Practice recommendations for neurovascular ultrasound investigations of acute stroke patients in the setting of the COVID-19 pandemic: an expert consensus from the European Society of Neurosonology and Cerebral Hemodynamics.

BACKGROUND AND PURPOSE: Patients with acute ischemic stroke are at high-risk for contracting COVID-19 infection. Additionally, healthcare professionals including neurovascular ultrasound providers are also at risk of being infected by SARS-CoV-2 virus. Yet, preparedness to continue to guarantee hyperacute treatment is vital for patients outcome. In light of this situation, the European Society of Neurosonology and Cerebral Hemodynamic (ESNCH) appointed a task force to provide consensus recommendations for the performance of neurovascular ultrasound investigations in acute ischemic stroke during the COVID-19 pandemic with the aim of protecting both patients and ultrasound providers. METHODS: The "ultrasound in acute stroke working group" of the ESNCH examined literature articles and reviews using the following key words: "corona virus" or "COVID-19" or "SARS-CoV-2 virus", and "acute stroke" or "cerebrovascular disease", and "ultrasound". Thereafter, a thorough discussion was conducted with the "education and guidelines working group" of the ESNCH. RESULTS: We propose rapid up-to-date recommendations for healthcare personnel involved in the pre-hospital and intra-hospital assessment of stroke patients, with a particular attention to neurovascular ultrasound performance. CONCLUSION: The ESNCH provides a guidance summary for the performance of neurovascular ultrasound investigations in acute ischemic stroke in the time of COVID-19.

[A systematic review of using myorelaxants in treatment of low back pain]. / Sistematicheskii obzor po primeneniiu miorelaksantov pri boli v nizhnei chasti spiny.

A systematic review summarizes the results of studies on the efficacy of myorelaxants (tolperisone, tizanidine, thiocolchicoside or baclofen) in the treatment of acute nonspecific low back pain published up to Dec. 2017. The authors conclude that there are enough data to confirm the efficacy of myorelaxants in treatment of nonspecific low back pain, myorelaxants are recommended as monotherapy or in combination with analgesics or NSAID, the nonsedative drugs tolperisone or thiocolchicoside should be preferred.

Intravenous thrombolysis for patients with in-hospital stroke onset: propensity-matched analysis from the Safe Implementation of Treatments in Stroke-East registry.

BACKGROUND AND PURPOSE: Recent cross-sectional study data suggest that intravenous thrombolysis (IVT) in patients with in-hospital stroke (IHS) onset is associated with unfavorable functional outcomes at hospital discharge and in-hospital mortality compared to patients with out-of-hospital stroke (OHS) onset treated with IVT. We sought to compare outcomes between IVT-treated patients with IHS and OHS by analysing propensity-score-matched data from the Safe Implementation of Treatments in Stroke-East registry. METHODS: We compared the following outcomes for all propensity-score-matched patients: (i) symptomatic intracranial hemorrhage defined with the safe implementation of thrombolysis in stroke-monitoring study criteria, (ii) favorable functional outcome defined as a modified Rankin Scale (mRS) score of 0-1 at 3 months, (iii) functional independence defined as an mRS score of 0-2 at 3 months and (iv) 3-month mortality. RESULTS: Out of a total of 19 077 IVT-treated patients with acute ischaemic stroke, 196 patients with IHS were matched to 5124 patients with OHS, with no differences in all baseline characteristics (P > 0.1). Patients with IHS had longer door-to-needle [90 (interquartile range, IQR, 60-140) vs. 65 (IQR, 47-95) min, P < 0.001] and door-to-imaging [40 (IQR, 20-90) vs. 24 (IQR, 15-35) min, P < 0.001] times compared with patients with OHS. No differences were detected in the rates of symptomatic intracranial hemorrhage (1.6% vs. 1.9%, P = 0.756), favorable functional outcome (46.4% vs. 42.3%, P = 0.257), functional independence (60.7% vs. 60.0%, P = 0.447) and mortality (14.3% vs. 15.1%, P = 0.764). The distribution of 3-month mRS scores was similar in the two groups (P = 0.273). CONCLUSIONS: Our findings underline the safety and efficacy of IVT for IHS. They also underscore the potential of reducing in-hospital delays for timely tissue plasminogen activator delivery in patients with IHS.

European Stroke Organisation (ESO) guidelines for the management of spontaneous intracerebral hemorrhage

"BACKGROUND: Intracerebral hemorrhage (ICH) accounted for 9% to 27% of all strokes worldwide in the last decade, with high early case fatality and poor functional outcome. In view of recent randomized controlled trials (RCTs) of the management of ICH, the European Stroke Organisation (ESO) has updated its evidence-based guidelines for the management of ICH. METHOD: A multidisciplinary writing committee of 24 researchers from 11 European countries identified 20 questions relating to ICH management and created recommendations based on the evidence in RCTs using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. RESULTS: We found moderate- to high-quality evidence to support strong recommendations for managing patients with acute ICH on an acute stroke unit, avoiding hemostatic therapy for acute ICH not associated with antithrombotic drug use, avoiding graduated compression stockings, using intermittent pneumatic compression in immobile patients, and using blood pressure lowering for secondary prevention. We found moderate-quality evidence to support weak recommendations for intensive lowering of systolic blood pressure to <140 mmHg within six-hours of ICH onset, early surgery for patients with a Glasgow Coma Scale score 9-12, and avoidance of corticosteroids. CONCLUSION: These guidelines inform the management of ICH based on evidence for the effects of treatments in RCTs. Outcome after ICH remains poor, prioritizing further RCTs of interventions to improve outcome."

Benefit of thrombolysis for stroke is maintained around the clock: results from the SITS-EAST Registry.

BACKGROUND AND PURPOSE: The outcome of thrombolysis for early morning and sleep time strokes may be worse because of uncertainty of stroke onset time or differences in logistics. The aim of the study was to analyze if stroke outcome after intravenous thrombolysis differs depending on time of day when the stroke occurs. METHODS: The data collected in the Safe Implementation of Treatments in Stroke - Eastern Europe (SITS-EAST) Registry between September 2000 and December 2011 were used. Strokes were categorized as night-time 00:00-07:59, day-time 08:00-15:59 and evening-time 16:00-23:59 and were compared in terms of several outcome measures. All results were adjusted for baseline differences. RESULTS: A total of 8878 patients were enrolled: 18% had night-time, 54% day-time and 28% evening-time strokes. Onset-to-treatment time in patients with night-time strokes was 10 min longer than in day-time and evening-time strokes (P < 0.001). Symptomatic intracerebral hemorrhage by ECASS II definition occurred in 5.6%, 5.6% and 5.3% (adjusted P = 0.41) of the night-time, day-time and evening-time stroke patients, respectively; by SITS definition it occurred in 2.5%, 1.9% and 1.3% (adjusted P = 0.013) and by NINDS definition in 7.8%, 7.6% and 7.5% (adjusted P = 0.74). Patients with night-time, day-time and evening-time strokes achieved modified Rankin Scale score 0-1 in 33%, 31%, 31% (adjusted P = 0.34) and 0-2 in 52%, 51%, 50% (adjusted P = 0.23), and 13%, 15%, 16% respectively of patients died (adjusted P = 0.17) by 3 months. CONCLUSIONS: The time when stroke occurs (day versus evening versus night) does not affect the outcome after thrombolysis despite the fact that patients with night-time strokes have worse time management.

Etiology of first-ever ischaemic stroke in European young adults: the 15 cities young stroke study.

BACKGROUND AND PURPOSE: Risk factors for IS in young adults differ between genders and evolve with age, but data on the age- and gender-specific differences by stroke etiology are scare. These features were compared based on individual patient data from 15 European stroke centers. METHODS: Stroke etiology was reported in detail for 3331 patients aged 15-49 years with first-ever IS according to Trial of Org in Acute Stroke Treatment (TOAST) criteria: large-artery atherosclerosis (LAA), cardioembolism (CE), small-vessel occlusion (SVO), other determined etiology, or undetermined etiology. CE was categorized into low- and high-risk sources. Other determined group was divided into dissection and other non-dissection causes. Comparisons were done using logistic regression, adjusting for age, gender, and center heterogeneity. RESULTS: Etiology remained undetermined in 39.6%. Other determined etiology was found in 21.6%, CE in 17.3%, SVO in 12.2%, and LAA in 9.3%. Other determined etiology was more common in females and younger patients, with cervical artery dissection being the single most common etiology (12.8%). CE was more common in younger patients. Within CE, the most frequent high-risk sources were atrial fibrillation/flutter (15.1%) and cardiomyopathy (11.5%). LAA, high-risk sources of CE, and SVO were more common in males. LAA and SVO showed an increasing frequency with age. No significant etiologic distribution differences were found amongst southern, central, or northern Europe. CONCLUSIONS: The etiology of IS in young adults has clear gender-specific patterns that change with age. A notable portion of these patients remains without an evident stroke mechanism according to TOAST criteria.

Mannheim carotid intima-media thickness and plaque consensus (2004-2006-2011). An update on behalf of the advisory board of the 3rd, 4th and 5th watching the risk symposia, at the 13th, 15th and 20th European Stroke Conferences, Mannheim, Germany, 2004, Brussels, Belgium, 2006, and Hamburg, Germany, 2011.

Intima-media thickness (IMT) provides a surrogate end point of cardiovascular outcomes in clinical trials evaluating the efficacy of cardiovascular risk factor modification. Carotid artery plaque further adds to the cardiovascular risk assessment. It is defined as a focal structure that encroaches into the arterial lumen of at least 0.5 mm or 50% of the surrounding IMT value or demonstrates a thickness >1.5 mm as measured from the media-adventitia interface to the intima-lumen interface. The scientific basis for use of IMT in clinical trials and practice includes ultrasound physics, technical and disease-related principles as well as best practice on the performance, interpretation and documentation of study results. Comparison of IMT results obtained from epidemiological and interventional studies around the world relies on harmonization on approaches to carotid image acquisition and analysis. This updated consensus document delineates further criteria to distinguish early atherosclerotic plaque formation from thickening of IMT. Standardized methods will foster homogenous data collection and analysis, improve the power of randomized clinical trials incorporating IMT and plaque measurements and facilitate the merging of large databases for meta-analyses. IMT results are applied to individual patients as an integrated assessment of cardiovascular risk factors. However, this document recommends against serial monitoring in individual patients.

Correlation between crossed cerebellar diaschisis and clinical neurological scales.

BACKGROUND: A common consequence of unilateral stroke is crossed cerebellar diaschisis (CCD), a decrease in regional blood flow (CBF) and metabolism (CMRglu) in the cerebellar hemisphere contralateral to the affected cerebral hemisphere. Former studies indicated a post-stroke time-dependent relationship between the degree of CCD and the clinical status of acute and sub-acute stroke patients, but no study has been performed in post-stroke patients. OBJECTIVES: The objective of this investigation was to evaluate the quantitative correlation between the degree of CCD and the values of clinical stroke scales in post-stroke patients. MATERIALS AND METHODS: We measured with positron emission tomography (PET) regional CBF and CMRglu values in the affected cortical regions and the contralateral cerebellum in ten ischaemic post-stroke patients. Based on these quantitative parameters, the degree of diaschisis (DoD) was calculated, and the DoD values were correlated with three clinical stroke scales [Barthel Index, Orgogozo Scale and Scandinavian Neurological Scale (SNS)]. RESULTS: There were significant linear correlations between all clinical stroke scales and the CCD values (Barthel Index and Orgogozo Scale: P < 0.001, for both CBF and CMRglu; SNS: P = 0.007 and P = 0.044; CBF and CMRglu, respectively). CONCLUSIONS: The findings indicate that DoD can be used as a quantitative indicator of the functional impairments following stroke, i.e. it can serve as a potential surrogate of the severity of the damage.

The outer arterial wall layers are primarily affected in spontaneous cervical artery dissection.

OBJECTIVE: To evaluate the macroscopic and microscopic phenotype of the distal superficial temporal artery (STA) in patients with spontaneous cervical artery dissection (sCAD, n = 14). Arteries of accident victims, free of clinically apparent vascular disease, served as reference samples (n = 9). METHODS: Specimens of distal STA branches were obtained by biopsy or at autopsy. Their fine and ultrafine structure was documented by close-up photography of native STA branches, light microscopy, and electron microscopy in a case-control study. RESULTS: STA specimens from patients with sCAD revealed pathologic changes mainly in the adventitial and medial layers. In these areas, vacuolar degeneration and fissuring were associated with neoangiogenesis of capillaries and microscopic erythrocyte extravasation into the connective tissue. In addition, some specimens showed overt microhematomas close to the medial/adventitial border visible at low magnification. The reference arteries showed virtually no pathologic changes in the outer arterial layers. CONCLUSION: Bearing in mind that the STA is only a surrogate for the cervical arteries affected by sCAD, we propose the following pathogenetic model. We hypothesize that sCAD affects primarily the outer arterial layers. The process starts with degenerative changes at the medial-adventitial border associated with neoangiogenesis of capillary vessels branching from vasa vasorum in the adventitia. Leakage of neoangiogenetic capillaries releases blood cells into the connective tissue and leads to formation of microhematomas along the medial/adventitial border, as well as disintegration of the medial and adventitial texture. Microhematomas might then cause successive rupture of multiple neoangiogenetic capillaries and vasa vasorum, ultimately resulting in dissection.

Clinical, radiological and pathological correlates of leukoaraiosis.

INTRODUCTION: Leukoaraiosis is characterized by an abnormal appearance of the brain white matter on imaging. Its pathogenesis is still a matter of investigation. The purpose of this study was to investigate the radiological, clinical and pathological correlates of leukoaraiosis. METHODS: The study population consisted of 93 deceased patients. The pre-mortem T2W magnetic resonance images were evaluated for the presence and grading of leukoaraiosis. The clinical and pathological characteristics based on the clinical charts and autopsy reports were evaluated. Tissue specimens of the blocks of 19 brains that demonstrated severe leukoaraiosis and those of five control brains were excised and stained. RESULTS: The variables found to be significantly associated with leukoaraiosis were age and a clinical history of Parkinson's disease. Other risk factors and pathological markers of atherosclerosis were not significantly correlated with leukoaraiosis. No significant difference was found between the scoring of the myelin integrity, glial fibrillary acidic protein, cluster of differentiation 68 and smooth muscle actin. There was a significant difference with respect to thickening of vessels walls. CONCLUSIONS: Our pathological results indicate that structural vascular abnormalities characterized by vessel wall thickening are associated with leukoaraiosis, supporting the assertion that vascular changes and ischemia generate leukoaraiosis. The relations between parkinsonism and leukoaraiosis may be explicable through vascular effects on the circuitry of the basal ganglia.

Immunological parameters, including CXCL8 (IL-8) characterize cerebro- and cardiovascular events in patients with peripheral artery diseases.

The most commonly occurring atherosclerotic manifestations are peripheral artery diseases (PAD). Immune-mediated processes contribute to the development of atherosclerosis, and affect the diseases outcome. The aim of the present study was to assess various immune-competent cells, cytokines and chemokines in patients with PAD and to evaluate whether the base immunological values reflect the subsequent development of cardio/cerebrovascular symptoms. One hundred sixty patients with PAD were followed-up for 42 months. At the time of enrolment, we determined blood lymphocyte subpopulations, both T-helper (Th)1/Th2-type intracytoplasmic cytokines and soluble cytokines, chemokines. Intracellular cytokines were measured on phorbol-myristate-acetate- and ionomycine- stimulated cells. Lymphocyte subgroups were quantified by flow cytometry, soluble cytokines by ELISA and intracellular cytokine levels were measured by flow cytometry. The ankle-brachial index (ABI), indicator of atherosclerosis, was also evaluated. The clinical results were correlated with the immune-parameters to assess the input of immune-inflammatory events in the propagation of vascular manifestation. CD4(+) T-cell proportions in patients with PAD with cerebro- cardio-vascular manifestations were decreased, which further reduced in patients with fatal outcome. Of circulating chemokines, IL-8 (CXCL-8) was increased in patients with subsequent cerebro- cardio-vascular manifestations, compared to those without the symptoms, and further raised in patients with fatal outcome. The percentage of interferon (IFN)-gamma positive cells showed clear negative correlation with ABI. We conclude that altered peripheral lymphocyte subsets and cytokine/chemokine imbalance play important roles in the proinflammatory cascade and reflect disease severity in patients with PAD.

The Debrecen Stroke Database: demographic characteristics, risk factors, stroke severity and outcome in 8088 consecutive hospitalised patients with acute cerebrovascular disease.

BACKGROUND: High stroke mortality in central-eastern European countries might be due to higher stroke incidence, more severe strokes or less effective acute care than in countries with lower mortality rate. Hospital databases usually yield more detailed information on risk factors, stroke severity and short-term outcome than population-based registries. PATIENTS AND METHODS: The Debrecen Stroke Database, data of 8088 consecutively hospitalised patients with acute cerebrovascular disease in a single stroke centre in East Hungary between October 1994 and December 2006, is analysed. Risk factors were recorded and stroke severity on admission was scored by the Mathew stroke scale. The modified Glasgow outcome scale was used to describe patient condition at discharge. RESULTS: Mean age was 68+/-13 years, 11.4% had haemorrhagic stroke. The rate of hypertension on admission was 79% in men, and 84% in women, 40.3% of men and 19.8% of women were smokers, and 34% of all patients had a previous cerebrovascular disease in their history. Case fatality was 14.9%, and 43% had some disability at discharge. Outcome at discharge was worse with higher age, higher glucose, higher blood pressure, higher white cell count and erythrocyte sedimentation rate and more severe clinical signs on admission. In multivariate analysis admission blood pressure lost its significance in predicting outcome. CONCLUSIONS: In this large Hungarian stroke unit database hypertension on admission, smoking and previous cerebrovascular disease were more frequent than in most western databases. These findings indicate major opportunities for more efficient stroke prevention in this and probably other eastern European countries.

Mannheim carotid intima-media thickness consensus (2004-2006). An update on behalf of the Advisory Board of the 3rd and 4th Watching the Risk Symposium, 13th and 15th European Stroke Conferences, Mannheim, Germany, 2004, and Brussels, Belgium, 2006.

Intima-media thickness (IMT) is increasingly used as a surrogate end point of vascular outcomes in clinical trials aimed at determining the success of interventions that lower risk factors for atherosclerosis and associated diseases (stroke, myocardial infarction and peripheral artery diseases). The necessity to promote further criteria to distinguish early atherosclerotic plaque formation from thickening of IMT and to standardize IMT measurements is expressed through this updated consensus. Plaque is defined as a focal structure that encroaches into the arterial lumen of at least 0.5 mm or 50% of the surrounding IMT value or demonstrates a thickness >1.5 mm as measured from the media-adventitia interface to the intima-lumen interface. Standard use of IMT measurements is based on physics, technical and disease-related principles as well as agreements on how to perform, interpret and document study results. Harmonization of carotid image acquisition and analysis is needed for the comparison of the IMT results obtained from epidemiological and interventional studies around the world. The consensus concludes that there is no need to 'treat IMT values' nor to monitor IMT values in individual patients apart from exceptions named, which emphasize that inside randomized clinical trials should be performed. Although IMT has been suggested to represent an important risk marker, according to the current evidence it does not fulfill the characteristics of an accepted risk factor. Standardized methods recommended in this consensus statement will foster homogenous data collection and analysis. This will help to improve the power of randomized clinical trials incorporating IMT measurements and to facilitate the merging of large databases for meta-analyses.

Factors influencing hemorrhagic transformation in ischemic stroke: a clinicopathological comparison.

As hemorrhagic transformation (HTr) is a frequent complication and can worsen the outcome of acute ischemic stroke, our aim was to assess the risk factors of HTr. Using the database of our neuropathological laboratory, 245 consecutive acute ischemic stroke patients were analyzed. An exploratory logistic regression procedure was carried out to find the best multiple model identifying the factors associated with HTr. The autopsy revealed ischemic infarct in 175 (71%) and ischemic infarct with HTr in 70 (29%) patients. Mean age was 71.5 +/- 11.4 years (mean +/- SD) and 74.8 +/- 10.2 years (mean +/- SD), respectively. The multiple model confirmed age in case of embolic stroke, and diabetes mellitus and infarct size as independent risk factors of HTr. It seems that not serum glucose level but diabetes mellitus in the case history is an independent predictor of HTr.

Role of cerebral amyloid angiopathy in intracerebral hemorrhage in hypertensive patients.

OBJECTIVE: To assess the interaction of cerebral amyloid angiopathy (CAA) and arterial hypertension as cofactors for intracerebral hemorrhage (ICH). METHODS: The authors investigated 129 postmortem brains of hypertensive patients with and without ICH. Sixty-four patients had had deep (n = 40) or lobar (n = 24) ICH. Sixty-five patients without ICH served as controls. Established risk factors for ICH (age, gender, severity of hypertension, bleeding disorders, intake of anticoagulants, and chronic alcoholism) were identified from medical records. Four specimens per brain were stained with hematoxylin-eosin and Congo red. The entire ICH cohort and subgroups were compared with controls using single-factor and multiple logistic regression analyses. RESULTS: CAA was found in 15 of 64 subjects (23%) with ICH and in five of 65 controls (8%; p = 0.026). In single-factor analysis, CAA was more prevalent in lobar ICH compared with controls (p = 0.007) but not in deep ICH. Poor control of hypertension was more prevalent in the entire ICH group (p = 0.01) and in deep ICH (p = 0.016) but not in lobar ICH. ICH was predictive of the presence of CAA (odds ratio: 5.6, 95% CI: 1.8 to 19.5, p = 0.003), and CAA was more likely to be found in lobar ICH in multivariable-adjusted analysis. After adjustment for conventional risk factors, there was a weak association between CAA and deep ICH. CONCLUSION: Cerebral amyloid angiopathy plays a major role in the pathogenesis of intracerebral hemorrhage even in patients with more evident risk factors.

Mannheim intima-media thickness consensus.

Intima-media thickness (IMT) is increasingly used in clinical trials as a surrogate end point for determining the success of interventions that lower risk factors for atherosclerosis. The necessity for unified criteria to distinguish early atherosclerotic plaque formation from thickening of IMT and to standardize IMT measurements is addressed in this consensus statement. Plaque is defined as a focal structure that encroaches into the arterial lumen of at least 0.5 mm or 50% of the surrounding IMT value or demonstrates a thickness of > or =1.5 mm as measured from the media-adventitia interface to the intima-lumen interface. Standard use of IMT measurements is recommended in all epidemiological and interventional trials dealing with vascular diseases to improve characterization of the population investigated. The consensus concludes that there is no need to 'treat IMT values' nor to monitor IMT values in individual patients apart from few exceptions. Although IMT has been suggested to represent an important risk marker, it does not fulfill the characteristics of an accepted risk factor. Standardized methods recommended in this consensus statement will foster homogenous data collection and analysis. This will help to improve the power of studies incorporating IMT measurements and to facilitate the merging of large databases for meta-analyses.

Acetazolamide as a vasodilatory stimulus in cerebrovascular diseases and in conditions affecting the cerebral vasculature.

Pathologic processes affecting the brain vessels may damage cerebral vasodilatory capacity. Early detection of cerebral dysfunction plays an important role in the prevention of cerebrovascular diseases. In recent decades acetazolamide (AZ) has frequently been used for this purpose. In the present work the mechanism of action and the previous studies are reviewed. The authors conclude that AZ tests are useful in cerebrovascular research. Further investigations are recommended to prove how impaired reserve capacity and reactivity influence the stroke risk in patients and whether these tests may indicate therapeutic interventions.

Absent collateral function of the circle of Willis as risk factor for ischemic stroke.

BACKGROUND: Autopsy studies show a higher prevalence of circle of Willis anomalies in brains with signs of ischemic infarction. Our goal was to examine the collateral function of the circle of Willis in ischemic stroke patients and to assess in a case-control study if a collateral deficient circle of Willis is a risk factor for ischemic stroke in patients with severe internal carotid artery (ICA) occlusive disease. METHODS: Our case-control study included 109 patients with an acute ischemic stroke in the anterior circulation and 113 patients with peripheral arterial disease and no known history of cerebral ischemia. The collateral function of the anterior and posterior communicating arteries of the circle of Willis was assessed by means of transcranial color-coded duplex ultrasonography (TCCD) and carotid compression tests. RESULTS: TCCD was successfully performed in 75 case patients (mean age 64 years, range 41-91 years) and in 100 control patients (mean age 61 years, range 35-89 years). In 26 cases and 19 controls, a >/=70% stenosis or occlusion of the ICA was found. A nonfunctional anterior collateral pathway in the circle of Willis was found in 33% of the cases and in 6% of the controls (p < 0.001). The posterior collateral pathway was nonfunctional in 57% of the cases and in 43% of the controls (p = 0.02). In patients with severe ICA occlusive disease, the odds ratios of a nonfunctional anterior and a nonfunctional posterior collateral pathway were 7.33 (95% confidence interval, CI, = 1.19-76.52) and 3.00 (95% CI = 0.77-12.04), respectively. CONCLUSIONS: Patients who suffer ischemic stroke in the anterior circulation have a higher incidence of collateral deficient circles of Willis than those with atherosclerotic vascular disease without ischemic cerebrovascular disease. The presence of a nonfunctional anterior collateral pathway in the circle of Willis in patients with severe ICA occlusive disease is strongly associated with ischemic stroke.