One or more migraine aura symptoms associated with an ischaemic brain lesion in the appropriate territory demonstrated by neuroimaging.
A. A migraine attack fulfilling criteria B and C
B. Occurring in a patient with 1.2 Migraine with aura and typical of previous attacks except that one or more aura symptoms persists for >60 min
C. Neuroimaging demonstrates ischaemic infarction in a relevant area
D. Not better accounted for by another diagnosis.
Ischaemic stroke in a migraine sufferer may be categorized as cerebral infarction of other cause coexisting with migraine, cerebral infarction of other cause presenting with symptoms resembling migraine with aura, or cerebral infarction occurring during the course of a typical migraine with aura attack. Only the last fulfils criteria for 1.4.3 Migrainous infarction.
1.4.3 Migrainous infarction mostly occurs in the posterior circulation and in younger women.
A two-fold increased risk of ischaemic stroke in patients with migraine with aura patients has been demonstrated in several population-based studies. However, it should be noted that these infarctions are not migrainous infarctions. The mechanisms of the increased risk of ischaemic stroke in migraine sufferers remain unclear; likewise, the relationship between frequency of aura and the nature of aura symptoms denoting the increase in risk is unknown. Most studies have shown a lack of association between migraine without aura and ischaemic stroke.