Acute Cardioembolic vs. Large Artery Atherosclerotic Infarction-related Lesion Topography and Right-Left Propensity: A Multi-center Quantitative Magnetic Resonance Imaging Study

Abstract

Background and Purpose: A recent study showed that cardiogenic emboli might flow more frequently into the right hemisphere, whereas atheromatous aortic arch emboli might flow more frequently into the left hemisphere. We tried to 1) see if cardioembolic (CE) infarct volume would be larger in the right hemisphere than in the left hemisphere, and 2) depict anatomical regions showing CE vs. large artery atherosclerotic (LAA) infarction-related right-left propensity. Methods: In this study on carotid artery territory CE (n = 694) vs. LAA (n = 1162) acute ischemic stroke patients who were enrolled consecutively from 11 nationwide stroke centers, we quantitatively registered diffusion magnetic resonance imaging lesions onto the Montreal Neurologic Institute brain template. Results: In patients with bilateral CE stroke (n = 163), right hemispheric infarct size was about two times bigger than the contralateral left hemispheric infarct size (p = 0.002). However, in patients with either unilateral (n = 925) or bilateral (n = 184) LAA stroke, there was no significant difference in the right vs. left hemispheric infarct size between the right vs. left unilateral infarct groups or within the bilateral infarct group (all p > 0.05). In patients with unilateral CE stroke (n = 510), there was no significant difference in the infarct size between the groups with right vs. left hemispheric lesions. Age and infarct volume-adjusted p-value maps of the CE vs. LAA stroke patients, which were corrected for multiple comparisons, revealed the brain regions with a significantly higher infarct frequency in CE stroke than in LAA stroke. The significant clusters were observed only in the right hemisphere, encompassing both the superior and inferior division middle cerebral artery territories, particularly in the pial and corticosubcortical regions including the claustrum and insula. Conclusion: The present multi-center quantitative magnetic resonance imaging study confirms the ‘right > left’ propensity of CE (vs. LAA) stroke.