Do migraines with an aura are linked to Epilepsy?

Children who have migraine with aura are at substantially increased risk of developing epilepsy, researchers from the United States and Iceland report. However, they found no apparent relationship between seizures and migraine without aura.

Senior investigator Dr. W. Allen Hauser told Reuters Health, "a possible association between migraine and epilepsy has long been recognized, but the exact relationship is not clear."
This study, he added, shows that "the relationship between epilepsy and migraine is strong, but only for migraine with aura, which accounts for only about 30 percent of all migraines.

Epidemiological studies have shown that the risk of migraine is about twice as great in adults with epilepsy as it is in those without, Hauser of Columbia University, New York and colleagues point out. They therefore hypothesized that children with migraine may have a higher risk of developing seizures and epilepsy.

The researchers identified 94 Icelandic children between 9 and 15 years old who experienced a first unprovoked seizure and had newly diagnosed epilepsy. These children with matched for age and sex to another 188 unrelated children without a history of seizures.

The investigators used a structured interview to assess headache symptoms in the children. Rather than using five or more migraine-like headaches to classified children with migraine, as stipulated by the International Headache Society, Hauser's group used two or more episodes of migraine-like headache to diagnose migraine. Visual symptoms were used to define aura.

Overall, children with migraine had a 3.7-fold increased risk of developing epilepsy. There was no increased risk in children with migraine without aura (odds ratio, 1.4) -- the increased risk was restricted to those who had migraine with aura (odds ratio, 8.2).

This finding, the researchers report in the January issue of the Annals of Neurology, "is consistent with the hypothesis that migraine with aura and migraine without aura may be different disorders."
Hauser added that "not only do the two conditions co-exist, but, at least in children, migraine precedes epilepsy."

Migraine with aura may cause epilepsy, a "plausible hypothesis" since blood vessel and possibly brain abnormalities can develop in association with migraine, or "migraine with aura and epilepsy share a common underlying mechanism. I prefer the latter."