经颅多普勒超声和颈动脉超声检测无脑缺血症状的2型糖尿病患者颅内外动脉粥样硬化病变

目的 分析无脑缺血症状的2型糖尿病患者颅内动脉粥样硬化性狭窄和颅外颈动脉粥样硬化病变的发生频率及分布特征,并探讨其危险因素.方法 对94例无脑缺血症状的2型糖尿病住院患者用经颅多普勒超声(TCD)和颈动脉超声判断颅内外动脉粥样硬化病变,颅内动脉只分析狭窄,颅外动脉病变包括颈动脉斑块及狭窄.分析各危险因素的影响.结果 55例(58.5%)有颅内外动脉粥样硬化病变.22例(23.4%)发现有颅内动脉狭窄,明显高于颅外颈动脉狭窄或闭塞(3/94,3.2%,χ~2=16.66,P＜0.01).大脑中动脉是颅内最常受累的动脉(狭窄率17.0%),占狭窄动脉数的58.5%.48例(51.0%)有颅外颈动脉粥样斑块或狭窄.Logistic多元回归分析显示糖尿病病程和合并高血压是颅内外动脉粥样硬化病变的独立危险因素.结论 无脑缺血症状的2型糖尿病住院患者,半数以上有颅内外动脉粥样硬化改变,且与糖尿病病程及合并高血压有关,提示对上述高危患者应常规进行超声检测.     

Racial differences in ischemic cerebrovascular disease: Clinical and magnetic resonance angiographic correlations of white and asian patients.

Objectives. We explored racial differences in ischemic cerebrovascular disease. Methods. Clinical and magnetic resonance angiographic (MRA) features were compared in 21 white and 21 Asian patients with symptomatic ischemic cerebrovascular disease. Results. When all carotid artery sites were combined and compared, whites had more stenotic lesions of internal carotid artery origin, and Asians had more stenotic lesions of the middle cerebral artery (MCA) stem. In the vertebrobasilar territory, there were no significant differences in the distribution of extracranial and intracranial stenotic lesions between the two races. In symptomatic territories, the distribution of extracranial and intracranial stenosis were not significant differences for white and Asian patients. In asymptomatic territories, whites had a higher tendency for isolated extracranial stenosis, whereas Asians had an increased incidence of isolated intracranial stenosis. In the combined symptomatic and asymptomatic, carotid and vertebrobasilar territories, there was an increased incidence of extracranial carotid stenotic lesions in white patients and intracranial anterior circulation stenotic lesions in Asians. Demographic factors alone seemed to explain the difference. Conclusions. Racial differences in the occurrence of extracranial and intracranial lesions raise the possibility of different pathophysiologic abnormalities.     

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。     

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。     

Distribution and correlates of sonographically detected carotid artery disease in the Cardiovascular Health Study. The CHS Collaborative Research Group.

BACKGROUND AND PURPOSE: This article describes the prevalence of extracranial carotid atherosclerosis assessed by ultrasonography, its association with risk factors, and its relation to symptomatic coronary disease and stroke in men and women aged > or = 65 years. METHODS: Maximum percent stenosis, maximum common carotid artery wall thickness, and maximum internal carotid artery wall thickness were assessed using duplex ultrasound in 5,201 men and women aged > or = 65 years in the Cardiovascular Health Study, a study of the risk factors and natural history of cardiovascular disease in the elderly. Existing coronary disease and stroke were assessed by physical examination and participant history. RESULTS: Detectable carotid stenosis was present in 75% of men and 62% of women, although the prevalence of > or = 50% stenosis was low, 7% in men and 5% in women. Maximum stenosis and maximum wall thickness measurements increased with age and were uniformly greater at all ages in men than in women (p < 0.00001). Established risk factors for atherosclerosis (hypertension, smoking, diabetes) and indications of vascular disease (left ventricular hypertrophy, major electrocardiographic abnormality, bruits, and history of heart disease or stroke) related to all three carotid artery measures in the elderly. Of the three ultrasound measures, the best correlate for a history of coronary disease was maximum internal carotid artery wall thickness. For stroke the best correlate was common carotid artery wall thickness. Multiple logistic regression models of prevalent coronary heart disease and stroke that included the ultrasound findings indicated, after adjustment for age and sex, that maximum internal wall thickness and maximum common carotid wall thickness were significant correlates of both. Maximum stenosis did not add significantly to the correlation. CONCLUSIONS: In the elderly the incidence of carotid atherosclerosis was high, although the frequency of severe disease was low. The prevalence and severity of carotid atherosclerosis continued to increase with age even in the late decades of life, and more disease was found in men than in women at all ages. Known risk factors for atherosclerosis continued to relate to carotid abnormalities in the later decades of life, both in symptomatic and asymptomatic subjects.     

Bilateral intracranial vertebral artery disease in the New England Medical Center, Posterior Circulation Registry.

BACKGROUND: Previous studies of patients with bilateral intracranial vertebral artery (ICVA) disease were selective and retrospective. METHODS: We studied risk factors, vascular lesions, symptoms, signs, and outcomes in patients with bilateral ICVA disease among 430 patients in the New England Medical Center Posterior Circulation Registry. RESULTS: Forty-two patients had bilateral ICVA occlusive disease (18 had bilateral stenosis; 16, unilateral occlusion and contralateral stenosis; and 8, bilateral occlusion). The most common risk factors were hypertension (32/42 [76%]) and hyperlipidemia (22/42 [52%]). Sixteen patients (38%) had transient ischemic attacks (TIAs) only; 18 (43%), TIAs before stroke. Occlusive vascular disease also involved the basilar artery in 29 patients (69%), the extracranial vertebral arteries in 18 (43%), and the internal carotid arteries in 11 (26%). Only 6 patients had no other major vascular lesion. Cerebellar symptoms were common. Among 30 patients with infarction, 21 (70%) had proximal intracranial territory involvement, and 15 (50%) had distal territory involvement. The location of occlusive lesions in relation to posterior inferior cerebellar artery origins did not significantly influence prognosis. During follow-up, 31 patients had no symptoms or slight disability, 2 had progression, and 7 died. Among 7 patients with poor outcome, 6 also had basilar artery stenosis or occlusion and 5 had proximal and distal intracranial territory infarcts. CONCLUSIONS: Most patients with bilateral ICVA occlusive disease have hypertension, other major occlusive lesions, and TIAs before stroke. Short- and long-term outcomes are usually favorable, but patients with bilateral ICVA and basilar artery-occlusive lesions often have poor outcomes.     

The differences of clinical parameters between small multiple ischemic lesions and single lesion detected by diffusion-weighted MRI

OBJECTIVES: The cause of small infarction is mainly considered to be intracranial small-vessel disease. However, it is difficult to explain the mechanism of multiple, acute infarctions by small-vessel disease. We examined the differences of clinical parameters between patients with multiple small lesions and single lesion detected by Diffusion-weighted MRI (DWI). MATERIAL AND METHODS: We reviewed the clinical records of 86 consecutive stroke patients with lacunar size ischemic lesions on DWI during the acute stage (within 72 h of onset). The subjects were 55 males and 31 females (mean age 72.4 +/- 9.9 years). Small multiple acute ischemic lesions were defined using the following criteria 1): the lesions were detectable by DWI 2), the diameter of each lesion on DWI was less than 1.5 cm, and 3) more than one vascular territory was involved. Included in the analysis were age, sex, lipoprotein (a) levels, hematocrit, atrial fibrillation (Af), stenosis of middle cerebral artery (MCA), internal carotid artery (ICA) or basilar artery stenosis detected by magnetic resonance angiography (MRA), National Institute of Health Stroke Scale (NIHSS) at admission, and a history of hypertension, diabetes mellitus, hyperlipidemia, and smoking. RESULTS: Twenty-one (24.4%) out of 86 patients with small acute infarctions had multiple acute ischemic lesions. Multiple logistic regression analysis showed that Af and stenosis of ICA or basilar artery were significantly more prevalent in patients with multiple lesions than single lesions. CONCLUSION: Multiple, small lesions visible in DWI are likely to be caused by emboli from heart or atheroma of the large vessels than single small lesion.     

短暂性脑缺血发作与颅内外血管狭窄的关系

目的 探讨短暂性脑缺血发作(TIA)与颅内外血管狭窄的关系.方法 对130例TIA患者的CT血管成像(CTA)进行分析,观察TIA患者颅内外段血管有无狭窄及TIA发作次数与狭窄数量关系.结果 130例TIA中有血管狭窄94例(占72.3%).颈内动脉系统TIA患者80例中有血管狭窄者55例(占68.75%),颈内动脉颅...     

颈动脉超声对冠状动脉狭窄患者缺血性脑血管疾病的评价及其与传统危险因素的关系

目的探讨颈动脉超声对预测冠状动脉狭窄患者颅内动脉狭窄的价值,以及颈动脉超声相对于其它动脉粥样硬化主要危险因素预测缺血性心脑血管疾病的优越性。方法对209例经血管造影证实冠状动脉狭窄(≥70%)的患者采用彩色多谱勒血流成像(CDFI)和经颅多普勒超声(TCD)分别检查颈动脉和颅内动脉,并将患者分为颈动脉狭窄组与非狭窄组;脑动脉狭窄组与非狭窄组,分别比较狭窄组与非狭窄组之间的危险因素及生化指标,进一步对冠状动脉狭窄合并颅内动脉狭窄的主要危险因素与颈动脉超声结果中具有显著性统计学意义的指标,分析二者之间的相关性。结果颈动脉超声对缺血性心脑血管疾病的预测价值较传统的危险因素更高。结论高血压病、颈动脉球部内膜增厚、多发斑块及不均质回声斑块对冠状动脉狭窄患者颅内动脉狭窄有明显的促进作用。采用CDFI对确诊冠状动脉狭窄患者进行检测,对心脑血管事件高危人群进行筛选、评价治疗疗效和预后具有重要意义。     

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.     

Stroke risk of asymptomatic intra- and extracranial large-artery disease in apparently healthy adults

BACKGROUND: The predictive value of asymptomatic intracranial artery stenosis for future stroke remains uncertain. The aim of this study is to assess the stroke risk of asymptomatic intracranial artery stenosis and to compare it with that of extracranial artery disease. METHODS: The study subjects were 2,924 participants (mean age 55 years) without any history of stroke. We examined the relation between intra- or extracranial large-artery disease and subsequent cerebrovascular events (mean follow-up 63 months). RESULTS: The incidence rate of total cerebrovascular events in persons with intracranial artery stenosis was 1.3% per year. In the group without plaque in the extracranial carotid arteries, the annual rate of total cerebrovascular events was only 0.6%, but in the group with plaque, the rate was 3.6%. Kaplan-Meier analysis of total events showed a significant difference between the 2 groups (p = 0.002). CONCLUSIONS: The stroke risk in subjects with asymptomatic extracranial artery disease is markedly increased if intracranial artery stenosis is also present.     

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.     

Detection of intracranial emboli in patients with symptomatic extracranial carotid artery disease.

BACKGROUND AND PURPOSE: Cerebral embolism from extracranial sources is an important cause of ischemic stroke. The purpose of this limited study using long-term transcranial Doppler ultrasonographic monitoring was to estimate the frequency of clinically silent intracranial embolisms in patients with symptomatic extracranial carotid artery disease. SUMMARY OF REPORT: By means of a 2-MHz pulsed-wave transcranial Doppler instrumentation, three consecutive patients with extracranial internal carotid artery stenosis (n = 2) or occlusion (n = 1) and recurrent ipsilateral ischemic events were monitored (19 hours total recording time). In addition, 10 control subjects without cerebrovascular disease were studied (25 hours total recording time). Formed-element emboli were defined as distinct signals within the fast Fourier-transform Doppler spectrum that were < 70 msec in duration and > 9dB greater in intensity than the background signal. Clinically silent formed-element embolism of ophthalmic or cerebral arteries was demonstrated in all three patients. Embolic events occurred only in the territory of the symptomatic internal carotid artery. The average rate of cerebral embolization at transcranial Doppler ultrasonography was 4.1/hr, with a mean signal duration of 47 msec. No emboli were found in control subjects. CONCLUSIONS: The observed high frequency of silent embolism of the intracranial arteries detected by transcranial Doppler monitoring in patients with recurrently symptomatic extracranial carotid artery disease should encourage studies of the prognostic and therapeutic implications of this method.     

缺血性脑血管病患者颅内外动脉狭窄分布研究

目的 研究缺血性脑血管病患者颅内外动脉狭窄分布特点.方法 本研究收集了1031例在院脑梗死和TIA患者的DSA资料,对其中资料完整的1000例患者进行分析.结果 DSA显示,1000例患者中有680例存在脑动脉狭窄,累计有1417条血管狭窄.发生部位依次为:大脑中动脉狭窄337条、椎动脉远端及基底动脉狭窄291条、颈内动脉颅外段狭窄280条、椎动脉起始段狭窄207条、颈内动脉虹吸段狭窄115条、大脑前动脉狭窄100条、大脑后动脉狭窄70条.大脑中动脉、椎基底动脉系统和颈动脉颅外段是最常见的动脉狭窄好发部位.颅内动脉狭窄331例,颅外动脉狭窄134例,颅内外动脉均见狭窄215例.结论 颅内动脉粥样硬化性狭窄仍是缺血性卒中的重要原因,最近三年,多发病变、颅外动脉病变检出率明显上升,值得关注,控制血压、血糖、血脂可预防脑动脉粥样硬化性狭窄的发生.     

缺血性卒中患者颅内动脉狭窄的相关危险因素分析

目的 探讨颅内动脉狭窄的狭窄程度、相关危险因素与缺血性脑卒中的关系,为缺血性卒中的防治提供重要依据.方法 90例缺血性卒中患者根据全DSA检查结果分为非狭窄组(狭窄<30%)与颅内动脉狭窄组(狭窄≥30%或闭塞),分析颅内动脉狭窄程度与年龄、性别、高血压、糖尿病、高脂血症、冠心病、家族史、总胆固醇(CHO)、三酰甘油(TG)、高密度脂蛋白胆同醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)、载脂蛋白 A1(ApoA1)、载脂蛋白B(ApoB)、血清脂蛋白(Lpa)等相关危险因素的关系.结果 (1)本组患者颅内动脉狭窄发生率为67.78%,发生率最高为大脑巾动脉,其次颈内动脉颅内段和椎基底动脉颅内段,发生率最低为大脑后动脉.(2)有高血压、糖尿病的缺血性卒中患者容易发生颅内动脉狭窄,其同归系数、OR值、P值分别为1.659、5.256、0.002,1.657、5.241、0.046.(3)颅内动脉狭窄组HDL-C含量[(0.99±0.30)mmol/L]比非狭窄组[(1.30±0.50)mmol/L]明显降低,差异有统计学意义(t=3.603,P=0.001).(4)年龄、性别、吸烟、既往卒中史、脑血管病家族史、TC、TG、LDL-C、ApoA1、ApoB、Lpa在两组间比较差异无统计学意义(P>0.05).结论 缺血性卒中患者颅内血管狭窄的主要危险因素有高血压、糖尿病,保护因素有HDL-C.     

缺血性卒中患者左心室质量指数与颅内、外动脉狭窄的相关性

目的 探讨左心室质量指数（left ventricular mass index,LVMI）与颅内外动脉粥样硬化狭窄程度的 关系。 方法 从东部战区总医院南京卒中登记系统纳入2017年1-10月间进行超声心动图和DSA检查的缺血 性卒中患者。对颅外和颅内动脉粥样硬化性狭窄程度进行评估,分为动脉轻度狭窄组和动脉中重度 狭窄组。LVMI根据美国超声心动图协会标准计算。在颅外和颅内动脉粥样狭窄患者中分别比较动脉 轻度狭窄和中重度狭窄组传统脑动脉粥样硬化的危险因素,如年龄、性别、高血压、糖尿病、冠状动 脉硬化心脏病、血脂及左心室质量（left ventricular mass,LVM）和LVMI。单因素分析及二元回归分析 影响颅内外动脉粥样硬化狭窄程度的独立危险因素并对LVMI与颅内外动脉狭窄率进行相关性分析。 结果 169例登记患者中,85例（50.3%）为颅外动脉粥样硬化性狭窄,84例（49.7%）为颅内动 脉粥样硬化狭窄。在颅外动脉粥样硬化性狭窄患者中,中重度狭窄患者年龄比轻度狭窄患者大 [（64.3±12.4）岁 vs（56.0±13.2）岁,P =0.001],LVMI较轻度狭窄患者高[（43.6±10.3）g/m2.7 vs （36.6±7.2）g/m2.7,P <0.001]。在颅内动脉粥样硬化性狭窄患者中,轻度狭窄患者LVMI低于中重度狭 窄患者（[ 36.5±7.2）g/m2.7 vs（46.1±13.6）g/m2.7,P <0.001]。Spearman相关分析结果表明LVMI与颅内 外动脉狭窄率呈正相关（r=0.553,P<0.001）。二元回归分析发现LVM（I OR 1.13,95%CI 1.05～1.21）、 年龄（OR 1.06,95%CI 1.01～1.11）是颅外动脉粥样硬化性重度狭窄的独立危险因素。 结论 缺血性卒中患者LVMI与颅内外动脉粥样硬化性狭窄率正相关,LVMI是颅外动脉粥样硬化性重 度狭窄的独立危险因素。     

颈动脉狭窄和缺血性脑血管病关系的研究

目的　探讨动脉粥样硬化所致的颈动脉颅外段狭窄与缺血性脑血管疾病的关系。方法　对214例脑梗死(CI)患者、26例短暂性脑缺血发作(TIA)患者、58例单纯高血压病(HBP)患者及43例正常健康人群,通过颈动脉彩色多普勒超声检测颈动脉颅外段的狭窄程度,并结合其病史进行对照研究。结果　CI、TIA患者的颈动脉颅外段狭窄率(分别为78.98%、57.69%)较HBP组(46.30%)和正常对照组(30.95%)明显升高(P <0.01,P <0.05),狭窄程度在1%~50%;CI各年龄组间狭窄程度无明显差异(P >0.05),但50岁以上的老年患者颈动脉狭窄率明显高于50 岁以下的患者(P <0.01);TIA与CI患者颈动脉狭窄度有症状侧重于无症状侧。结论　缺血性脑血管病与颈动脉狭窄程度有明显相关性。     

MR angiographic evaluation of carotid and intracranial arteries in Japanese patients scheduled for coronary artery bypass grafting

BACKGROUND AND PURPOSE: Stroke is a serious complication of coronary artery bypass grafting (CABG). Preoperative evaluation of the cerebral arteries to identify patients at increased risk of stroke after CABG is important. In a prospective study, we evaluated cerebral artery occlusive lesions with MR angiography in Japanese patients scheduled to undergo CABG to determine the prevalence of occlusive diseases in the extracranial carotid and intracranial arteries in this population and to identify preoperative risk factors for these patients. METHODS: The subjects were 151 consecutive patients (115 men and 36 women ranging in age from 41 to 82 years) who were scheduled for CABG under nonemergency conditions between October 1995 and February 1998. Carotid and intracranial arteries were examined for occlusive lesions with MR angiography. Patient demographics and risk factors including age, sex, hypertension, diabetes mellitus, hyperlipidemia, smoking habit, history of stroke, peripheral vascular disease and preoperative thromboembolic infarcts revealed by MR imaging were recorded and analyzed. RESULTS: Cervical carotid artery stenoses of more than 50% narrowing were detected in 16.6% of the subjects, and intracranial artery stenoses of more than 50% narrowing were detected in 21.2% of the subjects. Multiple logistic regression analyses identified peripheral vascular disease and lacunar infarcts in the basal ganglia as significant and independent predictors of cervical carotid arterial stenoses. No significant predictor for intracranial arterial stenoses was identified. CONCLUSIONS: The prevalence of extracranial carotid and intracranial artery stenosis in Japanese patients scheduled for CABG is considerably high. MR angiography is of value of identifying these patients. Preoperative evaluation of cranial arteries is recommended, particularly in patients with peripheral vascular disease and infarcts in the basal ganglia.     

The Prevalence of Asymptomatic Intracranial Large-Vessel Occlusive Disease: The Role of Diabetes

OBJECTIVE: To investigate the prevalence of asymptomatic intracranial stenosis using transcranial Doppler ultrasonography in patients with evidence of asymptomatic carotid stenosis. BACKGROUND: Symptomatic atherosclerotic intracranial largeartery stenosis accounts for approximately 10% of ischemic strokes annually. It is unknown whether a significant risk for stroke is associated with asymptomatic intracranial stenosis, especially in patients with known asymptomatic carotid disease. DESIGN AND METHODS: Transcutaneous real-time B-mode Doppler ultrasonography was performed on 510 patients referred for the evaluation of asymptomatic carotid bruits. A peak systolic flow velocity > 1.40 m/s indicated carotid stenosis. Transcranial Doppler ultrasound was performed to identify intracranial large-artery disease. The peak systolic flow velocity indicating stenosis was > 120 cm/s for anterior circulation and > 100 cm/s for posterior circulation. Demographic and cerebrovascular risk factor information was recorded at the time of examination. Chi-square analysis with Pearson correction was performed to examine the significance of the findings. RESULTS: Five hundred ten patients (252 male, 258 female) aged 71.4 +/- 10.45 years were studied. The laboratory's accuracy was previously established as 93% for each technique for laboratory certification. Two hundred patients (39.2%) were found to have extracranial carotid stenosis, and 66 (12.9%) were found to have intracranial stenosis. Thirty-seven patients (56%, P < .01) were found to have concurrent stenosis. In patients with intracranial stenosis, 19 (28.8%, P < .03) had diabetes, and 26 (39.4%, p < .03) had coronary disease. There was no corresponding correlation with extracranial carotid disease and diabetes or coronary artery disease. CONCLUSIONS: The prevalence of patients with asymptomatic intracranial stenosis with concurrent carotid stenosis was greater than expected. Coexisting diabetes and coronary disease were significant risk factors in this population. Doppler ultrasonography may be a useful technique in delineating asymptomatic intracranial stenosis in those patients with existing carotid stenosis. Further studies are needed to clarify the risk of this population for stroke from asymptomatic intracranial stenosis and to determine optimal therapy.     

Internal borderzone infarction following acute middle cerebral artery occlusion

In 36 patients suffering acute middle cerebral artery (MCA) occlusion, we studied the angiographic findings within 6 hours of the ictus and the chronic CT results at 3 months. Seven patients suffering distal pial MCA branch occlusion developed a pattern of internal borderzone infarction on follow-up CT. Carotid artery or carotid siphon stenosis or occlusion was absent in all seven. Proximal MCA branch occlusions, prior to the origin of the lenticulostriate arteries, were associated with extensive cortical and deep infarction in the entire MCA territory in 14 patients. There was proximal carotid artery or siphon stenosis or occlusion in 12 of these 14 patients. The remaining 15 patients showed a mixture of proximal and distal MCA occlusions and patchy ischemic damage in the MCA territory. There were no cases of superficial cortical watershed infarction. These data show that internal borderzone infarctions may result from intracranial MCA branch occlusions alone and need not be associated with hemodynamic alterations due to large vessel extracranial disease.