Diffusion-weighted lesions in acute ischaemic stroke patients with migraine

Objectives There is increasing knowledge about an association between migraine and ischaemic stroke. Cortical spreading depression (CSD) is the probable biological substrate of migrainous aura. To investigate the influence of CSD on the apparent stroke - migraine association, we hypothesized that magnetic resonance (MR) diffusion weighted images of acute ischaemic stroke patients would reveal an association between small cortical infarctions and migraine. Methods We included all patients admitted to the Bergen stroke unit between 2006 and 2012 with verified acute ischaemic stroke by MR imaging. Patients were grouped in a migraine and a no-migraine group. Baseline data and clinical characteristics were analysed between the groups. Imaging data were analysed with respect to infarct location and size. Multivariate analyses were performed to adjust for confounders and provide risk estimates for observed associations. Results A total of 1703 subjects were enrolled, 787 subjects were excluded due to uncertain or unobtainable migraine diagnosis, leaving 196 and 720 subjects in the migraine and no-migraine group, respectively. The migraine group was younger and included a higher proportion of females. There were more infarctions due to cardio-embolism (P=0.015) and fewer due to small vessel disease (P=0.018) in the migraine group. A higher rate of patients in the migraine group presented symptoms from the posterior circulation (P=0.008). Migraine was associated with cortical infarctions (OR 1.8 CI: 1.3-2.5, P=0.001). Migraine was also associated with small infarctions (OR 1.9 CI: 1.04-3.5, P=0.038). Conclusions Migraine was associated with small cortical infarctions. This association may be due to cortical spreading depression.