Migraine and stroke in young women.

In this paper we review the evidence that migraine is associated with ischaemic stroke in young women, emphasizing potential biases, factors that may influence the association, potential mechanisms, and potential public health impact. Consistency of case-control findings from several countries and supporting evidence from prospective data suggest that the association is not an artifact of study design or execution, although, due to methodological limitations, none of the studies mentioned can be considered definite proof of the association. However, it is less clear whether migraine without aura is associated with stroke or whether the association is restricted to migraine with aura. Similarly, there are few data examining the magnitude of the association among nonusers of oral contraceptives compared with those who use low oestrogen oral contraceptives. As a consequence, there is a lack of data concurrently stratifying both by the presence vs. the absence of aura and by the use of low oestrogen oral contraceptives vs. non-use of oral contraceptives. Moreover, there is still no convincing evidence on the mechanisms that would be implied and on the groups of migraineurs really at risk of ischaemic stroke. Despite the considerable advances in our understanding of the relationship between migraine and stroke, there are many gaps in the data needed for public health recommendations.