Occlusive disease of the middle cerebral artery

Correlation of silent brain infarcts and leukoaraiosis in middle-aged ischemic stroke patients: a retrospective study

Background

Cerebrovascular diseases of the brain are usually defined by transient ischemic attacks and strokes. However, they can also cause brain injuries without neurological events. Silent brain infarcts (SBI) and leukoaraiosis are symptoms of both vascular and neurological abnormalities. This study aims to investigate the association between SBI, leukoaraiosis, and middle-aged patients with ischemic stroke.

Methods

A single-center retrospective study of 50 middle-aged, ischemic stroke patients were studied from November 2022 and May 2023. The patients were divided into two groups based on the presence or absence of leukoaraiosis. History taking, physical examination, brain CT scan, and MRI were all part of the diagnostic process. Metabolic syndrome (MetS) was also assessed through various factors. The statistical analysis included descriptive statistics, logistic regression analysis, and chi-square test.

Results

Out of the cohort comprising 50 patients, characterized by a mean age of 52.26 years (SD 5.29), 32 were male, constituting 64% of the sample. Among these patients, 26 individuals exhibited leukoaraiosis, with 17 of them (65.4%) also presenting with SBI. Moreover, within this cohort, 22 patients were diagnosed with MetS, representing 84.6% of those affected. The Multivariate logistic regression analysis showed a strong and independent association between leukoaraiosis and SBI. Individuals with leukoaraiosis were nearly five times more likely to have SBI compared to those without leukoaraiosis.

Conclusion

The study highlights leukoaraiosis as a significant risk factor for SBI, alongside MetS. Advanced imaging techniques have facilitated their detection, revealing a higher prevalence among stroke patients, particularly associated with age and hypertension. Further research is needed to fully understand their complex relationship and develop better management strategies for cerebrovascular diseases, ultimately improving patient outcomes.

Vascularization of the uncus - Anatomical study and clinical implications

Background:

The objective of this paper was to describe the arterial supply of the uncus and quantify the branches directed to the anteromedial aspect of the human temporal cortex.

Methods:

We studied 150 human cerebral hemispheres identifying main afferent arteries supplying the anteromedial temporal cortex with particular attention to the uncus, determining the territory supplied by each artery through either cortical or perforating branches.

Results:

The uncus was supplied by 419 branches of the anterior choroidal artery (AChA), 210 branches of the internal carotid artery (ICA), 353 branches of the middle cerebral artery (MCA), and 122 branches of the posterior cerebral artery (PCA). The total of supplying vessels was 1104 among the 150 hemispheres studied, which corresponds to 7.36 arteries per uncus. The average of branches per hemisphere was as follows: 2.79 from AChA, 1.40 from ICA, 2.35 from MCA, and 0.81 from PCA. The relative contribution of each artery for the total of specimens studied was as follows: 38% from AChA, 19% from ICA, 32% from the MCA, and 11% from the PCA. We identified cortical anastomoses mostly between the MCA and PCA (27 cases).

Conclusion:

We described and quantified the uncus’ vascularization, including anatomical variations. This updated, detailed description of the mesial temporal vascularization is paramount to improve the treatment of neurosurgical conditions.

Association of Plaque Features with Infarct Patterns in Patients with Acutely Symptomatic Middle Cerebral Artery Atherosclerotic Disease

BACKGROUND AND PURPOSE

Understanding the stroke mechanism of middle cerebral artery (MCA) atherosclerosis is important for stroke triage and future trial design. The aim of this study was to characterize intrinsic MCA plaque and acute cerebral infarct in vivo by using high-resolution black-blood (BB) and diffusion-weighted magnetic resonance (MR) imaging and to investigate the relationship between plaque features and infarct patterns.

METHODS

A single-center retrospective study was conducted at a tertiary referral center between March 2017 and August 2019. Patients consecutively admitted for acute ischemic stroke with MCA stenosis underwent diffusion-weighted and BB MR imaging. Plaque features and infarct patterns were assessed. The association between plaque features and infarct patterns (binary variable: single/multiple) was evaluated using a multivariate logistic regression model.

RESULTS

Of 49 patients with MCA atherosclerotic stenosis, diffusion-weighted MR imaging showed that 28 patients (57%) had multiple acute cerebral infarcts and 21 patients had single acute cerebral infarcts. In contrast to single infarct, multiple infarcts were associated with greater plaque burden (81.9±7.24 versus 71.3±13.7; P=0.012). A multivariate logistic regression model adjusted for 7 potential confounders confirmed a statistically significant positive association between plaque burden and multiple acute infarcts (adjusted R² =0.432, P< 0.001). The rate of plaque surface irregularity was significantly greater in patients with multiple infarcts than those with single infarct (71% versus 43%, P=0.044). For single acute penetrating artery infarct, patients with infarct size > 2cm had greater plaque burden compared with patients with infarct size < 2cm (75.3±13.4 versus 63.4±10.9; P = 0.016).

CONCLUSIONS

Increased plaque burden, plaque surface irregularity in patients with MCA stenosis is associated with its likelihood to have caused an artery-to-artery embolism that produces multiple cerebral infarcts, especially along the border zone region, and increased plaque burden may promote subcortical single infarct size by occluding penetrating arteries. Our results provide important insight into stroke mechanism of MCA atherosclerosis.

Isolated Striatocapsular Infarcts after Endovascular Treatment of Acute Proximal Middle Cerebral Artery Occlusions: Prevalence, Enabling Factors, and Clinical Outcome

Background

Striatocapsular infarcts (SCIs) are defined as large subcortical infarcts involving the territory of more than one lenticulostriate artery. SCI without concomitant ischemia in the more distal middle cerebral artery (MCA) territory [isolated SCI (iSCI)] has been described as a rare infarct pattern. The purpose of this study was to assess the prevalence of iSCI in patients treated with endovascular thrombectomy (ET), to evaluate baseline and procedural parameters associated with this condition, and to describe the clinical course of iSCI patients.

Methods

A retrospective analysis of 206 consecutive patients with an isolated MCA occlusion involving the lenticulostriate arteries and treated with ET was performed. Baseline patient and procedural characteristics and ischemic involvement of the striatocapsular and distal MCA territory [iSCI, as opposed to non-isolated SCI (niSCI)] were analyzed using multivariate logistic regression models. Prevalence of iSCI was assessed, and clinical course was determined with the rates of substantial neurological improvement and good functional short- and mid-term outcome (discharge/day 90 Modified Rankin Scale ≤2).

Results

iSCI was detected in 53 patients (25.7%), and niSCI was detected in 153 patients (74.3%). Successful reperfusion [thrombolysis in cerebral infarction (TICI) 2b/3] [adjusted odds ration (aOR) 8.730, 95% confidence interval (95% CI) 1.069–71.308] and good collaterals (aOR 2.100, 95% CI 1.119–3.944) were associated with iSCI. In successfully reperfused patients, TICI 3 was found to be an additional factor associated with iSCI (aOR 5.282, 1.759–15.859). Patients with iSCI had higher rates of substantial neurological improvement (71.7 vs. 37.9%, p < 0.001) and higher rates of good functional short- and mid-term outcome (58.3 vs. 23.7%, p < 0.001 and 71.4 vs. 41.7%, p < 0.001). However, while iSCI patients, in general, had a more favorable outcome, considerable heterogeneity in outcome was observed.

Conclusion

High rates of successful reperfusion (TICI 2b/3) and in particular, complete reperfusion (TICI 3) are associated with iSCIs. The high prevalence of iSCI in successfully reperfused patients with good collaterals corroborates previous concepts of iSCI pathogenesis. iSCI, once considered a rare pattern of cerebral ischemia, is likely to become more prevalent with increases in endovascular stroke therapy. This may have implications for patient rehabilitation and pathophysiological analyses of ischemic damage confined to subcortical regions of the MCA territory.

Neuroprotective effects of the immunomodulatory drug Setarud on cerebral ischemia in male rats

Anti-inflammatory and anti-oxidant agents can alleviate ischemic cerebral injury. The immunomodulary drug Setarud, which is composed of herbal extracts including Rosa canina, Urtica dioica and Tanacetum vulgare, supplemented with selenium exhibits anti-inflammatory and anti-oxidant properties. Therefore, we hypothesized that Setarud will have a neuroprotective effect against ischemic cerebral injury. To validate this hypothesis, rats were intraperitoneally administered with 0.66 mL/kg Setarud for 30 minutes after middle cerebral artery occlusion. Triphenyltetrazolium chloride staining showed that Setarud could reduce cerebral infarct volume of rats subjected to cerebral ischemia. Transmission electron microscopy and hematoxylin-eosin staining results showed that Setarud could alleviate the degenerative changes in cortical neurons of rats with cerebral ischemia. The inclined plate test and prehensile test showed that Setarud could significantly improve the motor function of rats with cerebral ischemia. These findings suggest that Setarud shows neuroprotective effects against ischemic brain injury.

Intracranial stenosis: impact of randomized trials on treatment preferences of US neurologists and neurointerventionists

BACKGROUND AND PURPOSE

Medical and endovascular treatment options for stroke prevention in patients with symptomatic intracranial stenosis have evolved over the past several decades, but the impact of 2 major multicenter randomized stroke prevention trials on physician practices has not been studied. We sought to determine changes in US physician treatment choices for patients with intracranial atherosclerotic stenosis (ICAS) following 2 NIH-funded clinical trials that studied medical therapies (antithrombotic agents and risk factor control) and percutaneous transluminal angioplasty and stenting (PTAS).

METHODS

Anonymous surveys on treatment practices in patients with ICAS were sent to physicians at 3 time points: before publication of the NIH-funded Warfarin-Aspirin Symptomatic Intracranial Disease (WASID) trial (pre-WASID survey, 2004), 1 year after WASID publication (post-WASID survey, 2006) and 1 year after the publication of the NIH-funded Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis (SAMMPRIS) trial (post-SAMMPRIS survey, 2012). Neurologists were invited to participate in the pre-WASID survey (n=525). Neurologists and neurointerventionists were invited to participate in the post-WASID (n=598) and post-SAMMPRIS (n=2,080) surveys. The 3 surveys were conducted using web-based survey tools delivered by E-mail, and a fax-based response form delivered by E-mail and conventional mail. Data were analyzed using the χ2 test.

RESULTS

Before WASID, there was equipoise between warfarin and aspirin for stroke prevention in patients with ICAS. The number of respondents who recommended antiplatelet treatment for ICAS increased across all 3 surveys for both anterior circulation (pre-WASID=44%, post-WASID=85%, post-SAMMPRIS=94%) and posterior circulation (pre-WASID=36%, post-WASID=74%, post-SAMMPRIS=83%). The antiplatelet agent most commonly recommended after WASID was aspirin, but after SAMMPRIS it was the combination of aspirin and clopidogrel. The percentage of neurologists who recommended PTAS in >25% of ICAS patients increased slightly from pre-WASID (8%) to post-WASID surveys (12%), but then decreased again after SAMMPRIS (6%). The percentage of neurointerventionists who recommended PTAS in >25% of ICAS patients decreased from post-WASID (49%) to post-SAMMPRIS surveys (17%).

CONCLUSIONS

The surveyed US physicians' recommended treatments for ICAS differed over the 3 survey periods, reflecting the results of the 2 NIH-funded clinical trials of ICAS and suggesting that these clinical trials changed practice in the USA.

WebParc: a tool for analysis of the topography and volume of stroke from MRI

The quantitative assessment of the anatomic consequences of cerebral infarction is critical in the study of the etiology and therapeutic response in patients with stroke. We present here an overview of the operation of "WebParc," a computational system that provides measures of stroke lesion volume and location with respect to canonical forebrain neural systems nomenclature. Using a web-based interface, clinical imaging data can be registered to a template brain that contains a comprehensive set of anatomic structures. Upon delineation of the lesion, we can express the size and localization of the lesion in terms of the regions that are intersected within the template. We demonstrate the application of the system using MRI-based diffusion-weighted imaging and document measures of the validity and reliability of its uses. Intra- and inter-rater reliability is demonstrated, and characterized relative to the various classes of anatomic regions that can be assessed. The WebParc system has been developed to meet criteria of both efficiency and intuitive operator use in the real time analysis of stroke anatomy, so as to be useful in support of clinical care and clinical research studies. This article is an overview of its base-line operation with quantitative anatomic characterization of lesion size and location in terms of stroke distribution within the separate gray and white matter compartments of the brain.

Long-term prognosis of symptomatic isolated middle cerebral artery disease in Korean stroke patients

Background

This study aimed to investigate the long-term mortality and recurrence rate of stroke in first-time stroke patients with symptomatic isolated middle cerebral artery disease (MCAD) under medical management.

Methods

We identified 141 first ever stroke patients (mean age, 64.4 ± 12.5 years; 53% male) with symptomatic isolated MCAD. MCAD was defined as significant stenosis of more than 50% or occlusion of the MCA as revealed by MR angiography. The median follow-up was 27.7 months. We determined a cumulative rate of stroke recurrence and mortality by Kaplan-Meier survival analyses and sought predictors using the Cox proportional hazard model.

Results

The cumulative composite outcome rate (stroke recurrence or any-cause death) was 14%, 19%, 22%, and 28% at years 1, 2, 3, and 5, respectively. The annual recurrence rate of stroke was 4.1%. The presence of diabetes mellitus was the only significant independent predictor of stroke recurrence or any cause of death in multivariate analyses of Cox proportional hazard model adjusted for any plausible potential confounding factors.

Conclusions

We estimated the long-term prognosis of stroke patients with isolated symptomatic MCAD under current medical management in Korea. Diabetes mellitus was found to be a significant predictor for stroke recurrence and mortality.

Risk factors associated with severity and location of intracranial arterial stenosis

BACKGROUND AND PURPOSE

We sought to determine the vascular risk factors and demographic features associated with the severity and location of intracranial stenosis.

METHODS

Data on patients enrolled in the Warfarin-Aspirin Symptomatic Intracranial Disease (WASID) trial were used for the analyses. Demographic features and vascular risk factors were compared in patients with moderate stenosis (n=336) versus severe stenosis (n=225) and according to the location of intracranial stenosis (middle cerebral, internal carotid, basilar, or vertebral artery).

RESULTS

History of a lipid disorder (77% in severe vs 67% in moderate, P=0.01), metabolic syndrome (63% in severe vs 53% in moderate, P=0.05), and diabetes (43% in severe vs 35% in moderate, P=0.04) were more common in patients with severe intracranial stenosis by univariate analyses. A history of a lipid disorder was independently associated with severe stenosis (odds ratio=1.62; 95% CI, 1.09 to 2.42; P=0.02). The distribution of stenosis location differed among age groups (P=0.0015), sexes (P=0.0001), races (P=0.0243), qualifying events (P=0.0156), diabetes (P=0.0030), coronary artery disease (P=0.0030), and hyperlipidemia (P=0.054). Patients with basilar artery stenoses were older and more likely to have hyperlipidemia. Patients with middle cerebral artery stenoses were more likely to be women and black. Patients with internal carotid artery stenoses were more likely to have diabetes. Patients with vertebral artery stenoses were more likely to have coronary artery disease.

CONCLUSIONS

History of a lipid disorder had the strongest association with severity of intracranial stenosis and should be the target of prevention therapies. Different locations of intracranial stenoses are associated with different vascular risk factors and demographic features, suggesting that there may be a difference in the underlying pathophysiology of stenoses among the intracranial arteries.

Magnetic resonance angiography findings in patients with ischemic stroke from North India

BACKGROUND

We sought to evaluate the magnetic resonance (MR) angiography (MRA) findings in patients with ischemic stroke (IS) from North India and correlate the changes with various conventional and nonconventional risk factors.

METHODS

The study took place at a tertiary care teaching hospital. The patients with IS were clinically evaluated including body mass index, dietary habits, and family history of stroke. MR imaging, MRA, and testing for blood sugar, lipid profile, B12, folic acid, and homocysteine were carried out. The MRA abnormalities were considered significant if stenosis was 50% or greater and these were categorized into extracranial (EC), intracranial (IC), or combined lesions. The location of infarct on MR imaging was also noted.

RESULTS

There were 151 patients whose median age was 60 (22-85) years. The EC MRA was abnormal in 56.3% and the IC MRA in 63.3% of patients, the internal carotid artery being the most common site. Corresponding infarct was present in 64.7% and noncorresponding in 45.3% of patients. The MRA abnormality positively correlated with hypertension and diabetes, and negatively with alcohol consumption. The EC MRA abnormality was more common in upper caste Hindus and Muslims and in the city dwellers.

CONCLUSION

In North Indian patients with IS, the frequency of EC and IC MRA abnormality lies between Whites and the Orientals.

Diagnosis of intracranial atherosclerosis

IMPORTANCE OF THE FIELD

Intracranial atherosclerosis is quickly becoming the most common stroke mechanism worldwide. Accurate diagnosis is important in making treatment decisions.

AREAS COVERED IN THE REVIEW

In this article the clinical and radiographic diagnosis of intracranial atherosclerosis is reviewed. An overview is provided of widely available invasive and non-invasive methods for the detection of intracranial atherosclerosis, including transcranial Doppler, magnetic resonance and computed tomography angiography, as well as conventional angiography.

WHAT THE READER WILL GAIN

The reader will become familiar with the advantages and limitations of various imaging modalities used in the diagnosis of intracranial atherosclerosis.

TAKE HOME MESSAGE

Non-invasive imaging modalities have a high negative predictive value in detecting intracranial atherosclerosis. The gold standard for confirmation of the diagnosis remains catheter angiography.

Middle cerebral artery occlusive disease: the New England Medical Center Stroke Registry

To analyze the clinical features, vascular lesions, and infarct distribution in Asian and white patients with middle cerebral artery (MCA) territory ischemia, we studied age, sex, race, risk factors, angiographic, and neuroimaging findings among patients in the New England Medical Center Stroke Registry. We included patients with well-defined intrinsic occlusive lesions of the MCAs and patients with embolic MCA territory infarcts. Among 695 patients in the stroke registry, 89 (12.8%) qualified. They had 28 MCA intrinsic stenoses, 17 MCA embolic occlusions (cardiogenic or unknown origin), and 44 carotid artery (CA) stenoses or occlusions. MCA intrinsic disease patients were more often Asians and women, and more often had hypertension. Asians were older than whites. Coronary artery disease (27%), peripheral vascular disease (20.5%), and smoking (39%) were more common in CA disease patients. The most common site of MCA intrinsic stenosis (78%) and embolic occlusion (59%) was the mainstem MCA. Infarcts in patients with MCA intrinsic disease mostly involved the striatocapsular area (61%). Infarcts in patients with MCA embolic occlusion (75%) and CA disease (43%) most often involved the parietal lobe. In our hospital, most patients with MCA intrinsic disease are Asians and women and have hypertension and striatocapsular infarctions. Asian patients are usually older than white patients. The most common site of vascular lesions is the mainstem MCA.

Reporting standards for angioplasty and stent-assisted angioplasty for intracranial atherosclerosis

BACKGROUND AND PURPOSE

Intracranial cerebral atherosclerosis causes ischemic stroke in a significant number of patients. Technological advances over the past 10 years have enabled endovascular treatment of intracranial atherosclerotic stenosis. The number of patients treated with angioplasty or stent-assisted angioplasty for this condition is increasing. Given the lack of universally accepted definitions, the goal of this document is to provide consensus recommendations for reporting standards, terminology, and written definitions when reporting clinical and radiological evaluation, technique, and outcome of endovascular treatment using angioplasty or stent-assisted angioplasty for stenotic and occlusive intracranial atherosclerosis.

SUMMARY OF REPORT

This article was written under the auspices of Joint Writing Group of the Technology Assessment Committee, Society of NeuroInterventional Surgery, Society of Interventional Radiology; Joint Section on Cerebrovascular Neurosurgery of the American Association of Neurological Surgeons and Congress of Neurological Surgeons; and the Section of Stroke and Interventional Neurology of the American Academy of Neurology. A computerized search of the National Library of Medicine database of literature (PubMed) from January 1997 to December 2007 was conducted with the goal to identify published endovascular cerebrovascular interventional data in stenotic intracranial atherosclerosis that could be used as benchmarks for quality assessment. We sought to identify those risk adjustment variables that affect the likelihood of success and complications. This document offers the rationale for different clinical and technical considerations that may be important during the design of clinical trials for endovascular treatment of intracranial stenotic and occlusive atherosclerosis. Included in this guidance document are suggestions for uniform reporting standards for such trials. These definitions and standards are primarily intended for research purposes; however, they should also be helpful in clinical practice and applicable to all publications.

CONCLUSION

In summary, the definitions proposed represent recommendations for constructing useful research data sets. The intent is to facilitate production of scientifically rigorous results capable of reliable comparisons between and among similar studies. In some cases, the definitions contained here are recommended by consensus of a panel of experts in this writing group for consistency in reporting and publication. These definitions should allow different groups to publish results that are directly comparable.

Reporting Standards for Angioplasty and Stent-Assisted Angioplasty for Intracranial Atherosclerosis

Background and Purpose— Intracranial cerebral atherosclerosis causes ischemic stroke in a significant number of patients. Technological advances over the past 10 years have enabled endovascular treatment of intracranial atherosclerotic stenosis. The number of patients treated with angioplasty or stent-assisted angioplasty for this condition is increasing. Given the lack of universally accepted definitions, the goal of this document is to provide consensus recommendations for reporting standards, terminology, and written definitions when reporting clinical and radiological evaluation, technique, and outcome of endovascular treatment using angioplasty or stent-assisted angioplasty for stenotic and occlusive intracranial atherosclerosis.

Summary of Report— This article was written under the auspices of Joint Writing Group of the Technology Assessment Committee, Society of NeuroInterventional Surgery, Society of Interventional Radiology; Joint Section on Cerebrovascular Neurosurgery of the American Association of Neurological Surgeons and Congress of Neurological Surgeons; and the Section of Stroke and Interventional Neurology of the American Academy of Neurology. A computerized search of the National Library of Medicine database of literature (PubMed) from January 1997 to December 2007 was conducted with the goal to identify published endovascular cerebrovascular interventional data in stenotic intracranial atherosclerosis that could be used as benchmarks for quality assessment. We sought to identify those risk adjustment variables that affect the likelihood of success and complications. This document offers the rationale for different clinical and technical considerations that may be important during the design of clinical trials for endovascular treatment of intracranial stenotic and occlusive atherosclerosis. Included in this guidance document are suggestions for uniform reporting standards for such trials. These definitions and standards are primarily intended for research purposes; however, they should also be helpful in clinical practice and applicable to all publications.

Conclusion— In summary, the definitions proposed represent recommendations for constructing useful research data sets. The intent is to facilitate production of scientifically rigorous results capable of reliable comparisons between and among similar studies. In some cases, the definitions contained here are recommended by consensus of a panel of experts in this writing group for consistency in reporting and publication. These definitions should allow different groups to publish results that are directly comparable.

Neuropathology of central nervous system arterial syndromes. Part I: the supratentorial circulation

The objective of this review is to illustrate the principal cerebrovascular arterial pathoanatomical syndromes using the unique collection of whole brain sections in the Raymond Escourolle Neuropathology Laboratory at Salpêtrière in Paris. The arterial supratentorial syndromes are presented in Part I; the infratentorial and spinal cord syndromes will be presented subsequently in Part II. No attempt is made to be all-inclusive in the review of the literature; rather, we cite only those bibliographic references that are historically noteworthy and with some exceptions that particularly emphasize the neuropathologic rather than radiographic/imaging aspects of the vascular syndromes. From these studies and our own archival material, we have synthesized the salient clinicopathologic aspects of the individual syndromes.

Warfarin and low-dose aspirin for stroke prevention from severe intracranial stenosis

Management of symptomatic, intracranial, large-arterial atherosclerosis is controversial. We assessed the safety and efficacy of combining warfarin and low-dose aspirin to prevent stroke from intracranial atherosclerotic stenosis failing prior treatment with either aspirin or warfarin. Patients with severe intracranial stenosis were prescribed combination therapy, warfarin (international normalized ratio [INR] 2 to 3) and aspirin 81 mg daily. Ten men and six women treated with combination therapy had one recurrent ischemic event during 382 months of therapy. No patient suffered a myocardial infarction or sudden vascular death. No serious hemorrhagic complication occurred. The combination of warfarin and low-dose aspirin seems safe and effective in preventing recurrent stroke from symptomatic, intracranial, large-arterial occlusive disease after failure with either aspirin or warfarin monotherapy.

Large and Small Vessels Atherosclerosis: Similarities and Differences

Atherosclerosis is a systemic, multifocal disease leading to a various symptoms and clinical events. Beyond disparities related to the organs involved, some differences might exist according to whether the lesions occur in the large (proximal) or small (distal) arteries. Atherosclerotic lesions occur predominantly in the large vessels first, and more distal lesions occur with aging. Proximal lesions are usually more evolving, especially with higher rates of unstable plaques in the proximal segments of coronary arteries. Racial differences regarding lesion distribution exist, with higher rates of distal lesions observed in races other than caucaians. Despite conflicting results found in each vascular territory, there is a suggestion of a stronger association between large vessel disease and smoking and dyslipidemia, whereas diabetes appears more specific for small vessel disease. Hypertension is more frequently reported in intracranial than in extracranial cerebrovascular disease. Preliminary studies report inflammatory markers preferably associated to large-vessel atherosclerosis. Proximal lesions in 1 territory are more frequently associated with concomitant lesions in other territories. Geometric, hemodynamic, and histologic particularities in large and small vessels may at least partially explain these differences, and some recent data point out different biologic properties of the endothelium according to its location.

Statistical parametric mapping and statistical probabilistic anatomical mapping analyses of basal/acetazolamide Tc-99m ECD brain SPECT for efficacy assessment of endovascular stent placement for middle cerebral artery stenosis

INTRODUCTION

Statistical parametric mapping (SPM) and statistical probabilistic anatomical mapping (SPAM) were applied to basal/acetazolamide Tc-99m ECD brain perfusion SPECT images in patients with middle cerebral artery (MCA) stenosis to assess the efficacy of endovascular stenting of the MCA.

METHODS

Enrolled in the study were 11 patients (8 men and 3 women, mean age 54.2 +/- 6.2 years) who had undergone endovascular stent placement for MCA stenosis. Using SPM and SPAM analyses, we compared the number of significant voxels and cerebral counts in basal and acetazolamide SPECT images before and after stenting, and assessed the perfusion changes and cerebral vascular reserve index (CVRI).

RESULTS

The numbers of hypoperfusion voxels in SPECT images were decreased from 10,083 +/- 8,326 to 4,531 +/- 5,091 in basal images (P = 0.0317) and from 13,398 +/- 14,222 to 7,699 +/- 10,199 in acetazolamide images (P = 0.0142) after MCA stenting. On SPAM analysis, the increases in cerebral counts were significant in acetazolamide images (90.9 +/- 2.2 to 93.5 +/- 2.3, P = 0.0098) but not in basal images (91 +/- 2.7 to 92 +/- 2.6, P = 0.1602). The CVRI also showed a statistically significant increase from before stenting (median 0.32; 95% CI -2.19-2.37) to after stenting (median 1.59; 95% CI -0.85-4.16; P = 0.0068).

CONCLUSION

This study revealed the usefulness of voxel-based analysis of basal/acetazolamide brain perfusion SPECT after MCA stent placement. This study showed that SPM and SPAM analyses of basal/acetazolamide Tc-99m brain SPECT could be used to evaluate the short-term hemodynamic efficacy of successful MCA stent placement.

Aspirin or Anticoagulants in Stenosis of the Middle Cerebral Artery:A Randomized Trial

BACKGROUND

We report the results of an open, randomized, multicenter trial that compared the efficacy of aspirin to oral anticoagulants (OA) for the prevention of vascular events in patients with symptomatic stenosis of the middle cerebral artery (MCA).

METHODS

Participants were randomly assigned to receive 300 mg/day of aspirin or a dose of OA (target INR 2-3). The MCA stenosis was demonstrated by conventional angiography or by at least two noninvasive examinations. Patients had either transient ischemic attack or cerebral infarct (CI) attributable to the MCA stenosis within 90 days before inclusion. The primary endpoint was: nonfatal CI, nonfatal acute myocardial infarct, vascular death and major hemorrhage. The patients were followed-up for a minimum of 1 year and a maximum of 3 years.

RESULTS

The study included 28 patients (14 in each treatment group); the average age was 67 +/- 9.9 years. Men constituted 68% of the patients. After a mean follow-up of 23.1 +/- 10.9 months, there were no recurrences of CI in both groups. No endpoint was reported in the aspirin group, but 2 patients in the OA group (14.3%) exhibited vascular events: 1 acute myocardial infarct and 1 intracerebral hemorrhage). However, this difference was not statistically significant (p = 0.48).

CONCLUSIONS

Our study suggests that aspirin is the treatment of choice for the prevention of vascular events in patients with symptomatic MCA stenosis.

A possible explanation for the racial difference in distribution of large-arterial cerebrovascular disease: ancestral European settlers evolved genetic resistance to atherosclerosis, but confined to the intracranial arteries

The pattern of cerebral atherosclerosis is not the same among different races. White patients rarely have intracranial large arterial steno-occlusive disease even if their systemic arteries are extensively involved, while non-white patients frequently have their intracranial arteries affected. We postulate that during human population diversification, those who settled in Europe had acquired a stroke-suppressor genotype that increases their resistance against atherogenesis, but with protection confined to the intracranial large arteries. The contemporary affluent lifestyle accelerates the development of atherosclerosis. In the whites, it involves the whole arterial bed except the intracranial vessels. People living in non-Western countries used to have a healthier way of living. They did not develop significant atherosclerotic diseases until recently when a westernised lifestyle was adopted. Unlike the whites, their intracranial arteries will not be spared. Atherosclerosis has become a major cause of premature mortality in the modern world, and an anti-atherogenic mechanism would confer a selection advantage. With further adaptive intensification, this protection may extend to the rest of the arterial bed. As a result, future Homo sapiens will be able to tolerate an affluent lifestyle without much adverse sequel such as premature vascular death. Alternatively, if the mediator of this anti-atherogenic mechanism can be identified and applied therapeutically, we will have an ultimate mean to prevent atherosclerosis.

The Hyperdense Cerebral Artery Sign on Head CT Scan

The hyperdense artery sign on noncontrast head CT is thought to be one of the earliest and most useful signs of intra-arterial clot and probable (clinical) stroke. It should be evaluated in the context of the clinical scenario. Rigorous criteria should be applied in order to reduce potential false positives. The hyperdense middle cerebral artery sign is the most studied version and correlates with patient outcome. Our data suggest that the density on noncontrast head CT is not likely to universally represent in situ clot.

The clinico-radiologic properties of deep small basal ganglia infarction: Lacune or small striatocapsular infarction?

OBJECTIVE

Deep small basal ganglia infarction (DSBI) cannot be clearly classified as either lacune or striatocapsular infarction by their sizes only. We tried to elucidate clinical and other properties of DSBI to understand better in pathophysiology of ischemic lesion of basal ganglia.

METHODS

We analyzed 36 patients with acute ischemic lesion of basal ganglia with the size varying from 1.5 to 3 cm in maximal diameters. We assessed clinical features, laboratory data, risk factors of stroke, and radiologic findings such as MRI and MR angiography.

RESULTS

Patients with DSBI could be largely divided into two distinctive groups, small infarction with cortical sign (SICS) and lacunar syndrome (LS) according to their presence of cortical manifestations. Total of 11 patients were in SICS group and they showed cortical manifestations such as eyeball deviation, visual field defect, aphasia and neglect. They also showed severer non-cortical neurologic deficit compared with LS group. Whereas LS group showed various MRA patterns, 7 patients of SICS group (63.6%) showed proximal MCA stenosis in MRA.

CONCLUSIONS

We found that many patients with DSBI could have the features of either lacune or striatocapsular infarction. Although they have similar morphologic characteristics but they are presumed to have different pathophysiologic mechanism.

Middle cerebral artery stenosis: endovascular and surgical options

Atherosclerotic middle cerebral artery stenosis is a rare but potentially devastating cause of cerebral ischemia and stroke. While medical management remains the mainstay for stroke prevention, surgical and/or endovascular intervention is indicated in selected patients. This article reviews the role of surgery and endovascular techniques in the treatment of middle cerebral artery stenosis based on its natural history, pathophysiology, and prognosis when treated medically.

Prognostic factors and therapeutic outcome of isolated symptomatic middle cerebral artery stenosis

To analyze the prognostic factors and therapeutic outcome of adult patients with isolated symptomatic stenosis of the middle cerebral artery (MCA). Forty-nine patients were retrospectively verified with isolated symptomatic stenosis of the MCA through both magnetic resonance angiogram and transcranial color-coded duplex sonography. Therapeutic outcome at 1 year or more was determined using a modified Barthel index (BI). For the purpose of analysis, the patients were divided into two groups: a good outcome group (BI > or = 12) and a poor outcome group (BI < 12 or recurrent stroke). The association between different therapeutic regimens and the percent free of recurrent stroke after the first event of cerebral infarction was assessed with Kaplan-Meier plots compared by a log-rank test. These patients accounted for 2.8% of all patients with the first event of cerebral infarction during the same period. At follow-up of 1 year or more, 63% had good outcomes whilst the other 37% had poor outcomes. Overall, 26.5% suffered from recurrent strokes during the follow-up period. According to the statistical analysis, the stepwise logistic regression revealed that only the National Institutes of Health Stroke Scale (NIHSS) at the time of admission was independently associated with a poor outcome. Furthermore, Kaplan-Meier analysis showed a significantly higher percentage of patients free of recurrent stroke events amongst those who were treated with warfarin. The NIHSS at the time of admission was a predictor of outcome amongst our patients, and stenosis of the MCA implies the danger of recurrent cerebral events. Our study also demonstrates the efficacy of oral anticoagulants in the secondary prevention in this specific group of patients. Therefore, we look forward to more prospective multicenter investigations in evaluating the efficiency of therapy in the future.

Prognosis of asymptomatic stenosis of the middle cerebral artery

BACKGROUND

The risk of ischaemic events in asymptomatic intracranial atherosclerosis is unknown.

OBJECTIVE

To follow up patients with asymptomatic atherosclerotic middle cerebral artery stenosis (MCAS) to evaluate the long term stroke risk in its territory.

METHODS

Consecutive white patients with asymptomatic atherosclerotic MCAS were enrolled. Patients with MCAS of possible or proven non-atherosclerotic origin were excluded. MCAS was assessed by transcranial colour duplex sonography according to published angiography validated criteria. Medical treatment was given at the discretion of the treating physician.

RESULTS

50 patients were included and followed for (mean (SD)) 815 (351) days; three were lost to follow up. MCAS was < 50% in 38 and > or = 50% in 12. No patient suffered an ischaemic event in the MCAS territory; one had a transient ischaemic attack in the contralateral hemisphere. Three patients died, one from a subdural haematoma in the contralateral hemisphere, and two from non-stroke-related causes. Medical treatment at baseline included antithrombotic drugs in 42 cases (antiplatelet agent, n = 39; warfarin, n = 3), and statins in 22; at the end of follow up 45 of the 47 survivors were on antithrombotic drugs (antiplatelet agent, n = 37; warfarin, n = 8), and 30 were on statins.

CONCLUSIONS

Asymptomatic MCAS of atherosclerotic origin appears to have a benign long term prognosis with a low risk of ipsilateral stroke in medically treated white patients.

Distinct clinical expressions of striatocapsular infarction according to cortical manifestations

Striatocapsular infarction is known to have various neurologic manifestations including cortical symptoms. However, striatocapsular infarction patients without cortical dysfunctions can be easily found. Therefore, we tried to evaluate the properties and pathogenesis of two distinct expressions of striatocapsular infarction, striatocapsular infarction with and without cortical dysfunctions respectively. Forty-eight patients were divided into two groups according to their initial manifestations. Forty-eight patients with striatocapsular infarction were divided into cortical type of striatocapsular infarction (CSCI) and non-cortical type (NCSCI) according to their initial manifestations. We compared the properties such as stroke risk factors, laboratory data, and clinical features and assessed magnetic resonance imaging (MRI) and MR angiography for possible mechanisms in each type of striatocapsular infarction. Patients with CSCI and those with NCSCI had similar characteristics, laboratory data and morphologic findings in MRI. CSCI patients had more profound initial neurologic manifestations [Both National Institutes of Health Stroke Scale (NIHSS) score and Barthel index]. In MR angiography, patients with CSCI showed more frequent single middle cerebral artery (MCA) stenosis, whereas NCSCI patients had findings that were more heterogeneous. In conclusion, we found that not all the patients with striatocapsular infarction had cortical dysfunctions. It is possible for lesions with similar size and location to have different manifestations (cortical or non-cortical) according to their vascular integrity.

Ischemic stroke subtypes: a population-based study of incidence rates among blacks and whites

BACKGROUND AND PURPOSE

Blacks have an excess burden of stroke compared with whites; however, data comparing ischemic stroke subtypes among the 2 groups are limited and typically involve relative frequencies. The objective of this study is to compare the incidence rates of ischemic stroke subtypes between blacks and whites within a large, representative, biracial population.

METHODS

The Greater Cincinnati/Northern Kentucky Stroke Study is designed to measure incidence rates and trends of all strokes within a well-defined, large, biracial population. Hospitalized cases were ascertained by International Classification of Disease (9th revision; ICD-9) discharge codes. Out-of-hospital events were ascertained by prospective screening of emergency department admission logs, review of coroners' cases, and monitoring all public health and hospital-based primary care clinics. A sampling scheme was used to ascertain events from nursing homes and all other primary care physician offices. All potential cases underwent detailed chart abstraction and confirmed by physician review. Based on all available clinical, laboratory, and radiographic information, ischemic stroke cases were subtyped into the following categories: cardioembolic, large-vessel, small-vessel, other, and stroke of undetermined cause. Race-specific incidence rates were calculated and compared after adjusting for age and gender, and standardizing to the 1990 US population.

RESULTS

Between July 1, 1993, and June 30, 1994, 1956 first-ever ischemic strokes occurred among blacks and whites in the study population. Small-vessel strokes and strokes of undetermined cause were nearly twice as common among blacks. Large-vessel strokes were 40% more common among blacks than whites, and there was a trend toward cardioembolic strokes being more common among blacks.

CONCLUSIONS

The excess burden of ischemic strokes among blacks compared with whites is not uniformly spread across the different subtypes. Large-vessel strokes are more common and cardioembolic stroke are as common among blacks, traditionally thought to be more common among whites.

Elective stenting for symptomatic middle cerebral artery stenosis presenting as transient ischaemic deficits or stroke attacks: short term arteriographical and clinical outcome

BACKGROUND

Although stent assisted angioplasty is an effective treatment for coronary and peripheral arterial disease, its efficacy in intracranial arteriosclerotic disease has not been verified.

OBJECTIVES

To assess the radiographic and clinical outcome of stent assisted angioplasty for symptomatic middle cerebral artery (MCA) stenosis.

METHODS

We attempted stent assisted angioplasty in 14 patients with symptomatic high grade stenosis (>60%) on the proximal portion of the MCA, who had experienced either recurrent transient ischaemic attacks (TIAs) resistant to medical therapy or one or more stroke attacks. Patient records were analysed for angiographic characteristics, degree of stenosis, pre-procedural regimen of anti-platelet and/or anti-coagulation agents, use of devices, procedure related complications, pre-operative and post-operative single photon emission computed tomography (SPECT) findings, and clinical and radiographic outcomes.

RESULTS

Stent assisted angioplasty was successfully performed in 8 of 14 patients without any serious complications and unsuccessful in 2 of 14 patients due to the tortuous curve of the internal carotid artery siphon. Four patients had complications. Two patients had an arterial rupture; one patient was rescued by an additional stent and balloon tamponade, the other patient died. Complications in the other two patients included thrombotic occlusion and distal thrombosis. Residual stenosis was less than 50% in diameter in all the patients. All eight patients who underwent follow up cerebral angiography had no restenosis. Follow up SPECT showed improved perfusion in the affected MCA territory in all the tested patients with TIA and in one of three stroke patients. Using the modified Rankin Scale at follow up, four of five TIA patients and five of six stroke patients were assessed as functionally improved or having a stable clinical status.

CONCLUSION

Although the re-stenosis rate in stent assisted angioplasty seems to be better than in primary balloon angioplasty as reported previously, the complication rate is still high. Elective stenting is an alternative therapeutic method for the prevention of secondary ischaemic stroke in stroke patients with MCA stenosis, and seems to be a potentially effective but also hazardous therapeutic technique in patients with recurrent TIAs. This study indicates the need for randomised control trial data of this intervention. Additionally, long term follow up data and additional clinical experience are required to assess the durability of this procedure.

Natural history and treatment modalities of symptomatic bilateral middle cerebral artery stenosis

SUMMARY

To assess the natural history, pathogenesis, and treatment modalities of symptomatic bilateral middle cerebral artery stenosis, we retrospectively evaluated a consecutive series of patients for their medical history, anamnesis, and our treatment protocol. Treatment included transluminal angioplasty, bypass surgery and/or conservative antiplatelet therapy for prevention of the stroke attack and vessel reconstruction. Indications, feasibility, effectiveness, and complications of treatment are also discussed. A series of 19 patients with symptomatic bilateral middle cerebral artery (MCA) stenosis were treated consecutively from 1998 to 2002. Medical history, anamnesis, and treatment protocol were reviewed and evaluated retrospectively, Of these 19 patients, six (six vessels, 31.57%) were treated by balloon (two vessels) or stent-assistant angioplasty (four vessels), four (four vessels, 21.05%) were treated by bypass surgery, 18 vessels plus ten vessels occluded before treatment (47.37%) were conservatively treated by antiplatelet agents. 24 vessels (12 patients) were followed from three months to four years by angiography (nine cases), TCD (12 cases), or MRA (five cases). A total of 38 vessels were involved (19 vessels), of which ten vessels (10/38, 26.31%) had occluded before coming to our hospital. Three patients (3/19, 15.78%) had a history of hypertension, five had a history of smoking. The mean age of these 19 patients was 33 yrs (24 ~ 42 yrs), with a slight male preponderance (males/females = 13/6). Initial clinical presentations were TIAs (14/19, 73.68%) and minor stroke (5/19, 26.32%), symptoms attacked alternatively for five patients (5/38, 13.16%). Seven vessels (7/28, 25%) occluded within one to three years, of which three occluded asymptomatically, four acutely occluded vessels accompanied acute stroke. Nine vessels (9/28, 32.14%) were treated by conservative antiplatelet agents and one treated by bypass surgery had related recurrent TIAs. Vessels treated by angioplasty (balloon or stent) remained patent and free of symptoms. The stenosed bilateral MCA may occlude within one to three years without intervention. The pathogenesis of this special disease is unclear, it may be genetic or due to asymptomatic infection. The results showed that earlier appropriate treatment can resolve the clinical symptoms and somehow change the natural history of this disease. Conservative medical therapy cannot prevent further stroke attack. Collaterals are very important for these special patients.

Early experiences of elective stenting for symptomatic stenosis of the M1 segment of the middle cerebral artery: reports of three cases and review of the literature

The role of stenting in the treatment of patients with middle cerebral artery stenosis is not defined because of the high risk and difficulty in tracking. However, recent improvements in the technology, in particular of small, flexible stents and of small, flexible stents with accumulative stenting experience in occlusive intracranial disease endovascular treatment of this disease is now possible. We treated three patients with a symptomatic stenosis of the M1 segment of the middle cerebral artery despite combination anticoagulation therapy. All patients were successfully treated with a balloon-expandable S660 coronary stent. No procedure-related complications occurred and all patients were discharged and remained neurologically stable during the follow-up period (2-12 months). We propose stenting as one of the treatment modalities in patients with symptomatic stenosis of the M1 segment of the middle cerebral artery in selected cases. However, further studies on this new procedure should be done to determine its effect on long-term stroke prevention and to compare its safety with other treatment options.

Computed tomographic findings in patients undergoing intra-arterial thrombolysis for acute ischemic stroke due to middle cerebral artery occlusion: results from the PROACT II trial

BACKGROUND AND PURPOSE

The purpose of this study was to evaluate the role of noncontrast CT in the selection of patients to receive thrombolytic therapy for acute ischemic stroke and to predict radiological and clinical outcomes.

METHODS

One hundred eighty patients with stroke due to middle cerebral artery (MCA) occlusion were randomized 2:1 within 6 hours of onset to receive intra-arterial recombinant prourokinase plus intravenous heparin or intravenous heparin only. Four hundred fifty-four CT examinations were digitized to calculate early infarct changes, infarct volumes, and hemorrhagic changes among the 162 patients treated as randomized (108 recombinant prourokinase-treated patients and 54 control patients). CT changes were correlated with baseline stroke severity, angiographic clot location, collateral vessels, and outcome at 90 days.

RESULTS

Baseline CT scans, 120 (75%) of 159, showed early infarct-related abnormalities. The baseline CT abnormality volume was not correlated with the baseline National Institutes of Health Stroke Scale (NIHSS) score (r=-0.11) but was correlated weakly with the outcome (r=0.17, P<0.05). Compared with patients with M2 occlusions, patients with M1 MCA occlusions had significantly higher baseline NIHSS scores (P<0.05), more basal ganglia involvement on CT, and larger hypodensity volumes on follow-up CTs. Compared with patients with partial or no collateral supply, patients with full collateral supply had lower baseline NIHSS scores, significantly smaller baseline CT infarct volumes, and less cortical involvement (P<0.05).

CONCLUSIONS

Noncontrast CT is not correlated with baseline stroke severity and does not predict outcome in patients with stroke due to MCA occlusion. However, baseline CT changes, clinical presentation, and the evolution of CT changes are influenced by clot location and the presence of a collateral supply.

Deep cerebral infarcts extending to the subinsular region

BACKGROUND AND PURPOSE

We sought to determine the clinical and radiological features and pathogenesis of deep cerebral infarcts extending to the subinsular region (DCIs).

METHODS

- We defined DCIs as subcortical infarcts extending between the lateral ventricle and the subinsular region with a paraventricular extent >1.5 cm and a subinsular extent of at least one third of the anteroposterior extent of the insula. We identified patients by review of imaging records and noted the clinical information, risk factors, and investigations. We compared risk factors and clinical features between DCIs and "internal border zone" infarcts restricted to the paraventricular region.

RESULTS

- Eight patients were studied. The typical clinical features of DCIs were hemiparesis, aphasia, dysarthria, and dysphagia. Aphasia was seen in 3 of 5 patients with left-sided infarcts. Six of 8 patients (75%) had hypoperfusion as a possible pathogenetic factor (carotid occlusion in 4, surgical clipping of MCA in 1, low ejection fraction in 1), and 3 patients (38%) had cardioembolism as a possible pathogenetic factor (atrial fibrillation in 2, low ejection fraction in 1). One patient (12%) had no cause for stroke. Clinical features were similar to those for paraventricular infarcts. Carotid occlusion was more frequent (P=0.04), and there was a trend toward a higher frequency of hypertension (P<0.1) and smoking with DCIs than with paraventricular infarcts. DCIs were located in a deep vascular border zone.

CONCLUSIONS

- The clinical features and pathogenesis of DCIs overlap with those of internal border zone paraventricular infarcts. Hypoperfusion may give rise to DCIs since large-artery occlusion is their main risk factor. The larger size of DCIs compared with paraventricular infarcts may relate to a poorer collateral blood supply.

Transcatheter interventions for the treatment of peripheral atherosclerotic lesions: part II

Transcatheter endovascular procedures are increasingly used to treat symptomatic peripheral atherosclerosis. This second part of a two-part review assesses the existing supportive evidence for the application of recently introduced transcatheter treatments for lesions that cause cerebrovascular ischemia and stroke. Studies were identified via MEDLINE (January 1993 through April 1999) and reference lists of identified articles. When multicenter prospective randomized trials or other high-quality studies were unavailable, studies with at least 50 patients per treated group and a minimum follow-up duration of 6 months were included. For each application, the authors assessed the quality of evidence (efficacy, safety, and, where available, cost-effectiveness) and made recommendations with appropriate caveats. Although recommendations based on proven efficacy and cost-effectiveness cannot be made in general, the use of transcatheter therapies can be supported in specific circumstances based on expected reduction in procedure-related morbidity and/or mortality. It is hoped that the identification of deficiencies in the literature will inform and inspire critically needed research in this area.

Follow-up Study after Intracranial Percutaneous Transluminal Cerebral Balloon Angioplasty

SUMMARY

To find the angiographic lesions specific characteristics appropriate for intracranial percutaneous transluminal cerebral angioplasty (PTCBA). Forty-two clinically symptomatic patients with 42 haemodynamically significant intracranial lesions (% diameter stenosis > 70) were treated by PTCBA between January 1992 and May 1996. Before the angioplasty treatment, the patients were classified into three groups according to the angiographic lesions' characteristics summarised as follows: type A, a short and concentric stenosis; type B, a tubular lesion, or an extreme eccentric lesion; and type C, a diffuse lesion. They were followed after PTCBA from one month to six years to compare between the three groups. Primary end points were death, stroke, or bypass surgery. The clinical success rates in type A, B and C groups were 92%, 86% and 33% (p=0.0032), respectively. Cumulative risks of fatal or nonfatal ischaemic stroke / ipsilateral bypass surgery in type A, B and C groups were 8%, 26% and 87% (p < 0.0001), respectively. The cumulative risk of 8% in type A group patients appeared to be smaller than in historical studies. PTCBA for intracranial simple (type A) lesions produces a favourable clinical outcome for symptomatic patients.

Patterns of brain computed tomography infarction and carotid plaque echogenicity

PURPOSE

It was suggested that in the absence of cardioembolism the discrete subcortical and cortical infarctions on brain computed tomography (CT) are most likely associated with carotid atheroma, whereas the hemodynamic infarctions, diffuse widespread white matter lesions, lacunae and basal ganglia infarctions are most likely associated with other pathologic conditions. The aim of this study was to determine the ultrasonic characteristics of carotid plaques and the degree of stenosis that were associated with the different brain CT infarction patterns and normal CT (pattern A, discrete subcortical and cortical infarctions; pattern B, hemodynamic infarctions, diffuse widespread white matter lesions, lacunae and basal ganglia infarctions).

METHODS

Four hundred nineteen carotid plaques (315 patients), producing 50% to 99% stenosis on duplex scanning, were studied. These plaques were imaged on duplex scanning, captured, digitized, and normalized (standardized) in a computer. Subsequently, their gray scale median (GSM) was evaluated to distinguish quantitatively the hypoechoic (low GSM) from the hyperechoic (high GSM) plaques. The brain CT infarction patterns of A, B, or normal CT on the ipsilateral hemisphere were noted.

RESULTS

The pattern A brain CT infarction was associated with carotid plaques having median GSM of 11 and median degree of stenosis of 80%, as contrasted with pattern B (median GSM, 28.5; median degree of stenosis, 75%) or normal CT (median GSM, 22; median degree of stenosis, 75%) (Kruskal-Wallis test, P <.001 for the GSM and P =.002 for the degree of stenosis). In the logistic regression analysis only the GSM and not the degree of stenosis distinguished the plaques associated with the three CT patterns.

CONCLUSIONS

The pattern A brain CT infarction was associated with hypoechoic plaques suggesting an involvement of extracranial carotid artery embolization, whereas the pattern B was associated with hyperechoic plaques suggesting an involvement of other mechanisms (hemodynamic, intracranial small and large vessel disease).

Cerebrovascular angioplasty and stenting for the prevention of stroke

Until recently, stroke preventive strategies have focused on either medical regimens aimed at antagonizing or reversing atherosclerosis, or surgical intervention for revascularization of the cerebrovascular system. However, with the advent of rapidly emerging microcatheterization techniques and technology, endovascular surgical revascularization of the brain is rapidly emerging as a powerful therapeutic modality. In particular, significant advances already have been made in revascularization of the extracranial carotid artery and many common anatomic sites of intracranial athero-occlusive disease, using special adaptations of conventional percutaneous angioplasty and stenting techniques. This paper reviews the cumulative experience with these emerging techniques, with a particular emphasis on clinical outcomes and future directions. It also reports the substantial cumulative institutional experience of the authors over the past 18 months with both extracranial carotid and intracranial artery stent-assisted carotid angioplasty.