大脑中动脉狭窄脑梗死颅内血流动力学及侧支循环研究

目的 探讨大脑中动脉(MCA)狭窄或闭塞的脑梗死患者颅内血流动力学改变和侧支循环的代偿及神经功能缺损的关系.方法 通过经颅多普勒(TCD)检查,计算双侧大脑前动脉(ACA)、大脑后动脉(PCA)峰流速及其比值(RVACA、RVPCA),并与正常对照组比较.结果 共观察38例单侧MCA狭窄或闭塞的脑梗死患者.(1)病例组ACA、PCA血流速度代偿性增快,以ACA代偿为主(76.3%);(2)病例组RVACA明显较对照组高﹙P<0.01﹚;(3)MCA主干及皮层支梗死患者的RVACA明显较对照组及深穿支梗死组高﹙P<0.01,P<0.05﹚;MCA重度狭窄或闭塞脑梗死患者的RVACA较对照组及中度狭窄组高﹙P<0.05﹚;(4)病例组RVACA及RVPCA与NIHSS呈负相关(P<0.01﹚.结论 皮质软脑膜侧支吻合血管开放成为MCA狭窄或闭塞脑梗死侧支循环的主要途径,其代偿程度与预后相关.     

大脑中动脉重度狭窄或闭塞患者脑梗死病灶类型与CT灌注成像分析

目的比较大脑中动脉(MCA)重度狭窄或闭塞患者不同脑梗死病灶类型的灌注状态。方法对89例MCA严重狭窄或闭塞患者进行头颅320排CTA+CT灌注成像检查,比较不同梗死病灶类型患者MCA闭塞率、侧支循环程度、MCA供血区灌注情况。结果 89例患者中,穿支动脉梗死(PAI)8例(9.0%)、皮质分支动脉梗死(PI)7例(7.9%)、大面积梗死(LTI)7例(7.9%)、分水岭梗死(BZI)43例(48.3%)、多发性脑梗死(MI)13例(14.6%)、无梗死灶11例(12.4%);不同类型梗死灶间MCA M1段病变、血管闭塞及不良侧支循环比率差异无统计学意义(均P0.05)。不同类型梗死灶局部脑血流量(rCBF)患健比、达峰时间(TTP)患健比差异有统计学意义(均P0.05)。BZI组rCBF患健比显著高于LTI组与无梗死灶组(均P0.05);LTI组及BZI组TTP患健比显著高于无梗死灶组及PAI组(均P0.05),MI组TTP患健比较无梗死灶组升高(P0.05)。LTI组MCA供血区低灌注发生率显著高于无梗死灶组(P0.05)。不同亚型BZI组间低灌注异常及不良侧支循环率差异有统计学意义(均P0.05),各灌注参数、MCA M1段病变及闭塞比率差异无统计学意义(均P0.05)。结论 LTI为失代偿期表现,低灌注发生率最高,其余类型为代偿期表现。皮质下型分水岭梗死较其他亚型侧支循环差,低灌注发生率更高,与血流动力学受损为主要病因的观点相符。MCA重度狭窄或闭塞患者脑梗死病灶类型以BZI为主。     

颈内和大脑中动脉重度狭窄或闭塞的分水岭梗死类型与机制的研究

目的研究单侧动脉粥样硬化性大脑中动脉(MCA)及颈内动脉(ICA)重度狭窄或闭塞所致急性缺血性脑卒中患者分水岭梗死(WI)类型及发病机制。方法起病48h内DWI诊断的急性分水岭梗死伴有动脉粥样硬化性MCA/ICA重度狭窄与闭塞的患者102例,其中MCA组38例,ICA组64例,有潜在心源性栓子患者除外。急性期DWI上分水岭梗死病灶分为:(1)单纯分水岭梗死病灶;(2)含分水岭梗死的多发梗死病灶。结果 ICA组单纯分水岭梗死病灶较多,其中前+内分水岭梗死的例数最多,与MCA组比较具差异有统计学意义(P<0.05);ICA组复合梗死病灶中,出现最多的梗死类型为穿支动脉伴分水岭梗死,与MCA组比较差异具有统计学意义。MCA组以穿支动脉伴皮层支梗死伴分水岭梗死最多,且与ICA组比较,差异具有统计学意义(P<0.05)。结论颈内和大脑中动脉重度狭窄与闭塞所致分水岭梗死的类型有明显的不同,提示有着不同的发病机制。     

CTA评估分水岭脑梗死患者侧枝循环的初步研究

目的初步探讨侧枝代偿在分水岭脑梗死(CWI)发病中的作用。方法应用CT血管成像(CTA)技术,回顾性分析于我院住院治疗的139例分水岭脑梗死(包括皮质型、内侧型及混合型)患者的颅内动脉,比较各组患者相关血管病变及侧枝代偿情况。结果 (1)CTA显示110例患者存在颈动脉系统病变,其中49例为颈内动脉(ICA)狭窄/闭塞,61例为大脑中动脉(MCA)狭窄/闭塞;(2)在内侧型分水岭梗死(IWI)患者中,存在MCA狭窄/闭塞者(46例)高于ICA狭窄/闭塞(31例)和无明显狭窄(16例),差异有统计学意义(P=0.000);(3)ICA狭窄/闭塞时,前交通动脉(ACOA)未开放者在IWI患者所占比例(25/31例)明显多于皮质型分水岭梗死患者(5/11例)和混合型分水岭梗死患者(3/7例),差别有统计学意义(P=0.033);(4)MCA狭窄/闭塞时,软脑膜侧枝代偿较差者在皮质型分水岭梗死患者所占比例(6/9例)明显多于IWI患者(11/46例)和混合型分水岭梗死患者(1/6例),差别有统计学意义(P=0.028)。结论颈动脉系统病变所致的IWI受MCA的狭窄/闭塞影响程度更大;ICA狭窄/闭塞所致IWI梗死与ACOA缺乏或发育不良有关,ACOA的存在可以明显减少IWI发生;MCA病变时软脑膜代偿的出现可增加受累皮质的血供,软脑膜侧枝代偿较差可促进皮质型分水岭脑梗死的发生。     

116例大脑中动脉病变患者脑梗死类型分布和脑灌注异常分析

目的 应用神经影像检查,分析大脑中动脉闭塞性疾病(MCAOD)患者梗死类型分布和脑灌注异常. 方法 对经CT血管造影(CTA)证实的116例MCAOD患者的CT平扫、CT灌注成像(CTP)和CTA的影像资料进行回顾性分析,确定其脑梗死类型分布和脑灌注改变. 结果 116例患者中,CTA共检出133条大脑中动脉(MCA)狭窄或闭塞,其中单侧者99例,双侧者17例.其中MCA闭塞25条,重度狭窄39条,中、轻度狭窄69条.CT或MRI显示腔隙性脑梗死(LIS)45例,各型分水岭脑梗死(CWSI)38例,流域性脑梗死26例,纹状体内囊梗死(SCI)10例,未检出梗死病灶14例.CTP显示MCA供血区内脑血流灌注异常96例,其中58例有MCA供血区的大范围血流灌注减低.未检出血流灌注异常者37例. 结论 由于MCA狭窄的部位、程度和发病机制的不同以及侧支循环的建立,MCAOD可造成不同类型的脑梗死和血流灌注异常.     

彩色多普勒超声联合DSA在脑分水岭梗死颅外段动脉评价中的作用

目的探讨彩色多普勒超声(CDFI)联合全脑数字减影血管造影(DSA)对脑分水岭梗死患者颅外段动脉评价中的作用。方法分析本院2008年1月至2011年12月的92例脑分水岭梗死患者的临床及影像学资料,比较颈部CDFI及DSA两种检查手段对颅外段动脉评价中的优缺点;比较皮质分水岭梗死和内分水岭梗死的颅外段血管病变情况。结果对92例552条血管进行检查,DSA共发现52条血管狭窄,8条血管闭塞;CDFI共发现有64条血管狭窄,12条血管闭塞。两者总体对血管狭窄及闭塞的诊断比较差异无统计学意义(P>0.05)。对于动脉粥样硬化斑块性质的判断,两者之间比较差异有统计学意义(P<0.05)。皮质分水岭梗死与内分水岭在动脉狭窄或闭塞及不稳定斑块方面差异有统计学意义(P<0.05)。结论 CDFI及DSA对分水岭脑梗死颅外段供血动脉病变的判断具有重要意义且各具优缺点:DSA是诊断血管狭窄或闭塞的金标准,但对动脉硬化斑块性质的判断存在局限性;彩超能准确判断动脉粥样硬化斑块性质,但对血管狭窄或闭塞的判断存在一定的假阳性率。联合应用有助于对患者颅外段动脉的评价。     

伴颅内外动脉狭窄或闭塞的分水岭脑梗死类型分析

目的探讨由颈内动脉(ICA)或大脑中动脉(MCA)狭窄或闭塞引起的分水岭脑梗死(WSI)的梗死类型及发病机制。方法 81例急性WSI患者根据责任血管分为ICA组(53例)及MCA组(28例)。根据MRI检查结果对两组梗死类型进行分析比较。结果 ICA组皮质前型及皮质前型+内WSI+皮质后型的比率显著高于MCA组(均P<0.05)。结论合并颅内外血管狭窄或闭塞WSI类型以内WSI及皮质后型梗死最常见。ICA病变患者WSI皮质前型常见,其发病机制可能为血流动力学障碍;MCA病变患者WSI皮质上型及合并融合性病灶多见,其机制可能为微栓子对远端血管的微栓塞。     

大脑中动脉粥样硬化的狭窄度与卒中机制——一项高分辨磁共振研究

目的本研究旨在探索大脑中脉(middle cerebral artery,MCA)狭窄率与MCA斑块形态学及梗死类型的相关性,并探索不同狭窄率患者卒中的发生机制。方法连续收集2009-2014年于北京协和医院就诊的2周内发生MCA供血区缺血性卒中并进行高分辨磁共振(high-resolution magnetic resonance imaging,HRMRI)扫描的患者。纳入MCA M1段存在斑块的患者,排除心源性、颅外大动脉粥样硬化及其他病因的卒中患者。在弥散加权成像(diffusion weighted imaging,DWI)上将梗死类型分为穿支、皮层、分水岭和混合型梗死,并测量梗死体积。在矢状位HRMRI上测量MCA M1段狭窄率,并收集斑块位置、长度、厚度、信号和斑块连续性等形态学指标。将狭窄率50%的患者分入重度狭窄组,将狭窄率≤50%的患者归入轻度狭窄组。结果研究共纳入102例患者,其中重度狭窄组39例,轻度狭窄组63例。重度狭窄组患者卒中,穿支梗死14例(35.9%),皮层梗死9例(23.1%),分水岭梗死4例(10.3%),混合型梗死12例(30.8%);轻度狭窄组患者中,穿支梗死44例(69.8%),皮层梗死8例(12.7%),分水岭梗死3例(5.8%),混合型梗死8例(12.7%),两组构成类型比较,差异有显著性(P=0.014)。与轻度狭窄组比较,重度狭窄组患者斑块更长(P0.001)、更厚(P0.001)、更多混合信号斑块(P0.001)。斑块厚度(P0.001,OR 87.792,95%CI 13.120~587.453)和斑块混合信号(P=0.007,OR 7.358,95%CI 1.725~31.382)是MCA狭窄率50%的独立预测因子。重度狭窄组中,梗死体积与斑块表面不连续(P=0.004)相关。轻度狭窄组中,梗死类型与斑块表面不连续(P=0.002)及斑块厚度(P=0.032)相关。且斑块表面不连续是发生栓塞性梗死的独立预测因子(P=0.003,OR 5.778,95%CI 1.788~18.672)。结论 MCA狭窄率50%和≤50%的患者具有不同的卒中分型比例和斑块形态学;狭窄率≤50%的斑块表面不连续是栓塞性梗死独立预测因子,提示轻度狭窄MCA斑块破裂可能是引起栓塞性病灶的机制。     

基于MRI和DSA的ICA、MCA狭窄或闭塞患者发生不同供血区脑梗死的对比分析

目的 探讨颈内动脉(ICA)、大脑中动脉(MCA)狭窄或闭塞引发脑梗死的部位及特点。方法 选取2013年1月～2016年2月本院诊治的98例经头颅磁共振加权成像(DWI)和数字减影血管造影(DSA)确诊的ICA或MCA狭窄或闭塞引发脑梗死患者进行回顾性研究,根据患者起病1周内的DWI确诊梗死部位,对比ICA和MCA狭窄或闭塞引发脑梗死的部位和特点。结果 ICA组患者的完全性前循环脑梗死率(36.00%)显著高于MCA组的12.50%(P<0.05); ICA组的腔隙性脑梗死发生率(26.00%)显著低于MCA组的52.08%(P<0.05); ICA组和MCA组患者的PI、PAI、LTI供血区脑梗死发生率无明显差异(P>0.05); MCA组患者的BZI供血区脑梗死发生率(62.50%)显著高于ICA组的26.00%(P<0.05); ICA组患者的单发性脑梗死发生率(70.00%)显著高于MCA组患者的(47.92%)(P<0.05)。结论 ICA狭窄以单发性脑梗死多见,MCA以多发性脑梗死多见,MCA狭窄或闭塞患者的分水岭梗死发生率高于ICA狭窄或闭塞患者。     

颈内和大脑中动脉狭窄与闭塞的梗死类型及卒中机制的研究

目的 研究单侧动脉粥样硬化性MCA/ICA狭窄与闭塞的急性缺血性脑卒中患者在DWI上的梗死类型及发病机制.方法 起病48h内DWI诊断的急性脑梗死伴有动脉粥样硬化性MCA/ICA狭窄与闭塞的131例患者,有潜在心源性栓子患者除外.急性期DWI上梗死病灶分为：（1）单发病灶（小的穿动脉梗死灶;大的穿动脉梗死灶,皮层支梗死,大面积梗死,分水岭梗死）;（2）多发梗死病灶.结果 131例患者,ICA51例,MCA80例.ICA出现最多的梗死类型：穿支动脉伴分水岭梗死,但与MCA比较,皮层支伴分水岭梗死具有统计学意义（8/51,P=0.001）.MCA以穿支动脉伴皮层支梗死最多,且与ICA比较,具有统计学意义（12/80,P=0.003）.MCA中任何皮层支梗死与狭窄程度无关,ICA中任何分水岭梗死与狭窄程度相关.结论 颈内和大脑中动脉狭窄与闭塞在DWI上的梗死类型有明显的不同,提示有着不同的卒中发病机制.     

Ophthalmic artery fed by posterior communicating artery after trapping of the internal carotid artery

The authors report a 50-year-old man with a ruptured large carotid-ophthalmic aneurysm on the right side and an unruptured anterior communicating artery (A Com) aneurysm. The A Comm aneurysm was clipped and the carotid-ophthalmic aneurysm was managed by combining internal carotid artery (ICA) trapping with an interposed radial artery graft from the external carotid artery (ECA) to the middle cerebral artery (MCA). The patient had an uncomplicated postoperative recovery. Postoperative carotid angiography demonstrated no aneurysms and excellent flow through the bypass graft. Postoperative vertebral angiography showed the right ophthalmic artery to be fed by the posterior communicating artery. It is speculated that collateral circulation from the angular artery of the ECA to the ophthalmic artery did not develop because of high flow graft from the ECA to MCA and ICA trapping.     

Management of coexistent carotid artery and coronary artery disease

At the present time staged carotid reconstruction several days before elective coronary artery bypass surgery seems to be the safest and most logical approach for patients with neurological symptoms, stable cardiac symptoms, and acceptable coronary anatomy. Combined procedures may well be necessary for those who have active neurological symptoms or bilateral carotid lesions in conjunction with diffuse or unstable coronary artery disease, but the incidence of neurological complications at the time of simultaneous operations could exceed the stroke risk for either carotid endarterectomy or coronary bypass alone. The asymptomatic patient with unilateral carotid stenosis who presents for coronary artery bypass might be best managed by myocardial revascularization followed by medical or surgical management of the carotid disease. In order to obtain optimal long-term results, both coronary disease and associated carotid disease require appropriate evaluation and medical and surgical management.     

The relation of retinal artery occlusion and carotid artery stenosis

We retrospectively studied 46 patients with symptomatic retinal artery occlusion and assessed the pattern and extent of carotid artery disease ipsilateral to the retinal artery occlusion. Ipsilateral internal carotid artery atherosclerotic lesions were virtually limited to the cervical arterial segment; 50% of such lesions were plaques or stenoses of less than or equal to 60%, whereas 15% of the angiograms were normal. No clinical features were significantly associated with a flow-limiting carotid stenosis of greater than 60%. Contrary to previous reports, the type of retinal artery occlusion, whether branch or central artery occlusion, was not predictive of severe underlying carotid stenosis or occlusion. Likely mechanisms of retinal artery occlusion include in situ thrombosis and emboli from carotid, and possibly cardiac, sources. Extension of thrombus from an occluded carotid artery into the ophthalmic artery did not appear to be a mechanism of retinal artery occlusion.     

Clinical significance of the ophthalmic artery in carotid artery disease

A total of 141 subjects with tight stenosis (≥75%) or occlusion of internal carotid artery were followed up at intervals 3–6 months regularly for 40 ± 16 months. The direction of ophthalmic artery flow was used as a parameter of risk indicator on cerebral ischemic events. Eleven patients with bilateral carotid tight stenosis/occlusion were excluded in the analysis. Thus, the 130 carotid arteries were divided into three groups: (1) carotid artery with ipsilateral hemispheric TIA or stroke (85 patients), (2) carotid arteries with contralateral hemispheric TIA/stroke or VBI (15 patients), and (3) carotid arteries of asymptomatic patients (30 patients). The symptomatic carotid artery group (group 1) had significantly more often reversed ophthalmic flow than the other two groups (group 2 and 3, p < 0.001). During follow-up prospectively for four years, 41 patients had cerebral ischemic events, three had cardiac ischemic events and six died of malignancy. Patients with reversed OA flow had more often subsequent cerebral ischemic events than those with forward flow (27 vs 14, p = 0.010). However, the difference remained significant only in the asymptomatic patients (group 3, 4 vs 0, P < 0.001), not for groups 1 and 2, after further analysis. Our work supported that the clinical role of ophthalmic artery collateral varied between asymptomatic and symptomatic patients.     

Superior cerebellar artery infarction and vertebral artery dissection

Isolated superior cerebellar artery infarction is rare, and the mechanism is often not readily apparent. We describe a patient with an isolated superior cerebellar artery infarction resulting from an ipsilateral vertebral artery dissection. Angiography demonstrated intraluminal clot in the superior cerebellar artery, suggesting artery-to-artery embolus as a mechanism of this uncommon stroke syndrome.     

Rotational vertebral artery syndrome due to compression of nondominant vertebral artery terminating in posterior inferior cerebellar artery

Rotational vertebral artery syndrome (RVAS) is characterized by recurrent attacks of paroxysmal vertigo, nystagmus, and ataxia induced by head rotation. We report on a patient who developed atypical RVAS due to compression of the vertebral artery (VA) terminating in the posterior inferior cerebellar artery (PICA). A 59-year-old man suffered from vertigo and nystagmus induced by leftward head rotation and oculography showed right beating horizontal-torsional and downbeat nystagmus. Cerebral angiography showed hypoplastic right VA terminating in PICA without connection to the basilar artery. The basilar artery received its flow from the left VA only and branched out both anterior inferior cerebellar arteries. Cerebral angiography revealed a complete occlusion of the right distal VA at the level of the C1–2 junction when the head was rotated to a leftward position. In contrast, the blood flow through the left vertebral and basilar arteries remained intact while turning the head to either side. The hemodynamic compromise observed in our patient with RVAS indicates that isolated vertigo and nystagmus may occur due to transient ischemia of the inferior cerebellum or lateral medulla.