Prominent FLAIR Vascular Hyperintensity Is a Predictor of Unfavorable Outcomes in Non-thrombolysed Ischemic Stroke Patients With Mild Symptoms and Large Artery Occlusion

Abstract

Background and objective: The aim was to evaluate the clinical significance of prominent fluid-attenuated inversion recovery (FLAIR) vascular hyperintensity (FVH) on the prognosis of mild acute ischemic stroke with middle cerebral artery (MCA) occlusion. Methods: We recruited consecutive stroke patients with initial National Institutes of Health Stroke Scale (NIHSS) scores ≤5 and MCA occlusion on magnetic resonance angiography within 24 h of stroke onset. Prominent distal FVH was defined as an extension to more than one-third of the MCA territory. We compared clinical outcomes between prominent and non-prominent FVH groups in patients who had and had not received reperfusion therapy. Results: Of 112 participants [43 women; median age, 67 years [Interquartile range, 54-79]], prominent FVH was identified in 80 (71.4%). For 75 patients who had not received reperfusion therapy, the prominent FVH group had a more unfavorable outcome (modified Rankin Scale score >1) at 3 months than the non-prominent FVH group (44.4 vs. 15.0%, P = 0.029). In multivariate analysis, a higher NIHSS score [odd ratio [OR] = 1.67; 95% confidence interval [CI], 1.16-2.41; P = 0.006], proximal MCA occlusion [OR = 7.31; 95% CI, 1.68-31.9; P = 0.008], and prominent FVH [OR = 5.49; 95% CI, 1.29-23.4; P = 0.021], were independently associated with an unfavorable outcome. There was no association between prominent FVH and the clinical outcome in the reperfusion therapy group. Conclusions: For acute stroke patients with mild symptoms and MCA occlusion who do not receive reperfusion therapy, prominent FVH and proximal MCA occlusion may be independent predictors of an unfavorable outcome.

Keywords: fluid-attenuated inversion recovery vascular hyperintensity; middle cerebral artery occlusion; mild ischemic stroke; reperfusion therapy; unfavorable outcome.

Figure 1

Illustrative case of prominent fluid-attenuated inversion recovery (FLAIR) vascular hyperintensities (FVH) and FVH-diffusion-weighted image (DIW) mismatch. Magnetic resonance (MR) imaging of a 57-year-old man obtained 138 min after sudden onset of left hemiparesis. Right proximal middle cerebral artery (MCA) occlusion on MR angiography (A) and small hyperintense lesions in the right MCA territory on admission DWI (B,C) with prominent FVH on FLAIR (D–F), which is more extensive beyond the boundaries of the DWI high signal area, indicating an FVH-DWI mismatch.