Contribution of intracranial artery stenosis to white matter hyperintensities progression in elderly Chinese patients: A 3-year retrospective longitudinal study

Predictors for recurrent ischemic stroke in patients with watershed infarct induced by intracranial artery stenosis

BACKGROUND AND PURPOSE

Symptomatic intracranial artery stenosis (sICAS) is strongly associated with an elevated risk of recurrent ischemic stroke, yet the underlying risk factors remain elusive. In this present study, we aimed to investigate the risk factors and predictive value of imaging features for recurrent ischemic stroke in patients with watershed infarction caused by ICAS.

METHODS

We prospectively collected clinical information and imaging data from patients with watershed infarction caused by ICAS. The primary outcome was recurrent ischemic cerebrovascular events in the same territory within 1 year. The original magnetic resonance images (MRI) were post-processed by the Fast-processing of ischemic stroke (F-Stroke) software to compute the perfusion parameters. The assessment of white matter hyperintensity (WMH) was performed in accordance with the Fazekas scale. Binary logistic regression analysis was performed to explore the association of imaging characteristics and recurrent ischemic stroke. Subsequently, we performed ROC curve analyses to determine their discriminatory capacity for ischemic stroke recurrence.

RESULTS

A total of 139 patients were successfully enrolled in the present study. The recurrence rate in the total population was 18.71 %. Compared with patients without recurrent ischemic stroke, those who experienced recurrence had a higher proportion of prior ischemic stroke history (25.66 % vs. 53.85 %) and severe WMH (30.77 % vs. 7.97 %), as well as higher baseline NIHSS scores and volume of Tmax > 4 s. Logistic regression analysis revealed that both the volume of Tmax > 4 s and severe WMH significantly influenced the risk of recurrent ischemic stroke occurrence. Furthermore, ROC curve analyses demonstrated that the discriminatory capacity of the volume of Tmax > 4 s (AUC = 0.64, 95 %CI = 0.51-0.77, P = 0.029) was marginally superior to WMH scores (AUC = 0.62, 95 %CI = 0.49-0.75, P = 0.066). Whereas, the combination of the volume of Tmax > 4 s and the WMH scores showed better discriminatory capacity (AUC = 0.73, 95 %CI = 0.61-0.85, P < 0.001).

CONCLUSION

MR-guiding cerebral hypoperfusion and severe WMH is susceptible to recurrence of ischemic stroke, thereby serving as valuable predictors for recurrence in patients with watershed infarction caused by ICAS.

Imaging-validated correlates and implications of the pathophysiologic mechanisms of ageing-related cerebral large artery and small vessel diseases: a systematic review and meta-analysis

BACKGROUND

Cerebral large artery and small vessel diseases are considered substrates of neurological disorders. We explored how the mechanisms of neurovascular uncoupling, dysfunctional blood-brain-barrier (BBB), compromised glymphatic pathway, and impaired cerebrovascular reactivity (CVR) and autoregulation, identified through diverse neuroimaging techniques, impact cerebral large artery and small vessel diseases.

METHODS

Studies (1990-2024) that reported on neuroradiological findings on ageing-related cerebral large artery and small vessel diseases were reviewed. Fifty-two studies involving 23,693 participants explored the disease mechanisms, 9 studies (sample size = 3,729) of which compared metrics of cerebrovascular functions (CF) between participants with cerebral large artery and small vessel diseases (target group) and controls with no vascular disease. Measures of CF included CVR, cerebral blood flow (CBF), blood pressure and arterial stiffness.

RESULTS

The findings from 9 studies (sample size = 3,729, mean age = 60.2 ± 11.5 years), revealed negative effect sizes of CVR [SMD = - 1.86 (95% CI - 2.80, - 0.92)] and CBF [SMD = - 2.26 (95% CI - 4.16, - 0.35)], respectively indicating a reduction in cerebrovascular functions in the target group compared to their controls. Conversely, there were significant increases in the measures of blood pressure [SMD = 0.32 (95% CI 0.18, 0.46)] and arterial stiffness [SMD = 0.87 (95% CI 0.77, 0.98)], which signified poor cerebrovascular functions in the target group. In the combined model the overall average effect size was negative [SMD = - 0.81 (95% CI - 1.53 to - 0.08), p < 0.001]. Comparatively, this suggests that the negative impacts of CVR and CBF reductions significantly outweighed the effects of blood pressure and arterial stiffness, thereby predominantly shaping the overall model. Against their controls, trends of reduction in CF were observed exclusively among participants with cerebral large artery disease (SMD = - 2.09 [95% CI: - 3.57, - 0.62]), as well as those with small vessel diseases (SMD = - 0.85 [95% CI - 1.34, - 0.36]). We further delineated the underlying mechanisms and discussed their interconnectedness with cognitive impairments.

CONCLUSION

In a vicious cycle, dysfunctional mechanisms in the glymphatic system, neurovascular unit, BBB, autoregulation, and reactivity play distinct roles that contribute to reduced CF and cognitive risk among individuals with cerebral large artery and/or small vessel diseases. Reduction in CVR and CBF points to reductions in CF, which is associated with increased risk of cognitive impairment among ageing populations ≥ 60 years.

Stroke with White Matter Lesions: Potential Pathophysiology and Therapeutic Targets

Stroke is one of the most common causes of morbidity and mortality among adults globally. Significant advancements have been made in elucidating its pathophysiology, with stroke categorized into pathological subtypes, such as ischemic stroke (IS) and hemorrhagic stroke. White matter lesions (WMLs) identified on magnetic resonance imaging rank as a hallmark of cerebral small vessel disease and are associated with vascular risk factors. They are linked to adverse outcomes like dementia, depression, and an increased risk of both first-ever and recurrent strokes, independent of other risk factors. Despite the evidence indicating the close link between WMLs and stroke, their underlying pathophysiological relationship remains unclear. This study aims to provide an overview of the current knowledge and recent advances in epidemiology, risk factors, and pathophysiological mechanisms of WMLs and stroke, focusing on their interconnection and emerging therapeutic targets.

Pathophysiological link between carotid atherosclerosis and cerebral white matter lesions

Carotid atherosclerosis is associated with white matter hyperintensity (WMH), potentially resulting in cognitive and gait problems. We assessed the relationship between carotid atherosclerosis patterns and regional WMH, offering insights into possible mechanisms. We reviewed 1,058 consecutive healthy individuals in a health check-up program, who chose both optional carotid doppler ultrasonography and brain magnetic resonance imaging. Total, periventricular, and subcortical WMH volumes were measured using automatic segmentation and quantification. Carotid atherosclerosis stages were defined as: normal, no atherosclerosis; plaque without stenosis, atherosclerotic plaque without stenosis; anatomic stenosis, angiographic stenosis without sonographic flow alteration; and hemodynamic stenosis, sonography-measured hemodynamically significant stenosis. These stages were analyzed for association with regional WMH volumes using linear regression. Total and periventricular WMH volumes increased with anatomic and subsequent hemodynamic stenosis; however, only hemodynamic stenosis was independently associated with total (B [95% confidence interval], 0.240 [0.057-0.423]; p = 0.010) and periventricular WMH volumes (0.232 [0.066-0.399]; p = 0.006). Hemodynamic stenosis degree, not plaque extent and anatomic stenosis degree, was significantly associated with total (0.178 [0.033-0.323]; p = 0.016) and periventricular WMH volumes (0.176 [0.044-0.308]; p = 0.009). Subcortical WMH was not associated with carotid atherosclerosis. Hemodynamic compromise may be a key factor linking carotid atherosclerosis and WMH, mainly affecting periventricular white matter.

The correlation between intracranial atherosclerosis and white matter hyperintensities in cerebral small vessel disease: a high-resolution magnetic resonance imaging study

Objective

Recent studies have indicated a close relationship between intracranial arterial stenosis and white matter hyperintensities (WMHs), but few have reported on the correlation between the characteristics of intracranial arterial wall plaques and WMHs. The aim of this study was to comprehensively assess the correlation between intracranial atherosclerosis plaques and WMHs using 3.0T high-resolution magnetic resonance imaging (HR-MRI).

Patients and methods

Ninety-two ischemic stroke patients with middle cerebral artery (MCA) stenosis <50% on cranial magnetic resonance angiography (MRA) underwent conventional MRI and HR-MRI examinations. T2-weighted fluid-attenuated inversion recovery (T2-FLAIR) images were processed using 2D VBNeT automatic segmentation technology to segment WMH volume. HR-MRI images were analyzed using ImageJ software to evaluate the luminal area, outer wall area, plaque distribution, luminal stenosis rate, remodeling patterns, and other plaque parameters at the stenosis site and reference points of the MCA M1 segment. The correlation between the presence of plaques, plaque distribution, luminal stenosis rate, T1 hyperintensity, remodeling patterns, remodeling ratio (RR), eccentric plaques, and plaque burden with the volume of cerebral WMHs was analyzed.

Results

Compared with the no-plaque group, the plaque group had significantly higher age, male ratio, total WMH volume, periventricular WMH (PVWMH) volume, deep WMH (DWMH) volume, and juxtacortical WMH (JCWMH) volume (all p < 0.05). The Kruskal-Wallis H test showed that patients with plaques on the superior and dorsal sides of the MCA M1 segment had higher levels of total WMH volume, PVWMH volume, DWMH volume, and JCWMH volume than patients with plaques on the inferior and ventral sides (all p < 0.05). Age, diabetes, previous stroke events, plaque distribution, positive remodeling, eccentric plaques, and RR were positively correlated with total WMH volume, PVWMH volume, and JCWMH volume (all p < 0.05). The presence of plaques, plaque distribution, and positive remodeling were independent risk factors for total WMH volume (all p < 0.05).

Conclusion

The presence of intracranial atherosclerotic plaques, plaque distribution, and positive remodeling are closely associated with increased cerebral WMHs burden in patients with ischemic stroke, which further supports the relationship between large artery atherosclerosis and CSVD.

Association of vulnerable plaques with white matter hyperintensities on high-resolution magnetic resonance imaging

Background

One of the widespread manifestations of cerebral small vessel disease (CSVD) of the brain parenchyma is white matter lesion, which appears as white matter hyperintensities (WMHs) on magnetic resonance imaging (MRI). Previous studies have illustrated that large artery atherosclerosis is related to CSVD, but the precise progress of pathogenesis remains unknown. High-resolution MRI (HR-MRI) has the ability to delineate intracranial vascular walls, enabling a thorough exploration of the structure and composition of unstable plaques. This study aimed to apply HR-MRI to characterize the wall changes and plaque characteristics of middle cerebral arteries in patients with WMHs and to investigate the correlation between plaque vulnerability parameters and different degrees of WMHs.

Methods

In this study, 138 patients with acute ischemic stroke at Harbin Medical University's First Clinical Hospital (May 2021 to October 2023) were cross-sectionally reviewed and underwent conventional brain and HR-MRI using T1-weighted 3D volumetric isotropic turbo spin echo acquisition (T1W-3D-VISTA) of the unilateral middle cerebral artery (MCA). According to Fazekas grade (0-6), the patients were divided into two groups: Fazekas score 0-2, no-or-mild WMHs; and Fazekas 3-6, moderate-to-severe WMHs. The intraplaque hemorrhage, plaque distribution, plaque enhancement, plaque load, remodeling pattern, and stenosis of the two groups were measured. Binary logistic regression analysis was conducted to evaluate the relationship between vulnerable plaques and WMHs.

Results

Of the participants who were initially considered for inclusion, 71 were deemed eligible, among whom 34 were placed in the no-or-mild WMH group and 37 in the moderate-to-severe WMH group. Between the two groups, there were significant differences in intraplaque hemorrhage (P=0.01), a wide distribution (P=0.02), and plaque enhancement (P=0.02). Univariate analysis showed that WMHs were associated with age [odds ratio (OR) =1.080; 95% confidence interval (CI): 1.020-1.144; P=0.008], hypertension (OR =3.500; 95% CI: 1.276-9.597; P=0.01), intraplaque hemorrhage (OR =3.955; 95% CI: 1.247-12.538; P=0.02), a wide distribution (OR =3.067; 95% CI: 1.159-8.115; P=0.02), and significant plaque enhancement (OR =4.372; 95% CI: 1.101-17.358; P=0.03); however, the multivariate results showed that the only independent factors associated with WMHs were age (OR =1.095; 95% CI: 1.019-1.176; P=0.01) and intraplaque hemorrhage (OR =5.88; 95% CI: 1.466-23.592; P=0.01).

Conclusions

Our findings suggest that age and intraplaque hemorrhage may be associated with more severe WMHs in patients with acute ischemic stroke, which may be helpful for further clinical examination and intervention treatment.

Association between intracranial and extracranial atherosclerosis and white matter hyperintensities: a systematic review and meta-analysis

Background

White matter hyperintensities (WMHs) are key neuroimaging markers of cerebral small vessel diseases. This study aimed to investigate whether intracranial and extracranial atherosclerotic stenosis is associated with WMHs.

Methods

Following a previously registered protocol (PROSPERO protocol: CRD42023407465), PubMed, Web of Science, and Embase were systematically searched for relevant literature published until March 2023. Cross-sectional studies examining the association between intracranial and extracranial atherosclerotic stenosis and WMHs were included. Random effects models were used to calculate the pooled estimates.

Results

Twenty-one eligible studies, including 10,841 participants, were identified. Intracranial and extracranial atherosclerotic stenosis was associated with an increased risk of WMHs (OR 1.80, 95% CI 1.25-2.57, I2 = 75%) and increased WMH volumes (SMD 0.40, 95% CI 0.18-0.63, I2 = 63%). Heterogeneity resulted from the WMHs rating method and the location. Extracranial atherosclerotic stenosis (ECAS) was significantly associated with WMHs (OR 2.10, 95% CI 1.22-3.62, I2 = 71%), but intracranial atherosclerotic stenosis (ICAS) was insignificantly associated with WMHs (OR 1.75, 95% CI 0.97-3.15, I2 = 84%). The association was stable in the subgroup analysis based on WMHs location, which included deep WMHs and periventricular WMHs.

Conclusion

Intracranial and extracranial atherosclerotic stenosis is associated with WMHs. This association is significant in ECAS, but attenuated in ICAS.