Stroke risk factors and development of collateral flow in carotid occlusive disease

Background and purpose – Blood flow through collateral vessels compensates for reduced blood flow through stenotic or occluded extracranial carotid arteries. Previous studies have shown that extent of collateral flow influences likelihood of stroke and its outcome. Here we analyzed the relationship between stroke risk factors (hypertension, coronary artery disease, diabetes mellitus, tobacco smoking and hypercholesterolemia) and number of patent intracranial collaterals detected by transcranial Doppler ultrasonography. Subjects and methods – We studied 182 patients with various degrees of angiography proven unilateral stenosis of the internal carotid artery. Contribution of the anterior and posterior communicating arteries to the perfusion of the cerebral hemisphere on the side of the stenosis or occlusion was evaluated by a series of compression tests performed during continuous insonation of the middle cerebral artery. The number of detected collateral vessels was correlated with analyzed stroke risk factors. Results – Subjects with stenosis more than 75% or occlusion of the internal carotid artery had a higher frequency of two major intracranial collateral vessels ( P 0.01 and P 0.001, respectively). Hypertensive patients with stenosis more than 75% or total carotid occlusion were more likely to have only a single collateral vessel than patients without hypertension ( P 0.01 and P 0.05, respectively). Other risk factors did not influence the patency of preformed collateral vessels. Conclusions – Hypertension hindered the development of preformed intracranial collateral vessels in our patients with carotid occlusive disease.     

Diabetes as a determinant of high-grade carotid artery stenosis: Evaluation of 1,058 cases by Doppler sonography

Our objective was to investigate the association of risk factors, especially diabetes mellitus, with high-grade carotid artery stenosis. The study group was chosen from the patients who were sent to our Doppler ultrasonography laboratory for detecting the vascular anatomy. Doppler sonography was performed in 1,058 patients. High-grade carotid artery stenosis with a diameter reduction of 70% to 99% was detected in 89 patients. In the moderate and mild stenosis groups, we had 85 and 884 patients, respectively. Patients in the moderate stenosis group had a 40% to 69% carotid stenosis, and patients in the mild group had a 0% to 39% stenosis or normal ultrasonographic findings. Parameters of age, sex, alcohol, smoking, ischemic heart disease, hypertension, and diabetes were considered potential risk factors for stenosis. Multivariate logistic regression model was used as the statistical test in comparing the 3 groups. In the high-grade stenosis group, sex distribution was 34.8% female and 65.2% male with a mean age of 64.48 ± 10.19 years. In the second and third groups these distributions were 51.8% female and 48.2% male with a mean age of 65.15 ± 9.66 years, and 54.30% female and 45.70% male with a mean age 59.56 ± 12.37, respectively. Diabetes mellitus (odds ratio [OR] = 2.77), ischemic heart disease (OR = 1.67), age (OR = 1.02), and male gender (OR = 1.75) were found to be significantly associated with high-grade carotid stenosis. As a cost-effective, noninvasive, easily performed, and fast technique, Doppler sonography is used in vascular evaluation of patients. Early diagnosis of carotid artery disease in patients with modifiable risk factors like diabetes may play an important role in the prevention of a consequent stroke.     

H型高血压与急性脑梗死患者颈动脉粥样硬化斑块的相关性分析

目的探讨H型高血压与急性脑梗死患者颈动脉粥样硬化斑块形成的相关性。方法将132例患者分为斑块组和无斑块组（对照组）,采用循环酶法测定血浆Hcy水平,比较H型高血压亚组、高血压亚组、高Hcy血症亚组（无高血压）及正常亚组颈动脉粥样斑块的检出率。结果颈动脉超声诊断显示,132例患者中99例患者存在颈动脉粥样硬化斑块,其余33例患者未发现。2组性别、年龄、吸烟、饮酒史、糖尿病史等比较差异无统计学意义（P〉0.05）。斑块组中不同亚组检出率依次为H型高血压亚组〉高Hcy血症亚组〉高血压亚组〉正常组,差异有统计学意义（P〈0.05）。结论 H型高血压与颈动脉粥样硬化斑块的形成密切相关,为急性脑梗死患者颈动脉粥样硬化斑块形成的独立危险因素。     

缺血性卒中患者颅内外血管狭窄率研究

目的:研究缺血性卒中患者颅内外血管狭窄或闭塞的发生率,并对其相关病因进行分析。方法:对经CT/MRI/DWI诊断的缺血性卒中患者的人口构成情况进行登记,了解其相关危险因素。并经TCD和/或MRA了解其颅内外血管狭窄或闭塞的情况。结果:579例缺血性卒中患者中,颅内外血管狭窄的发生率为70.98%(411/579例);411例大动脉狭窄或闭塞患者中,以大脑中动脉狭窄或闭塞最常见(64.48%),其次为颈内动脉(50.36%)。大动脉狭窄或闭塞的主要原因为动脉粥样硬化,引起动脉粥样硬化的危险因素的发病率依次为:高血压病(77.24%),吸烟(63.68%)。通过Logistic回归分析发现,糖尿病、高血压、吸烟是血管狭窄的主要相关危险因素(P值均<0.05)。结论:国内缺血性卒中患者颅内外血管狭窄或闭塞的发生率高,其主要病因为动脉粥样硬化,糖尿病是大动脉狭窄或闭塞的最主要危险因素。     

The size of territorial brain infarction on CT relates to the degree of internal carotid artery obstruction

We studied the relationship between infarct size and degree of internal carotid artery stenosis in 227 stroke patients without a source of embolism in the heart, who had a CT-verified territorial brain infarct. We used logistic regression analysis adjusting for differences between groups in co-associated variables such as age, sex, hypertension, diabetes mellitus, and a history of ischaemic heart disease. Ipsilateral carotid stenosis greater than 50% was more strongly associated with large than small infarcts; adjusted odds ratio [(a)OR]: 4.56; 95% confidence interval (CI): 1.21-17.2;P = 0.02. For ipsilateral carotid occlusion the association was even stronger - (a)OR: 36.80; 95% CI: 2.54-533;P = 0.007. When large infarcts were compared with infarcts of small and moderate size together the ORs were 2.29, 95% CI 1.14–4.58 and 2.57, 95% CI 1.17–5.67 for carotid stenosis or occlusion, respectively. Our data show a relationship between greater than 50% carotid stenosis or occlusion and large brain infarcts. We suggest that haemodynamic impairment may contribute to infarct size in territorial infarcts of non-cardiac origin.     

颈动脉狭窄患者认知功能障碍临床分析

目的探讨颈动脉狭窄与认知功能障碍之间的关系。方法选取颈动脉狭窄组80例和对照组78例,两组患者年龄、性别和文化程度比较差异无统计学意义。所有患者均予颈部MRA及颈动脉彩超检查,并进行MMSE及MoCA评定,同时对脑血管病常见危险因素进行登记。所有数据采用SPSS13.0统计软件进行分析。结果 80例颈动脉狭窄患者均经颈部MRA及血管超声检查证实,其中轻度狭窄32例(40%),中度狭窄26例(32.5%),重度狭窄16例(20%),完全闭塞6例(7.5%)。颈动脉狭窄组无论MMSE还是MoCA评分均小于对照组,差异有统计学意义。随着颈动脉狭窄程度的加重,Mo-CA及MMSE评分越低,两两比较差异有统计学意义(P<0.05)。结论颈动脉狭窄存在认知功能障碍,且随着狭窄程度加重而加重,糖尿病、高血脂、高血压、吸烟是颈动脉狭窄的危险因素。     

Transcranial Doppler ultrasonography of the middle cerebral artery in the hemodynamic assessment of internal carotid artery stenosis

We performed transcranial Doppler ultrasonography of the middle cerebral arteries in 43 patients who underwent cerebral angiography. Twelve patients had normal arteriograms, 18 had internal carotid artery stenosis, and 13 had complete occlusion. Parameters measured included: flow velocity (mean, maximum, and peak systolic), flow acceleration, systolic-to-diastolic ratio, and pulsatility index. Patients with 75% to 100% stenosis had lower average ipsilateral flow acceleration and mean velocity than did normal subjects. Correlation analysis revealed an inverse relationship between degree of stenosis and ipsilateral flow acceleration, as well as ipsilateral mean velocity. These correlations were no longer significant when we excluded normals, however. There was a linear relationship between right and left velocity values for both normal subjects and patients with occlusion but not for patients with stenosis. This technique has potential for the reliable assessment of the hemodynamic effect of carotid stenosis on intracranial circulation.     

胼胝体梗死的临床研究

目的:探讨胼胝体梗死的临床特点和临床诊断应该注意的方面。方法:收集1995年至2005年住院病例中的18例胼胝体梗死患者,对其进行临床和影像(头CT或MRl)分析和统计学比较。结果:18例患者中,男11例,女7例,高血压11例、糖尿病7例、冠心病2例、高脂血症8例、高同型半胱氨酸血症1例、TIA2例、高血压合并糖尿病5例、吸烟5例、饮酒4例,4例既往无特殊病史。临床症状有偏瘫、语言障碍、智能障碍、情感障碍、感觉障碍、二便障碍、失用等。影像学示:梗死部位有膝部13例、体部7例、压部3例,膝部合并体部5例。TCD示脑动脉硬化12例、颅内血管狭窄或闭塞10例,CA示颈动脉狭窄5例、颈动脉闭塞2例。2例经DSA证实存在动脉闭塞或狭窄。结论:胼胝体梗死多有脑血管病高危因素,临床表现以偏瘫、语言障碍、智能障碍为主,梗死部位多见膝部。病因为脑动脉硬化基础上的血流动力学改变。     

Duplex Doppler and spectral flow analysis of racial differences in cerebrovascular atherosclerosis

We compared carotid artery disease in 99 black and 106 white patients using duplex ultrasonography (B-mode imaging and Doppler spectral analysis). Blacks had significantly less stenosis of the extracranial internal carotid artery than whites. Among the risk factors investigated, hypertension alone, ischemic heart disease, diabetes mellitus, and smoking failed to explain the racial difference. Although carotid stenosis of greater than or equal to 40% correlated significantly with age in both races (p = 0.001 in whites and p = 0.005 in blacks), blacks had significantly less carotid stenosis of any degree even when age was taken into account. Multivariate analysis showed that race is a significant and independent risk factor for carotid stenosis (p less than 0.0001). Hypertension interacting with race was also significant. Our results require verification in population-based studies. Carotid duplex ultrasonography offers a noninvasive method for carrying out such studies.     

Asymptomatic carotid bruit as related to single risk factors. A flowmetric study

The prevalence of asymptomatic carotid bruit is 4 per cent in the general population aged over 40 years. According to most authors, it is an evident risk factor for stroke and myocardial infarction. In the present study the clinical data and Doppler flowmeter analysis of 5 groups of patients are reported. These patients had risk factors for cerebrovascular disease, without cerebral symptoms. An age matched group of healthy control subjects was also studied. The prevalence of haemodynamic stenosis (more than 50 per cent) of carotid artery is significantly higher among subjects with peripheral arteriopathy and arterial hypertension compared with other groups. On the other hand nonhaemodynamic stenosis (below 50 per cent) of carotid artery occurs to the same extent in patients and control groups. The possible implications of these findings on the knowledge of cerebrovascular obstructive disease are discussed.     

Occlusive cerebrovascular disease in young adults

13 patients under 40 years of age had cerebral infarction and angiographic evidence of arterial stenosis or occlusion. None of them had cardiac disorders prone to cerebral embolism. Five patients had occlusion at the origin of the internal carotid artery, one had occlusion of the common carotid artery and one each had stenosis at the origin of the internal carotid and common carotid arteries, respectively. Two patients had unilateral occlusion of the supraclinoid portion of the carotid artery with basal collaterals that had some resemblance to the Moyamoya disease. Three patients demonstrated stenosis or occlusion of the middle and/or anterior cerebral arteries. Three patients had hypercholesterolemia, one of whom was hypertensive. None had confirmed diabetes mellitus. One female, who died, had taken oral contraceptives for 3 years. A male, with internal carotid artery occlusion, had serological evidence for syphilis.     

TCD对颅内动脉狭窄或闭塞诊断的临床研究

目的分析经颅多普勒超声(TCD)对颅内动脉狭窄或闭塞诊断的意义。方法回顾性分析50例疑为颅内动脉狭窄或闭塞的脑血管病患者(观察组)和30例正常体检者(对照组)的TCD结果(主要针对大脑中动脉、大脑前动脉、椎动脉和基底动脉等血管),并与MRA及DSA结果作对比分析。结果观察组与对照组所查脑血管平均血流速度有明显差异(P<0.05);以DSA检查为金标准,TCD结果的假阳性率为17.2%,假阴性率为17.1%,特异性为82.8%,敏感性为82.9%;与MRA检查相比,对颅内动脉狭窄或闭塞的阳性检出率无显著差异(P>0.05)。结论 TCD可作为诊断颅内动脉狭窄和闭塞的常用辅助检查手段。     

Cerebrovascular reactivity in carotid artery occlusion: possible implications for surgical management of selected groups of patients

OBJECTIVES: The aim of this study was to use transcranial Doppler ultrasonography to investigate cerebrovascular reactivity to hypercapnia in the middle cerebral arteries of patients with carotid occlusion with different outcomes. PATIENTS AND METHODS: Cerebrovascular reactivity to hypercapnia was calculated with the breath-holding index (BHI). Patients with unilateral carotid occlusion were divided as follows: asymptomatic (20 patients), transient ischemic attack (TIA) (20 patients), minor (20 patients) and major stroke (14 patients). Values of BHI homolateral to the carotid occlusion were compared with those of 25 healthy subjects and 34 stroke patients without significant carotid stenosis. RESULTS: BHI values were comparable in healthy controls, non stenotic stroke patients and asymptomatic occluded patients. BHI values of patients with symptomatic occlusion were significantly lower than those of the above-mentioned groups (P<0.0001). Moreover, the reduction of BHI was significantly associated with the extent of the neurological impairment. In fact, BHI values were significantly higher in TIA than in minor and major stroke (P<0.0001) and in minor than in major stroke patients (P<0.02). Finally, we found that a BHI value homolateral to carotid occlusion of 0.69 can be considered the cut-point for distinguishing between symptomatic and asymptomatic patients. CONCLUSION: Prospective studies are needed to demonstrate if the presence of this threshold value may help in selecting a subset of patients with asymptomatic carotid occlusion or with transient or mild neurological deficit with the highest probability of benefiting from surgical therapy.     

Amount of smoking independently predicts carotid artery atherosclerosis severity.

BACKGROUND AND PURPOSE: Cigarette smoking is correlated with extracranial carotid artery plaque thickness. Our aim in the present study was to determine whether the level of prior cigarette use is a significant predictor of carotid artery plaque thickness when age, history of hypertension, and history of diabetes are controlled. METHODS: We studied a continuous sample of 790 patients with a history of smoking referred for diagnostic ultrasound imaging of the carotid arteries. Subjects (mean age 61 years) had an average of 51 pack-years of cigarette use. History of hypertension was present in 44% and history of diabetes in 18%. RESULTS: Right and left maximum carotid artery plaque thicknesses were averaged for each patient; the average of this value for all 790 subjects was 1.9 mm. In bivariate analysis, age (p less than 0.0001), pack-years (p less than 0.0001), history of hypertension (p = 0.0003), and history of diabetes (p = 0.037) were each positively associated with carotid artery plaque thickness. In multiple regression analysis, age (p less than 0.0001), pack-years (p = 0.0005), and history of hypertension (p = 0.0044) were statistically significant independent predictors of carotid artery plaque thickness, but history of diabetes (p = 0.2451) was not. CONCLUSIONS: In smokers, the level of cigarette use is associated with an acceleration of carotid artery atherosclerosis development. This effect is independent of age, hypertension, and diabetes. These results support smoking abatement as an important element to stroke prevention in clinical practice.     

脑梗死患者颈动脉颅外段狭窄危险因素分析

目的:探讨脑梗死患者颈动脉颅外段狭窄的相关危险因素,为脑梗死发病机制、临床诊断、治疗和预防提供重要依据。方法:应用HDI-5000彩色多普勒超声仪对脑梗死患者的颈动脉颅外段进行检测,观察血管解剖形态,内膜情况,有无斑块形成及斑块大小,管腔是否狭窄和狭窄程度。按颈动脉超声检测结果将脑梗死患者分为狭窄组和非狭窄组,进行相关危险因素分析。结果:年龄、男性、糖尿病、高血压、高TG、高apoB和高Fib与脑梗死患者颈动脉颅外段狭窄呈正相关,高HDL-C与脑梗死患者颈动脉颅外段狭窄呈负相关。结论:脑梗死患者颈动脉颅外段狭窄的危险因素有年龄、性别、糖尿病、高血压病、高TG、高APOB和高Fib,保护因素有高HDL-C。     

缺血性卒中患者颅内外动脉狭窄与高血压、糖尿病的研究

目的 探讨缺血性卒中患者的颅内外动脉狭窄特点及程度与高血压病、糖尿病的病史及控制水平的 关系。 方法 回顾性分析住院治疗的存在颅内外动脉狭窄且并发高血压或糖尿病的大动脉粥样硬化性急 性缺血性卒中患者资料。将高血压患者分为高年限组（病史>5年）和低年限组（病史≤5年）,血压 控制良好组和不良组;将糖尿病患者也分为高年限组（病史>5年）和低年限组（病史≤5年）,血糖 控制良好组和不良组。比较不同组间颅内外动脉狭窄分布情况、血管狭窄程度。 结果 共入组216例急性缺血性卒中患者,其中57例颅外动脉狭窄,105例颅内动脉狭窄,54例颅内 外动脉均狭窄。轻度狭窄发生73例,中度狭窄发生101例,重度狭窄及闭塞发生42例。高血压病患者 共140例,高年限组动脉狭窄最常见于颅内动脉（54.5%）,低年限组血管狭窄的部位多见于颅外动脉 （51.3%）,差异有统计学意义（P＜0.001）。两组间动脉狭窄程度差异也有统计学意义。糖尿病患者共 76例,高年限组发生动脉狭窄最常见于颅内动脉（72.2%）,低年限组血管狭窄的部位多见于颅外动脉 （65%）,差异有统计学意义,两组间动脉狭窄程度差异也有统计学意义。高血压控制不良组发生重度 狭窄或闭塞的概率高于血压控制良好组（20.7% vs 8.6%）;血糖控制情况不良组发生重度狭窄或闭 塞的概率高于血糖控制良好组（40.9% vs 6.3%）。 结论 随着高血压病年限的增长,急性缺血性卒中患者颅内动脉狭窄的发生率增高,其中以中度狭 窄程度多见;血压控制不良的患者发生重度狭窄或闭塞的比率高。随着糖尿病年限的增长,颅内动 脉狭窄的发生率增高,其中以中度狭窄程度多见,血糖控制不良者发生重度狭窄或闭塞的比例高。     

Asymptomatic cervical artery stenoses in Moscow

The risk of stroke related to asymptomatic carotid artery stenosis is known to be increased in high-grade or rapidly progressive stenosis. Information of the prevalence in the general population is required for the recommendation of screening methods to detect patients needing prophylactic treatment. We studied the prevalence and the grade of severity of extracranial carotid and vertebral artery obstructions by means of Doppler sonography in 529 asymptomatic Russians (m: 343, f: 186; 36-84 years, mean: 58.4 years) living in Moscow city. Internal carotid artery obstructions of more than 50% stenosis were present in 22 (=4.2%) subjects, 8 of them (1.5%) had bilateral lesions. Appropriate abnormal findings in vertebral arteries were found in 11 (=2.1%) subjects, in 1 of them bilaterally. Affection of both the carotid and the vertebral arteries was noted in 4 (=0.8%) individuals. There were no sexual differences. The risk factor which correlated most significantly with cervical arterial lesions was hypertension. Carotid lesions were also significantly associated with age and smoking, but not with diabetes or hyperlipoproteinemia. The prevalence of cervical artery stenoses was found to be lower than in western reports, which may be due to different technical equipment and different study design.     

Correlation of intracranial atherosclerosis with carotid stenosis in ischemic stroke patients

Introduction:

Carotid stenosis is a major risk factor for ischemic stroke. However, the effect of carotid stenosis on the site of stroke is still under investigation.

Aims:

This study aimed to elucidate how the presence of carotid stenosis influenced the pattern of stroke and also how it interacted with other risk factors for stroke.

Materials and Methods:

Thirty-eight patients with ischemic stroke were included in this study and were investigated with carotid artery Doppler and magnetic resonance angiography for carotid stenosis and intracranial stenosis in the circle of Willis, respectively. Other known risk factors of stroke were also studied in and compared between the subgroups with and without carotid stenosis.

Results:

In patients without carotid stenosis, anterior cerebral artery was the commonest site of stenosis. In patients with carotid stenosis, middle cerebral artery was the commonest site of stenosis. Overall, middle cerebral artery was the commonest territory of stroke. Patients with hypertension, diabetes and history of smoking had preferential stenosis of the anterior cerebral artery.     

颈动脉内膜斑块剥脱术治疗颈内动脉狭窄(附16例报告)

目的探讨颈动脉内膜斑块剥脱术的手术适应证、操作要点和麻醉方法。方法回顾性分析2004年11月至2009年12月经颈动脉内膜斑块剥脱术治疗的16例颈内动脉狭窄患者的临床资料。16例患者均有临床症状,其中颈内动脉中度狭窄者2例,重度狭窄者14例。均采用经气管内插管全身麻醉,术中应用诱导性高血压,应用显微外科技术剥除颈动脉内膜斑块,所有病例均未应用术中转流术。结果术后均行多普勒超声检查,结果示颈动脉血流量较术前明显增加。12例反复发作一过性脑缺血的患者术后随访6个月均未再发作。1例糖尿病合并高血压有脑卒中史者死亡,其余患者随访6个月至2年脑缺血症状明显改善。结论颈内动脉内膜斑块剥脱术是颈动脉狭窄安全有效的治疗方法。     

缺血性脑卒中患者动脉粥样硬化分布的临床研究

目的探讨急性缺血性脑卒中不同亚型与颈动脉粥样硬化分布的相关性。方法通过经颅多普勒超声(TCD)和颈动脉彩色多普勒血流成像(CDFI)方法检测颅内、外动脉粥样硬化程度,并结合病史、生化指标及影像学提示的病变部位进行综合分析。结果411例急性缺血性脑卒中患者,颅内动脉狭窄率为38.93%(160/411),颈动脉颅外段狭窄率24.09%(99/411)。颈动脉颅外段狭窄者年龄大、吸烟比例高,与无狭窄者比较差异有统计学意义(P=0.020,0.013);而颅内动脉狭窄者糖尿病发病率明显高于无狭窄者(P=0.005)。411例中皮质梗死49例、皮质下梗死108例、腔隙性梗死72例和短暂性脑缺血发作30例,颈动脉颅外段狭窄者以皮质梗死为主(P=0.001),并且动脉内-中膜层厚度明显增加(P=0.020);而颅内动脉狭窄者以腔隙性梗死更多见(P=0.016)。颅内、外动脉狭窄者的年龄、性别、血糖及血脂之间差异无统计学意义(均P>0.05)。结论临床和影像学检查所确定的急性缺血性脑卒中亚型与颅内、外动脉粥样硬化的病变部位相关,提示发病的原因可能不同。糖尿病与吸烟是引起颅内、外动脉病变的重要原因。