Thrombolysis Outcomes in Acute Ischemic Stroke by Fluid-Attenuated Inversion Recovery Hyperintense Arteries

Individualized interpretation for the clinical significance of fluid-attenuated inversion recovery vessel hyperintensity in ischemic stroke and transient ischemic attack: A systematic narrative review

Fluid-attenuated inversion recovery (FLAIR) vessel hyperintensity（FVH）refers to the hyperintensity corresponding to the arteries in the subarachnoid space. It is caused by critically slowed blood flow and is commonly encountered in patients with large artery steno-occlusions. Quite a few studies have focused on the clinical significance of FLAIR vessel hyperintensity in terms of its relationship to the prognosis of transient ischemic attack (TIA), baseline severity or infarction volume, early neurological deterioration or infarction growth, and functional outcomes in acute ischemic stroke (AIS). However, inconsistent or conflicting findings were common in these studies and caused confusion in the clinical decision-making process guided by this imaging marker. Through reviewing the available studies on the etiologic mechanism of FVH and investigating findings on its clinical significance in AIS and TIA, this review aims to elucidate the key factors for interpreting the clinical significance of FVH individually.

Factors associated with functional disability in patients with acute stroke excluded from alteplase administration due to minor non-disabling neurological deficits

Background

Although the PRISMS study did not demonstrate the benefit of intravenous alteplase administration in patients with mild stroke within 3 h, about 30% of patients presenting with mild symptoms showed unfavorable functional outcomes. We investigated the factors predictive of functional disability at 90 days in patients who were excluded from alteplase administration due to the National Institutes of Health Stroke Scale (NIHSS) scores of 0-5 and a score between 0 and 2 for each NIHSS score item.

Methods

All patients were diagnosed with acute ischemic stroke or transient ischemic attack within 4.5 h of admission to a tertiary hospital and did not receive alteplase due to a minor stroke between January 2013 and December 2020. Radiological data and clinical information were collected, including baseline and discharge NIHSS scores and modified Rankin Scale (mRS) scores at 90 days. Early neurological deterioration (END) was defined as an increase of two or more NIHSS scores. We defined moderate motor weakness as a NIHSS limb motor score of more than 3 and defined a favorable outcome as a mRS score at 90 days that was 0 or 1.

Results

During the investigation period, 400 patients did not receive alteplase. END occurred significantly more frequently in patients with large artery disease (LAD) than in those with other TOAST classifications. In the multivariate regression analysis, NIHSS per 1-point increase, presenting as moderate motor weakness, and LAD were independent predictors of poor functional outcome (OR, 1.811 NIHSS per 1-point increase; 95% confidence interval [CI], 1.503-2.182; P < 0.0001; OR, 2.173 moderate motor weakness; 95% CI 1.028-4.595; P = 0.042; OR, 2.033 LAD; 95% CI 1.099-3.762; P = 0.024, respectively).

Conclusion

Moderate motor weakness presentation and LAD may be important factors associated with poor functional outcomes in patients with acute stroke excluded from alteplase administration due to mild symptoms.

Fluid-Attenuated Inversion Recovery Vascular Hyperintensity in Cerebrovascular Disease: A Review for Radiologists and Clinicians

Neuroradiological methods play important roles in neurology, especially in cerebrovascular diseases. Fluid-attenuated inversion recovery (FLAIR) vascular hyperintensity (FVH) is frequently encountered in patients with acute ischemic stroke and significant intracranial arterial stenosis or occlusion. The mechanisms underlying this phenomenon and the clinical implications of FVH have been a matter of debate. FVH is associated with large-vessel occlusion or severe stenosis, as well as impaired hemodynamics. Possible explanations suggested for its appearance include stationary blood and slow antegrade or retrograde filling of the leptomeningeal collateral circulation. However, the prognostic value of the presence of FVH has been controversial. FVH can also be observed in patients with transient ischemic attack (TIA), which may have different pathomechanisms. Its presence can help clinicians to identify patients who have a higher risk of stroke after TIA. In this review article, we aim to describe the mechanism and influencing factors of FVH, as well as its clinical significance in patients with cerebrovascular disease.

Hyperintense Vessel Sign in Large-Vessel Occlusion Stroke of Mild-to-Moderate Severity Ineligible for Recanalization

Background and Purpose

The impact of fluid-attenuated inversion recovery hyperintense vessels (FHVs) on outcomes in patients ineligible for recanalization therapy with large-vessel occlusion (LVO) is unclear. We investigated the impact of FHVs determined using the FHV–Alberta Stroke Program Early CT Score (ASPECTS) on clinical outcomes in patients with LVO stroke of mild-to-moderate severity ineligible for recanalization therapy.

Methods

Sixty-eight consecutive patients with M1-middle cerebral artery occlusion who underwent magnetic resonance imaging within 24 hours of symptom onset and were ineligible for recanalization were included. Patients were dichotomized into a severe-FHV group (FHV-ASPECTS ≤4; n=33) and a mild-FHV group (FHV-ASPECTS >4; n=35), and multiple logistic regression analysis was used to examine the relationships of FHV scores with early neurological deterioration (END) and an unfavorable 3-month outcome (modified Rankin Scale score ≥3).

Results

Mean age was 66.2±13.5 years (mean±SD), and 30 (44%) were female. The severe-FHV group had a larger infarct volume (median, 5.5 mL vs. 3 mL) and more frequently exhibited the susceptibility vessel sign (30% vs. 3%) than the mild-FHV group. Ipsilateral old nonlacunar infarct was more frequent in the mild-FHV group than in the severe-FHV group (37% vs. 15%). The severe-FHV group had a fivefold higher risk of END (odds ratio [OR] 5.02, 95% confidence interval [CI] 1.36–18.45) and unfavorable outcome (OR 5.97, 95% CI 1.18–33.31, p=0.03) compared with the mild-FHV group.

Conclusions

Greater FHV extent was associated with higher risk of END and unfavorable outcome in patients with LVO stroke of mild-to-moderate severity.

Functional Genetic Variation in the 3'-UTRNTRK2 is Associated with Risk of Ischemic Stroke

Background

Stroke is a leading cause of death and disability worldwide. It remains difficult to treat brain injury and improve functional rehabilitation after cerebral ischemia. Brain-derived neurotrophic factor (BDNF) is involved in ischemic stroke (IS) through interactions in the CREB1-BDNF-NTRk2 pathway. In this study, we aimed to determine the association of NTRK2 gene polymorphisms and the effects of intergenetic interactions in the Chinese population.

Materials and Methods

A total of 400 patients diagnosed with IS and 400 healthy controls were enrolled for genotyping. Detailed sequence-based analysis was predicted through bioinformatical investigation. Polymorphisms associated with miRNA were analyzed by a dual-luciferase reporter assay system.

Results

Analysis of clinical characteristics revealed that IS was highly associated with exposure to cigarette smoking, alcohol intake, as well as metabolic diseases, such as diabetes, hypertension, and higher serum triglyceride concentration. Three polymorphisms in NTRK2 located in the 3ʹ-untranslated region (3ʹ-UTR) were genotyped. Logistic regression analysis showed that IS patients with rs11140793, rs7047042, and rs1221 polymorphisms had a higher risk of stroke and indicated a worse short-term recovery. The mRNA level of NTRK2 was suppressed in a mutant genotype compared with wild genotype. The suppression of NTRK2 was induced by the gain-of-binding ability of certain miRNAs through the direct binding of 3ʹ-UTR.

Conclusion

Our research indicated that, by influencing the expression of NTRK2, the SNPs rs11140793, rs7047042, and rs1221 in the 3′UTR of NTRK2 can be used as risk factors for IS patients.