Association of inferior division MCA stroke location with populations with atrial fibrillation incidence

ABSTRACT Background and Aim Anatomical features of Middle Cerebral Artery (MCA) bifurcation favors larger emboli entering the inferior rather than superior division. As cardiac source emboli are on average larger than arterial source emboli, we hypothesize that patients with atrial fibrillation have infarcts that involve more temporal and parietal lobes than frontal lobes. Methods From 1,849 patients admitted with evidence of acute or early subacute ischemic stroke on diffusion-weighted MRI (DWI), 482 affected exclusively the “lobar” MCA (sparing the lenticulostriates). They were classified as “frontal predominant” (n=105) or “temporoparietal predominant” (n=197) if at least 75% of the infarct affected the frontal lobe or the temporal and parietal lobes, respectively. Differences between stroke location (frontal or temporoparietal), sex, and race were analyzed by Chi-square test. Results: Men were more likely than women, and white people were more likely than black people to have temporoparietal strokes versus frontal strokes. Patients with confirmed diagnosis of atrial fibrillation have more temporoparietal strokes, compared to frontal strokes. Conclusion MCA ischemic strokes occur more often in temporoparietal areas in men and in white patients, populations with known elevated incidence of atrial fibrillation. Patients with confirmed diagnosis of atrial fibrillation have more temporoparietal strokes, compared to frontal strokes. Results align with the hypothesis that large emboli (mostly from cardiac source) are more likely to cause temporoparietal strokes in the MCA territory, compared to frontal strokes. This association can help guide search for the most likely etiology of infarcts.