Intracranial Atherosclerosis

Impact of qualifying artery on the efficacy of stenting plus medical therapy versus medical therapy alone in patients with symptomatic intracranial stenosis: a post-hoc analysis of the CASSISS trial

BACKGROUND

A recent trial failed to show any benefit of stenting plus medical therapy over medical therapy alone in patients with symptomatic intracranial stenosis. We aimed to examine whether the symptomatic qualifying artery modifies the effect of stenting plus medical therapy.

METHODS

This is a post-hoc analysis of the CASSISS trial that included patients with symptomatic intracranial stenosis, randomly assigned to undergo stenting plus medical therapy or medical therapy alone; 358/380 patients were included. Multivariable logistic regression analysis was used with an interaction term to estimate the altered treatment effect by the qualifying artery. The primary outcome was a composite of stroke or death within 30 days or stroke in the qualifying artery territory beyond 30 days through 1 year. The five secondary outcomes included stroke or death related to the qualifying artery territory at 2 and 3 years.

RESULTS

No significant treatment allocation-by-stenosis site interaction was observed (Pinteraction=0.435). Compared with medical therapy alone, the adjusted ORs for stenting plus medical therapy were 2.73 (95% CI 0.42 to 17.65) for internal carotid artery stenosis, 1.20 (95% CI 0.29 to 4.99) for M1 stenosis, 0.23 (95% CI 0.02 to 2.31) for vertebral artery stenosis, and 1.33 (95% CI 0.34 to 5.28) for basilar artery stenosis. Of the five secondary outcomes, none showed a significant treatment allocation-by-stenosis site interaction including stroke in the qualifying artery territory at 2 years (Pinteraction=0.659) and 3 years (Pinteraction=0.493).

CONCLUSIONS

Among patients with transient ischemic attacks or ischemic stroke due to severe intracranial atherosclerotic stenosis, there was no evidence that the symptomatic qualifying artery could determine the addition of stenting to medical therapy.

Burden of intracranial artery calcification in white patients with ischemic stroke

INTRODUCTION

The diagnostic workup of stroke doesn't identify an underlying cause in two-fifths of ischemic strokes. Intracranial arteriosclerosis is acknowledged as a cause of stroke in Asian and Black populations, but is underappreciated as such in whites. We explored the burden of Intracranial Artery Calcification (IAC), a marker of intracranial arteriosclerosis, as a potential cause of stroke among white patients with recent ischemic stroke or TIA.

PATIENTS AND METHODS

Between December 2005 and October 2010, 943 patients (mean age 63.8 (SD ± 14.0) years, 47.9% female) were recruited, of whom 561 had ischemic stroke and 382 a TIA. CT-angiography was conducted according to stroke analysis protocols. The burden of IAC was quantified on these images, whereafter we assessed the presence of IAC per TOAST etiology underlying the stroke and assessed associations between IAC burden, symptom severity, and short-term functional outcome.

RESULTS

IAC was present in 62.4% of patients. Furthermore, IAC was seen in 84.8% of atherosclerotic strokes, and also in the majority of strokes with an undetermined etiology (58.5%). Additionally, patients with larger IAC burden presented with heavier symptoms (adjusted OR 1.56 (95% CI [1.06-2.29]), but there was no difference in short-term functional outcome (1.14 [0.80-1.61]).

CONCLUSION

IAC is seen in the majority of white ischemic stroke patients, aligning with findings from patient studies in other ethnicities. Furthermore, over half of patients with a stroke of undetermined etiology presented with IAC. Assessing IAC burden may help identify the cause in ischemic stroke of undetermined etiology, and could offer important prognostic information.

A bibliometric analysis of the 100 most-cited clinical articles in the research of intracranial artery stenosis and intracranial atherosclerosis

Background

Intracranial arterial stenosis (ICAS), caused by intracranial atherosclerosis, is one of the major causes of ischemic stroke. This study identified the top 100 most-cited publications on ICAS through a bibliometric analysis.

Methods

Two independent authors conducted a search in the Web of Science database for clinical articles on ICAS published between 1993 and 2022. The top 100 most-cited articles were then extracted. For each article, the analysis covered the title, author, country of origin/affiliation, journal, total number of citations, number of citations per year, and type of study.

Results

The top 100 most-cited papers in the ICAS were authored by 565 authors from 12 countries and published in 29 journals. In terms of the 5-year trend, the largest number of papers were published between 2003 and 2007 (n = 31). The median number of citations for the 100 papers was 161 (range 109-1,115). The journal with the highest proportion of the 100 most published articles was Stroke, accounting for 41% of articles and 37% of the citations. According to country of origin, the United States of America accounted for the largest number of articles, followed by China, Japan, and South Korea, with these four countries together accounting for 81% of the total number of articles and 88% of the citations. Trends in the past five years included the use of terms such as acute ischemic stroke and mechanical thrombectomy.

Conclusion

The findings of this study provide novel insight into this field and will facilitate future research endeavors.

Delayed Enhancement of Intracranial Atherosclerotic Plaque Can Better Differentiate Culprit Lesions: A Multiphase Contrast-Enhanced Vessel Wall MRI Study

BACKGROUND AND PURPOSE

Intracranial plaque enhancement (IPE) identified by contrast-enhanced vessel wall MR imaging (VW-MR imaging) is an emerging marker of plaque instability related to stroke risk, but there was no standardized timing for postcontrast acquisition. We aim to explore the optimal postcontrast timing by using multiphase contrast-enhanced VW-MR imaging and to test its performance in differentiating culprit and nonculprit lesions.

MATERIALS AND METHODS

Patients with acute ischemic stroke due to intracranial plaque were prospectively recruited to undergo VW-MR imaging with 1 precontrast phase and 4 consecutive postcontrast phases (9 minutes and 13 seconds for each phase). The signal intensity (SI) values of the CSF and intracranial plaque were measured on 1 precontrast and 4 postcontrast phases to determine the intracranial plaque enhancement index (PEI). The dynamic changes of the PEI were compared between culprit and nonculprit plaques on the postcontrast acquisitions.

RESULTS

Thirty patients with acute stroke (aged 59 ± 10 years, 18 [60%] men) with 113 intracranial plaques were included. The average PEI of all intracranial plaques significantly increased (up to 14%) over the 4 phases. There was significantly increased PEI over the 4 phases for culprit plaques (an average increase of 23%), but this was not observed for nonculprit plaques. For differentiating culprit and nonculprit plaques, we observed that the performance of IPE in the second postcontrast phase (cutoff = 0.83, AUC = 0.829 [0.746-0.893]) exhibited superior accuracy when compared with PEI in the first postcontrast phase (cutoff = 0.48; AUC = 0.768 [0.680-0.843]) (P = .022).

CONCLUSIONS

A 9-minute delay of postcontrast acquisition can maximize plaque enhancement and better differentiate between culprit and nonculprit plaques. In addition, culprit and nonculprit plaques have different enhancement temporal patterns, which should be evaluated in future studies.

Imaging of intracranial arterial disease: a comparison between MRI and unenhanced CT

Background and purpose

Arterial calcifications on unenhanced CT scans and vessel wall lesions on MRI are often used interchangeably to portray intracranial arterial disease. However, the extent of pathology depicted with each technique is unclear. We investigated the presence and distribution of these two imaging findings in patients with a history of cerebrovascular disease.

Materials and methods

We analyzed CT and MRI data from 78 patients admitted for stroke or TIA at our institution. Vessel wall lesions were assessed on 7 T MRI sequences, while arterial calcifications were assessed on CT scans. The number of vessel wall lesions, severity of intracranial internal carotid artery (iICA) calcifications, and overall presence and distribution of the two imaging findings were visually assessed in the intracranial arteries.

Results

At least one vessel wall lesion or arterial calcification was assessed in 69 (88%) patients. Only the iICA and vertebral arteries (VA) showed a substantial number of both calcifications and vessel wall lesions. The other vessels showed almost exclusively vessel wall lesions. The number of vessel wall lesions was associated with the severity of iICA calcification (p = 0.013).

Conclusions

The number of vessel wall lesions increases with the severity of iICA calcifications. Nonetheless, the distribution of vessel wall lesions on MRI and arterial calcifications on CT shows remarkable differences. These findings support the need for a combined approach to examine intracranial arterial disease.

Improvement of cerebral blood flow after balloon angioplasty and stenting for symptomatic middle cerebral artery stenosis

OBJECTIVE

Although reports of endovascular treatment for intracranial arterial stenosis have been increasing recently, their efficacy remains to be elucidated. This study aimed to investigate the changes in cerebral hemodynamics of severe middle cerebral artery (MCA) stenosis patients by performing CT perfusion (CTP) after endovascular treatment.

METHODS

Subjects were those who underwent balloon angioplasty and stenting for symptomatic MCA M1 stenosis refractory to medical therapy at our hospital between 2008 and 2022. We included 36 patients (mean age 63.69 ± 15.24 years, 20 males) who underwent CTP before and within three weeks after treatment. The CTP parameters such as relative cerebral blood flow (rCBF), relative cerebral blood volume (rCBV), and relative mean transit time (rMTT) were calculated as ipsilateral values divided by contralateral value.

RESULTS

Endovascular treatment consisted of 26 balloon angioplasty and 10 stenting procedures performed at an average of 1 month from onset. CTP was performed at an average of 5.5 days postoperatively. The mean overall stenosis rate decreased from 79.0% to 30.3%. In the balloon angioplasty group, it decreased from 77.6% to 35.3%, and in the stent group, it decreased from 82.7% to 17.5%. After treatment, rCBF and rMTT measured by CTP improved significantly (both p < 0.001), whereas there was no significant change in rCBV. The improvement rates of rCBF and rMTT were mild higher in the stent group, but not significantly so.

CONCLUSION

Balloon angioplasty and stenting for symptomatic MCA improved cerebral hemodynamics, resulting in significantly increased rCBF and decreased rMTT.

Epidemiology, Pathophysiology, and Imaging of Atherosclerotic Intracranial Disease

Intracranial atherosclerotic disease (ICAD) is one of the most common causes of stroke worldwide. Among people with stroke, those of East Asia descent and non-White populations in the United States have a higher burden of ICAD-related stroke compared with Whites of European descent. Disparities in the prevalence of asymptomatic ICAD are less marked than with symptomatic ICAD. In addition to stroke, ICAD increases the risk of dementia and cognitive decline, magnifying ICAD societal burden. The risk of stroke recurrence among patients with ICAD-related stroke is the highest among those with confirmed stroke and stenosis ≥70%. In fact, the 1-year recurrent stroke rate of >20% among those with stenosis >70% is one of the highest rates among common causes of stroke. The mechanisms by which ICAD causes stroke include plaque rupture with in situ thrombosis and occlusion or artery-to-artery embolization, hemodynamic injury, and branch occlusive disease. The risk of stroke recurrence varies by the presumed underlying mechanism of stroke, but whether techniques such as quantitative magnetic resonance angiography, computed tomographic angiography, magnetic resonance perfusion, or transcranial Doppler can help with risk stratification beyond the degree of stenosis is less clear. The diagnosis of ICAD is heavily reliant on lumen-based studies, such as computed tomographic angiography, magnetic resonance angiography, or digital subtraction angiography, but newer technologies, such as high-resolution vessel wall magnetic resonance imaging, can help distinguish ICAD from stenosing arteriopathies.

Differences in characteristics between patients from Egypt and Germany presenting with lacunar stroke

Despite the enormous health burden of lacunar stroke, data from low- and middle-income countries on lacunar stroke characteristics and its comparison with that of high-income countries are scarce. Thus, we aimed to investigate and compare the variable characteristics and vascular status in patients from Egypt and Germany suffering lacunar stroke. Two cohorts of lacunar stroke patients from Ain Shams University Hospital, Egypt and Goethe University Hospital Frankfurt, Germany were retrospectively collected between January 2019 and December 2020 and analyzed for demographics, risk factors, mode of presentation, neuroimaging features, treatment protocols and outcomes. MRI showed a different distribution pattern of lacunar strokes between cohorts, detecting posterior circulation lacunar infarctions preponderantly in patients from Egypt and anterior circulation lacunar infarctions preponderantly in patients from Germany. Complementary MR/CT angiography revealed a significantly higher proportion of intracranial and combined intracranial and extracranial arterial stenosis in patients from Egypt than in patients from Germany, suggesting differences in pathological processes. Younger age, higher NIHSS on admission, and posterior circulation lacunar infarction were predictors of Egyptian origin, whereas hypertension was a predictor of German origin. Our results support the idea of clinical and neuroimaging phenotype variations in lacunar stroke, including different sources of lacunar stroke in patients of different populations and geographical regions. This implies that guidelines for management of lacunar stroke might be tailored to these differences accordingly.

Prevalence of intracranial artery stenosis in a general population using 3D-time of flight magnetic resonance angiography

BACKGROUND

Data on prevalence of intracranial artery stenosis (ICAS) in Western populations is sparse. The aim of the study was to assess the prevalence and risk factors for ICAS in a mainly Caucasian general population.

METHODS

We assessed the prevalence of ICAS in 1847 men and women aged 40 to 84 years who participated in a cross-sectional population-based study, using 3-dimensional time-of-flight 3 Tesla magnetic resonance angiography. ICAS was defined as a focal luminal flow diameter reduction of ≥50 %. The association between cardiovascular risk factor levels and ICAS was assessed by multivariable regression analysis.

RESULTS

The overall prevalence of ICAS was 6.0 % (95 % confidence interval (CI) 5.0-7.2), 4.3 % (95 % CI 3.1-5.7) in women and 8.0 % (95 % CI 6.3-10.0) in men. The prevalence increased by age from 0.8 % in 40-54 years age group to 15.2 % in the 75-84 years age group. The majority of stenoses was located to the internal carotid artery (52.2 %), followed by the posterior circulation (33.1 %), the middle cerebral artery (10.8 %) and the anterior cerebral artery (3.8 %). The risk of ICAS was independently associated with higher age, male sex, hypertension, hyperlipidemia, diabetes mellitus, current smoking and higher BMI.

CONCLUSIONS

The prevalence of ICAS in a general population of Caucasians was relatively high and similar to the prevalence of extracranial internal carotid artery stenosis in previous population-based studies.

Greater burden of white matter lesions and silent infarcts ipsilateral to carotid stenosis

OBJECTIVES

Carotid stenosis may cause silent cerebrovascular disease (CVD) through atheroembolism and hypoperfusion. If so, revascularization may slow progression of silent CVD. We aimed to compare the presence and severity of silent CVD to the degree of carotid bifurcation stenosis by cerebral hemisphere.

MATERIALS AND METHODS

Patients age ≥40 years with carotid stenosis >50% by carotid ultrasound who underwent MRI brain from 2011-2015 at Mayo Clinic were included. Severity of carotid stenosis was classified by carotid duplex ultrasound as 50-69% (moderate), 70-99% (severe), or occluded. White matter lesion (WML) volume was quantified using an automated deep-learning algorithm applied to axial T2 FLAIR images. Differences in WML volume and prevalent silent infarcts were compared across hemispheres and severity of carotid stenosis.

RESULTS

Of the 183 patients, mean age was 71±10 years, and 39.3% were female. Moderate stenosis was present in 35.5%, severe stenosis in 46.5% and occlusion in 18.0%. Patients with carotid stenosis had greater WML volume ipsilateral to the side of carotid stenosis than the contralateral side (mean difference, 0.42±0.21cc, p=0.046). Higher degrees of stenosis were associated with greater hemispheric difference in WML volume (moderate vs. severe; 0.16±0.27cc vs 0.74±0.31cc, p=0.009). Prevalence of silent infarct was 23.5% and was greater on the side of carotid stenosis than the contralateral side (hemispheric difference 8.8%±3.2%, p=0.006). Higher degrees of stenosis were associated with higher burden of silent infarcts (moderate vs severe, 10.8% vs 31.8%; p=0.002).

CONCLUSIONS

WML and silent infarcts were greater on the side of severe carotid stenosis.

Large Vessel Occlusion Stroke due to Intracranial Atherosclerotic Disease: Identification, Medical and Interventional Treatment, and Outcomes

Large vessel occlusion stroke due to underlying intracranial atherosclerotic disease (ICAD-LVO) is prevalent in 10 to 30% of LVOs depending on patient factors such as vascular risk factors, race and ethnicity, and age. Patients with ICAD-LVO derive similar functional outcome benefit from endovascular thrombectomy as other mechanisms of LVO, but up to half of ICAD-LVO patients reocclude after revascularization. Therefore, early identification and treatment planning for ICAD-LVO are important given the unique considerations before, during, and after endovascular thrombectomy. In this review of ICAD-LVO, we propose a multistep approach to ICAD-LVO identification, pretreatment and endovascular thrombectomy considerations, adjunctive medications, and medical management. There have been no large-scale randomized controlled trials dedicated to studying ICAD-LVO, therefore this review focuses on observational studies.

Prevalence and Clinico-Radiologic Spectrum of Intracranial Atherosclerotic Disease-Related Stroke: An Observation from a Single Center in Saudi Arabia

BACKGROUND

Intracranial atherosclerotic disease (ICAD) is an important etiologic subtype of acute ischemic stroke (AIS). However, little direct evidence is available regarding ICAD-related stroke in Saudi Arabia (SA). This study aimed to identify the prevalence and describe the clinico-radiological spectrum of ICAD-related AIS in a SA cohort.

METHODS

This was a hospital-based retrospective study enrolling patients with ICAD-related AIS between 2017 and 2020. The electronic charts were reviewed. The mechanisms of stroke were identified as artery-to-artery embolization (AAE), in situ thrombotic occlusion, hypoperfusion, or perforator branch occlusion. Pearson's χ 2 test was performed to calculate the P values to establish the statistical significance of factors that could correlate with the mechanisms of stroke and functional outcome.

RESULTS

ICAD was found in 133 of AIS comprising 26% of total. Data from all patients were reviewed. Left ICA (25%) was the most frequently affected vessel. Territorial pattern (63.9%) was the most common infarct pattern, and AAE (44.3%) was the most common underlying mechanism. Perforator branch occlusion was more prevalent in women than in men. Malignant and hemorrhagic transformation ( P =0.00) were more prevalent in the AAE group. Left-sided vascular involvement was statistically associated with unfavorable outcomes than the right ( P =0.019).

CONCLUSIONS

The prevalence of ICAD in our cohort from Western Asia did not differ from that in Southern Asia. ICA involvement was observed more frequently than previously reported. Further research from SA is required to better understand ICAD-related strokes in this region.

The role of protein glycosylation in the occurrence and outcome of acute ischemic stroke

Acute ischemic stroke (AIS) is a serious and life-threatening disease worldwide. Despite thrombolysis or endovascular thrombectomy, a sizeable fraction of patients with AIS have adverse clinical outcomes. In addition, existing secondary prevention strategies with antiplatelet and anticoagulant drugs therapy are not able to adequately decrease the risk of ischemic stroke recurrence. Thus, exploring novel mechanisms for doing so represents an urgent need for the prevention and treatment of AIS. Recent studies have discovered that protein glycosylation plays a critical role in the occurrence and outcome of AIS. As a common co- and post-translational modification, protein glycosylation participates in a wide variety of physiological and pathological processes by regulating the activity and function of proteins or enzymes. Protein glycosylation is involved in two causes of cerebral emboli in ischemic stroke: atherosclerosis and atrial fibrillation. Following ischemic stroke, the level of brain protein glycosylation becomes dynamically regulated, which significantly affects stroke outcome through influencing inflammatory response, excitotoxicity, neuronal apoptosis, and blood-brain barrier disruption. Drugs targeting glycosylation in the occurrence and progression of stroke may represent a novel therapeutic idea. In this review, we focus on possible perspectives about how glycosylation affects the occurrence and outcome of AIS. We then propose the potential of glycosylation as a therapeutic drug target and prognostic marker for AIS patients in the future.

Intracranial steno-occlusive lesion detection on time-of-flight MR angiography using multi-task learning

Steno-occlusive lesions in intracranial arteries refer to segments of narrowed or occluded blood vessels that increase the risk of ischemic strokes. Steno-occlusive lesion detection is crucial in clinical settings; however, automatic detection methods have hardly been studied. Therefore, we propose a novel automatic method to detect steno-occlusive lesions in sequential transverse slices on time-of-flight magnetic resonance angiography. Our method simultaneously detects lesions while segmenting blood vessels based on end-to-end multi-task learning, reflecting that the lesions are closely related to the connectivity of blood vessels. We design classification and localization modules that can be attached to arbitrary segmentation network. As blood vessels are segmented, both modules simultaneously predict the presence and location of lesions for each transverse slice. By combining outputs from the two modules, we devise a simple operation that boosts the performance of lesion localization. Experimental results show that lesion prediction and localization performance is improved by incorporating blood vessel extraction. Our ablation study demonstrates that the proposed operation enhances lesion localization accuracy. We also verify the effectiveness of multi-task learning by comparing our approach with those that individually detect lesions with extracted blood vessels.

Incidental vascular findings on brain magnetic resonance angiography

Given the ever-increasing utilization of magnetic resonance angiography, incidental vascular findings are increasingly discovered on exams performed for unconnected indications. Some incidental lesions represent pathology and require further intervention and surveillance, such as aneurysm, certain vascular malformations, and arterial stenoses or occlusions. Others are benign or represent normal anatomic variation, and may warrant description, but not further work-up. This review describes the most commonly encountered incidental findings on magnetic resonance angiography, their prevalence, clinical implications, and any available management recommendations.

Nomogram to Predict Cognitive Impairment in Patients with Asymptomatic Middle Cerebral Artery Stenosis

Purpose

This study aims to investigate the characteristics and influencing factors of cognitive impairment in patients with asymptomatic middle cerebral artery stenosis (aMCAS) and to construct a nomogram to predict the risk of cognitive impairment in patients with aMCAS.

Patients and Methods

We collected 54 patients with aMCAS and 35 healthy controls to investigate the impaired cognitive domains and pathogenesis in patients with aMCAS. All patients underwent a cranial MRI, CT perfusion, transcranial Doppler ultrasound, blood tests, and a comprehensive neuropsychological evaluation. According to the MoCA score, patients were divided into cognitively normal and cognitively impaired groups. To construct the nomogram, we conducted univariate and multivariate logistic regression analyses to identify factors that affect cognitive function. And the performance of nomogram was evaluated by ROC curves, calibration curves, decision curve analysis (DCA), and clinical impact curve (CIC).

Results

In 54 patients with aMCAS, 24 patients presented with cognitive normal, and 30 patients presented with cognitive impairment. The results of multivariate logistic regression suggested that perfusion decompensation, middle cerebral artery mean flow velocity, and LDL-cholesterol levels were independent influencing factors of cognitive impairment. In the following step, a nomogram was constructed. The AUC of the nomogram is 0.862. Calibrating curves show good agreement between nomogram predictions and actual observations, while DCA and CIC show great clinical usefulness.

Conclusion

Patients with aMCAS have cognitive impairment in multiple cognitive domains, and impaired executive function was observed during the perfusion compensation period. Furthermore, a nomogram was constructed and validated to predict the risk of cognitive impairment in patients with aMCAS, which can help clinicians to identify at an early stage and improve the management of patients.

Apolipoprotein E genotypes were not associated with intracranial atherosclerosis: a population-based autopsy study

BACKGROUND

Apolipoprotein E gene (APOE) ε4 allele is associated with a higher risk of carotid atherosclerosis, but less is known about the association of APOE with intracranial atherosclerotic disease (IAD). We aimed to investigate the association of APOE alleles with IAD in a cross-sectional autopsy study.

METHODS

We measured the stenosis in the 12 arteries of the Circle of Willis using postmortem morphometric measurements. The APOE polymorphism was determined by real-time polymerase chain reaction. We assessed the association between APOE polymorphism and IAD using regression models adjusted for sociodemographic and clinical variables. We also verified the modifier effect of age, sex, and race on this association. We stratified the analysis by age group to investigate the possibility of attrition bias.

RESULTS

In 400 participants (mean age=73.2±12.3 years old, 51% female, and 64% White), IAD was evaluated in 4,504 artery segments. APOE-ε4 was not associated with IAD nor with the number of artery stenosis compared to non-APOE-ε4 carriers. Sociodemographic variables did not modify this relationship. Among participants older than 70 years, there was a trend towards an association between APOE allele ε4 and a lower stenosis index in the middle cerebral artery, suggesting attrition bias related to the APOE-ε4 effect on mortality.

CONCLUSIONS

APOE alleles were not associated with IAD in this population-based autopsy study. Lower stenosis in older participants suggests the possibility of attrition bias.

The concept of comorbidity of dyscirculatory encephalopathy and vascular optical neuropathy (literature review)

The analysis of literature data on ischemic damage to the brain and the organ of vision was carried out in order to study etiological factors, pathogenetic processes, parallel flow and mutual influence of two nosological forms: dyscirculatory encephalopathy and vascular optic neuropathy. According to the World Health Organization, there is much more people suffering from cardiovascular diseases: atherosclerosis, hypertension, diabetes mellitus and coronary heart disease. These diseases result in ischemic damage to a number of vital organs, including the central nervous system and the visual analyzer. Chronic vascular pathology of both the brain and the eye is one of the leading causes of patients’ life quality decrease of and their disability. The “triggering” causes of brain and eye damage, according to researchers, are cerebral atherosclerosis, elevating/fluctuating blood pressure, coronary heart disease, and carbohydrate metabolism disorders. Disorders of the systemic blood supply caused by these etiological factors lead to a progressive lack of oxygen supply to organs and tissues, followed by the development of intracellular and cellular hypoxia, and an ischemic intracellular cascade of biochemical disorders leading to dysfunction and sometimes cell death.In addition to direct hypoxic-ischemic damage of the nervous and visual systems cells, endothelial dysfunction contributes to the progression of these diseases, leading to a pronounced change in the wall at the level of small vessels, a change in its reactivity and a violation of the coagulation properties of blood, and as a consequence, to a gradual accumulation of ischemic and secondary degenerative changes in brain and eye cells.Knowledge of etiological factors and patterns of development of brain and eye combined ischemic damage can allow clarifying the complex of diagnostic measures, developing preventive measures, as well as prescribe pathogenetically justified treatment of existing pathology.

European Stroke Organisation guidelines on treatment of patients with intracranial atherosclerotic disease

The aim of the present European Stroke Organisation guideline is to provide clinically useful evidence-based recommendations on the management of patients with intracranial atherosclerotic disease (ICAD). The guidelines were prepared following the Standard Operational Procedure of the European Stroke Organisation guidelines and according to GRADE methodology. ICAD represents a major cause of ischemic stroke worldwide, and patients affected by this condition are exposed to a high risk for future strokes and other major cardiovascular events, despite best medical therapy available. We identified 11 relevant clinical problems affecting ICAD patients and formulated the corresponding Population Intervention Comparator Outcomes (PICO) questions. The first two questions refer to the asymptomatic stage of the disease, which is being increasingly detected thanks to the routine use of noninvasive vascular imaging. We were not able to provide evidence-based recommendations regarding the optimal detection strategy and management of asymptomatic ICAD, and further research in the field is encouraged as subclinical ICAD may represent a big opportunity to improve primary stroke prevention. The second block of PICOs (3-5) is dedicated to the management of acute large vessel occlusion (LVO) ischemic stroke caused by ICAD, a clinical presentation of this disease that is becoming increasingly relevant and problematic, since it is associated with more refractory endovascular reperfusion procedures. An operational definition of probable ICAD-related LVO is proposed in the guideline. Despite the challenging context, no dedicated randomized clinical trials (RCTs) were identified, and therefore the guideline can only provide with suggestions derived from observational studies and our expert consensus, such as the escalated use of glycoprotein IIb-IIIa inhibitors and angioplasty/stenting in cases of refractory thrombectomies due to underlying ICAD. The last block of PICOs is devoted to the secondary prevention of patients with symptomatic ICAD. Moderate-level evidence was found to recommend against the use of oral anticoagulation as preferred antithrombotic drug, in favor of antiplatelets. Low-level evidence based our recommendation in favor of double antiplatelet as the antithrombotic treatment of choice in symptomatic ICAD patients, which we suggest to maintain during 90 days as per our expert consensus. Endovascular therapy with intracranial angioplasty and or stenting is not recommended as a treatment of first choice in high-grade symptomatic ICAD (moderate-level evidence). Regarding neurosurgical interventions, the available evidence does not support their use as front line therapies in patients with high-grade ICAD. There is not enough evidence as to provide any specific recommendation regarding the use of remote ischemic conditioning in ICAD patients, and further RCTs are needed to shed light on the utility of this promising therapy. Finally, we dedicate the last PICO to the importance of aggressive vascular risk factor management in ICAD, although the evidence derived from RCTs specifically addressing this question is still scarce.

Comprehensive Risk Analysis of the Wingspan Stent in Relation to Target Vessels

Objective

To facilitate understanding for the safe use of the Wingspan stent, a comprehensive literature analysis was conducted, and incidence rates of 30-day stroke or death before and after the Stenting versus Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis (SAMMPRIS) trial were compared. We also investigated the associations between 30-day stroke or death rate and four lesion vessels, the internal carotid artery (ICA), middle cerebral artery (MCA), basilar artery (BA), and vertebral artery (VA).

Methods

We searched MEDLINE, Embase, Web of Science, and Cochrane Library databases. The incidence rates of 30-day stroke or death in pre- and post-SAMMPRIS were compared using forest plots and funnel plots.

Results

Thirty studies (15 before and 15 after the SAMMPRIS) were identified, comprising 2071 patients. Post-SAMMPRIS studies showed lower incidence rates of 30-day stroke or death compared to the pre-SAMMPRIS studies (8.5% vs. 5.6%, p = 0.014). The odds ratio of 30-day stroke or death of the post-SAMMPRIS group compared to that of the pre-SAMMPRIS group was 0.64 (95% confidence interval: 0.45-0.92, p = 0.014). The average 30-day stroke or death rates of overall, pre-, and post-SAMMPIS studies were 1.1%, 1.1%, and 1.1% for ICA; 6.2%, 8.8%, and 5.3% for MCA; 0.9%, 6.0%, and 2.7% for VA; and 13.5%, 15.1%, and 12.5% for BA, respectively. The post-SAMMPRIS study group showed significantly lower event rates for the treatment of MCA and VA than the pre-SAMMPRIS group did (p = 0.003 and p = 0.006, respectively). The incidence rates of ischemic and hemorrhagic stroke were 3.5% and 2.0%, respectively.

Conclusion

This systematic surveillance study indicated that the modification of the indications for use based on the results of the SAMMPRIS trial for the Wingspan stent was effective in reducing 30-day stroke or death.

High-Risk Intracranial Atherosclerotic Stenosis Despite Aggressive Medical Treatment: Protocol for a Prospective Nested Case-Control Study

Introduction

Intracranial atherosclerotic disease (ICAD) is one of the most important etiologies of ischemic stroke, especially in Asia. Although medical treatment was recommended as the first-line therapy for ICAD, the recurrent stroke rate was still high in severe stenosis of ICAD despite aggressive medical treatment. Traditionally, the degree of luminal stenosis is used as the principal index for stroke risk stratification in patients with ICAD, while recent evidence suggested that symptomatic atherosclerotic plaques were characterized by plaque features and hemodynamics. This prospective, longitudinal, and nested case-control study aims to identify multimodal imaging predictors of high-risk patients with ICAD refractory to medical treatment and explore a refined risk stratification model based on the above multimodal imaging predictors.

Methods

This prospective, longitudinal, and nested case-control study includes 400 symptomatic patients with ICAD with 50–99% of stenosis treated with aggressive medical therapy. All patients who meet the eligibility criteria are assessed by multimodal imaging examination from three aspects, including lumen stenosis, plaque characteristics, and hemodynamic features. The enrolled patients receive aggressive medical management, including antiplatelet therapy and cardiovascular risk control. The primary outcome is ischemic stroke or death attributable to the lesion of the target vessel within 1 year. The secondary endpoints are (1) any stroke or death; (2) all-cause mortality; (3) any stroke out of the territory of the responsible lesion; (4) functional outcome with the modified Rankin Scale (mRS).

Ethics and Dissemination

This study has been approved by the ethics committee of our center ([2021]083) and has been prospectively registered (Registration No: ChiCTR2100048832). Study findings will be disseminated through peer-reviewed publications and presentations at scientific meetings.

MRA-free intracranial vessel localization on MR vessel wall images

Analysis of vessel morphology is important in assessing intracranial atherosclerosis disease (ICAD). Recently, magnetic resonance (MR) vessel wall imaging (VWI) has been introduced to image ICAD and characterize morphology for atherosclerotic lesions. In order to automatically perform quantitative analysis on VWI data, MR angiography (MRA) acquired in the same imaging session is typically used to localize the vessel segments of interest. However, MRA may be unavailable caused by the lack or failure of the sequence in a VWI protocol. This study aims to investigate the feasibility to infer the vessel location directly from VWI. We propose to synergize an atlas-based method to preserve general vessel structure topology with a deep learning network in the motion field domain to correct the residual geometric error. Performance is quantified by examining the agreement between the extracted vessel structures from the pair-acquired and alignment-corrected angiogram, and the estimated output using a cross-validation scheme. Our proposed pipeline yields clinically feasible performance in localizing intracranial vessels, demonstrating the promise of performing vessel morphology analysis using VWI alone.

Pathological haemodynamics of a middle cerebral artery stenosis validated by computational fluid dynamics

Intracranial arterial stenosis (ICAS) is one of the important causes of ischaemic stroke. However, the treatment for ICAS is not optimised, including medical therapies, because the mechanisms are diverse. The authors report a case of severe middle cerebral arterial stenosis accompanied by a floating thrombus, which caused artery-to-artery cerebral emboli. The patient was successfully treated with multiple antithrombotics including an anticoagulant, and the thrombus disappeared. Local haemodynamics around the middle cerebral arterial stenosis was analysed by computational fluid dynamics (CFD) using the patient-specific model. CFD analysis demonstrated that thrombus formation occurred at the poststenotic area with severe stagnant flow, which was judged by both wall shear stress and shear rate less than the specific thresholds. These findings suggest that CFD may be useful to diagnose the risk of stagnant flow-induced thrombosis and to predict the effectiveness of anticoagulant agents to prevent distal embolisms in ICAS.

Plaque Characteristics in Young Adults With Symptomatic Intracranial Atherosclerotic Stenosis: A Preliminary Study

Purpose

To determine how intracranial vascular wall and atherosclerosis plaque characteristics differ between young and old adults with sICAS.

Methods

Eighty-four consecutive patients with sICAS who underwent high-resolution magnetic resonance imaging (HRMRI) from December 2017 to July 2020 were retrospectively collected. These participants were divided into young adult group (18–50 years, n = 28) and old adult group (>50 years, n = 56). Reviewers were blinded to any clinical information and HRMRI scans were analyzed for qualitative and quantitative indicators of vascular walls and plaque at the maximal lumen narrowing site using the independent-sample t-test, Mann–Whitney U-test, chi-square test or Fisher exact test, and logistic regression analysis.

Results

Young patients with sICAS had significantly smaller maximum wall thickness (1.45 ± 0.38 vs.1.75 ± 0.51 mm², P = 0.003), higher prevalence of positive remodeling (53.57 vs. 21.43%, P = 0.003), and lower prevalence of diabetes mellitus (14.29 vs. 35.71%, P = 0.04) than old patients. Plaque burden and other plaque features were comparable between young and old patients.

Conclusion

Young patients with sICAS have smaller maximum wall thickness and greater ability to reconstruct, and are more likely to show positive remodeling, which may lead to some atherosclerotic lesions being missed. Young patients with evidence of vessel narrowing should be carefully examined for presence of high-risk atherosclerotic plaque.

Automated Segmentation and Volume Measurement of Intracranial Internal Carotid Artery Calcification at Noncontrast CT

Purpose

To develop and evaluate a fully-automated deep learning-based method for assessment of intracranial internal carotid artery calcification (ICAC).

Materials and Methods

This was a secondary analysis of prospectively collected data from the Rotterdam study (2003-2006) to develop and validate a deep learning-based method for automated ICAC delineation and volume measurement. Two observers manually delineated ICAC on noncontrast CT scans of 2319 participants (mean age, 69 years ± 7 [standard deviation]; 1154 women [53.2%]), and a deep learning model was trained to segment ICAC and quantify its volume. Model performance was assessed by comparing manual and automated segmentations and volume measurements to those produced by an independent observer (available on 47 scans), comparing the segmentation accuracy in a blinded qualitative visual comparison by an expert observer, and comparing the association with first stroke incidence from the scan date until 2016. All method performance metrics were computed using 10-fold cross-validation.

Results

The automated delineation of ICAC reached a sensitivity of 83.8% and positive predictive value (PPV) of 88%. The intraclass correlation between automatic and manual ICAC volume measures was 0.98 (95% CI: 0.97, 0.98; computed in the entire dataset). Measured between the assessments of independent observers, sensitivity was 73.9%, PPV was 89.5%, and intraclass correlation coefficient was 0.91 (95% CI: 0.84, 0.95; computed in the 47-scan subset). In the blinded visual comparisons of 294 regions, automated delineations were judged as more accurate than manual delineations in 131 regions, less accurate in 94 regions, and equally accurate in the rest of the regions (131 of 225, 58.2%; P = .01). The association of ICAC volume with incident stroke was similarly strong for both automated (hazard ratio, 1.38 [95% CI: 1.12, 1.75]) and manually measured volumes (hazard ratio, 1.48 [95% CI: 1.20, 1.87]).

Conclusion

The developed model was capable of automated segmentation and volume quantification of ICAC with accuracy comparable to human experts.Keywords CT, Neural Networks, Carotid Arteries, Calcifications/Calculi, Arteriosclerosis, Segmentation, Vision Application Domain, Stroke Supplemental material is available for this article. © RSNA, 2021.

Devastating iatrogenic internal carotid artery rupture in endoscopic endonasal surgery rescued by a covered stent

Iatrogenic ICA injury is a life-threatening and underreported complication of EES. For selected patients, covered stent implantation is the best and only way to block the rupture spot immediately and maintain ICA blood flow.

Drug-Coated Balloons for the Treatment of Symptomatic Intracranial High-Grade Stenosis: A Review of the Current Rationale

Symptomatic intracranial atherosclerotic disease (sICAD) remains a challenging disorder in the neurovascular field. Despite best medical treatment, the recurrence rate for stroke remains high in patients with intracranial high-grade stenosis (>70–99%). Furthermore, two large randomized trials (SAMMPRIS and VISSIT) failed to prove the efficacy of percutaneous transluminal angioplasty and stenting in patients with sICAD. Drug-coated balloon percutaneous transluminal angioplasty (DCB-PTA) represents an alternative treatment modality with therapeutic benefits for interventional cardiology. However, there are very few articles in the existing literature that relate to the use of DCB-PTA in sICAD patients. Here, we aimed to review the rationale underlying the use of DCB-PTA in sICAD patients and summarize recent developments in the neurovascular field.

Glucose Fluctuation and Severe Internal Carotid Artery Siphon Stenosis in Type 2 Diabetes Patients

The impact of glucose fluctuation on intracranial artery stenosis remains to be elucidated. This study aimed to investigate the association between glucose fluctuation and intracranial artery stenosis. This was a cross-sectional study of type 2 diabetes mellitus (T2DM) patients equipped with the FreeStyle Libre Pro continuous glucose monitoring system (Abbott Laboratories) between February 2019 and June 2020. Glucose fluctuation was evaluated according to the standard deviation (SD) of blood glucose, coefficient of variation (%CV), and mean amplitude of glycemic excursions (MAGE). Magnetic resonance angiography was used to evaluate the degree of intracranial artery stenosis. Of the 103 patients, 8 patients developed severe internal carotid artery (ICA) siphon stenosis (≥70%). SD, %CV, and MAGE were significantly higher in the severe stenosis group than in the non-severe stenosis group (<70%), whereas there was no significant intergroup difference in the mean blood glucose and HbA1c. Multivariable logistic regression analysis adjusted for sex showed that SD, %CV, and MAGE were independent factors associated with severe ICA siphon stenosis. In conclusion, glucose fluctuation is significantly associated with severe ICA siphon stenosis in T2DM patients. Thus, glucose fluctuation can be a target of preventive therapies for intracranial artery stenosis and ischemic stroke.

Agreement of novel hemodynamic imaging parameters for the acute and chronic stages of ischemic stroke: a matched-pair cohort study

OBJECTIVE

In symptomatic patients with cerebrovascular steno-occlusive disease, impaired blood oxygenation level-dependent cerebrovascular reactivity (BOLD-CVR) and increased flow velocity of the P2 segment of the posterior cerebral artery (PCA-P2) on transcranial Doppler (TCD) ultrasonography have been introduced as emerging clinical imaging parameters to identify patients at high risk for recurrent ischemic events. Since hemodynamic physiology differs between the acute and chronic stages of ischemic stroke, the authors sought to investigate whether those parameters have merit for both the acute and chronic stages of ischemic stroke.

METHODS

From a prospective database, patients who underwent BOLD-CVR and TCD examinations in the acute stroke stage (< 10 days) were matched to patients in the chronic stroke stage (> 3 months). A linear regression analysis for both groups was performed between ipsilateral PCA-P2 systolic flow velocity and BOLD-CVR of the ipsilateral (affected) hemisphere, the ipsilateral middle cerebral artery (MCA) territory, and the ipsilateral steal volume (i.e., paradoxical BOLD-CVR response). The resulting slopes and intercepts were statistically compared to evaluate differences between groups.

RESULTS

Forty matched patient pairs were included. Regression analysis showed no significant difference for either the intercept (p = 0.84) or the slope (p = 0.85) between PCA-P2 flow velocity and BOLD-CVR as measured for the ipsilateral (affected) hemisphere. Similarly, no significant difference was seen between PCA-P2 flow velocity and BOLD-CVR of the ipsilateral MCA territory (intercept, p = 0.72; slope, p = 0.36) or between PCA-P2 flow velocity and steal volume (intercept, p = 0.59; slope, p = 0.34).

CONCLUSIONS

The study results indicated that the relationship between ipsilateral PCA-P2 systolic flow velocity and BOLD-CVR remains the same during the acute and chronic stages of ischemic stroke. This provides further support that these novel hemodynamic imaging parameters may have merit to assess the risk for recurrent ischemic events for a wide ischemic stroke population. PCA-P2 systolic flow velocity, in particular, may be a highly practical screening tool, independent of ischemic stroke stage.

Intracranial Atherosclerotic Burden and Cerebral Parenchymal Changes at 7T MRI in Patients With Transient Ischemic Attack or Ischemic Stroke

The relevance of intracranial vessel wall lesions detected with MRI is not fully established. In this study (trial identification number: NTR2119; www.trialregister.nl), 7T MRI was used to investigate if a higher vessel wall lesion burden is associated with more cerebral parenchymal changes in patients with ischemic stroke or transient ischemic attack (TIA). MR images of 82 patients were assessed for the number of vessel wall lesions of the large intracranial arteries and for cerebral parenchymal changes, including the presence and number of cortical, small subcortical, and deep gray matter infarcts; lacunes of presumed vascular origin; cortical microinfarcts; and periventricular and deep white matter hyperintensities (WMHs). Regression analyses showed that a higher vessel wall lesion burden was associated with the presence of small subcortical infarcts, lacunes of presumed vascular origin, and deep gray matter infarcts (relative risk 1.18; 95% CI, 1.03–1.35) and presence of moderate-to-severe periventricular WMHs (1.21; 95% CI, 1.03–1.42), which are all manifestations of small vessel disease (SVD). The burden of enhancing vessel wall lesions was associated with the number of cortical microinfarcts only (1.48; 95% CI, 1.04–2.11). These results suggest an interrelationship between large vessel wall lesion burden and cerebral parenchymal manifestations often linked to SVD or, alternatively, that vascular changes occur in both large and small intracranial arteries simultaneously.

Prevalence, prognosis, and treatment of atherosclerotic intracranial stenosis in Caucasians

BACKGROUND

Intracranial atherosclerotic stenosis is a highly prevalent cause of stroke worldwide with important ethnic disparities. Widely considered to be a common cause of stroke in Asian and Afro-Caribbean populations, relatively less is known about the burden and significance of intracranial atherosclerotic stenosis in Caucasians.

AIMS

We aim to highlight recent insights and advances into the prevalence, prognosis, and treatment of symptomatic and asymptomatic atherosclerotic intracranial atherosclerotic stenosis in Caucasian patients.

SUMMARY OF REVIEW

We identified 48 articles studying intracranial atherosclerotic stenosis in Caucasian patients with ischemic stroke or transient ischemic attack. Most studies were on hospital-based cohorts of consecutive patients and half were graded as "fair" quality. There was significant variation between studies in the definition of intracranial atherosclerotic stenosis and in the imaging modalities used to detect intracranial atherosclerotic stenosis. Overall, 12.1% of Caucasian patients were found to have any intracranial atherosclerotic stenosis, 6.4% symptomatic intracranial atherosclerotic stenosis and 11.1% asymptomatic intracranial atherosclerotic stenosis, with higher rates at older ages. In studies reporting prognosis, there were 61 and 10 same-territory ischemic strokes in 1000 person-years in patients with symptomatic and asymptomatic intracranial atherosclerotic stenosis, respectively. Percutaneous stenting and angioplasty have not proven superior to intensive medical management in patients with symptomatic intracranial atherosclerotic stenosis.

CONCLUSIONS

Intracranial atherosclerotic stenosis has previously been neglected as a cause of stroke in Caucasians but is highly prevalent at older ages and frequently discovered with the growing use of noninvasive angiography. Intensive medical therapy is the treatment of choice, but there is a need to develop novel treatments or therapeutic approaches to lower the risk of stroke in higher risk patients.

High-Resolution Magnetic Resonance Vessel Wall Imaging for the Evaluation of Intracranial Vascular Pathology

Intracranial vessel wall imaging (IVWI) is an advanced MR imaging technique that allows for direct visualization of the walls of intracranial blood vessels and detection of subtle pathologic vessel wall changes before they become apparent on conventional luminal imaging. When performed correctly, IVWI can increase diagnostic confidence, aid in the differentiation of intracranial vasculopathies, and assist in patient risk stratification and prognostication. This review covers the essential technical underpinnings of IVWI and presents emerging clinical research highlighting its utility for the evaluation of multiple intracranial vascular pathologies.

Evaluation of Cerebral Blood Flow Dynamics in Transient Ischemic Attacks Patients with Fast Cine Phase Contrast Magnetic Resonance Angiography

Fast cine phase contrast magnetic resonance angiography (PC-MRA) has the potential to provide a quantitative measurement method for the diagnosis and treatment of cerebrovascular disease. To evaluation the changes of cerebral blood flow and the characteristics of artery lesion distribution in the patients of transient ischemic attacks (TIA). In all, 98 normal subjects and 106 TIA patients who underwent MRI examination within 72 h after the last symptom onset including the DWI sequence to exclude acute cerebral infarction were enrolled. The blood flow of the cranial total, the area of the internal carotid artery and vertebral artery, the average velocity, and the average blood flow were obtained and compared in normal subjects and TIA group. Analysis of Variance (ANOVA), t-test, and Kruskal-Wallis test were used for statistical assessments. The total cerebral blood flow of the TIA group and normal control group was no significant statistical difference (P > 0.05). The total blood flow decreased with increasing age, and the TIA group was much lower than the control group. The blood flow of the right internal carotid artery in the TIA group had a significant difference compared with controls (P < 0.05). However, the same situation did not happen in both of the left internal carotid artery and vertebral artery. Phase contrast magnetic resonance imaging has the potential to evaluate the change of cerebral blood flow in TIA patients. The decrease in the total blood flow and the symptom onset of TIA is consistent. Phase contrast magnetic resonance imaging could provide guidance to the diagnosis of TIA.

Hemodynamics is associated with vessel wall remodeling in patients with middle cerebral artery stenosis

OBJECTIVES

To evaluate the relationship between hemodynamics and vessel wall remodeling patterns in middle cerebral artery (MCA) stenosis based on high-resolution magnetic resonance imaging and computational fluid dynamics (CFD).

METHODS

Forty consecutive patients with recent ischemic stroke or transient ischemic attack attributed to unilateral atherosclerotic MCA stenosis (50-99%) were prospectively recruited. All patients underwent a cross-sectional scan of the stenotic MCA vessel wall. The parameters of the vessel wall, the number of patients with acute infarction, translesional wall shear stress ratio (WSSR), wall shear stress in stenosis (WSSs), and translesional pressure ratio were obtained. The patients were divided into positive remodeling (PR) and negative remodeling (NR) groups. The differences in vessel wall parameters and hemodynamics were compared. Correlations between the parameters of the vessel wall and hemodynamics were calculated.

RESULTS

Of the 40 patients, 16 had PR, 19 had NR, and the other 5 displayed non-remodeling. The PR group had a smaller lumen area (p = 0.004), larger plaque area (p < 0.001), normal wall index (p = 0.004), and higher WSSR (p = 0.004) and WSSs (p = 0.023) at the most narrowed site. The PR group had more enhanced plaques (12 vs 6, p = 0.03). The number of patients with acute stroke in the PR group was more than that in the NR group (11 vs 4, p = 0.01). The remodeling index (r = 0.376, p = 0.026) and plaque area (r = 0.407, p = 0.015) showed a positive correlation with WSSR, respectively.

CONCLUSIONS

Hemodynamics plays a role in atherosclerotic plaques and vessel wall remodeling. Individuals with greater hemodynamic values might be more prone to stroke.

KEY POINTS

• Stenotic plaques in middle cerebral artery with positive remodeling have smaller lumen area and larger resp. higher plaque area, normal wall index, translesional wall shear stress ratio, and wall shear stress than negative remodeling. • The remodeling index and plaque area are positively correlated with translesional wall shear stress ratio. • Hemodynamic may help to understand the role of positive remodeling in the development of acute stroke.

Acute ischemic stroke versus transient ischemic attack: Differential plaque morphological features in symptomatic intracranial atherosclerotic lesions

BACKGROUND AND AIMS

Intracranial atherosclerotic disease (ICAD) is a major etiologic cause for acute ischemic stroke (AIS) and transient ischemic attack (TIA). The study was designed to investigate if differential morphological features exist in symptomatic atherosclerotic lesions between AIS and TIA patients.

METHODS

The culprit plaques from 45 AIS patients and 42 TIA patients were analyzed for the degree of stenosis, vessel wall irregularity, normalized wall index (NWI), remodeling index, plaque-wall contrast ratio (CR), high signal intensity on T1-weighted images, plaque enhancement ratio and enhancement grade. These plaque features along with clinical characteristics were compared between AIS and TIA groups as well as between their stenosis degree-matched subgroups.

RESULTS

Overall, grade 2 enhancement (OR 3.85, 95%CI 1.42-10.46, p = 0.006) and hyperlipidemia (OR 3.04, 95%CI 1.13-8.22, p = 0.025) were independent indicators for AIS, whereas high NWI (OR 1.47, 95%CI 0.76-2.86, p = 0.004) was associated with TIA. In the comparison between the subgroups with moderate (30%-69%) stenosis, high plaque-wall CR (OR 5.38, 95%CI 1.39-20.75, p = 0.008) was associated with AIS, whereas high NWI (OR 2.50, 95%CI 0.61-10.00, p = 0.006) was associated with TIA.

CONCLUSIONS

Our study reveals differential morphological features in symptomatic ICAD lesions between AIS and TIA patients. Probing these features with MR vessel wall imaging may provide insights into the prognosis of patients with ICAD.

CYP2C19 Loss-of-Function is Associated with Increased Risk of Ischemic Stroke after Transient Ischemic Attack in Intracranial Atherosclerotic Disease

OBJECTIVES

Intracranial atherosclerotic disease (ICAD) is responsible for 8-10% of acute ischemic strokes, and resistance to antiplatelet therapy is prevalent. CYP2C19 gene loss-of-function (up to 45% of patients) causes clopidogrel resistance. For patients with asymptomatic ICAD and ICAD characterized by transient ischemic attack (TIA), this study measures the effect of CYP2C19 loss-of-function on ischemic stroke risk during clopidogrel therapy.

MATERIALS AND METHODS

From a deidentified database of medical records, patients were selected with ICD-9/10 code for ICAD, availability of CYP2C19 genotype, clopidogrel exposure, and established patient care. Dual-antiplatelet therapy patients were included. Patients with prior ischemic stroke, other neurovascular condition, intracranial angioplasty/stenting, or observation time <1 month were excluded. Time-to-event analysis using Cox regression was conducted to model first-time ischemic stroke events based on CYP2C19 loss-of-function allele and adjusted for age, gender, race, length of aspirin, length of concurrent antiplatelet/anticoagulant treatment, diabetes, coagulopathy, hypertension, heart disease, atrial fibrillation, and lipid disorder. Subset analyses were performed for asymptomatic and post-TIA subtypes of ICAD.

RESULTS

A total of 337 patients were included (median age 68, 58% male, 88% Caucasian, 26% CYP2C19 loss-of-function). A total of 161 (47.8%) patients had TIA at time of ICAD diagnosis, while 176 (52.2%) were asymptomatic. First-time ischemic stroke was observed among 20 (12.4%) post-TIA ICAD patients and 17 (9.7%) asymptomatic ICAD patients. Median observation time was 2.82 [IQR 1.13-5.17] years. CYP2C19 loss-of-function allele was associated with ischemic stroke event (HR 2.2, 95% CI 1.1-4.3, p=0.020) after adjustment. Post-TIA ICAD patients had a higher risk of ischemic stroke from CYP2C19 loss-of-function (HR 3.4, 95% CI 1.4-8.2, p=0.006).

CONCLUSIONS

CYP2C19 loss-of-function was associated with 3-fold increased risk of first-time ischemic stroke for ICAD patients treated with clopidogrel after TIA. This effect was not observed for asymptomatic ICAD. CYP2C19-guided antiplatelet selection may improve stroke prevention in ICAD after TIA.

Instantaneous Wave-Free Ratio Measurement During Intracranial Submaximal Angioplasty: Case Series and 2-Dimensional Operative Video

BACKGROUND

Instantaneous wave-free ratios (iFRs) are functional measures of arterial stenosis that have become essential to interventional cardiology procedures. Their use for intracranial submaximal angioplasty (angioplasty with an undersized balloon) has not been studied extensively.

OBJECTIVE

To describe the feasibility and technique of iFR measurement for stenosis assessment during intracranial angioplasty.

METHODS

We present a series of consecutive patients treated between January 1, 2017 and June 30, 2018 with submaximal intracranial angioplasty in whom pre- and postprocedure iFR measurements were obtained with a Verrata-Volcano pressure wire (Philips, Amsterdam, The Netherlands). We collected patient data on age, sex, comorbid conditions, presenting complaints, modified Rankin scale (mRS) score at admission, neurological findings, procedure duration, fluoroscopy time, intraprocedural complications, length of hospital stay, and mRS score at last clinical follow-up (favorable outcome, 0-2). Angiographic stenosis severity and iFR values were recorded before and after angioplasty.

RESULTS

A total of 12 patients underwent iFR-guided angioplasty during the study period. The median patient age was 69.5 yr (range 48-81 yr). All patients had symptomatic intracranial arterial stenosis (3-basilar, 2-vertebral, 6-middle cerebral, 1-internal carotid). Preangioplasty stenosis ranged from 55% to 90%. The median postangioplasty reduction in stenosis was 17% (range 9%-30%). Preangioplasty values ranged from 0.30 to 0.40 (n = 4). Postangioplasty values ranged from 0.6 to 0.9 (n = 5). iFR values improved considerably in all patients. No procedure-related complications occurred. The median follow-up was 8.9 mo (range 3-25 mo). Follow-up outcomes were favorable in 10 patients.

CONCLUSION

iFR measurement before and after intracranial angioplasty is feasible. It may be used to assess the adequacy of intracranial angioplasty.

Association of carotid and intracranial stenosis with Alzheimer's disease biomarkers

Background

To clarify whether atherosclerosis of the carotid and intracranial arteries is related to Alzheimer’s disease (AD) pathology in vivo, we investigated the associations of carotid and intracranial artery stenosis with cerebral beta-amyloid (Aβ) deposition and neurodegeneration in middle- and old-aged individuals. Given different variations of the pathologies between cognitive groups, we focused separately on cognitively normal (CN) and cognitively impaired (CI) groups.

Methods

A total of 281 CN and 199 CI (mild cognitive impairment and AD dementia) subjects underwent comprehensive clinical assessment, [¹¹C] Pittsburgh compound B-positron emission tomography, and magnetic resonance (MR) imaging including MR angiography. We evaluated extracranial carotid and intracranial arteries for the overall presence, severity (i.e., number and degree of narrowing), and location of stenosis.

Results

We found no associations between carotid and intracranial artery stenosis and cerebral Aβ burden in either the CN or the CI group. In terms of neurodegeneration, exploratory univariable analyses showed associations between the presence and severity of stenosis and regional neurodegeneration biomarkers (i.e., reduced hippocampal volume [HV] and cortical thickness in the AD-signature regions) in both the CN and CI groups. In confirmatory multivariable analyses controlling for demographic covariates and diagnosis, the association between number of stenotic intracranial arteries ≥ 2 and reduced HV in the CI group remained significant.

Conclusions

Neither carotid nor intracranial artery stenosis appears to be associated with brain Aβ burden, while intracranial artery stenosis is related to amyloid-independent neurodegeneration, particularly hippocampal atrophy.

Hyperglycemia, duration of diabetes, and intracranial atherosclerotic stenosis by magnetic resonance angiography: The ARIC-NCS study

AIMS

The association of hyperglycemia and duration of diabetes with intracranial atherosclerotic stenosis (ICAS) in the general population is not well documented. We examined whether elevated glucose and longer diabetes duration is independently associated with ICAS in a community-based sample.

METHODS

We cross-sectionally analyzed 1644 participants (age 67-90 years) of the Atherosclerosis Risk in Communities Study who underwent cerebrovascular magnetic resonance angiography in 2011-13. We applied multivariable ordinal logistic regression to evaluate the association of ICAS category ("no stenosis", "stenosis <50%", or "stenosis ≥50%") with glucose or diabetes duration (<10, 10 to 20, and ≥20 years). We also obtained the corresponding odds ratios applying inverse-probability weighting to account for potential selection bias due to attrition.

RESULTS

Compared to non-diabetic participants in the lowest glucose quartile, the weighted odds ratios (95% confidence interval) of higher ICAS category were 1.88 (1.18, 3.00) and 2.01 (1.08, 3.72) for non-diabetic and diabetic participants in the corresponding highest glucose quartile, respectively. We observed significant positive trends of ICAS across diabetes duration categories in unweighted, but not in weighted, analyses.

CONCLUSIONS

Hyperglycemia and longer duration of diabetes were independently associated with ICAS, suggesting the importance of maintaining glycemic control to prevent stroke.

Feasibility and Safety of Paclitaxel-Coated Balloon Angioplasty for the Treatment of Intracranial Symptomatic In-Stent Restenosis

Objective: Symptomatic in-stent restenosis (sISR) is the major cause of medium- or long-term cerebral infarctions in patients who underwent percutaneous transluminal angioplasty and stenting for severe intracranial atherosclerotic stenosis. This study aims to evaluate the feasibility and safety of paclitaxel-coated balloon (PCB) angioplasty for the treatment of intracranial sISR. Methods: We report 11 cases of PCB angioplasty for intracranial sISR. Lesion locations and number were as follows: intracranial internal carotid artery (n = 4), M1 segment of middle cerebral artery (MCA) (n = 1), V4 segment of vertebral artery (n = 6). The technical success rate, periprocedural complications, and short-term outcome were retrospectively analyzed. Results: All procedures were successfully performed without periprocedural complication. Asymptomatic vessel dissection after PCB inflation occurred in one case. Postprocedural diffusion-weighted imaging (DWI) showed new asymptomatic ipsilateral infarction in one case. All 11 cases did not experience ipsilateral stroke or death within 30 days or ischemic stroke in the territory of the target artery between 31 and 90 days after procedure. Conclusion: This preliminary study indicates that PCB angioplasty is feasible and safe for the treatment of intracranial sISR. Further studies are needed to clarify its efficiency and long-term outcome.

Endovascular therapy versus medical treatment for symptomatic intracranial artery stenosis

BACKGROUND

Intracranial atherosclerotic stenosis (ICAS) is an arterial narrowing in the brain that can cause stroke. Endovascular therapy and medical management may be used to prevent recurrent ischaemic stroke caused by ICAS. However, there is no consensus on the best treatment for people with ICAS.

OBJECTIVES

To compare the safety and efficacy of endovascular therapy (ET) plus conventional medical treatment (CMT) with CMT alone for the management of symptomatic ICAS.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (30 August 2019), Cochrane Central Register of Controlled Trials (CENTRAL: to 30 August 2019), MEDLINE Ovid (1946 to 30 August 2019), Embase Ovid (1974 to 30 August 2019), Scopus (1960 to 30 August 2019), Science Citation Index Web of Science (1900 to 30 July 2019), Academic Source Complete EBSCO (ASC: 1982 to 30 July 2019), and China Biological Medicine Database (CBM: 1978 to 30 July 2019). We also searched the following trial registers: ClinicalTrials.gov, WHO International Clinical Trials Registry Platform, and Stroke Trials Registry. We also contacted trialists and researchers where additional information was required.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing ET plus CMT with CMT alone for the treatment of symptomatic ICAS. ET modalities included angioplasty alone, balloon-mounted stent, and angioplasty followed by placement of a self-expanding stent. CMT included antiplatelet therapy in addition to control of risk factors such as hypertension, hyperlipidaemia, and diabetes.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened trials to select potentially eligible RCTs and extracted data. Any disagreements were resolved by discussing and reaching consensus decisions with the full team. We assessed risk of bias and applied the GRADE approach to assess the quality of the evidence. The primary outcome was death of any cause or non-fatal stroke of any type within three months of randomisation. Secondary outcomes included any-cause death or non-fatal stroke of any type more than three months of randomisation, ipsilateral stroke, type of recurrent event, death, restenosis, dependency, and health-related quality of life.

MAIN RESULTS

We included three RCTs with 632 participants who had symptomatic ICAS with an age range of 18 to 85 years. The included trials had high risks of performance bias and other potential sources of bias due to the impossibility of blinding of the endovascular intervention and early termination of the trials. Moreover, one trial had a high risk of attrition bias because of the high rate of loss of one-year follow-up and the high proportion of participants transferred from endovascular therapy to medical management. The quality of evidence ranged from low to moderate, downgraded for imprecision. Compared to CMT, ET probably results in a higher rate of 30-day death or stroke (risk ratio (RR) 3.07, 95% confidence interval (CI) 1.80 to 5.24; 3 RCTs, 632 participants, moderate-quality evidence), 30-day ipsilateral stroke (RR 3.54, 95% CI 1.98 to 6.33; 3 RCTs, 632 participants, moderate-quality evidence), 30-day ischaemic stroke (RR 2.52, 95% CI 1.37 to 4.62; 3 RCTs, 632 participants, moderate-quality evidence), and 30-day haemorrhagic stroke (RR 15.53, 95% CI 2.10 to 115.16; 3 RCTs, 632 participants, low-quality evidence). ET was also likely associated with a worse outcome in one-year death or stroke (RR 1.69, 95% CI 1.21 to 2.36; 3 RCTs, 632 participants, moderate-quality evidence), one-year ipsilateral stroke (RR 2.28, 95% CI 1.52 to 3.42; 3 RCTs, 632 participants, moderate-quality evidence), one-year ischaemic stroke (RR 2.07, 95% CI 1.37 to 3.13; 3 RCTs, 632 participants, moderate-quality evidence), and one-year haemorrhagic stroke (RR 10.13, 95% CI 1.31 to 78.51; 2 RCTs, 521 participants, low-quality evidence). There were no significant differences between ET and CMT in 30-day transient ischaemic attacks (TIA) (RR 0.52, 95% CI 0.11 to 2.35, P = 0.39; 2 RCTs, 181 participants, moderate-quality evidence), 30-day death (RR 5.53, 95% CI 0.98 to 31.17, P = 0.05; 3 RCTs, 632 participants, low-quality evidence), one-year TIA (RR 0.82, 95% CI 0.32 to 2.12; 2 RCTs, 181 participants, moderate-quality evidence), one-year death (RR 1.20, 95% CI 0.50 to 2.86, P = 0.68; 3 RCTs, 632 participants, moderate-quality evidence), and one-year dependency (RR 1.90, 95% CI 0.91 to 3.97, P = 0.09; 3 RCTs, 613 participants, moderate-quality evidence). No data on restenosis and health-related quality of life for meta-analysis were available from the included trials. Two RCTs are ongoing.

AUTHORS' CONCLUSIONS

This systematic review provides moderate-quality evidence showing that ET, compared with CMT, in people with recent symptomatic severe intracranial atherosclerotic stenosis probably does not prevent recurrent stroke and appears to carry an increased hazard. The impact of delayed ET intervention (more than three weeks after a qualifying event) is unclear and may warrant further study.

Plaque characteristics of middle cerebral artery assessed using strategically acquired gradient echo (STAGE) and vessel wall MR contribute to misery downstream perfusion in patients with intracranial atherosclerosis

OBJECTIVES

To assess plaque vulnerability of the middle cerebral artery (MCA) using strategically acquired gradient echo (STAGE) versus high-resolution vessel wall MRI (hr-vwMRI), and explore the relationship between plaque characteristics and misery downstream perfusion.

METHODS

Ninety-one patients with single MCA atherosclerotic plaques underwent STAGE and hr-vwMRI were categorized into a group with misery perfusion and a group without based on the Alberta Stroke Program Early CT score (MTT-ASPECTS) with a threshold of 6. Plaque characteristics including inner lumen area (IWA), susceptibility, presence of hyperintensity within plaque (HIP), surface irregularity, stenosis degree, remodeling index, lipid ratio, and enhancement grade were compared between the two groups. The vulnerability of each plaque was retrospectively assessed on both STAGE and hr-vwMRI according to the combination of plaque features. Logistic regression analysis and ROC curve were performed to evaluate the effect of plaque characteristics on the presence of misery perfusion.

RESULTS

Taking hr-vwMRI as the reference, STAGE showed good efficiency in detecting vulnerable plaques. Patients with misery perfusion had less IWA, higher stenosis degree, more irregular surface and HIP, higher enhancement grade, and susceptibility (p < 0.01 for all). Higher susceptibility and stenosis degree were independent predictors for the occurrence of misery perfusion (p = 0.025, p = 0.048). The AUC was 0.900 for the combination of the two variables.

CONCLUSION

STAGE shows good efficiency to assess MCA plaque vulnerability versus hr-vwMRI. Plaque susceptibility evaluated using STAGE provides incremental value to predict misery perfusion combined with hr-vwMRI plaque features.

KEY POINTS

• STAGE has good efficiency in evaluating MCA plaque vulnerability versus hr-vwMRI. • Higher plaque susceptibility assessed using STAGE and higher grade luminal stenosis based on hr-vwMRI attribute to misery downstream perfusion. • STAGE provides incremental value on the understanding of plaque vulnerability in addition to conventional hr-vwMRI.

Intracranial vessel wall imaging: applications, interpretation, and pitfalls

Vessel wall imaging (VWI) is being increasingly used as a non-invasive diagnostic method to evaluate the intra- and extracranial vascular bed. Whereas conventional vascular imaging primarily assesses the vessel lumen, VWI changes the focus of analysis toward the vessel wall. As the technical challenges of high spatial resolution, signal-to-noise ratio, and contrast-to-noise ratio and long scans times are addressed, interest in the clinical applications of this technique has steadily increased over the years. In this review, the authors will discuss the various applications of VWI as well as principles of interpretation and common imaging findings, focusing on intracranial atherosclerosis, vascular dissection, vasculitides (such as primary angiitis of the central nervous system (PACNS) and neurosarcoidosis), vasculopathies (such as reversible cerebral vasoconstriction syndrome (RCVS), cocaine-induced vasculopathy, moyamoya disease, and radiation-induced arteriopathy), aneurysms, and post-thrombectomy changes. The authors will also discuss the potential pitfalls of VWI and helpful cues to avoid being tricked.

Optical coherence tomography evaluation of vertebrobasilar artery stenosis: case series and literature review

BACKGROUND

Intracranial vertebrobasilar artery stenosis is an important cause of ischemic stroke. With its high resolution, intravascular optical coherence tomography (OCT) provides detailed assessment of vessel wall features. It is widely applied to identify high-risk plaque in the cardiovascular system, but its use in the intracranial artery has been limited.

OBJECTIVE

To explore, in this pilot study, the usefulness of OCT in imaging of the intracranial artery wall.

METHODS

Between November 2017 and July 2018, four patients with severe intracranial vertebrobasilar artery stenosis were enrolled for preintervention OCT evaluation of the lesion artery. Stenosis was present in the basilar artery in one case and in the intracranial vertebral artery in three cases.

RESULTS

OCT images of the lesions showed various features of plaque vulnerability, such as intraluminal thrombus, lipid-rich plaque with plaque rupture, thin fibrous cap, macrophage accumulations, and a mixed lesion with dissecting aneurysm. In view of the OCT findings, all patients received balloon angioplasty and stent implantation.

CONCLUSIONS

These cases describe the successful implementation of OCT in intracranial vertebrobasilar artery stenosis. No side effects were seen during the OCT imaging. This technology may help in the diagnosis and treatment of cerebrovascular disease.

Effect of atherosclerosis and the protective effect of the antioxidant vitamin E on the rabbit cerebellum

BACKGROUND

Atherosclerosis is a major cardiovascular disease and one of the commonest causes of mortality in the world. Speech, balance, fine motor control and cognition are affected by atherosclerosis of cerebellar arteries. This study investigated the protective role of vitamin E against induced atherosclerosis in the rabbit cerebellum.

MATERIALS AND METHODS

Forty Rex New Zealand adult male rabbits were randomly divided into four groups (10 rabbits each). Group I was designated as the control and received an ordinary diet. Group II received an ordinary diet, but with vitamin E (12 mg/kg/day) added. Group III were given an ordinary diet along with 1% cholesterol powder for 6 weeks. Finally, group IV received an ordinary diet with both 1% cholesterol powder and vitamin E (12 mg/kg/day). Cerebellum samples were stained with haematoxylin and eosin and examined using light microscopy, along with quantitative immunohistochemical assessments of the expression of caspase-3, glial fibrillary acidic protein (GFAP) and inducible nitric oxide synthase (iNOS).

RESULTS

Cerebellum sections from cholesterol-treated rabbits showed ischaemic changes as fibre density decreased, with vacuolation of the molecular layer, and deformed and shrunken Purkinje cells. A significant increase in caspase-3, GFAP and iNOS immunoreactivity was found. However, vitamin E administration reduced these ischaemic manifestations.

CONCLUSIONS

The results demonstrate the neurological protective role of vitamin E therapy in atherosclerosis.

Intracranial Atherosclerosis and Stage 1 Hypertension Defined by the 2017 ACC/AHA Guideline

BACKGROUND

In 2017, the American College of Cardiology (ACC)/American Heart Association (AHA) released a new, stricter definition of stage 1 hypertension which was previously considered prehypertension. However, impacts of the novel stage 1 hypertension on deleterious target-organ outcomes are still controversial. In this study, we evaluated the relationship between this newly defined stage 1 hypertension and the presence of intracranial atherosclerosis (ICAS) lesions in neurologically healthy participants.

METHODS

We assessed consecutive participants in routine health checkups between January 2006 and December 2013. Blood pressure (BP) was classified according to the 2017 ACC/AHA hypertension guideline, and ICAS was defined as occlusion or ≥50% stenosis of intracranial vessels on flight magnetic resonance angiography.

RESULTS

Among 3,111 healthy participants (mean age: 56 years, sex: 54% men), 85 (3%) had ICAS lesions. In multivariate analysis, stage 1 hypertension (adjusted odds ratio: 2.46, 95% confidence interval: 1.10-5.51, P = 0.029) remained an independent predictor of ICAS after adjustment for confounders. Stage 2 hypertension showed a higher odds ratio and a lower P value, indicating a dose-response effect. Age and HbA1c level were also significantly associated with ICAS, independent of the BP categories. The ICAS lesion burden showed a dose-response effect across the BP categories (P for trend <0.001), whereas ICAS lesion location did not (P for trend = 0.699).

CONCLUSIONS

We demonstrated that stage 1 hypertension, defined according to the 2017 ACC/AHA guideline, was associated with a higher prevalence and burden of ICAS lesions in a neurologically healthy population.