The foramen ovale is a hole located between the top two chambers of the heart of fetuses. Normally, within the year after birth the hole closes but for some people it stays open and is known as patent (open) foramen ovale. This hole between the upper chambers of the heart (atria) results in abnormal blood flow from the right side of the heart to the left. Migraine and patent foramen ovale are both risk factors for stroke.
“Later, a number of studies found that the incidence of PFO in migraine patients was 14.6-66.5% while the incidence in the general population was 9-27.3%.”1