OBJECTIVE: To determine whether there is an association between previous migraine and cryptogenic TIA or ischemic stroke at older ages. METHODS: We determined the age-specific associations of history of migraine and Trial of Org 10172 in Acute Stroke Treatment (TOAST) subtype of TIA and ischemic stroke in a population-based cohort study (Oxford Vascular Study; 2002-2012). RESULTS: Among 1,810 eligible patients with TIA or ischemic stroke, 668 (36.9%) had cryptogenic events, of whom 187 (28.0%) had previous migraine. Migraine was more commonly associated with cryptogenic events than with those of known etiology (odds ratio [OR] 1.73, 95% confidence interval [CI] 1.38-2.16, p < 0.0001; cardioembolic 2.00, 1.50-2.66, p < 0.0001; large artery 1.75, 1.20-2.53, p = 0.003; small vessel 1.32, 0.95-1.83, p = 0.096). The association of migraine with cryptogenic events was independent of age, sex, and all measured vascular risk factors (RFs) (adjusted OR 1.68, 1.33-2.13, p < 0.0001) and was strongest at older ages (<55 years, OR 1.11, 0.55-2.23; 55-64 years, 1.48, 0.83-2.63; ≥65 years, 1.81, 1.39-2.36) and in patients without vascular RFs (0 RFs OR 2.62, 1.33-5.15; 1 RF 2.01, 1.35-3.01; 2 RFs 1.80, 1.21-2.68; 3 RFs 1.21, 0.71-2.07; 4 RFs 0.92, 0.28-2.99). Results were consistent for migraine with or without aura and for analyses excluding TIA or stratified by sex or vascular territory of event. CONCLUSIONS: In this population-based study of stroke etiology stratified by age, migraine was most strongly associated with cryptogenic TIA and ischemic stroke, particularly at older ages, suggesting a causal role or a shared etiology.
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Age Factors, Aged, Aged, 80 and over, Angina Pectoris, Atrial Fibrillation, Cohort Studies, Female, Humans, Hypertension, Ischemic Attack, Transient, Male, Middle Aged, Migraine Disorders, Myocardial Infarction, Peripheral Vascular Diseases, Prospective Studies, Risk Factors, Sex Factors, Smoking, Stroke, United Kingdom