Background: Stroke patients with coexisting intracranial artery stenosis (ICAS) and white matter lesions (WML) usually have a poor outcome. However, how WML affects stroke prognosis has not been determined.
Objective: To investigate the quantitative forward flow at the middle cerebral artery in ICAS patients with different degrees of WML using 4D flow.
Design: Single-center cross-sectional cohort study.
Methods: Ischemic stroke patients with symptomatic middle cerebral artery (MCA) atherosclerosis were included, and they were divided into 2 groups based on Fazekas scale on Flair image (mild group = Fazekas 0-2, and severe group = Fazekas >2), TOF-MRA and 4D flow were performed to quantify the stenosis degree and forward flow at the proximal of stenosis. The flow parameters were compared between different white matter hyperintensity (WMH) groups, as well as in different MCA stenosis groups, logistic regression was used to validate the association between forward flow and WMH.
Results: A total of 66 patients were included in this study (mean age 56 years old, 68.2% male). 77.3% of them presented with WMH (Fazekas 1-5). Comparison of flow index between mild and severe WMH groups found a significantly lower forward flow (2.34 ± 1.09 vs 3.04 ± 1.35), higher PI (0.75 ± 0.43 vs 0.66 ± 0.32), and RI (0.49 ± 0.19 vs 0.46 ± 0.15) at ipsilateral infarction MCA in the severe WMH group, all P-values <0.05. After adjusting for other covariates, forward mean flow at ipsilateral infarction MCA is still associated with severe WMH independently, OR = 0.537, 95% CI (0.294, 0.981), P = 0.043.
Conclusion: Intracranial artery stenosis patients with coexisting severe WMH suffer from significantly decreased flow, which could explain the poor clinical outcome in this population, and also provide some insight into recanalization therapy in the future.
Keywords: Ischemic stroke; middle cerebral artery; quantitative flow; white matter hyperintensity.
Why was the study done? stroke patients with intracranial artery stenosis (ICAS) have a high prevalence of white matter hyperintensities (WMH), a surrogate biomarker of small vessel disease (SVD), and patients with coexisting ICAS and WMH are more likely to have unfavorable clinical outcomes and higher stroke recurrence risk. However, how WMH affects stroke outcomes has been unknown. What did the researchers do? In this study, we compared the flow and perfusion index between different WMH groups, as well as in different ICAS groups using 4D flow combined with ASL, to obtain the quantitative flow relationship in this population. What did the researchers find? As a result, we found that both the degree of intracranial artery stenosis and WMH burden is associated with decreased flow, and the flow decrease is more significant at the ipsilateral of infarct. What do the findings mean? This is the first study investigating the complicated hemodynamic status using 4D flow combined with ASL in stroke patients with coexisting ICAS and WMH. The results in this study could not only provide some evidence for unfavorable clinical outcomes in ICAS patients with severe WMH burden but also give us some insight into recanalization therapy in this population.
© The Author(s) 2024.