Association between leukoaraiosis and cerebral blood flow territory alteration in asymptomatic internal carotid artery stenosis

White matter hyperintensities had a correlation with the cerebral perfusion level, but no correlation with the severity of large vessel stenosis in the anterior circulation

OBJECTIVE

The contribution of large vessel stenosis to the development of white matter hyperintensities (WMHs) has not been fully elucidated. This study aims to explore the correlation between ipsilateral white matter hyperintensities (WMHs) and the severity of large vessel stenosis in the anterior circulation and cerebral perfusion level, as well as analyze the factors influencing WMHs.

METHODS

A cross-sectional study of 150 patients with unilateral anterior circulation large vessel stenosis of ≥50% was conducted. The severity of ipsilateral WMHs was assessed by Fazekas scale on T2-weighted image and/or fluid-attenuated inversion recovery MR imaging, vascular stenosis severity was evaluated on computed tomography angiography images, and the level of cerebral perfusion was rated according to a staging system for abnormal cerebral perfusion based on CTP results. The relationships between the stenosis severity, cerebral perfusion level and ipsilateral WMHs severity were analyzed. A multivariate logistic regression analysis was performed to determine the factors independently influencing WMHs.

RESULTS

Among 150 patients (mean age, 63.12 ± 10.55 years), there was a statistically significant positive correlation between cerebral perfusion level and the severity of DWMHs and PWMHs (Gamma = 0.561, p < .001; Gamma = 0.600, p < .001), and a positive correlation between cerebral perfusion level and the severity of vascular stenosis (Gamma = 0.495, p < .001).While, there was no statistically significant correlation between the severity of vascular stenosis and the severity of DWMHs and PWMHs (Gamma = 0.188, p = .08; Gamma = 0.196, p = .06). The multivariate logistic regression analysis results demonstrated that age (OR = 1.047, 95% CI 1.003-1.093; p = .035), stroke/TIA history (OR = 2.880, 95% CI 1.154-7.190; p = .023) and stage II of cerebral perfusion (OR = 2.880, 95% CI 1.154-7.190; p = .023) were independent influencing factors on ipsilateral DWMHs. Age (OR = 1.051, 95% CI 1.009-1.094; p = .018), and stage II of cerebral perfusion (OR = 12.871, 95% CI 3.576-46.322; p < .001) were factors independently influencing ipsilateral PWMHs.

CONCLUSION

White matter hyperintensities may be attributed to cerebral hypoperfusion secondary to vascular stenosis but not directly to the severity of stenosis in the large vessels of anterior circulation. Moreover, longitudinal studies with sequential imaging exams may further reveal the impact of cerebral perfusion secondary to vascular stenosis on the development and progression of WMHs.

The relationship between severe extracranial artery stenosis or occlusion and cerebral small vessel disease in patients with large artery atherosclerotic cerebral infarction

Background and purpose

Extracranial artery stenosis (ECAS) is associated with the presence of individual markers of cerebral small vessel disease (CSVD). Here, we investigated the relationship between severe extracranial artery stenosis or occlusion and CSVD in patients with large artery atherosclerotic (LAA) cerebral infarction.

Methods

A total of 128 patients with LAA cerebral infarction who met our specific inclusion criteria were selected, including 92 males and 36 females. These patients were divided into three groups based on whether they had severe symptomatic extracranial arterial stenosis or occlusion, severe asymptomatic extracranial artery stenosis or occlusion, or severe extracranial artery stenosis or occlusion (both symptomatic and asymptomatic). Intra-group comparisons were then performed to examine whether there were any differences in the total CSVD scores and Fazekas scores.

Results

Patients with severe extracranial arterial stenosis or occlusion and those with severe asymptomatic extracranial arterial stenosis or occlusion had a significantly higher total CSVD score (P < 0.05), but there were no significant differences between the groups in terms of Fazekas scores. Furthermore, there were no significant difference in the total CSVD scores and Fazekas scores when compared between patients with or without severe symptomatic extracranial arterial stenosis or occlusion.

Conclusion

Severe stenosis or occlusion of the contralateral extracranial artery may increase the incidence of CSVD in patients with LAA cerebral infarction. Active and effective clinical intervention following comprehensive evaluation should be undertaken for unilateral cerebral infarction patients with severe stenosis or occlusion of the contralateral extracranial arterial.

Impact of carotid stenosis on cerebral hemodynamic failure and cognitive impairment progression: a narrative review

Carotid atherosclerosis has a relevant impact on cerebral blood flow regulation. There is accruing evidence that hemodynamic impairment related to the presence of a significant carotid lumen narrowing may predispose to the development of cerebral dysfunctions, including a reduction in cognitive abilities. In the last years an increasing number of findings showed that carotid stenosis did contribute to cognitive impairment not only in relation to the occurrence of cerebral ischemic lesions, but also as an independent risk factor. The principal mechanisms involved are chronic hypoperfusion, microembolization and cerebrovascular reactivity impairment. Moreover, more recent studies showed alterations of regional functional connectivity. In this narrative review, we analyzed the relationships between carotid stenosis, cerebral hemodynamic derangement and cognitive impairment onset and progression, and underlined that cognitive impairment is the final result of the complex interaction between different elements, including also collateral circulation, cerebral hemodynamic status, brain connectivity and pro-inflammatory state. Further, therapeutic approaches, with a specific focus on vascular risk factors correction and on the effectiveness of surgical or endovascular interventions were discussed. We particularly focused our attention on the concept of “asymptomatic carotid stenosis”, and how could a cognitive impairment improve after an intervention, and how this could change the indications to surgical approach. Larger studies and randomized controlled trials are urgently required to better define time, characteristics and effectiveness of both medical and surgical/endovascular approaches.

Silent brain infarcts and white matter lesions in patients with asymptomatic carotid stenosis

The association of carotid atherosclerosis with silent brain infarcts (SBIs) and white matter lesions (WMLs) currently remains unknown. This study aims to compare SBIs, deep white matter lesions (DWMLs), and periventricular white matter lesions (PWMLs) in ipsilateral and contralateral hemispheres to internal carotid artery (ICA) stenosis, and investigate their association with stenosis grade in patients with asymptomatic ≥ 50% unilateral extracranial ICA stenosis. Patients without previous history of stroke and/or transient ischemic attack who had ≥ 50% stenosis in unilateral ICA on carotid color Doppler ultrasound were enrolled in the study. Patient demographics, vascular risk factors and ICA stenosis grades; number, location, and size of SBIs, DWMLs, and PWMLs in ICA territory were evaluated in both hemispheres using magnetic resonance imaging of the brain. Of the 69 patients, 53 had 50-69% (76.8%) and 16 had ≥ 70% (23.2%) unilateral ICA stenosis. There was no statistically significant difference in SBIs between ipsilateral and contralateral hemispheres to ≥ 50% ICA stenosis. Comparison of ICA stenoses as 50-69% and ≥ 70% revealed a greater number of patients with SBI in ipsilateral hemisphere to ≥ 70% stenosis compared to contralateral (p = 0.025). The number of SBIs was also higher in ipsilateral hemisphere to ≥ 70% stenosis compared to contralateral (p = 0.022). While DWMLs and PWMLs did not differ between hemispheres, frequency of Fazekas grade 1 DWMLs was lower in ipsilateral hemisphere to either 50-69% or ≥ 70% ICA stenosis compared to contralateral (p = 0.035 and p = 0.025, respectively). Results of the present study indicate that stenosis grade may be relevant in the association between asymptomatic carotid stenosis and SBIs, and ≥ 70% stenosis may pose a risk of SBI development.

The Asymmetry of White Matter Hyperintensity Burden Between Hemispheres Is Associated With Intracranial Atherosclerotic Plaque Enhancement Grade

Purpose

The contribution of intracranial atherosclerotic stenosis (ICAS) to the development of white matter hyperintensities (WMHs) has not been fully elucidated. We aimed to retrospectively assess the relationship between WMH burden and unilateral ICAS by combined examination of lumen stenosis, plaque enhancement, and cerebral perfusion.

Materials and methods

A cross-sectional study of 41 patients with symptomatic unilateral ICAS (mean age 57 ± 10 years; 26 males) was conducted. Detailed clinical data, including vascular risk factors, were obtained. WMH volume was derived from 3D-fluid-attenuated inversion recovery (3D-FLAIR) and was assessed by using a validated semi-automated protocol. Lumen stenosis, plaque enhancement, and cerebral perfusion (assessed on time-to-peak parameter using the Alberta Stroke Program Early CT score (TTP-ASPECTS) scale) were evaluated. The WMH volumes of peri-ventricular (PWMH) and deep (DWMH) white matter were calculated separately and compared between hemispheres. Associations between WMH volume (inter-hemispheric volume difference, ipsilateral and contralateral to the ICAS site separately), unilateral ICAS imaging metrics, and vascular risk factors were assessed by using linear regression.

Results

The DWMH volume ipsilateral to the ICAS site (ipsilateral DWMH volume) was significantly greater than that of the contralateral site (P < 0.001), while the PWMH volume difference between hemispheres did not reach statistical significance. The inter-hemispheric DWMH volume difference was significantly associated with a higher plaque enhancement grade (β = 0.436, P = 0.005) and inversely associated with cerebral hypoperfusion (lower TTP-ASPECTS) (β = −0.613, P < 0.001). In the between-subject multivariable regression analysis, while older age (β = 0.323, P = 0.025), hypoperfusion (β = −0.394, P = 0.007), and hypertension (β = 0.378, P = 0.011) were independently associated with ipsilateral DWMH volume, plaque enhancement did not show an association with ipsilateral DWMH volume. The association between ipsilateral DWMH volume and lumen stenosis approached statistical significance (β = 0.274, P = 0.084).

Conclusion

The DWMH was attributed to chronic hypoperfusion secondary to atherosclerotic stenosis. The association between the asymmetry of deep white matter lesions and plaque enhancement might suggest that increased deep white matter lesions are those ischemic lesions, which are more prone to the development of stroke.

Is there a relation between sudden sensorineural hearing loss and white matter lesions?

PURPOSE

Sudden sensorineural hearing loss (SSNHL) has similarities to conditions with vascular etiologies such as myocardial infarction and cerebral stroke. Thus, it could be considered as an early sign of a vascular disease and not only a specific local condition. Chronic hypoperfusion in the brain districts leads to a chronic ischemic damage, called cerebral small vessel disease (CSVD), detectable with brain magnetic resonance imaging (MRI).

METHODS

The authors used CSVD to establish the presence of vascular risk factors in individuals with SSNHL and used the Fazekas score scale to classify them.

RESULTS

Our study showed that individuals with SSNHL aged between 48 and 60 years have 26% more probability to have a Fazekas score higher than 1 compared to the general population. Individuals younger than 28 years showed a statistically significant negative correlation to have a Fazekas score higher than 0. The higher is the Fazekas score, the less is the probability of hearing recovery. The medium hearing-recovery probability is 46%. This decreases by 16% for every increase of score in the Fazekas scale. In the present study, the recovery probability decreased from 80% in individuals younger than 48 years with a score of 0 to 14% in individuals with a Fazekas scores of 3 and 4.

CONCLUSIONS

The authors assessed a higher prevalence of CSVD compared to the general population in patients aged between 48 and 60 years with SSNHL. Moreover, they assessed that the presence of CSVD is related to a decreased probability of recovery, as it has already been demonstrated for stroke.