CBF side-to-side asymmetries in stenosis-occlusion of internal carotid artery. Relevance of CT findings and collateral supply.

Cerebral blood flow (CBF) was studied at rest by 133-Xenon inhalation method in 15 normal subjects, in 10 patients with cerebral infarction and normal angiograms of major cerebral arteries and in 28 patients with unilateral stenosis-occlusion of the internal carotid artery (ICA), with or without cerebral infarction. All the normals and 20 patients with ICA stenosis-occlusion were tested again after cerebral vasodilatation induced by an intravenous bolus of acetazolamide. At rest the patients with cerebral infarction, irrespective of whether ICa stenosis-occlusion was present or not, showed abnormal side-to-side CBF asymmetry. After cerebral vasodilation variations in side-to-side asymmetry were shown to depend on the inefficiency of the collaterals and not on the degree of ICA obstruction or on the presence of cerebral infarction. These data indicate that at rest side-to-side CBF distribution is influenced more by the presence of an ischemic zone than by a ICA stenosis-occlusion and that under these circumstances the hemodynamic effect of the vascular stenosis cannot be assessed. After cerebral vasodilatation a subset of patients--irrespective of the degree of ICA obstruction and of whether or not cerebral infarction is present--with true cerebrovascular insufficiency can be isolated.     

Cerebrovascular reactivity to acetazolamide in carotid artery disease: Enhancement of side-to-side CBF asymmetry indicates critically reduced perfusion pressure

Cerebral blood flow (CBF), measured with a mobile 10 detector unit and non-invasive Xenon-133 technique, was investigated before and after cerebral vasodilation with acetazolamide (Diamox) in 78 patients prior to carotid endarterectomy. The change in side-to-side CBF asymmetry from baseline to Diamox study, the Diamox asymmetry enhancement, was compared with the intraoperatively measured cerebral perfusion pressures. Asymmetry enhancement exceeded the methodological variation in 14 patients, 13 of whom had a perfusion pressure below 65 mmHg, Insignificant asymmetry enhancement was found in 64 patients: 52 with unilateral and 12 with bilateral disease. Of these two and four patients, respectively, had perfusion pressures below 65 mmHg. Enhancement of CBF asymmetry following a potent cerebral vasodilator stimulus is a reliable predictor, in unilateral carotid artery disease, of critically reduced cerebral perfusion pressure.     

Cerebral cortical microinfarcts in patients with internal carotid artery occlusion

Cerebral cortical microinfarcts (CMI) are small ischemic lesions that are associated with cognitive impairment and probably have multiple etiologies. Cerebral hypoperfusion has been proposed as a causal factor. We studied CMI in patients with internal carotid artery (ICA) occlusion, as a model for cerebral hemodynamic compromise. We included 95 patients with a complete ICA occlusion (age 66.2 ± 8.3, 22% female) and 125 reference participants (age 65.5 ± 7.4, 47% female). Participants underwent clinical, neuropsychological, and 3 T brain MRI assessment. CMI were more common in patients with an ICA occlusion (54%, median 2, range 1–33) than in the reference group (6%, median 0; range 1–7; OR 14.3; 95% CI 6.2–33.1; p<.001). CMI were more common ipsilateral to the occlusion than in the contralateral hemisphere (median 2 and 0 respectively; p<.001). In patients with CMI compared to patients without CMI, the number of additional occluded or stenosed cervical arteries was higher (p=.038), and cerebral blood flow was lower (B −6.2 ml/min/100 ml; 95% CI −12.0:–0.41; p=.036). In conclusion, CMI are common in patients with an ICA occlusion, particularly in the hemisphere of the occluded ICA. CMI burden was related to the severity of cervical arterial compromise, supporting a role of hemodynamics in CMI etiology.     

颈内动脉狭窄程度和血流速度与颈内动脉支架置入术后高灌注损伤的相关性研究

目的 探讨颈内动脉狭窄程度和血流速度与颈内动脉支架置入术后高灌注损伤的相关性。方法 选取2014年1月-2019年2月本院收治的298例颈内动脉狭窄患者为研究对象,全部患者采取颈内动脉支架置入术治疗,根据术后是否发生高灌注脑出血将其分为高灌注脑出血组(观察组,n=8)与未发生高灌注脑出血组(对照组,n=290); 采用改良RANKIN量表(mRS评分)评估2组受试者手术前、手术30 d后残疾程度,分别于手术前、手术后3 d采用彩色多普勒超声测定2组受试者患侧颈内动脉狭窄程度及血流速度,应用经颅多普勒TCD测定2组受试者患侧大脑中动脉血流速度; 采用NIHSS评分评估2组受试者手术前、手术30 d后神经功能缺损程度,采用LOGSTIC多元回归分析颈内动脉支架置入术后高灌注脑出血的影响因素。结果 观察组手术30 d后mRS评分高于对照组(P<0.05); 观察组手术前患侧颈内动脉狭窄程度高于对照组(P<0.05); 观察组手术前患侧大脑中动脉动脉血流速度(Vm)低于对照组(P<0.05); 观察组手术30 d后NIHSS评分高于对照组(P<0.05); Logistic多因素回归分析显示,颈内动脉支架置入术后高灌注脑出血与术前颈内动脉狭窄程度、血流速度、术后3 d患侧大脑中动脉血流速度(Vm)呈正相关(P<0.05),与术前患侧大脑中动脉血流速度(Vm)呈负相关(P<0.05)。结论 颈内动脉狭窄程度和血流速度是颈内动脉支架置入术后发生高灌注脑出血的独立影响因素。     

Hemodynamic significance of internal carotid artery disease

Neurologic symptoms in the region of an internal carotid artery stenosis are considered to be embolic in most instances. Only in a subgroup has carotid occlusive disease with impairment of the collateral supply, caused a state of hemodynamic failure with marked reduction of perfusion pressure. Though unproven, it is reasonable to assume that without surgical intervention, the risk is higher than average for patients with hemodynamic failure. Equally, should there be any postoperative improvement of cerebral blood flow or neurologic deficits, it should be looked for in this group. Thus, it is necessary to distinguish those with low perfusion pressure from the population of patients with carotid artery disease. Preoperative clinical evaluation and direct visualization of the carotid bifurcation should be supplemented by indirect physiological tests which allow assessment of collateral perfusion. Examination of periorbital flow direction or oculoplethysmography could be used as a screening procedure. Negative tests most certainly rule out any severe pressure gradient across the stenosis, irrespective of the luminal reduction. A positive result, on the other hand, should be further quantified since most indirect tests become positive at relatively small pressure gradients. Studies of cerebral blood flow at rest and during cerebral vasodilation makes it possible to identify patients with severe reduction of cerebral perfusion pressure. Such hemodynamic failure of one hemisphere may be identified in most cases by a conventional non-invasive xenon-133 technique and stationary detectors. Smaller focal regions of hypoperfusion may be identified by computer emission tomography, either by the detection of single-photon emission or by paired detection of annihilation photons. Endarterectomy does improve cerebral hemodynamics in terms of increased flow through the reconstructed vessel and elimination of pressure gradients. The cerebral blood flow, though remains unchanged in the majority of patients, at least when measured at baseline. Only in those patients with a reduction in perfusion pressure can a significant improvement in baseline flow occur. Flow reserve determined by cerebral vasodilation, however, will improve in most patients with hemodynamic failure. In addition, some patients in the low-pressure group develop marked, but temporary, hyperperfusion after reconstruction of very high grade carotid stenosis. This is considered a result of chronic low perfusion pressure with subsequent loss of autoregulation, and autoregulatory control is first regained after some days.(ABSTRACT TRUNCATED AT 400 WORDS)     

Clinical implications of collateral middle cerebral artery flow in acute ischaemic stroke with internal carotid artery occlusion

Background and purpose: The presence of collateral middle cerebral artery (MCA) flow via the primary collateral pathway is thought to protect against the progression of cerebral ischaemia. However, there have been few reports on early clinical outcomes according to the presence of collateral MCA flow in acute ischaemic stroke (AIS) with internal carotid artery (ICA) occlusion. Therefore, we sought to investigate the early clinical outcomes and lesion patterns according to the presence of collateral MCA flows in AIS with ICA occlusion. Methods: This is a retrospective study of patients with AIS with ICA occlusion consecutively admitted to our stroke center between October 2008 and March 2010. Patients were included if they were admitted within 12 h of symptom onset with AIS and symptomatic ICA occlusion. Collateral MCA flow was defined as the presence of MCA signals from proximal M1 to distal MCA branches ipsilateral to the ICA occlusion by magnetic resonance angiography. Early neurological deterioration (END) was defined as a 4‐point increase in the National Institutes of Health Stroke Scale (NIHSS) score and persistent neurological deterioration for at least 24 h or newly developed neurological symptoms within 7 days. Results: Sixty‐five patients (42 men, 23 women) were finally included. Initial NIHSS scores were significantly lower, and favorable outcomes at 3 months were better in patients with collateral MCA flow than in those without (P < 0.001). Initial lesion patterns were different according to the collateral MCA flow. However, patients with mild AIS might more frequently deteriorate than those with moderate to severe AIS. Conclusions: In our study, collateral MCA flow reduced initial stroke severity and was associated with favorable outcomes at 3 months but did not seem to protect against END in mild AIS patients with ICA occlusion. Therefore, the results of this study suggest that mild AIS patients with ICA occlusion should be carefully managed because their conditions may deteriorate.     

颈内动脉重度狭窄或闭塞患者的侧支循环与神经功能的单因素分析

目的 探讨颈内动脉重度狭窄或闭塞患者侧支循环的代偿作用与临床神经功能缺损程度的关系. 方法对52例连续颈内动脉狭窄或闭塞所致的脑梗死患者入院时行神经功能缺损评分(NIHSS)评分,利用数字减影脑血管造影技术(DSA)评估颅内动脉的侧支循环代偿情况.应用统计学方法探讨两者之间的关系.结果 DSA发现52例患者18例出现颈内动脉闭塞,单侧颈内动脉重度狭窄28例,6例双侧重度狭窄.52例患者中出现前交通动脉代偿18例,后交通动脉代偿8例,前后交通动脉同时代偿12例,14例患者未出现Willis环血管的代偿.无Willis环代偿组与Willis环代偿组NIHSS评分平均秩次分别为35.75和23.09,两组差异有统计学意义(P<0.05).前交通代偿组与后交通代偿组NIHSS评分平均秩次分别为12.42和15.94,两组差异无统计学意义(P<0.05).结论颈内动脉狭窄或闭塞时可通过多种方式进行有效的代偿.NIHSS评分与血管代偿及阻塞位置显著有关.DSA对侧支循环的判定在治疗干预中显得尤为重要.     

颈内动脉狭窄相关性脑缺血病变的临床分析

目的 探讨颈内动脉狭窄致脑缺血病变的临床特点及发生机制,为临床指导治疗及判断预后提供依据.方法 回顾分析111 例经CT 血管造影(CTA)证实的颈内动脉狭窄患者的颅内Willis 环形态、TCD 资料及临床表现.结果 颈内动脉轻、中、重度狭窄组脑梗死发生率分别为14.7% 、30.6% 、46.3%,三组间差异具有显...     

颈内动脉急性闭塞致大面积脑梗死侧支循环建立及影响因素

目的评估颈内动脉急性闭塞致大面积脑梗死侧枝循环建立情况及影响因素。方法纳入29例经诊断为颈内动脉急性闭塞致大面积脑梗死的患者,所有患者均行颈动脉超声、经颅多普勒超声(TCD)、头颅CT、头颅磁共振血管造影(MRA)、心电图检查,同时收集患者基本信息。结果一级侧枝循环建立与糖尿病显著相关(P 0. 05),与房颤、高血压、吸烟、NIHSS评分无关(P 0. 05)。二级侧枝循环建立与房颤、高血压、糖尿病、吸烟、NIHSS评分均无关(P 0. 05)。心源性脑栓塞导致的急性大面积脑梗死与脑疝显著相关(P 0. 05)。TCD评估一级侧枝循环的建立与MRA具有高度一致性(Kappa值=0. 656,P 0. 05)。结论糖尿病可促进颈内动脉急性闭塞导致的大面积脑梗死一级侧枝开放。心源性脑栓塞导致的大面积脑梗死易发生脑疝。TCD可以较好评估颈内动脉急性闭塞导致的大面积脑梗死的一级侧枝循环建立。     

An audit of carotid endarterectomy for internal carotid artery disease at Dunedin Hospital

Carotid endarterectomy, mostly for symptomatic internal carotid artery stenosis, has been successfully performed in both the vascular and neurological surgery units at Dunedin Hospital. This study was performed to compare our results with those of the North American Symptomatic Carotid Endarterectomy Trial and the European Carotid Surgery Trial. The 30-day perioperative morbidity and mortality rate was 4.3% (1.2% < 95% Cl > 7.4%) which compares favourably with an estimated upper limit of 5.5% based on recent trial reports. The present study highlights the difficulty in modelling local clinical practice on results of major trials when standards of patient evaluation and surgical skill may differ from those of the large studies. To justify generalization of indications for intervention based on the multicentre trials, there must be continual monitoring of local surgical results, and standardized use of diagnostic investigations.     

症状性和无症状性颈内动脉狭窄的大脑中动脉微栓子信号监测

目的观察症状性和无症状性颈内动脉狭窄的患者大脑中动脉微栓子信号（microembolicsig-nals,MES）阳性率及MES计数的变化,研究微栓子与临床症状和颈内动脉狭窄程度的关系。方法选取症状性颈内动脉狭窄患者26例,无症状性颈内动脉狭窄患者20例及正常对照组30例;症状性颈内动脉狭窄组又分为短暂性脑缺血发作（transient ischemic attack,TIA）组（12例）和脑梗死组（14例）;症状性和无症状性颈内动脉狭窄的患者均行DSA或CTA检查,并对颈内动脉狭窄程度进行分级;所有颈内动脉狭窄的患者均对颈内动脉狭窄同侧的大脑中动脉进行MES监测,正常对照组则对双侧大脑中动脉进行MES监测。结果有症状和无症状颈内动脉狭窄组的MES阳性率高于正常对照组（P〈0．01）;有症状颈内动脉狭窄组MES阳性率较无症状组高（P〈0．05）;TIA组和脑梗死组比较,MEs阳性率无显著性差异（P〉0．05）;症状性和无症状性颈内动脉狭窄患者,轻、中、重度狭窄三组的MES阳性率比较均有显著性差异（P〈0．05）;MES阳性患者MES计数与颈内动脉狭窄程度呈正相关（r=0．9155,P〈0．01）。结论MES多见在颈内动脉狭窄患者,特别是症状性颈内动脉狭窄的患者,是缺血性脑血管疾病发生的高危因素。     

DSA对单侧颈内动脉系统大动脉狭窄或闭塞后侧支循环建立的应用价值

目的 探讨DSA对单侧颈内动脉系统大动脉狭窄或闭塞后侧支循环建立的应用价值,探讨三级侧支循环在单侧颈内动脉开口部位狭窄或闭塞及大脑中动脉M1段狭窄或闭塞中的特点.方法 分别对56例颈内动脉开口处狭窄或闭塞及94例大脑中动脉M1段狭窄或闭塞的患者进行脑血管造影检查,根据其狭窄程度分析其侧支循环建立的情况.结果 颈内动脉开口部位闭塞组大脑动脉环开放率约38.5%,颅内外沟通开放率30.8%,软脑膜吻合支开放率约30.8%;重度狭窄组大脑动脉环开放率35.1%,软脑膜吻合支开放率16.2%,颅内外沟通开放率约5.4%;中轻度狭窄组无侧支循环建立.大脑中动脉M1段闭塞组大脑动脉环开放率5%,软脑膜吻合支开放率95%;重度狭窄组仅软脑膜吻合支开放,开放率约61%;轻中度狭窄组无侧支形成.结论 在颈内动脉开口部位重度狭窄或闭塞的病例中,一级侧支循环的开放代偿最为重要,二级侧支循环起着重要的辅助作用.在大脑中动脉M1段重度狭窄或闭塞的病例中,二级和三级侧支循环的开放起主要的代偿作用.     

Blood supply of the posterior cerebral artery by the carotid system on angiograms

Background and Purpose Occipital lobe infarcts are traditionally attributed to vertebrobasilar disease. However, anatomical studies indicate that in some people the supply of the posterior cerebral artery is via the carotid system. We investigated how often such a developmental variant in the cerebral blood supply was present during life. Methods We retrospectively studied 212 conventional four-vessel cerebral angiograms. Eighteen subjects were excluded beforehand, because of vascular abnormalities causing important hemodynamic changes. We determined whether a fetal variant was present, and in other cases whether there was a functioning posterior communicating artery. Results In 11 % of hemispheres the posterior cerebral artery was exclusively supplied by the internal carotid artery; in a further 46 % of hemispheres the internal carotid artery might contribute, via a patent posterior communicating artery. In 75 % of subjects the internal carotid artery contributed in at least one hemisphere to the blood flow of the posterior cerebral artery. Conclusions The implication of our findings is that an occipital lobe infarct can be caused by ipsilateral carotid disease in a proportion of cases between 10 and 60 %. This implies that carotid endarterectomy might be beneficial in some patients with severe carotid stenosis and infarction in the territory of the posterior cerebral artery. Received: 21 February 2001, Received in revised form: 16 August 2001, Accepted: 1 October 2001     

急性前循环脑梗死患者血浆脂蛋白相关磷脂酶A2活性与颈内动脉狭窄的关系

目的 探讨血浆脂蛋白相关磷脂酶A2(Lp-PLA2)活性与急性前循环脑梗死患者颈内动脉狭窄的关系.方法 采用CTA检查133例急性前循环脑梗死患者的颈内动脉狭窄的程度,将其分为轻-中度狭窄组及重度狭窄组.收集133例患者及70名正常对照者(正常对照组)的临床资料,并采用速率法检测血浆Lp-PLA2活性.结果 重度狭窄组...     

Xenon-enhanced CT assessment of cerebral blood flow in stroke-in-progress patients with unilateral internal carotid artery or middle cerebral artery stenosis

Carotid or cerebral artery stenosis resulting in low perfusion is a major cause of ischemic stroke.Understanding the unique hemodynamic features in each patient undergoing a stroke-in-progress（SIP） and the correlation between progression and cerebral blood flow（CBF） status would help in the diagnosis and treatment of individual patients.We used xenonenhanced CT（Xe-CT） to examine cerebral perfusion in patients with or without SIP（30 patients/group）,recruited from October 2009 to October 2010.Only SIP patients with unilateral stenosis in the internal or middle cerebral artery were recruited.The occurrence of watershed infarction was higher in the SIP group than in the non-SIP group（P ＆lt;0.05）.In the SIP group,larger hypoperfused areas were found around the lesions than in the non-SIP group.In the SIP group,the CBF values in the ipsilateral areas were significantly lower than those in corresponding regions on the contralateral side.CBF values in the contralateral hemisphere were significantly lower in the SIP group than in the non-SIP group.In SIP patients,infarctions were surrounded by larger hypoperfused areas than in non-SIP patients.These larger hypoperfused areas may result in pathological damage to the brain that is responsible for the progression of stroke.     

Correlating cognitive impairment with carotid atherosclerosis and carotid artery stenosis in patients with acute cerebral infarction*★

BACKGROUND：Studies have demonstrated that carotid atherosclerosis and carotid artery stenosis are closely associated with cognitive impairment in patients with and without clinically evident cerebrovascular disease. OBJECTIVE： To investigate the correlation between the degree of pathological changes in carotid atherosclerosis, carotid artery stenosis, and cognitive impairment in patients with acute cerebral infarction through the use of color Doppler imaging. DESIGN, TIME AND SETTING： The present concurrent, non-randomized, controlled experiment was performed at the Departments of Neurology and Ultrasound, Affiliated Hospital of North Sichuan Medical College between November 2006 and August 2007. PARTICIPANTS： Fifty-five patients with cerebral infarction, consisting of 35 males and 20 females, aged 50–82 years, were admitted to the hospital between November 2006 and August 2007 and recruited for this study. An additional 30 subjects consisting of 18 males and 12 females, aged 47–78 years, that concurrently received a health examination at the same hospital, were also included as normal controls. METHODS： Intima-media thickness （IMT）, plaque shape, size, and echo intensity of all subjects were detected by color Doppler flow imaging. Assessment criteria： IMT 〉 1.0 mm was considered to be intimal thickening, and IMT 〉 1.2 mm was determined to be formed atherosclerotic plaques. In the position of the largest plaque, the degree of carotid artery stenosis was determined by the following formula： （1-cross-sectional area of residual vascular luminal area/vascular cross-sectional area） × 100%. Less than 30% exhibited mild stenosis, 30%-40% moderate stenosis, and 〉 50% severe stenosis. MAIN OUTCOME MEASURES： IMT and the degree of carotid artery stenosis were evaluated by color Doppler flow imaging. The Mini-Mental State Examination （MMSE）, as well as the clinical memory scale, was compared between patients with cerebral infarction and normal controls. RESULTS： In the cerebral infarc     

Correlating cognitive impairment with carotid atherosclerosis and carotid artery stenosis in patients with acute cerebral infarction

BACKGROUND:Studies have demonstrated that carotid atherosclerosis and carotid artery stenosis are closely associated with cognitive impairment in patients with and without clinically evident cerebrovascular disease. OBJECTIVE: To investigate the correlation between the degree of pathological changes in carotid atherosclerosis, carotid artery stenosis, and cognitive impairment in patients with acute cerebral infarction through the use of color Doppler imaging. DESIGN, TIME AND SETTING: The present concurrent...     

纤维蛋白原与重度颈动脉狭窄所致不同类型脑梗死关系中的研究

目的探讨纤维蛋白原在颅外段颈动脉重度狭窄所致脑梗死中的作用。方法对重度颈动脉狭窄导致脑梗死患者83例,无症状的颈动脉狭窄患者35例及健康查体者50例(作为对照组)均测定纤维蛋白原含量,分析它们之间的关系,并分析纤维蛋白原含量与狭窄后脑梗死类型、神经功能缺失程度及预后的关系。结果梗死组纤维蛋白原水平明显高于无症状狭窄组及健康对照组,区域性脑梗死的纤维蛋白原水平明显高于其他各型(P<0.05),纤维蛋白原水平越高神经功能缺失程度越重,且其水平越高,预后越差。结论纤维蛋白原增高与重度颈动脉狭窄及其所致脑梗死密切相关,支持特定的梗死类型,可能对病情的严重程度和预后有预示作用。     

脑梗死患者颈部动脉杂音与颈动脉狭窄的关系

目的 研究脑梗死患者颈部动脉杂音与颈动脉狭窄的关系.方法 对245例脑梗死患者进行颈部动脉听诊与血管造影检查.根据颈部动脉杂音部位分为锁骨上窝杂音、颈前弥漫杂音及颈前局限杂音,并根据杂音强度分为1～5级.对颈部动脉听诊及血管造影结果进行分析、比较.结果 听诊发现本组145例(59.2％)患者有颈部动脉杂音,其中锁骨上窝杂音62例、颈前弥漫杂音44例、颈前局限杂音39例,100例患者(40.8％)无杂音;1 ～5级杂音分别有28例、26例39例、34例及18例.有颈部动脉杂音的患者颈动脉狭窄的发生率(64.1％,93例)显著高于无杂音患者(49％,49例)(P＜0.05).颈前局限杂音患者颈动脉狭窄及重度狭窄的发生率显著高于锁骨上窝杂音及颈前弥漫杂音杂音患者(均P＜0.01).颈部动脉杂音分级越高,颈动脉重度狭窄率越高(P＜0.05).结论 有颈部动脉杂音的脑梗死患者颈动脉狭窄的发生率高,尤以颈前局限性杂音患者显著;杂音强度与颈动脉狭窄的程度有关.     

Transient ischaemic attacks in two cases of internal carotid artery hypoplasia

Abstract Congenital anomalies of the internal carotid arteries (ICA) and cerebral arteries have not been frequently reported. Moreover, in the literature there is no clear association between hypoplastic carotid and cerebral vessel systems and the occurrence of cerebral ischaemia. We report two cases of unilateral hypoplasia of the ICA affecting two young patients suffering from an episode of minor stroke and from recurrent transient ischaemic attacks, respectively. Congenital variations in the configuration and size of the carotid and cerebral arteries should not always be considered benign conditions and may predispose to cerebral ischaemia in young adults.