Infarction Distribution Pattern in Acute Stroke May Predict the Extent of Leptomeningeal Collaterals.

Rajeev Kumar Verma,Marcel Arnold,Monika Buehlmann,Simon Jung,Matthias F Lang,Jan Gralla,Kety Hsieh,Christoph Zubler,Pascal Pedro Klinger-Gratz,Pasquale Mordasini,Marwan El-Koussy,Adrian Schankath,Jeroen Hendrikse

doi:10.1371/journal.pone.0137292

Abstract

ObjectiveThe aim of this study was to evaluate whether the distribution pattern of early ischemic changes in the initial MRI allows a practical method for estimating leptomeningeal collateralization in acute ischemic stroke (AIS).MethodsSeventy-four patients with AIS underwent MRI followed by conventional angiogram and mechanical thrombectomy. Diffusion restriction in Diffusion weighted imaging (DWI) and correlated T2-hyperintensity of the infarct were retrospectively analyzed and subdivided in accordance with Alberta Stroke Program Early CT score (ASPECTS). Patients were angiographically graded in collateralization groups according to the method of Higashida, and dichotomized in 2 groups: 29 subjects with collateralization grade 3 or 4 (well-collateralized group) and 45 subjects with grade 1 or 2 (poorly-collateralized group). Individual ASPECTS areas were compared among the groups.ResultsMeans for overall DWI-ASPECTS were 6.34 vs. 4.51 (well vs. poorly collateralized groups respectively), and for T2-ASPECTS 9.34 vs 8.96. A significant difference between groups was found for DWI-ASPECTS (p<0.001), but not for T2-ASPECTS (p = 0.088). Regarding the individual areas, only insula, M1-M4 and M6 showed significantly fewer infarctions in the well-collateralized group (p-values <0.001 to 0.015). 89% of patients in the well-collateralized group showed 0–2 infarctions in these six areas (44.8% with 0 infarctions), while 59.9% patients of the poor-collateralized group showed 3–6 infarctions.ConclusionPatients with poor leptomeningeal collateralization show more infarcts on the initial MRI, particularly in the ASPECTS areas M1 to M4, M6 and insula. Therefore DWI abnormalities in these areas may be a surrogate marker for poor leptomeningeal collaterals and may be useful for estimation of the collateral status in routine clinical evaluation.

Highlights

Several studies have investigated the role of pial collaterals in patients with acute ischemic stroke (AIS)
A significant difference between groups was found for Diffusion weighted imaging (DWI)-Alberta Stroke Program Early CT score (ASPECTS) (p
DWI abnormalities in these areas may be a surrogate marker for poor leptomeningeal collaterals and may be useful for estimation of the collateral status in routine clinical evaluation

Summary

Introduction

Several studies have investigated the role of pial collaterals in patients with acute ischemic stroke (AIS). The relationship between the collateralization grade and the predictability of infarct evolution was a main study focus in recent years [1,2,3,4,5]. In a few studies a better collateralization grade was associated with better recanalization, reperfusion, and subsequently better clinical outcome [6,7,8,9]. In a retrospective CTbased volumetric study Christoforidis et al [16] reported that infarct volume and clinical severity at discharge were lower for patients with better pial collateral status, regardless whether recanalization was complete or partial. Other trials reported correlations between collateralization and infarct volume, perfusion characteristics, and/or extent of prominent cortical veins on susceptibility weighted imaging (SWI) [15,17,18]

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Conclusion