Migraine and the risk of stroke: a systematic review and meta-analysis

Abstract Background and Purpose The relationship between migraine status and stroke risk was not determined. This study aims to summarize the existing evidence from prospective cohort studies. Methods We searched Pubmed, Embase, and the Cochrane Library from inception to Dec 2020, and all retrieved articles were screened by two independent reviewers. We extracted and assessed data by a structured and standardized data extraction form. The effect values were calculated using a random-effects model. This review was prospectively registered with the PROSPERO database (CRD42020197137). Results Out of 10,705 records, 19 cohort studies including a combined total of 3,523,235 participants were finally included in the meta-analysis. At a mean of 9.31 years (range 1.4–20 years) follow-up, migraine was associated with an elevated risk of total stroke (pooled RR 1.69, 95%CI 1.36 to 2.11, P < 0.001, I2 = 86%), ischemic stroke (pooled RR 1.46, 95%CI 1.14 to 1.87, P < 0.001, I2 = 95.8%), and hemorrhagic stroke (pooled RR 1.37, 95%CI 1.04 to 1.81, P < 0.001, I2 = 85.9%). The prespecified subgroup analysis found that this kind of relationship existed in migraine with aura (ischemic stroke: pooled RR 1.75, 95%CI 1.35 to 2.29, P < 0.001, I2 = 81.7%; hemorrhagic stroke: pooled RR 1.63, 95%CI 1.26 to 2.10, P = 0.266, I2 = 23.2%), but not migraine without aura. Conclusions Our study implies that migraine, particularly migraine with aura, was associated with an increased risk for both ischemic and hemorrhagic stroke.