Remote ischemic conditioning improves cerebral hemodynamics in symptomatic intracranial atherosclerosis: A PET/CT-guided randomized controlled study.

Patients with symptomatic intracranial arterial stenosis (sICAS) suffer embarrassed hemodynamic status and acute ischemic stroke (AIS) recurrence. We aimed to assess the efficacy of remote ischemic conditioning (RIC) on improving this status by evaluating cerebral blood flow (CBF) and cerebral glucose metabolism (CGM) via PET/CT. Adult patients with unilateral sICAS in middle cerebral artery and/or intracranial segment of internal carotid artery-related AIS or transient ischemic attack within 6 months prior to randomization were enrolled. Individuals who received intravenous thrombolysis or endovascular treatment, or sICAS caused by cardiac embolism, small vessel occlusion, or other determined causes were excluded. Twenty-three eligible patients were randomly assigned to standard medical treatment (SMT) (n = 10) or RIC group (n = 13). The RIC protocol consisted of 5 cycles, each for 5-min bilateral upper limb ischemia and 5-min reperfusion period, twice a day, with a total duration of 3 months. Ten healthy volunteers were enrolled as healthy control group. We tested CBF and CGM at the rest stage and the methazolamide-induced stress stage. All patients received PET/CT at baseline and three-month followup. Both CBF and CGM in ipsilateral hemisphere of sICAS patients were significantly decreased at the rest stage and the stress stage (p < .05), which were improved by three-month RIC (p < .05). The lesions decreased notably in RIC group compared to SMT group (p < .05). RIC ameliorated the hemodynamic status and glucose metabolism in regions at high risk of infarction, which might improve the resistance capacity towards ischemic load in sICAS patients.

Association between atherogenic index of plasma and asymptomatic intracranial arterial stenosis in middle-aged and elderly women: A cross-sectional study in Shandong, China.

BACKGROUND AND AIMS: The atherogenic index of plasma (AIP) is associated with progression of atherosclerosis and used to describe how pro- or anti-atherogenic components are balanced. However, the association of AIP with asymptomatic intracranial arterial stenosis (aICAS) is uncertain. The purpose of this study is to investigate the association between AIP and aICAS in rural China. METHODS AND RESULTS: A total of 1990 participants aged ≥40 years free of stroke or transient ischemic attack were enrolled in this study. The presence of aICAS was examined by Transcranial Doppler ultrasound and confirmed by magnetic resonance angiography. The adjusted AIP (aAIP) was calculated according to the ratio of TG and HDL-C and further separated into 4 quartiles. Multiple logistic regression was used to investigate the association between aAIP and aICAS, and the dose-response relationship was explored by restricted cubic spline. After adjusting for conventional confounders, aAIP was significantly higher in the aICAS group than that in the non-aICAS group. Furthermore, the common odds ratios for aICAS risk increased with increasing aAIP quartiles. Multivariate logistic regression revealed that aAIP was independently associated with aICAS in female or middle-aged and elderly (age ≥50 years), and superior to other lipid profiles. Multiple-adjusted spline regression showed the dose-response association between aAIP levels and aICAS prevalence. CONCLUSIONS: AIP might be independently and positively associated with the prevalence of aICAS in middle-aged and elderly women, which might be superior to traditional and nontraditional lipid profiles in rural China.

Diagnostic value of high-resolution vessel wall imaging technique in intracranial arterial stenosis and occlusion: a comparative analysis with digital subtraction angiography.

OBJECTIVE: To analyze the diagnostic value of HR-VWI in intracranial arterial stenosis and occlusion and compare it with DSA. METHODS: A retrospective analysis of clinical data of 59 patients with intracranial arterial stenosis in our hospital was conducted to compare the diagnostic results of the two methods for different degrees of intracranial stenosis and various morphological plaques. RESULTS: The diagnosis of stenosis and occlusion by both methods showed no significant difference (p > 0.05). Comparison of plaque morphology detected by HR-VWI with pathological examination results showed no significant difference (p > 0.05); however, there was a significant difference between plaque morphology detected by DSA and pathological examination results (p < 0.05). Additionally, there was a significant difference between plaque morphology detected by HR-VWI and DSA (p < 0.05). CONCLUSION: HR-VWI technique is comparable to DSA technique in diagnosing intracranial arterial stenosis and occlusion, but it is superior to DSA in plaque morphology diagnosis.

Homocysteine Associated With Low Cognitive Function Independent of Asymptomatic Intracranial and Carotid Arteries Stenoses in Chinese Elderly Patients: An Outpatient-Based Cross-Sectional Study.

INTRODUCTION: A high homocysteine (Hcy) concentration is correlated with cognitive impairment; however, the exact underlying mechanism is still not fully elucidated. The present study aimed to investigate whether asymptomatic intracranial and carotid arteries stenoses are involved in Hcy-related low cognitive function. METHODS: This was a cross-sectional study in outpatient clinics. Residents aged ≥60 years, who came to the Stroke and Rehabilitation Clinic of Shandong Provincial Third Hospital in Jinan, Shandong Province from December 2019 to May 2020 to seek consultation due to abnormal transcranial Doppler reports (eg., increased cerebral blood flow velocity) were eligible. Information including demographics, medical history, lifestyle habits were collected. Fasting blood was used to detect total serum homocysteine level (tHcy). Cerebrovascular magnetic resonance angiography and neck vascular ultrasound examination were used to confirm the diagnosis of intracranial and carotid artery stenoses. The Mini-Mental State Examination was used to assess the cognitive function of each participant. Logistic regression was used to evaluate the relationship between tHcy levels and cognitive function. RESULTS: This study included 236 participants (mean age: 64.0 (SD, 7.5) years, female: 58.1%). Multivariable analyses adjusted for several potential confounders, including creatinine and cardiovascular risk factors, showed that tHcy was associated with carotid artery stenosis (CAS). After adjusting for CAS, ICAS and several potential confounders, the association between tHcy level and low cognitive function remained significant (odds ratio: 1.09, 95% confidence interval: (1.03, 1.16), P = 0.032) . CONCLUSION: Increased serum tHcy level was associated with low cognitive function independent of asymptomatic intracranial and carotid arteries stenoses.

Association Between Intracranial Pulsatility and White Matter Hyperintensities in Asymptomatic Intracranial Arterial Stenosis: A Population-Based Study in Shandong, China.

OBJECTIVES: The effects of increased intracranial pulsatility on the severity of white matter hyperintensities (WMH) in participants with asymptomatic intracranial arterial stenosis (aICAS) remain uncertain. We aimed to investigate whether an increased pulsatility index (PI) is associated with WMH volume (WMHV) in individuals with aICAS. MATERIALS AND METHODS: All participants were recruited from the Kongcun Town aICAS Study, including a total of 103 participants with aICAS and 98 healthy controls (age- and sex-matched). PI was assessed using transcranial Doppler ultrasound. The WMHV was calculated through the lesion segmentation tool system for the Statistical Parametric Mapping package based on magnetic resonance imaging. The association between PI and lnWMHV was analyzed by linear regression models adjusting for demographics, lifestyle, and vascular risk factors. RESULTS: The lnWMHV and PI between the aICAS and control groups showed no significant differences (P = 0.171 and 0.287, respectively). In a multivariable model, age ≥ 60 years and male sex (P = 0.000 and 0.006, respectively) were significant predictors of lnWMHV in the aICAS group. In sex-stratified analyses, there was a significant association between PI and lnWMHV in males with aICAS (P = 0.038). CONCLUSIONS: This study suggest there might be a likely association between increased intracranial pulsatility and WMH burden in males with aICAS.

Association of triglyceride-glucose index and high-sensitivity C-reactive protein with asymptomatic intracranial arterial stenosis: A cross-sectional study.

BACKGROUND AND AIMS: Triglyceride-glucose index (TyG) and high-sensitivity C-reactive protein (hsCRP) have been shown to play important roles in the pathophysiological mechanisms of atherogenesis. However, the cumulative value of TyG and hsCRP in identifying asymptomatic intracranial arterial stenosis (aICAS), as well as its severity and numerical burden, is uncertain. This study seeks to fill this knowledge gap. METHODS AND RESULTS: This study included 1938 participants aged ≥40 years who were free of stroke or transient ischemic attack. All participants were classified into four groups based on the participants' TyG and hsCRP levels, including low-TyG and low-hsCRP, low-TyG and high-hsCRP, high-TyG and low-hsCRP, and high-TyG and high-hsCRP groups. The presence of aICAS was screened via transcranial Doppler ultrasound and confirmed by magnetic resonance angiography. The TyG was calculated as ln [fasting triglyceride (mg/dL) × fasting glucose (mg/dL)/2]. We used multinomial logistic regression analysis to investigate the cumulative value of TyG and hsCRP on identifying the severity of aICAS or its numerical burden. After adjustment for conventional confounders, isolated high-hsCRP, isolated high-TyG, and high-TyG combined with high-hsCRP were independently associated with moderate-to-severe aICAS. Compared with the low-TyG and low-hsCRP group, participants with high-TyG and high-hsCRP had a 2.6 times higher odds ratio (OR) of having a single moderate-to-severe aICAS and a 3.3 times higher OR of having multiple moderate-to-severe aICASs. CONCLUSION: The cumulative value of TyG and hsCRP may better identify moderate-to-severe aICAS as well as its numerical burden.

Endovascular Treatment of Symptomatic Intracranial Vertebrobasilar Stenosis: A 10-Year Single Centre Experience Using Balloon-Expandable Coronary Artery Stents.

BACKGROUND: Symptomatic intracranial vertebro-basilar stenoses (SIVBS) are associated with high risk of recurrent ischemic stroke, even in patients receiving the best medical treatment. Although medical treatment is still the standard of care, non-responding patients may require endovascular treatment; balloon-mounted coronary stents (BMCS) could be successfully employed. This study aims to retrospectively analyze our high volume Interventional Neurovascular center ten-year experience in the off-label use of BMCS for the treatment of SIVBS, in order to assess its feasibility and safety. METHODS: We retrospectively analyzed all consecutive patients with SIVBS treated with BMCS in the last ten years in our center. Data collected included patient demographics, stenosis location and characteristics, early (<30 days) and late (>30 days) stroke and death rates, pre-symptomatic and post-treatment modified Rankin Scale (mRS) scores. RESULTS: 42 patients (35 males, average age 65,7 ± 10,7, range 37-85) with SIVBS were treated with BMCS. Thirty-four (80,9%) patients were symptomatic despite ongoing best medical therapy; eight (19,1%) patients were treated in emergency for large vessel occlusion, due to an underlying stenosis. BMCSs were successfully deployed in all cases. The incidence of stroke and death at one month was 7,1% (3/42). The incidence of TIA, stroke and death at long-term follow-up (average time of 3 years) was 14,3% (4,7 per 100 person-years). At long-term follow-up, mRS improved in 82% of patients who underwent elective treatment. CONCLUSIONS: In our experience, the off-label use of BMCS in the endovascular treatment of SIVBS resistant to medical treatment is feasible and safe.

Impaired cerebrovascular reactivity is associated with recurrent stroke in patients with severe intracranial arterial stenosis: A C02 BOLD fMRI study.

BACKGROUND AND PURPOSE: Severe intracranial atherosclerotic stenosis (SIAS) remains at risk of recurrent ischemic events despite intensive medical management. Exhausted cerebrovascular reserve seems to be associated with higher risk of recurrent stroke. MATERIALS AND METHODS: We used whole brain MRI to estimate basal perfusion using dynamic susceptibility contrast and cerebrovascular reactivity (CVR) to hypercapnic challenge (CO2 inhalation) using BOLD contrast, in 20 patients with symptomatic SIAS (>70%) of the middle cerebral artery (MCA) or the distal internal carotid artery. We studied relationships between individual clinical, biological, radiological baseline characteristics, recurrent ischemic events, basal perfusion parameters (mean transit time, delay, time to peak, cerebral blood flow and volume), and CVR measured in MCA territories (CVRMCA), and reported using laterality indices (LI). RESULTS: Ten patients had an impaired CVR with (|LI| CVRMCA≥0.08). During a mean follow-up of 3.3 years, all recurrent ipsilateral ischemic events occurred within the first year. They were more frequent in impaired CVRMCA group (n=7/10 patients) than in normal CVRMCA group (n=1/10), with different survival curves (log rank, P=0.007). CONCLUSION: Impaired CVR is associated with an increased rate of recurrent stroke in patients with symptomatic SIAS. CVR mapping should be used as a well tolerated method to select higher-risk patients in further therapeutic trials such as endovascular procedures.

Metabolomics and Lipidomics Profiling in Asymptomatic Severe Intracranial Arterial Stenosis: Results from a Population-Based Study.

No data are available on the serum metabolomics and lipidomics profiles of people with asymptomatic intracranial arterial stenosis. We explored the characteristic metabolites of individuals with asymptomatic severe intracranial arterial stenosis (asICAS) using untargeted serum metabolomics and lipidomics analyses based on ultra-high-performance liquid chromatography high-resolution mass spectrometry (UPLC-HRMS). This case-control study included 25 participants with asICAS and 25 age- and sex-matched controls free of asICAS, who were all diagnosed by using magnetic resonance angiography and derived from the same population-based study. Serum metabolomics and lipidomics profiles were determined using UPLC-HRMS, and possible biomarker metabolites were identified. Compared with the control group, the asICAS group showed higher levels of free choline, glycerophosphocholine, uracil, taurine, and four peptide molecules and lower levels of free fatty acids, hydroxydodecanedioic acid, hydroxy valeryl carnitine, hydroxytetradecanedioic acid, and two sphingomyelin molecules. The serum metabolomics and lipidomics profiles for people with asICAS are characterized by abnormal metabolism of sphingomyelin, taurine/hypotaurine, pyrimidine, and protein (peptide). The biological changes in asICAS may mainly involve taurine/hypotaurine, glycerophospholipid, and sphingolipid metabolism pathways. Biofunctional analysis indicated that these differential metabolites were correlated with metabolic diseases such as early myocardial injury, heart failure, and diabetes.

Intracranial arterial stenosis associated with Hashimoto's disease: angiographic features and clinical outcomes.

BACKGROUND: Hashimoto's disease has reportedly been associated with stroke; however, cerebrovascular morphology and clinical course remain poorly documented. The present study aimed to determine the angiographic features and clinical outcomes of intracranial arterial stenosis (IAS) associated with Hashimoto's disease in a retrospective cohort. METHODS: Overall, 107 adult patients with IAS were screened for anti-thyroid antibodies; of these, 26 patients tested positive. The 42 affected hemispheres were classified into subgroups according to the steno-occlusion site and the development of abnormal collateral (moyamoya) vessels. These subgroups were dichotomized into moyamoya vessels positive (MM type) and negative (non-MM type). The initial presentation, IAS progression, and vascular events during the follow-up period were compared. RESULTS: The following sites of stenosis were identified: the bifurcation of the internal carotid artery in 11 (26.2%), M1 or A1 in 29 (69.0%), and more distal (M2-M4/A2-A4) in 2 (4.8%) hemispheres. Further, 17 hemispheres were categorized into the MM type and 25 were classified into the non-MM type. During the follow-up period (mean 2.5 years), IAS progression was identified in 8 (32%) hemispheres of the non-MM type and 0 (0%) hemispheres of the MM type (p = 0.041). Ischemic attacks occurred in 5 (20.0%) hemispheres of the non-MM type (4.6%/year) and 0 hemispheres of the MM type (p = 0.08). Further, 4 (23.5%) hemispheres of the MM type experienced intracerebral hemorrhage, whereas none of the non-MM type hemorrhaged (p = 0.012). CONCLUSIONS: Hashimoto's disease-associated IAS exhibits various angiographic morphologies, resulting in different clinical presentations. Screening for anti-thyroid antibodies and careful management based on vascular morphology appears important in adults with IAS.

Asymmetrical cortical vein sign predicts early neurological deterioration in acute ischemic stroke patients with severe intracranial arterial stenosis or occlusion.

BACKGROUND: Susceptibility weighted imaging (SWI) provides an approximate assessment of tissue perfusion and shows prominent hypointense cortical veins in the ischemic territory because of the increased concentration of deoxyhemoglobin. We aimed to evaluate whether asymmetrical prominent cortical vein sign (APCVS) on SWI can predict early neurological deterioration (END) in acute ischemic stroke patients with severe intracranial arterial stenosis or occlusion (SIASO). METHODS: One hundred and nine acute ischemic stroke patients with SIASO who underwent SWI were retrospectively recruited. END was defined as an increase in the National Institutes of Health Stroke Scale score ≧2 points despite standard treatment in the first 72 h after admission. The APCVS was defined as more and/or large vessels with greater signal loss than those in the opposite hemisphere on SWI. RESULTS: Thirty out of the 109 (27.5%) patients developed END. Sixty (55.0%) patients presented with APCVS on SWI. APCVS occurred in 24 (80%) patients with END, whereas it only occurred in 36 (45.6%) patients without END (P = 0.001). Patients with APCVS were more likely to have END (40.0%, vs. 12.2%, P = 0.001) than those without END. Multivariate logistic regression indicated that APCVS (OR = 4.349, 95% C.I. = 1.580-11.970, P = 0.004) was a significant predictor of END in acute ischemic stroke patients with SIASO, adjusted for previous stroke history and acute infarct volume. CONCLUSIONS: In acute ischemic stroke patients with SIASO, the APCVS might be a useful neuroimaging marker for predicting END, which suggests the importance of evaluation of perfusion status.

Transcranial color-coded sonography may indirectly reveal an intracranial meningioma.

Meningiomas are extra-axial tumors with a long-standing indolent clinical course. Sphenoid wing meningiomas may slowly grow, spreading toward the orbitofrontal and temporal regions as well as encasing the middle cerebral artery (MCA). Herein, we report the incidental finding of a sphenoid wing meningioma compressing the MCA in a patient who undergone a transcranial sonography study for recurrent speech disorders. We illustrate the associated sonographic "red flags" which should prompt to suspect an underlying compressive space-occupying lesion.

Risk factors outperform intracranial large artery stenosis predicting unfavorable outcomes in patients with stroke.

BACKGROUND: This study examined how intracranial large artery stenosis (ILAS), symptomatic and asymptomatic ILAS, and risk factors affect unfavorable outcome events after medical treatment in routine clinical practice. METHODS: This was a 24-month prospective observational study of consecutively recruited stroke patients. All participants underwent magnetic resonance angiography, and their clinical characteristics were assessed. Outcome events were vascular outcome, recurrent stroke, and death. Cox regression analyses were performed to identify potential factors associated with an unfavorable outcome, which included demographic and clinical characteristics, the risk factors, and stenosis status. RESULTS: The analysis included 686 patients; among them, 371 were assessed as ILAS negative, 231 as symptomatic ILAS, and 84 as asymptomatic ILAS. Body mass index (p < .05), hypertension (p = .01), and old infarction (p = .047) were factors relating to vascular outcomes. Hypertension was the only factor for recurrent stroke (p = .035). Poor glomerular filtration rate (< 30 mL/min/1.73 m2) (p = .011) and baseline National Institutes of Health Stroke Scale scores (p < .001) were significant predictors of death. CONCLUSIONS: This study extended previous results from clinical trials to a community-based cohort study by concurrently looking at the presence/absence of stenosis and a symptomatic/asymptomatic stenotic artery. Substantiated risk factors rather than the stenosis status were predominant determinants of adverse outcome. Although the degree of stenosis is often an indicator for treatment, we suggest risk factors, such as hypertension and renal dysfunction, should be monitored and intensively treated.

Long-Term Effects on Preventing Stroke after Endovascular Treatment or Bypass Surgery for Intracranial Arterial Stenosis.

BACKGROUND: Intracranial arterial stenosis (ICAS) is an important cause of ischemic stroke worldwide due to its higher risk of recurrence with medical therapy. Although some large randomized studies failed to show the superiority of surgical treatment compared with medical therapy, the results of medical therapy are not sufficient. There are patients who still benefit from surgical treatment. This retrospective analysis aimed to evaluate the long-term efficacy of surgical therapy with percutaneous transluminal angioplasty and/or stenting (PTA/PTAS) or extracranial-intracranial (EC/IC) bypass surgery for patients with ICAS. METHODS: Between October 2005 and December 2016, 55 ICAS patients were treated with PTA/PTAS or EC-IC bypass surgery. Their electronic medical records were retrospectively reviewed and analyzed. The primary outcome was all adverse events beyond 30 days after a revascularization procedure. RESULTS: We performed 21 cases (35%) of PTA, 4 cases (7%) of PTAS, and 34 cases (58%) of EC-IC bypass surgery and the median follow-up duration was 66 months (range 1-144 months). The occurrence rate of the primary outcome was 10.2% and only 1 patient (1.8%) experienced ipsilateral disabling ischemic stroke beyond 30 days. The long-term functional independent survival rate was 83.6%. CONCLUSIONS: We demonstrated a long-term favorable outcome of combined surgical intervention for ICAS patients with PTA/PTAS and EC-IC bypass surgery, and the result was better than previously reported outcomes of medical therapy. Additional multicenter studies are required to draw firm conclusions on the efficacy of reduction of recurrent stroke in patients with ICAS.

Catastrophic Secondary Infarctions with Onset Seizure Following Tissue Plasminogen Activator Therapy.

Fatalities following intravenous recombinant tissue-type plasminogen activator therapy have been reported. Major fatal complications following intravenous recombinant tissue-type plasminogen activator therapy include intracranial hemorrhage, aortic dissection, and extracranial bleeding. However, the possibility that intravenous recombinant tissue-type plasminogen activator therapy itself paradoxically induces synchronized multiple cerebral novel infarctions has never been considered. We herein report the first case of bilateral internal carotid artery infarction with onset seizure following intravenous recombinant tissue-type plasminogen activator therapy for a vertebral-basilar artery infarction. A 75-year-old man was transferred to our hospital and diagnosed with acute ischemic stroke in the basilar artery. His National Institute of Health Stroke Scale score was 4. The intravenous recombinant tissue-type plasminogen activator therapy was initiated 234 minutes after stroke onset because no contraindications were present. Almost 2 hours after the intravenous recombinant tissue-type plasminogen activator therapy, the patient suddenly fell into a deep coma with generalized convulsions. A huge secondary infarction was found in the bilateral anterior circulation territories, and he died 7 days after stroke onset. This case alerts clinicians to the possibility of synchronized multiple cerebral infarctions following intravenous recombinant tissue-type plasminogen activator therapy as a dangerous complication in patients with multiple severe stenoses in the cerebral arteries.

The association between serum uric acid and asymptomatic intracranial arterial stenosis in middle-aged Koreans.

BACKGROUND AND AIMS: Intracranial arterial stenosis (ICAS) is one of the most common causes of stroke, especially in Asians. Hyperuricemia has been associated with an increased risk of comorbidities such as metabolic syndrome or cardiovascular diseases. However, there are few studies focusing on the association between serum uric acid (SUA) levels and asymptomatic ICAS. The aim of this study was to explore the association between SUA and the prevalence of ICAS in middle-aged Korean health screening examinees. METHODS AND RESULTS: A cross-sectional study was performed on 9417 males and 7755 females who underwent a comprehensive health examination including transcranial Doppler (TCD) ultrasonography. The association of SUA and ICAS was analyzed using multivariate logistic regression. The prevalence of ICAS among the total examinee population was 3.55%. In females, the multivariate-adjusted odds ratio for ICAS was 1.52 (confidence interval 1.13-2.04) in the 3rd quartile of SUA and 1.45 (1.05-2.00) in the highest quartile, compared to the reference (P for trend 0.008). This trend was evident in all clinically relevant subgroups evaluated, including women with low inflammation status. SUA was not significantly associated with the prevalence of ICAS among males. In a sensitivity analysis, the multivariate-adjusted odds ratio of middle cerebral artery stenosis in females was 1.60 (1.09-2.37) in the highest quartile compared to the reference (P for trend 0.023). CONCLUSIONS: Higher SUA level was associated with increased risk of ICAS among middle-aged females but not males. A further cohort study is warranted to elucidate the effect of SUA on asymptomatic ICAS.

Impact of Side Branches on the Computation of Fractional Flow in Intracranial Arterial Stenosis Using the Computational Fluid Dynamics Method.

BACKGROUND: Computational fluid dynamics (CFD) allows noninvasive fractional flow (FF) computation in intracranial arterial stenosis. Removal of small artery branches is necessary in CFD simulation. The consequent effects on FF value needs to be judged. METHODS: An idealized vascular model was built with 70% focal luminal stenosis. A branch with one third or one half of the radius of the parent vessel was added at a distance of 5, 10, 15 and 20 mm to the lesion. With pressure and flow rate applied as inlet and outlet boundary conditions, CFD simulations were performed. Flow distribution at bifurcations followed Murray's law. By including or removing side branches, five patient-specific intracranial artery models were simulated. Transient simulation was performed on a patient-specific model, with a larger branch for validation. Branching effect was considered trivial if the FF difference between paired models (branches included or removed) was within 5%. RESULTS: Compared with the control model without a branch, in all idealized models the relative differences of FF was within 2%. In five pairs of cerebral arteries (branches included/removed), FFs were 0.876 and 0.877, 0.853 and 0.858, 0.874 and 0.869, 0.865 and 0.858, 0.952 and 0.948. The relative difference in each pair was less than 1%. In transient model, the relative difference of FF was 3.5%. CONCLUSION: The impact of removing side branches with radius less than 50% of the parent vessel on FF measurement accuracy is negligible in static CFD simulations, and minor in transient CFD simulation.

Variants in COX-2, PTGIS, and TBXAS1 Are Associated with Carotid Artery or Intracranial Arterial Stenosis and Neurologic Deterioration in Ischemic Stroke Patients.

BACKGROUND: Eicosanoids may play a role in ischemic stroke (IS). However, the association of variants in eicosanoid genes with symptomatic carotid artery or intracranial arterial stenosis and neurologic deterioration (ND) is not fully understood. The aim of the present study was to investigate the association of 11 variants in eicosanoid genes with symptomatic carotid artery or intracranial arterial stenosis and ND. METHODS: Eleven variants in eicosanoid genes were examined using mass spectrometry method in 297 IS patients. The symptomatic carotid artery or intracranial arterial stenosis was assessed by computed tomographic angiography. Platelet aggregation and platelet-leukocyte aggregates were measured. The primary outcome was ND within 10 days of admission. ND was defined as an increase of 2 or more points in National Institutes of Health Stroke Scale score. RESULTS: Among 297 IS patients, 182 (61.3%) cases had symptomatic carotid artery or intracranial arterial stenosis, and 88 (29.6%) patients experienced ND within 10 days after admission. Symptomatic carotid artery or intracranial arterial stenosis was significantly associated with higher ND (P < .001). Rs20417CC, rs41708TT, and rs5629CC were independent risk factors for symptomatic carotid artery or intracranial arterial stenosis and ND, and associated with higher platelet aggregation and platelet-leukocyte aggregates. CONCLUSIONS: Symptomatic carotid artery or intracranial arterial stenosis was associated with higher ND. Rs20417CC, rs41708TT, and rs5629CC were not only independent risk factors for symptomatic carotid artery or intracranial arterial stenosis, but also independent risk predictors for ND.

Relationship of retinal vascular caliber variation with intracranial arterial stenosis.

BACKGROUND & PURPOSE: To investigate the associations of retinal vessel parameters with intracranial arterial stenosis (ICAS) assessed by Transcranial Doppler ultrasonography. METHOD: Data on transcranial Doppler ultrasonography and quantitative retinal vessel parameters from 627 participants in a health screening program were included in this study. ICAS was defined as >50% intracranial arterial stenosis (ICAS) based on criteria modified from the stroke outcomes and neuroimaging of intracranial atherosclerosis (SONIA) trial assessed by transcranial Doppler (TCD) ultrasonography. A semi-automated computer-assisted program (Singapore I Vessel Assessment) was used to measure the retinal vascular parameters from the photographs. Multivariate analysis was performed to identify which retinal vessel parameters were associated with increased risk of ICAS. RESULTS: Among 627 participants, 24 (3.8%) had ICAS diagnosed by TCD. Subjects with ICAS had eyes with wider mean central retinal artery equivalent (CRAE) and central retinal vein equivalent (CRVE) in comparison to subjects without ICAS. Men (odds ratio [OR]:13.1, 95% confidence interval: 3.13-33.33) and a large standard deviation of mean arterial width (STDWa) were associated with ICAS (first vs. third tertile: OR ratio: 14.04, 95% confidence interval: 1.71-115.32; first vs. third tertile: OR ratio: 22.1, 95% confidence interval: 2.56-190.97) after adjusting for possible confounders. CONCLUSION: A large variation in retinal arteriolar diameter is associated with ICAS. This study suggests the possible relationship between retina vessel and early changes within the cerebrovascular network.

Blood Pressure Is the Determinant for the Increased Risk for Intracranial Arterial Stenosis in Subjects with Elevated Glycated Hemoglobin Levels: The Kangbuk Samsung Health Study.

BACKGROUND AND PURPOSE: Ischemic stroke is known to be an important vascular complication of diabetes. Intracranial arterial stenosis (ICAS) is considered as an important cause of stroke in Asians. We aimed to analyze the risk for ICAS assessed by transcranial Doppler (TCD) ultrasonography in different groups of young Korean subjects divided by glycated hemoglobin (HbA1c) levels. METHODS: This study included 10,437 participants without history of cardiovascular diseases (81.3% men, mean age 43 years) from a health screening program, in whom TCD ultrasonography was used to detect greater than 50% ICAS based on criteria modified from the SONIA (Stroke Outcomes and Neuroimaging of Intracranial Atherosclerosis) trial. The subjects were divided into 3 groups according to HbA1c levels: HbA1c < 5.7%, 5.7 ≤ HbA1c < 6.5%, and HbA1c ≥ 6.5% or under medication for diabetes. RESULTS: Among the participants, 3.0% of the subjects had ICAS. The subjects with ICAS tended to have higher mean HbA1c level compared with those without ICAS (5.8 ± .8 versus 5.7 ± .6, P = .063). The proportion of subjects with ICAS significantly increased as the HbA1c increased from the first to the third group (2.8%, 3.0%, 4.6%, P for linear trend = .022). In logistic regression analysis with ICAS as the dependent variable, the group with HbA1c ≥ 6.5% showed significantly increased odds ratio for ICAS with subjects with HbA1c < 5.7% as the reference after adjustment for confounding variables (1.575, 95% confidence interval 1.056-2.347). However, this significance disappeared with inclusion of presence of hypertension in the model. CONCLUSIONS: The risk for ICAS assessed by TCD was increased in young Korean subjects with HbA1c ≥ 6.5%. However, this significance was attenuated after adjustment for presence of hypertension, suggesting the importance of hypertension in ICAS.