How can Migraine Lead to Ischemic Stroke?
So far, no fully convincing evidence has been produced to explain the exact mechanism of the increased risk of ischemic stroke in migraine. Numerous hypotheses have been raised including vasospasm, endothelial dysfunction, congenital thrombophilia, platelet hyperaggregability, and association with cardiac abnormalities, among others.A first hypothesis is that stroke can occur during the course of migraine attacks with aura (migrainous stroke). Migraine is considered to be a neurovascular disorder in which arterial constriction and decreased blood flow to the posterior circulation are consequences of a spreading wave of neuronal depression in the cerebral cortex. In this regard, CSD may induce short-lived increases in cerebral blood flow and tissue hyperoxia (Cao et al, 1999), followed by a more profound oligemia and consequent increased intraparenchymal vascular resistance (Cutrer et al, 1998). Thus, low flow in major intracerebral vessels may be due to increased downstream resistance
