成、建立和发挥代偿作用的内在机理。5.未来的在脑卒中研究中，要将那些动脉慢性闭塞且有充分时间建立侧支，但是其侧支代偿很差的患者重点纳入到研究当中。更多还原

【Abstract】 BackgroundIn recent years, onset of cerebral infarction showing a younger trend, the reason of i nfarction incidence, its risk factors and the internal mechanism is the focus of recent research.When the feeding artery were severe stenosis or occlusion, the establishment of collateral circulation can increase cerebral blood flow and prevent the occurrence of cerebral ischemia, a network of cerebral collateral circulation establishment and its development take an extremely important role in prevention and treatment of ischemic cerebrovascular disease. Small vessel infarction is a very complex phenomenon, and its internal mechanism is a research hotspot in recent years. Most current research focuses on the clinical features, factors and treatment methods of large vessels infarction, but for some unexplained cerebral infarction, such as studies of cerebral infarction after chronic cerebral artery occlusion was relatively rare, the studies of young small vessel infarction was less, which causing great restrictions to elucidating the mechanism of cerebral infarction and clinically targeted therapy of small blood vessels. Patients in this study were all with unilateral middle cerebral artery M1segment chronic occlusion, and among whom proportions of patients with small vessel infarction was high, so it can carry out research on the characteristics of small vessels infarction. At the same time, What kind of relationship between the collateral circulation and small vessel infarction in these patients? Previous conclusions about the relationship between the traditional risk factors and cerebrovascular collateral circulation were inconsistency, so for patients with unilateral middle cerebral artery M1segment chronic occlusion, what kind of relationship between its risk factors and the establishment of collateral circulation? That is the issue this study explores.ObjectiveTo explore the relationships between the cerebral infarction and cerebral vascular risk factors, and it between cerebral vascular risk factors and collateral circulation establishing and in young patients with cerebral infarction after their initial segment of unilateral MCA-M1slowly occlused.MethodsA study was conducted to analyze90patients admitted to the internal medicine-neurology of our hospital with simple slow MCA-M1occlusion from July2009to June2013,48males and42females, mean44.6±9.7years, who were devided into two groups:there were50patients with fresh infarction group, those without infarct40people wre in non-infarction group; We analysised the relationship between the new cerebral infarction and cerebral vascular risk factors, and it between the new cerebral infarction with the collateral circulation.Results1. The age distribution trend of90cases of patients with MCA-M1chronic total occlusion was that the50-59age group were most, accounted for37.8%, and the age group of20-29were least, accounted for8.9%. There was no significant difference between two groups of patients with and without cerebral infarction in age distribution,χ2=4.394, P>0.2.2. There is no significant correlation between risk factors as high cholesterol, diabetes, smoking, hypertension, homocysteine and cerebral infarction.3. Collateral flow classification level1and2accounted for84%in new onset of cerebral infarction group, level1and2accounted for only10%, and level3and4accounted for90%in no cerebral infarction group, which was higher than that of cerebral infarction, collateral blood flow grading and cerebral infarction were negatively correlated, γs=-0.76, P<0.01.4. The difference of collateral openness at level1,2and3between cerebrovascular risk factors set and don’t have cerebrovascular risk factors set was not statistically significant (P>0.05). Spearman correlation analysis showed that collateral openness at level1were positively correlated with age, hypertension, high cholesterol, diabetes and smoking, and it was negatively correlated with high homocysteine, but the difference was not statistically significant (P>0.05); collateral openness at level2were negatively correlated with a ge, hypertension, smoking, homocysteine, and it were positively correlated with high blood cholesterol and diabetes, but the difference was not statistically significant (P>0.05); collateral openness at level3were positively correlated with hypertension, high cholesterol, diabetes, smoking, and it were negatively correlated with age and homocysteine, but the difference was not statistically significant (P>0.05).5. Collateral flow grade it were negatively correlated with high blood pressure, homocysteine, smoking, and it were positively correlated with high cholesterol and diabetes, but the difference not statistically significant (P>0.05). Only the relevant between collateral flow grade and diabetes was statistically significant.Conclusion1. This study show no correlation between traditional risk factors of cerebrovascular disease and cerebral infarction, it neither shows correlation between traditional risk factors of cerebrovascular disease nether collateral openness nor cllateral blood flow classification2. MCA-M1slowly occlusing gives sufficient time for establishing collateral circulation and their flow classification of collateral circulation plays a very important role, that is the higher the rating, the less prone to occurr cerebral infarction.3. The results supports from the side the idea that when the middle cerebral artery chronic occlusion, if it is not sufficient to establish the neural network of blood vessels, perfusion resistance of arterial perfusion upstream of the neurovascular unit will increase, which will reduce the perfusion of the downstream of the neurovascular unit, making the blood does not completely and causing infarction, which may be one important mechanism of occurrence of such infarction.4. Te results of this study have shown that collateral flow grade as a collateral evaluation index is a more sensitive and effective indicator. Future research on collateral circulation should fully consider the characteristics of the dynamic changes of collateral circulation over time, and it is necessary to incorporate it into important research targets, to explore the internal mechanism of the collateral circulation formation and its compensatory role.5. The focus of stroke research in the future should be those patients with chronic arterial occlusion and have sufficient time to build collateral but with poor collateral circulation.更多还原