Extracranial Atherosclerosis Research Articles

Classic Risk Factors for Atherosclerosis Are Not Major Determinants for Location of Extracranial or Intracranial Cerebral Atherosclerosis

Background: The prevalence of extracranial (EC) and intracranial (IC) atherosclerosis varies among races. Although several studies have sought to identify specific vascular risk factors that are associated with EC or IC atherosclerosis, the exact relationships are uncertain. This study aimed to determine if there are any specific risk factors for EC or IC atherosclerosis. Methods: For this study, we considered 3,349 consecutive patients who had been entered into a stroke registry between January 1999 and June 2007. After the exclusion of patients who had not undergone angiography, patients with cardiac sources of embolism or other causes of stroke, and non-Koreans, we had a total of 2,169 patients of single ethnicity with an angiographic analysis. Patients with atherosclerosis in both the IC and EC arteries (856 patients) were excluded. Finally, we identified 1,313 patients who had EC atherosclerosis (EC group, n = 256), IC atherosclerosis (IC group, n = 566) or normal angiographic findings (no-lesion group, n = 488). The frequency of risk factors and the demographic parameters were compared among these groups. Results: When compared to the normal group, the IC group was associated with older age and hypertension, and the EC group was associated with older age, higher initial blood sugar and low-density lipoprotein cholesterol levels. However, in a direct comparison between the IC and EC groups, we did not observe any significant risk factors or variables except for a higher frequency of males and higher total cholesterol levels in the EC group. Conclusions: Vascular risk factors may not be major determinants of location for atherosclerosis in the EC or IC arteries.

Autopsy Prevalence of Proximal Extracranial Atherosclerosis in Patients With Fatal Stroke

Extracranial atherosclerosis, proximal to the carotid bifurcation and V3 segment of the vertebral artery, is considered to be an infrequent condition with a benign prognosis. However, its prevalence may be underestimated due to lack of data. We aimed to determine the prevalence of proximal extracranial plaques and stenosis in the common carotid artery, innominate and subclavian arteries, and proximal vertebral artery. We performed a systematic analysis of intra- and extracranial arteries, the aortic arch, and the heart in 339 consecutive autopsies of patients with stroke; 259 patients had brain infarction; 80 patients had brain hemorrhage and were used as control subjects. Clinical history, risk factors, imaging data, and general autopsy reports were analyzed. Proximal extracranial plaques and stenosis were present in the arteries of 46.9% and 19.8% of patients, respectively, without a significant difference between brain infarction and brain hemorrhage groups. Proximal extracranial atherosclerosis occurred more frequently in the proximal vertebral artery than in other arteries (stenosis prevalence 12.7% versus 5.3% in the common carotid artery) and in patients with posterior circulation brain infarction (except for the posterior cerebral artery territory). More specifically, atherosclerosis in the proximal vertebral artery was significantly associated with posterior circulation brain infarction (age- and sex-adjusted OR, 2.31; 95% CI, 1.28 to 4.17 for plaques and 2.10; 95% CI, 1.01 to 4.38 for stenosis) using patients with isolated anterior circulation infarctions as control subjects. Proximal extracranial atherosclerosis was frequent and was significantly associated with brainstem infarcts. These findings support the importance of a systematic workup, including the evaluation of proximal extracranial atherosclerotic lesions.

Correlation Between Insulin Resistance and Intracranial Atherosclerosis in Patients With Ischemic Stroke Without Diabetes

Insulin resistance (IR) is associated with an increased risk for cardiovascular morbidity and mortality including ischemic stroke. Its final complications are cardiovascular and cerebrovascular disease caused by atherosclerosis. However, few studies on the relationship between IR and intracranial (IC) atherosclerosis have been reported. We analyzed 110 patients with acute stroke without diabetes who underwent brain magnetic resonance angiography and cerebral angiography. Patients were divided into 3 equal groups according to the tertiles of homeostasis model assessment of IR (HOMA-IR): group I (n = 36; HOMA-IR < 0.92), group II (n = 37; 0.92 <or= HOMA-IR < 1.55), and group III (n = 37; HOMA-IR >or= 1.55). Cerebral artery atherosclerosis was classified as either IC or extracranial (EC). Patients with IC or EC atherosclerosis showed higher level of HOMA-IR than those without. When the association was assessed according to the site of atherosclerosis, HOMA-IR showed a significant association with the site of atherosclerosis (IC + EC > IC > EC, P < .01). Multivariate analysis revealed that HOMA-IR was an independent predictor of IC atherosclerosis. Although the association between IR and stroke patterns in patients with atherosclerosis remains uncertain, IR is associated with IC atherosclerosis in patients with acute ischemic stroke without diabetes.

Prospective Evaluation of the Role of Atherosclerosis on Cerebral Atrophy: Pilot Study

Our purpose was to study the association between atherosclerosis measured by arterial calcium on computed tomography (CT) and cerebral atrophy demonstrated by brain magnetic resonance imaging (MRI). IRB approved this prospective study. Twenty-one consecutive patients with acute stroke-like symptoms who are scheduled to have brain MRI were recruited on a voluntary basis. electrocardiogram (ECG)-gated helical CT scans were used to determine the arterial calcium as a reliable index of underlying atherosclerosis. Extracranial arterial calcium content was measured quantitatively by special software available in our CT scanner. Intracranial calcium was graded qualitatively. Brain MRI was independently evaluated to identify cortical, central atrophy, and ischemic changes. Relationship between CT demonstrated atherosclerosis and cerebral ischemic changes, brain atrophy patterns were evaluated both without and with adjustment for age and hypertension. Out of 21 patients 20 were included in final study group. There was no correlation between atherosclerotic calcium measures and cortical atrophy, ischemic findings. Both intracranial and extracranial atherosclerosis had partial correlation with central atrophy (R= 0.43 and 0.52, respectively). After adjustment for age, only intracranial atherosclerosis maintained a partial correlation with central atrophy (R= 0.41). However, this correlation did not reach a statistically significant level (P= .10). Intracranial atherosclerosis demonstrated a possible correlation with central atrophy.

Association between metabolic syndrome and previous ischemic lesions in patients with intracranial atherosclerotic stroke

Objectives To elucidate the relationship between MetS and ischemic stroke, we evaluated the association of MetS and individual components with frequency of ischemic stroke lesions and investigated the independent associations between them in acute ischemic stroke patients. Patients and methods We evaluated 370 acute ischemic stroke patients who underwent brain magnetic resonance (MR) imaging and MR angiography. The stroke subgroups were categorized as intracranial large artery atherosclerosis (IC-LAA, n = 151), extracranial large artery atherosclerosis (EC-LAA, n = 35), and nonatherosclerosis (NA, n = 184). MetS was defined using the criteria of the International Diabetes Federation. Results Patients with IC-LAA group showed a higher rate of MetS and previous ischemic lesions (predominantly deep gray/white matter) than those with EC-LAA and NA (all P < 0.001). The number of previous ischemic lesions showed a tendency to increase as the number of MetS components increased in the IC-LAA group ( P = 0.004). In the IC-LAA group, age (OR, 1.04) and MetS (OR, 3.28) were independently associated with previous ischemic lesions (all P < 0.001), which was prominent with more severe MetS components after adjustment for risk factors ( P < 0.001). Among the component conditions, high blood pressure, impaired fasting glucose, and abdominal obesity were more associated with previous ischemic lesions (all P < 0.001) than low high-density lipoprotein and high triglyceride levels ( P = 0.010 and 0.028, respectively). Conclusion Our study showed a strong association between MetS and previous ischemic lesions, more in patients with IC-LAA.

Polymorphism in the human C-reactive protein (CRP) gene, serum concentrations of CRP, and the difference between intracranial and extracranial atherosclerosis

BackgroundC-reactive protein, a proinflammatory factor, is involved in the development of atherosclerosis. The CRP 1059G>C polymorphism appeared to be a susceptive marker for atherosclerosis. We investigated the relationship of the distribution of cerebral atherosclerosis with triggered serum CRP concentrations following acute ischemic stroke/transient ischemic attack (IS/TIA) and CRP 1059G>C polymorphism. MethodsWe recruited 222 IS/TIA patients (122 with only intracranial atherosclerotic lesions and 100 with isolated extracranial atherosclerotic lesions) and 227 controls. Intra- and extracranial atherosclerotic lesions were determined by digital subtraction angiography. Serum CRP concentrations were measured by particle-enhanced immunonephelometry assay. CRP 1059G>C genotypes were obtained through PCR amplification and restriction enzyme digestion. ResultsCRP concentrations were significantly higher in intra- and extracranial groups than in controls. No significant difference was found in CRP concentrations between intra- and extracranial groups. The CRP 1059G>C single-nucleotide polymorphism did not influence CRP serum concentrations. CRP genotype and allele frequencies did not differ significantly between patients and controls. However, the frequencies of GC genotype and C allele were significantly higher in extracranial group than that in intracranial group. The GC individuals showed a higher risk of extracranial atherosclerosis compared with GG individuals (OR 3.41; 95%CI, 1.124–10.347; P=0.030). ConclusionsSerum CRP is associated with cerebral atherosclerotic disease. CRP 1059G>C polymorphism is one possible genetic determinant for the difference between intra- and extracranial atherosclerosis.

Differences in Stroke Subtypes Between Black and White Patients With Stroke

Determining whether the distribution of stroke subtypes differs between ethnic groups is important in understanding the mechanisms of the increased stroke incidence in black patients. In this study, 600 black and 600 white patients with stroke were prospectively and consecutively recruited to determine differences in stroke subtypes. The pathophysiological Trial of Org 10172 (TOAST) classification was used and compared with a clinical (Oxfordshire Community Stroke Project) subtype classification. Stroke subtypes were determined by one investigator by review of original imaging. Black patients with stroke were significantly younger and had higher prevalences of hypertension, diabetes, and obesity. They were less likely to be smokers and had lower prevalences of myocardial infarction and atrial fibrillation. In the black patients, 33% of stroke was due to cerebral small vessel disease compared with 14% in the white stroke cohort (odds ratio, 2.94; 95% confidence interval, 1.97 to 4.39; P<0.001, controlling for age, gender, cardiovascular risk factors, and social class). The black stroke cohort had less large vessel atherosclerosis (odds ratio, 0.49; 95% confidence interval, 0.29 to 0.82; P=0.007) and cardioembolic disease (odds ratio, 0.54; 95% confidence interval, 0.37 to 0.80; P=0.002). Using a classification based on clinical syndrome alone gave a higher estimate of the frequency of small vessel disease stroke, particularly in white patients. A relative excess of small vessel disease was observed in black patients with stroke compared with an excess of extracranial atherosclerosis and cardioembolic stroke in white patients with stroke that was independent of conventional risk factors and social class. Whether these excesses are due to differences in genetic susceptibility or as-yet undetermined differences in environmental risk remains to be determined.

Prevalence of Carotid Siphon Stenosis in Patients Referred for Cerebrovascular Evaluation

Introduction The carotid siphon is second only to the carotid bifurcation in the prevalence of hemodynamically significant atherosclerotic plaque formation, yet few noninvasive vascular laboratories report interrogation of this region during routine noninvasive vascular evaluations. The purpose of this investigation was to determine the prevalence of carotid siphon stenosis in patients referred for noninvasive cerebrovascular evaluation. Materials and Methods During a 2-month period, 178 patients (94 male, 84 female, mean age, 71.8 years) were referred to the vascular laboratory for cerebrovascular evaluation, which included interrogation of the extracranial carotid, vertebral, and subclavian arteries as well as the intracranial ophthalmic artery and carotid siphon. All intracranial examinations were performed using a phased array imaging transducer (2–4 MHz). Results Ten patients (6%, 10/178) were found to have hemodynamically significant carotid siphon stenosis. There was a statistically significant association between the presence of carotid siphon stenosis and cervical bruit ( p ≤ 0.05), follow-up of known extracranial carotid artery atherosclerosis ( p ≤ 0.001), and a combination of hypertension, hyperlipidemia, and coronary artery disease ( p ≤ 0.01). Conclusion Investigation of the carotid siphon is worthwhile when performed in conjunction with extracranial carotid duplex examinations. Siphon lesions detected during the cerebrovascular examination, especially in those with cervical bruits, known extracranial atherosclerotic disease, and combinations of risk factors, may affect medical or interventional therapy and can lead to a reduction in neurovascular events.

Adiponectin levels in patients with intracranial atherosclerosis

Adiponectin is a protein secreted by adipose cells that improves insulin sensitivity and possesses antiatherogenic properties. In this study, we investigated the relationship between adiponectin levels and ischemic stroke subtype. Using clinical, imaging, and laboratory data, 231 consecutive patients admitted to a university medical center over a 2-year period with acute cerebral infarcts were categorized into four subtypes: intracranial atherosclerosis (n = 67), extracranial atherosclerosis (n = 61), small arterial occlusion (n = 63), and cardioembolic (n = 40). Clinical features, risk factors including the presence of metabolic syndrome, and levels of s-adiponectin were compared between groups. Patients with more severe metabolic abnormalities were more likely to have lower s-adiponectin levels (p = 0.002). S-adiponectin levels differed by stroke subtype: highest in the cardioembolic group and lowest in the intracranial atherosclerosis group (8.42 +/- 5.07 vs 5.60 +/- 2.79 microg/mL, p = 0.01). Extracranial atherosclerosis (6.45 +/- 4.10 microg/mL) and small arterial occlusion (6.07 +/- 3.44 microg/mL) groups were intermediate. Patients with advanced intracranial atherosclerosis (> or =1 additional lesion outside the symptomatic arterial territory) had lower s-adiponectin levels than those with isolated intracranial atherosclerosis (4.95 +/- 2.63 vs 6.13 +/- 2.84 microg/mL, p = 0.003). In multiple regression analysis, s-adiponectin levels, but not metabolic syndrome, were independently associated with intracranial atherosclerosis. Symptomatic intracranial atherosclerosis is associated with lower s-adiponectin levels vs other ischemic stroke subtypes.

Lower blood flow velocity, higher resistance index, and larger diameter of extracranial carotid arteries are associated with ischemic stroke independently of carotid atherosclerosis and cardiovascular risk factors

To investigate the association between diameter and flow velocity of the carotid arteries and ischemic stroke. Peak systolic velocity, end diastolic velocity, Pourcelot resistance index, blood flow volume, luminal diameter, and carotid plaque burden were measured and compared in 240 ischemic stroke (IS) patients without history of stroke, 163 chronic stable IS patients, and 236 nonstroke controls (age, >or=40 years). Data were also compared between stroke subtypes (large artery atherosclerosis, lacunar, cardioembolic, or undetermined origin). Acute as well as chronic stable IS patients had significantly lower flow velocities and flow volume, higher resistance index than nonstroke controls in the common carotid artery (CCA), internal carotid artery and external carotid artery, and larger common carotid artery diameter. The differences were found across all IS subtypes and in stroke patients with as well as without carotid plaque. Comparisons between these subgroups showed significant differences in end diastolic velocity, resistance index, flow velocity, and diameter that were more prominent in the CCA. After adjusting for carotid plaque and cardiovascular risk factors, the associations between the above-mentioned parameter and stroke remained significant. Stroke patients in acute as well as chronic stable phase appeared to have larger CCA diameters, lower carotid flow velocities and volume, and higher resistance index than nonstroke patients independently of extracranial carotid atherosclerosis. These findings need to be confirmed by a prospective study.

Metabolic syndrome is more associated with intracranial atherosclerosis than extracranial atherosclerosis

To elucidate the relationship between metabolic syndrome (MetS) and cerebrovascular stenosis, we performed comparative studies of MetS and its components between ischemic stroke patients with intra- and extracranial atherostenosis. We evaluated 378 acute ischemic stroke patients who underwent brain magnetic resonance (MR) imaging and MR angiography. Stenosis was diagnosed in cases showing a degree of luminal narrowing of > or = 50%. The stroke subtypes were categorized as large artery atherosclerosis (LAA), small artery occlusion (SAO), cardioembolism (CE), and stroke of undetermined etiology (SUE). MetS was defined using the criteria of the Adult Treatment Panel III. The mean carotid intimal medial thickness values showed increased tendency as the number of MetS components increased (P < 0.001). Regardless of stroke subtype, the MetS (+) group showed an increasing tendency toward stenosis (LAA, SAO, all P < 0.001; CE, P = 0.001; SUE, P = 0.077). MetS was independently associated with intracranial atherosclerosis (odds ratio, 3.58; 95% CI, 2.28-5.63), which was prominent with more severe MetS components after adjustment for other risk factors (P < 0.001). Amongst the component conditions, elevated blood pressure, increased blood glucose/hyperglycemia, and abdominal obesity were dominantly associated with stenosis (all P < 0.001). Modifications of the individual MetS components need to be considered for stroke prevention because of intracranial atherogenic progression.

Stenting for Middle Cerebral Artery Stenosis

Recent developments in stroke prevention have once more followed the cardiac paradigm, where removal of a symptomatic atherosclerotic source can improve clinical outcomes. Coronary artery stenting is now the mainstay of treatment of severe, symptomatic coronary artery disease. In the early 1990s, proof for the benefits of carotid endarterectomy for symptomatic extracranial atherosclerosis was provided by large randomized clinical trials. There is now accumulating experience and evidence concerning the role of carotid stenting for extracranial disease, with some encouraging results in high-risk patients, although considerable uncertainty of risks and benefits still …

Risk factors of carotid stenosis in first-ever ischemic stroke in Taiwan: a hospital-based study.

The aim of this study is to identify the risk factors of extracranial carotid atherosclerosis in patients with first-ever ischemic stroke. A total of 541 consecutive first-ever ischemic stroke patients were enrolled in the present study. We examined clinical and laboratory factors that were potentially relevant to extracranial carotid artery atherosclerosis. The degree of carotid stenosis was diagnosed based on B-mode ultrasonography. The sample contained 325 men and 216 women. Among these patients, 80% had a < 50% carotid stenosis and 20% had a > or = 50% carotid stenosis. Multiple logistic regression analysis revealed that age (odds ratio = 2.15, 95% CI = 1.06-1.11, P < 0.001) and smoking (odds ratio = 1.52, 95% CI = 1.17-3.54, P = 0.012) were significantly associated with > or = 50% carotid stenosis. In the present study, age and smoking are found to be the independent risk factors for carotid atherosclerosis. The identification of these risk factors may improve our knowledge in the primary prevention of ischemic stroke in Taiwan.

Interhemispheric Asymmetry in Brain Perfusion Before and After Carotid Stenting:A99mTc-HMPAO SPECT Study

To assess the effect of unilateral carotid angioplasty and stenting (CAS) on cerebral perfusion asymmetry in patients with severe extracranial carotid stenosis by means of technetium Tc 99m hexamethyl-propyleneamine oxime brain single photon emission computed tomography ((99m)Tc-HMPAO SPECT). Twenty-nine consecutive patients (22 men; median age 68 years, range 58-80; 13 symptomatic) undergoing unilateral CAS were included in the study. Brain perfusion was assessed by (99m)Tc-HMPAO brain SPECT prior to the procedure and postoperatively at 8 hours and at 2 to 4 months. The asymmetry index (AI), a measure of the interhemispheric asymmetry in perfusion, was calculated as [(counts in "healthy" hemisphere-counts in hemisphere with carotid stenosis)/counts in "healthy" hemisphere]x100. The preoperative AI demonstrated a wide variation (mean -0.5%+/-8.4%, range -19.5% to 14.1%). There was no significant correlation between the degree of carotid stenosis and preoperative AI. The mean preoperative AI in the asymptomatic patients was lower than in the symptomatic group [-4.0%+/-8.5% (range -19.5% to 8.2%) versus 3.8%+/-6.4% (range -5.2% to 14.1%), p=0.01], suggesting reduced perfusion of the ipsilateral cerebral hemisphere compared to the contralateral side in symptomatic patients. AI variation did not improve after CAS; there was no difference in AI among the 3 SPECT studies (p=0.75). Preoperative AI correlated significantly with late AI (r=0.74, p<0.0001); however, there was no statistically significant correlation between immediate postoperative AI and either preoperative (r=0.24, p=0.217) or late (r=0.24, p=0.249) AI. Asymmetry in cerebral perfusion in patients with severe extracranial carotid atherosclerosis does not correlate with the degree of carotid stenosis. Symptomatic patients demonstrate compromised perfusion of the ipsilateral hemisphere compared to asymptomatic patients. As judged by (99m)Tc-HMPAO SPECT scanning, cerebral perfusion patterns do not significantly change after CAS.

C-Reactive Protein, Carotid Atherosclerosis, and Cerebral Small-Vessel Disease

C-reactive protein (CRP) is an inflammatory marker known to be a risk factor for stroke. We examined the associations between CRP, carotid atherosclerosis, white matter lesions, and lacunes as manifestations of cerebral large- and small-vessel disease. In the community-based Austrian Stroke Prevention Study, CRP concentrations were measured by a highly sensitive assay in 700 participants at baseline. All underwent carotid duplex scanning, and a subset of 505 subjects underwent brain magnetic resonance imaging. Imaging was repeated after 3 and 6 years. We graded carotid atherosclerosis in both common and internal carotid arteries on a 5-point scale and calculated the sum of scores as an index of the severity of carotid atherosclerosis. The volume of white matter lesions and the number of lacunes were considered small vessel disease-related brain abnormalities. After adjustment for vascular risk factors, the severity and progression of extracranial carotid atherosclerosis increased with increasing quintiles of CRP. Only study participants in the fourth and fifth quintile (>2.50 mg/L) had significantly more baseline atherosclerosis and greater progression when we used the first quintile (<0.80 mg/L) as a reference. No interactions were seen between CRP quintiles and vascular risk factors for carotid atherosclerosis. The associations between severity and progression of small vessel disease-related brain abnormalities and CRP were nonsignificant. We found evidence for differential effects of CRP in different beds of the arterial brain supply. CRP was a marker for active carotid atherosclerosis but not for small vessel disease-related brain lesions.

Association of aortic plaque with intracranial atherosclerosis in patients with stroke

To determine whether there is a relationship between aortic plaques and intracranial (IC) atherosclerosis. We reviewed 922 patients with stroke who had both transesophageal echocardiography and cerebral angiography. The plaques of these patients were classified as either complex aortic plaques (CAP), which protruded > or =4 mm or were present as mobile lesions in the proximal aorta, or simple aortic plaques (SAP), which were <4 mm or present in the descending aorta. Cerebral artery atherosclerosis was classified as either an IC or extracranial (EC) atherosclerosis. Among the 922 patients, we found aortic plaques in 237 patients (26%). There were 111 (47%) patients of SAP, 74 (31%) patients with CAP, and 52 (22%) patients that had both SAP and CAP. Angiography showed IC or EC atherosclerosis in 511 patients (55%). The presence of aortic plaques was significantly associated with IC or EC atherosclerosis. The significance appeared to be due to the strong association between the presence of SAP and IC atherosclerosis (51% SAP vs 35% no plaques; odds ratio = 1.94, 95% CI: 1.17 to 3.21). In the multiple logistic regression analysis, SAP were independent predictors of IC atherosclerosis The presence of simple aortic plaques may be a marker of advanced vascular disease. Detection of simple aortic plaques during transesophageal echocardiography may have clinical implications because patients with these plaques frequently had concomitant intracranial atherosclerosis, a risk factor for stroke.

Intracranial atherosclerotic stroke: Specific focus on the metabolic syndrome and inflammation

Stroke is the second leading cause of mortality world-wide and is well suited for prevention because it has a high prevalence, high burden of economic cost, well-defined modifiable risk factors, and effective prevention measures. Atherosclerosis is one of the major mechanisms of ischemic stroke, but the apparent differences in risk factors for intra- and extracranial atherosclerosis are unclear and the mechanisms that underlie strokes in patients with intracranial atherosclerosis are not well known. Consequently, patients with intracranial stenosis receive the same treatment as those with carotid -atherosclerosis. Several novel substances have emerged recently as risk factors for atherosclerosis. Specifically, it has recently been suggested that both the metabolic syndrome, which refers to a constellation of metabolic risk factors that are linked to insulin resistance, and vascular inflammation are associated with increased risk of coronary heart disease and stroke. The results of the studies reviewed here suggest that these factors play a differential role in the development of atherosclerotic stroke between the intra- and extracranial arterial systems.

Assessment of carotid intima–media thickness in subjects with ischemic cerebrovascular events undergoing endarterectomy

Background and aim In clinical settings, the degree of lumen stenosis is the parameter used to select patients for carotid surgery. The present study was designed to measure carotid intima–media thickness (IMT), an indicator of atherosclerotic burden, in a sample of consecutive patients with ischemic cerebrovascular events referred for endarterectomy. Methods and results Carotid endarterectomy specimens from 55 consecutive patients (age 66 ± 10 years) admitted to hospital with recent documented atherothrombotic ischemic cerebrovascular events were compared with 24 carotid arteries from people (age 68 ± 11 years) who had died from documented causes unrelated to cerebrovascular disease. Measurement of extracranial carotid atherosclerosis was made from three anatomically defined segments, using image-processing software. A total of 426 cross sections was analyzed. Increasing IMT measures were clearly associated with increased risk of an ischemic event. Single maximum IMT values of 2.33 mm (95% CI, 1.69–2.96) for the common carotid, 2.45 mm (95% CI, 1.97–2.93) for the bifurcation, and 2.23 (95% CI, 1.83–2.64) for the internal carotid were associated with a 75% probability of a cerebrovascular ischemic accident. Receiver operator characteristic curve analyses demonstrated that the diagnostic ability of IMT measurements performed at the level of internal carotid artery to separate cases from controls was greater than common carotid artery or bifurcation measurements. Conclusions The present pathology study provides data on IMT in patients admitted to hospital for cerebrovascular accidents and referred for carotid endarterectomy.

Association between plasma homocysteine concentrations and extracranial carotid stenosis

BACKGROUNDIncreasing epidemiologic data support a relationship between elevated plasma total homocysteine levels and an increased risk for vascular disease. Higher plasma total homocysteine (tHcy) levels have been associated with extracranial carotid atherosclerosis and cerebral infarction in whites. However, data regarding such associations are limited for Asians. This study examined the association between tHcy level and carotid stenosis in Iranian subjects.PATIENTS AND METHODSIn this retrospective study, the subjects were 158 patients with ischemic stroke, including 105 with a normal tHcy level and 53 with a high tHcy level. We investigated the extracranial carotid arteries by ultrasonography and measured serum tHcy by the ELISA method in these two groups.RESULTSWe found no meaningful association between a high tHcy level and carotid stenosis.DISCUSSIONThe lack of any meaningful difference in carotid stenosis between patients with normal and elevated tHcy levels is probably due to the low frequency of extracranial disease in the Asian population and to the nature of homocysteine atherosclerosis.

Prevalence and Risk Factors of Intracranial Atherosclerosis in an Asymptomatic Korean Population

Background and PurposeIntracranial atherosclerosis (ICAS) is one of the major risk factors for ischemic stroke, particularly in Asian populations. We investigated the prevalence and risk factors of ICAS in asymptomatic subjects.MethodsWe prospectively evaluated 835 asymptomatic Korean adults who voluntarily visited a tertiary referral hospital for a health screening examination that included brain magnetic resonance angiography. The subjects had no history of stroke or transient ischemic attacks; those who had potential cardiac sources of emboli were excluded. ICAS and extracranial atherosclerosis were defined as a reduction in luminal diameter of at least 50%. Vascular risk factors were screened through questionnaires, interviews, and examinations.ResultsICAS was found in 25 subjects (3.0%) and extracranial atherosclerosis was found in 4 patients (0.5%). No patient had combined lesions. ICAS was distributed in 31 arteries in 25 subjects: anterior cerebral arteries (5 subjects, 16%), middle cerebral arteries (16 subjects, 52%), posterior cerebral arteries (8 subjects, 26%), and distal internal carotid arteries (2 subjects, 7%). The ratio of ICAS of the anterior circulation (23 of 31 arteries with ICAS, 74%) to that of the posterior circulation (8 of 31 arteries with ICAS, 26%) was 3:1. The ratio of ICAS (23 of 27 arteries with atherosclerosis in the anterior circulation, 85%) to extracranial atherosclerosis (4 of 27 arteries with therosclerosis in the anterior circulation, 15%) was 6:1. An older age [odds ratio (OR)=1.05, 95% confidence interval (CI)=1.00-1.10] and hypertension (OR=2.41, 95% CI=1.01-5.72) were independent risk factors for ICAS.ConclusionsICAS is more prevalent than extracranial atherosclerosis among neurologically asymptomatic Korean adults. Subjects with ICAS are significantly older and have an increased frequency of hypertension compared to those subjects without atherosclerotic stenosis.