Migraine with Aura and Migrainous Infarction
In rare cases, an ischemic infarction can occur during an attack of migraine with aura. An infarction is an area of tissue death due to obstruction of the local circulation, aka stroke. When this occurs, without other reasons, it's termed a migrainous infarction. It can occur in a migraine with aura attack that's like previous attacks, except that one or more aura symptoms last longer than 60 minutes.
A diagnosis of migrainous infarction requires imaging to confirm the infarction and to rule out other causes. Since time is critical in treating infarction successfully, it's essential to get care immediately if we think it's possible that we've had an infarction. Therefore, it's important for everyone to know the symptoms of infarction / stroke. You can read more about these symptoms in Stroke - The Basics.
For consistency in diagnosing and classifying head pain disorders, the _International Headache Society'_s International Classification of Headache Disorders, 3rd Edition (ICHD-3), is generally accepted as the "gold standard." This provides standardization of diagnoses, providing guidance and reducing confusion.
The ICHD-3 on Migrainous Infarction:
1.4.3 Migrainous infarction
One or more migraine aura symptoms associated with an ischaemic brain lesion in the appropriate territory demonstrated by neuroimaging.
- A migraine attack fulfilling criteria B and C
- Occurring in a patient with 1.2 Migraine with aura and typical of previous attacks except that one or more aura symptoms persists for more than 60 minutes
- Neuroimaging demonstrates ischaemic infarction in a relevant area
- 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 fulfills 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.
More Helpful Information:
Headache Classification Committee of the International Headache Society. "The International Classification of Headache Disorders, 3rd edition (beta version)." Cephalalgia. July 2013 vol. 33 no. 9 629-808. 10.1177/0333102413485658.