Evaluation of cerebral blood flow in acute ischemic stroke patients with atrial fibrillation: A sonographic study

Seasonal Variations in Stroke and a Comparison of the Predictors of Unfavorable Outcomes among Patients with Acute Ischemic Stroke and Cardioembolic Stroke

We investigated the seasonal variations in stroke in 4040 retrospectively enrolled patients with acute ischemic stroke (AIS) admitted between January 2011 and December 2022, particularly those with cardioembolic (CE) stroke, and compared predictors of unfavorable outcomes between AIS patients and CE stroke patients. The classification of stroke subtypes was based on the Trial of ORG 10172 in Acute Stroke Treatment. Stroke occurrence was stratified by seasons and weekdays or holidays. Of all AIS cases, 18% were of CE stroke. Of all five ischemic stroke subtypes, CE stroke patients were the oldest; received the most thrombolysis and thrombectomy; had the highest initial National Institutes of Stroke Scale (NIHSS) and discharge modified Rankin Scale (mRS) scores; and had the highest rate of in-hospital complications, unfavorable outcomes (mRS > 2), and mortality. The highest CE stroke prevalence was noted in patients aged ≥ 85 years (30.9%); moreover, CE stroke prevalence increased from 14.9% in summer to 23.0% in winter. The main predictors of death in patients with CE stroke were age > 86 years, heart rate > 79 beats/min, initial NIHSS score > 16, neutrophil-to-lymphocyte ratio (NLR) > 6.4, glucose > 159 mg/dL, cancer history, in-hospital complications, and neurological deterioration (ND). The three most dominant factors influencing death, noted in not only patients with AIS but also those with CE stroke, are high initial NIHSS score, ND, and high NLR. We selected the most significant factors to establish nomograms for predicting fatal outcomes. Effective heart rhythm monitoring, particularly in older patients and during winter, may help develop stroke prevention strategies and facilitate early AF detection.

Effects of abnormal vertebral arteries and the circle of Willis on vertebrobasilar dolichoectasia: A multi-scale simulation study

BACKGROUND

Vertebrobasilar dolichoectasia is a rare cerebrovascular disease characterized by obvious extension, dilation and tortuosity of vertebrobasilar artery, and its pathophysiological mechanism is not clear. This study focused on local hemodynamic changes in basilar arteries with typical vertebrobasilar dolichoectasia, together with unbalanced vertebral arteries and abnormal structures of the circle of Willis, through multi-scale modeling.

METHODS

Three-dimensional models of 3 types of vertebrobasilar arteries were constructed from magnetic resonance images. The first type has no vertebrobasilar dolichoectasia, the second type has vertebrobasilar dolichoectasia and balanced vertebral arteries, and the third type has vertebrobasilar dolichoectasia and unbalanced vertebral arteries. A lumped parameter model of the circle of Willis was established and coupled to these three-dimensional models.

FINDINGS

The results showed that unbalanced bilateral vertebral arteries, especially single vertebral artery deletion mutation, might associate with higher wall shear stress on anterior wall of basilar artery in patients with vertebrobasilar dolichoectasia. And unbalanced bilateral vertebral arteries would increase the blood pressure in basilar artery. Meanwhile, missing communicating arteries in the circle of Willis, especially bilateral posterior communicating arteries absences, would significantly increase blood pressure in basilar artery. The unilateral absence of posterior communicating arteries would increase differences in blood flow between the left and right posterior cerebral arteries.

INTERPRETATION

This study provided a multi-scale modeling method and some preliminary results for helping understand the role of hemodynamics in occurrence and development of vertebrobasilar dolichoectasia.

Early Cerebrovascular Ultrasonography as a Predictor of Hemorrhagic Transformation After Thrombectomy

OBJECTIVES

To determine the predictive value of early transcranial color-coded sonography (TCCS) for intracranial hemorrhage (ICH) in patients with large artery occlusion (LAO) stroke of carotid circulation, who were submitted to endovascular therapy (EVT) with successful reperfusion.

MATERIALS AND METHODS

Retrospective study evaluating a cohort of consecutive stroke patients with LAO of the carotid circulation that were recanalyzed with EVT. We measured angle-corrected peak systolic velocities, end-diastolic velocities and mean flow velocities (PSV, EDV and MFV) of the symptomatic and asymptomatic middle cerebral artery (MCA). The ratio between MFV of the symptomatic MCA and MFV of the asymptomatic MCA (MCA-Ra) was calculated. Parenchymal hematoma in the 24 hours control CT was considered as ICH. Univariate associations and multivariate analyses were used to identify early independent predictors for ICH among TCCS findings.

RESULTS

We included 234 patients, mean age 72.5 (SD 12.6) years, 52.1% male. The mean time between recanalization and TCCS was 12.3 hours (range 3-22). Patients who developed postinterventional ICH showed a higher MCA-Ra (1.02 ± 0.26 vs 1.16 ± 0,21, p = 0.036). In multivariate analysis, only higher MCA-Ra remained independently associated with postinterventional ICH (OR: 6.778, 95%CI: 1.152-39.892, p = 0.034). A value of MCA-Ra ≥ 1,05 was associated with ICH, showing a sensitivity of 81.3% and a specificity of 65.9%; the AUC based of the ROC analysis was 0.688 (95% CI 0.570-0.806).

CONCLUSION

TCCS performed within the first 24 hours after stroke onset can help to predict hemorrhagic transformation in patients with LAO.

RNA Binding Protein Motif 3 Inhibits Oxygen-Glucose Deprivation/Reoxygenation-Induced Apoptosis Through Promoting Stress Granules Formation in PC12 Cells and Rat Primary Cortical Neurons

As a sensitive cold-shock protein, RNA binding protein motif 3 (RBM3) exhibits a neuroprotective function in the condition of brain injury. However, how RBM3 is involved in acute ischemic stroke by affecting stress granules (SGs) remains unclear. Here, we established an oxygen-glucose deprivation/reperfusion (OGD/R) model in rat primary cortical neurons and PC12 cells to explore the potential mechanism between RBM3 and SG formation in acute ischemic/reperfusion (I/R) condition. The immunofluorescence results showed that the SG formation significantly decreased in rat primary cortical neurons and PC12 cells during the reperfusion period after 6 h of OGD stimulation. The western blot results, flow cytometry analysis, and cell viability assessment showed that the RBM3 expression and ratio of cell viability significantly decreased, while the rate of apoptosis increased in PC12 cells during the reperfusion period after 6 h of OGD stimulation. Co-immunoprecipitation (Co-IP) and immunofluorescence indicated that RBM3 and GTPase-activating protein-binding protein 1 (G3BP1) colocalized cytoplasm of PC12 cells after 6 h of OGD stimulation when the SGs formation reached the highest level. Besides, overexpression and knockdown of the RBM3 were achieved via plasmid transfection and CRISPR-Cas9 technology, respectively. The results of overexpression and knockdown of RBM3 gene illustrated the pivotal role of RBM3 in affecting SG formation and apoptosis level in OGD-treated PC12 cells. In conclusion, RBM3 could combine with G3BP1 resulted in increasing stress granules generation in rat primary cortical neurons and PC12 cells after 6 h of oxygen-glucose deprivation (OGD) injury, which ultimately reduced the apoptosis in OGD-induced cells. Our study may enable a new promising target for alleviating ischemia-reperfusion injury in cells.

Evaluation of hemodynamic characteristics in posterior circulation infarction patients with vertebral artery dominance by color doppler flow imaging and transcranial doppler sonography

PURPOSE

The aim of this study was to investigate the hemodynamic characteristics of posterior circulation infarction (PCI) patients with the vertebral artery dominance (VAD) using Color Doppler flow imaging (CDFI) and Transcranial Doppler sonography (TCD) and to explore the pathogenesis of PCI caused by VAD.

MATERIALS AND METHODS

A total of 186 consecutive PCI patients were enrolled. All the patients underwent magnetic resonance (MR) examination and the clinical data were collected. According to the brain magnetic resonance angiography (MRA), the patients were divided into VAD and non-VAD groups. CDFI and TCD were performed to identify the hemodynamic parameters of the vertebral artery (VA) and basilar artery (BA).

RESULTS

The male population was significantly more frequent in the VAD group (71.3%) as compared to the non-VAD group (53.1%). The significant difference in hemodynamic parameters was observed between VAD and non-VAD groups. Resistance index (RI) of extracranial and intracranial VA was different as well. There were also differences in the VA side-to-side diameter difference-value, peak velocity (Vp), mean velocity (Vm) and pulsatility index (PI) with varying degrees of BA curvature.

CONCLUSIONS

VA and BA hemodynamic changes caused by VAD may be an important risk factor in the process of occurrence of PCI. The combination of CDFI and TCD can help to detect the hemodynamic changes in the intracranial and extracranial segments of VA and BA. This can have important clinical value in understanding the pathogenesis of PCI.

Application of FLAIR Vascular Hyperintensity-DWI Mismatch in Ischemic Stroke Depending on Semi-Quantitative DWI-Alberta Stroke Program Early CT Score

Objective: Diffusion-weighted imaging (DWI)-Alberta Stroke Program Early CT Score (ASPECTS) is a simple, widely used method to estimate the size of the infarct. Our aim is to determine whether there is a relationship between DWI-ASPECTS and fluid-attenuated inversion recovery (FLAIR) vascular hyperintensity (FVH)-DWI mismatch and to better quantify FVH-DWI mismatch to assess the prognosis of cerebral infarction.

Materials and Methods: A retrospective analysis of 109 patients with MCA stenosis or occlusion with cerebral infarction was performed by dividing this cohort into FVH-DWI match group and FVH-DWI mismatch group based on FVH and DWI results. The clinical and imaging data of these two groups of patients were reviewed and analyzed to identify associations between FVH-DWI mismatch and prognosis of patients for preservation of neurological function. Correlation between DWI-ASPECTS and FVH-DWI mismatch was also performed.

Results: FVH-DWI mismatch was present in 66/109 (60.55%) patients, and FVH-DWI match was present in 43/109 (39.45%). Patients with FVH-DWI mismatch had higher DWI-ASPECTS (7.0 vs. 4.0, P < 0.001) and lower mRS at 3 months (3.0 vs. 4.0, P < 0.001) than patients without FVH-DWI mismatch. Multiple regression analysis suggested that DWI-ASPECTS (OR = 4.7, 95% CI = 2.5–9.2, P < 0.001) remained significantly associated with FVH-DWI mismatch. Two threshold points for DWI-ASPECTS of 3 and 8 can be used to distinguish whether there is a mismatch in FVH-DWI by smooth curve fitting.

Conclusions: The DWI-ASPECTS score was an independent predictor of FVH-DWI mismatch. At DWI-ASPECTS ≤ 3, the FVH-DWI mismatch offers no prognostic value; whereas, at DWI-ASPECTS ≥ 8, the FVH-DWI mismatch had the highest prognostic value. DWI-ASPECTS can roughly determine whether there is a FVH-DWI mismatch in order to select optimal clinical treatment and accurately assess prognosis.

Added assessment of middle cerebral artery and atrial fibrillation to FLAIR vascular hyperintensity-DWI mismatch would improve the outcome prediction of acute infarction in patients with acute internal carotid artery occlusion

BACKGROUND AND AIMS

Whether fluid-attenuated inversion recovery (FLAIR) vascular hyperintensities (FVH)-DWI mismatch could predict the outcome or not remains in debate. The aim of this study was to identify if FVH combined with the other markers improved favorable outcome prediction of acute infarctions in patients with unilateral acute internal carotid artery (ICA) occlusion.

METHODS

Consecutive 68 adult acute middle cerebral artery (MCA) territory infarction patients caused by acute ICA occlusion, including favorable (n = 38, mRS ≤ 2) and unfavorable (n = 30, mRS > 2) groups, were enrolled in this retrospective analysis. The diagnostic efficiency of favorable clinical outcome of FVH-DWI mismatch was compared with those of DWI lesions volumetry and the combined marker of FVH-DWI mismatch and other factors.

RESULTS

There were more prominent FVH-DWI mismatch (≥ 3 sections) (84%), less atrial fibrillation (AFib) (13%), and more tandem MCA normal or mild stenosis (63%) in favorable outcome group than those (30%, 40%, and 27%, respectively) in unfavorable group. Univariate and multivariate analyses showed that the prominent FVH-DWI mismatch was the positive predictive factor for favorable outcome (OR = 2.643 and 3.200). Prominent FVH-DWI mismatch, in combination with tandem MCA normal or mild stenosis, and absence of Afib, had better performance (AUC = 0.875) than that of initial DWI lesion volumetry (AUC = 0.854) and any other single factor (AUC = 0.634~0.820) in predicting favorable outcome.

CONCLUSIONS

Prominent FVH-DWI mismatch was associated with favorable outcome in acute infarctions in unilateral ICA occlusion patients. Its predictive performance would be improved when combined with the assessment of tandem lesions of MCA and AFib.

Association Between Net Vertebral Artery Flow Volume and Non-AF Stroke: A Retrospective 2-Year Analysis

Objectives: Association between net vertebral artery flow volume (NVAFV) and stroke types remains unclear. We hypothesize NVAFV is low in patients with posterior circulation infarction (PCI) and an ideal cut-off value for discriminating PCI from anterior circulation infarction (ACI) and controls may be present.

Materials and Methods: As study candidates, we retrospectively enrolled hospitalized patients with first-time non-AF stroke within 2-years period. Consecutive non-AF, non-stroke subjects were enrolled as the control group. We compared NVAFV values among the PCI, ACI, and control groups.

Results: Overall, 866 candidates—213, 418, and 235 candidates in the PCI, ACI, and control groups, respectively—were enrolled. NVAFV (mean ± SD) values were 134.8 ± 52.7, 152.3 ± 59.2, and 172.0 ± 54.7 mL/min in the PCI, ACI, and control groups, respectively. Statistics revealed significant difference (p < 0.001) among three groups. To use NVAFV as a diagnostic parameter, the AUC of any two groups should be between 0.58 and 0.69. Most (93.6%) of the controls had NVAFV above 100 mL/min. The odds ratio of any non-AF stroke is 3.48 if the NVAFV is below 100 mL/min.

Conclusions: NVAFV is lowest in non-AF PCI group. Low NVAFV is associated with both non-AF ACI and PCI. No ideal cut-off value is available to discriminate PCI from other two conditions. We agree that an NVAFV of 100 mL/min is the lower limit of a normal value. Any value below 100 mL/min indicates high stroke risk and implies diffuse cerebral atherosclerosis and impaired cerebral perfusion.

Doppler Resistivity and Cerebral Small Vessel Disease: Hemodynamic Structural Correlation and Usefulness for the Etiological Classification of Acute Ischemic Stroke

INTRODUCTION AND GOAL

Lacunar stroke is defined as an <1.5 cm diameter infarct located in the territory of a perforating artery, that is not accessible for direct study using conventional imaging techniques. Diagnosis requires exclusion of other causes. It usually occurs in the context of chronic cerebral small vessel disease, which can be suspected during the neurosonography study in the form of high pulsatility [PI] or resistance index [RI]. Clinical research was performed to confirm that PI and RI correlate with cerebral small vessel lesion burden and to determine whether these parameters are useful for supporting a lacunar origin (LO) in acute stroke.

MATERIAL AND METHODS

We prospectively recorded internal carotid artery resistivity and the Fazekas score for all patients with acute ischemic stroke who met inclusion but not exclusion criteria over a 6-month period.

RESULTS

The study population comprised 74 patients. A correlation was observed between the Fazekas score and resistivity. Both parameters predicted a LO, with an area under the curve of .78 and .696, respectively. The optimal cut-offs were PI = .96/RI = .58 for screening (sensitivity, 96%) and PI = 1.46/RI = .83 for confirmation (specificity, 89%).

CONCLUSIONS

Doppler ultrasound is a useful technique for determining the LO of acute stroke.

Prognostic value of high-resolution magnetic resonance imaging in evaluating carotid atherosclerotic plaque in patients with ischemic stroke

BACKGROUND

Ischemic stroke (IS) is a devastating occurrence affecting millions worldwide. This study aimed to evaluate the prognostic value of high-resolution magnetic resonance imaging (HRMRI) in assessing carotid atherosclerotic plaque in IS patients.

METHODS

Between January 2013 and March 2015, 338 IS patients were recruited for the investigative purposes of the study. All participants of the study underwent an HRMRI inspection procedure after being admitted into the hospital. During this study, we systematically analyzed and measured various types of fibrous caps, lipid compositions, and plaque lipid ratios. Univariate and multivariate logistic regression analyses were performed for predicting prognosis of IS patients. A receiver-operating characteristic (ROC) curve was employed to determine the accuracy of the IS prognosis.

RESULTS

The percentage of type I fibrous caps exhibited significant decrease, while the percentage of type III fibrous caps, lipid compositions, and lipid ratios all displayed increase. The results of the univariate analysis indicated that age, hypertension, hyperlipidemia, treatment regimens, fibrous cap type, plaque type, lipid composition, and lipid ratio shared a correlation in regards to the poor prognosis of IS patients. Multivariate logistic regression analysis demonstrated that the prognosis of IS patients was not necessarily dependent on fibrous cap type, plaque type, or age. ROC curves revealed that the HRMRI possessed a strong predicative ability in relation to the identification of the prognosis of IS patients through factors such as type of plaque and fibrous caps determination.

CONCLUSION

Our study conclusively intimated the promise of HRMRI as an evaluative tool for the determination of carotid atherosclerotic plaques in patients with IS.