Introduction and Hypothesis: Epidemiological studies have shown that migraine with aura (MA) is an independent risk factor for ischemic stroke. We assessed the hypothesis that migraine with aura is associated with specific ischemic stroke subtypes in the Atherosclerosis Risk In Communities (ARIC) study.
Methods: We included 12844 participants among this ongoing prospective cohort of ARIC. All participants completed an in-person headache questionnaire: headaches are classified as MA, migraine without aura, or non-migraine headaches. All stroke diagnoses are based on computer-derived diagnosis and physician medical record review, with differences adjudicated by a second physician reviewer. Classification required evidence of sudden or rapid onset of neurological symptoms lasting ≥24 hours. Strokes were further classified according to etiologic subtype as thrombotic brain infarction, lacunar infarction, and cardioembolic stroke.
Results: At the third ARIC study visit, 12.7% (1633) of participants had migraine and 8.5% (1093) had non-migraine headaches. 29% (472) of participants among migraineurs had MA. A total of 817 ischemic strokes occurred from1987-1989 to 2012, of which 51% (417) were thrombotic, 27% (224) were cardioembolic, and 22% (176) were lacunar stroke. Participants with MA had an increased odd of ischemic stroke, compared with participants with migraine without aura (unadjusted OR 2.4, 95% CI 1.6-3.6, P<0.0001). MA had a stronger association with cardioembolic stroke (OR 3.3, 95% CI: 1.4-8.0, p=0.009), compared with thrombotic stroke (OR 2.0, 95% CI: 1.2-3.4, p=0.01). There was no significant association between MA and lacunar stroke.
Conclusions: Results from this prospective cohort are consistent with previous studies demonstrating an association between MA and ischemic stroke. Further, we report a stronger and significant association with the cardioembolic stroke subtype, with a significant but smaller association with thrombotic strokes. Etiology of the observed association is currently being evaluated in this population.