Randomized trials of B vitamins for secondary stroke prevention are needed in patients with stroke or TIA who do not consume folate-fortified foods. These trials may also need to consider the formulation and dose of B vitamins, the level of hyperhomocysteinemia, specific methylenetetrahydrofolate genetic polymorphisms, and the patient s renal function as possible modifiers of the relationship between B vitamins and secondary stroke Migraine has been associated with ischemic stroke and white matter hyperintensities in numerous stud- In patients with migraine who have had an ischemic stroke, data on the risk of recurrent stroke are limited and conflicting.640 642 Neuroimaging studies sug- gest that there is brain hypoperfusion during migraine attacks, at least in severe migraine attacks with aura.643 On the basis of these limited data, practitioners may consider implementing preventive treatments to reduce migraine frequency in patients with migraine and prior ischemic stroke. The use of oral contraceptive agents with exogenous estrogen among women with migraine, especially when combined with active smoking, has been associated with an increased risk of stroke in numerous studies, although the quality of such studies On the basis of these data, avoiding oral con- traceptive agents with exogenous estrogen in women with migraine with aura and prior ischemic stroke may perhaps be appropriate. Knowledge Gaps and Future Research Observational studies provide conflicting evidence about the association between triptan therapy and stroke risk, and these studies excluded patients with prior ischemic stroke.645 There are theoretical risks of cerebral vasoconstriction and ischemia with the use of calcitonin gene related peptide receptor antago- but clinical evidence to quantify such risks is lacking. Therefore, no recommendations can be made for the use of triptans and calcitonin gene related peptide receptors in patients with migraine and prior ischemic stroke. 