The prognosis of hemiplegic migraine is usually good. Hemiplegic migraine patients often stop experiencing attacks after the age of 50 (Bradshaw and Parsons 1965; Ducros et al 2001). Young patients with migraine with aura are at increased risk for stroke. Other causes of ischemia, including patent foramen ovale, lupus anticoagulant, cervical carotid dissection, arteriovenous malformation, and hyperactivity of the clotting system, should be identified in patients with migraine (Weinberger 2007). Data on the incidence of migrainous infarction are lacking. Cerebral angiography carries a 1% risk of stroke, and the risk is not more common in migraineurs than in nonmigraineurs (Shuaib and Hachinski 1988). However, it can precipitate a severe migraine attack leading to stroke in patients with familial hemiplegic migraine (Harrison 1981). An increased release of glutamate could have a role in increased susceptibility to ischemic cerebral tissue in familial hemiplegic migraine models (Eikermann-Haerter et al 2012).
Ischemic stroke and migraine with aura are major parts of various syndromes, including MELAS (Pavlakis et al 1984), CADASIL (Tournier-Lasserve et al 1993; Vahedi et al 2004), and autosomal dominant vascular retinopathy, migraine, and Raynaud phenomenon (Terwindt 1998b). The prognosis of these syndromes depends on the presenting disorder. A 7-year follow-up assessment in 6 members of a familial hemiplegic migraine family revealed no global cognitive decline, but figural memory, attention, and some executive functions were impaired (Karner et al 2012).