Scientists find those with epilepsy who have a strong family history of the disorder are also more likely to have migraines. The study showed a higher prevalence of migraines among epileptics who also had two or more family members with epilepsy. The results suggest similar genetics may underlie both conditions.
'Epilepsy and migraine are each individually influenced by genetic factors. Our study is the first to confirm a shared genetic susceptibility to epilepsy and migraine in a large population of patients with common forms of epilepsy', says lead author of the study Dr Melodie Winawer of Columbia University, New York.
Migraine affects 15 percent of adults in the UK, of which a third experience aura before the onset of migraine. Aura refers to symptoms signalling the start of a migraine, such as visual problems or stiffness in the neck and shoulders. Epileptics with two or more first-degree relatives with epilepsy - defined as parents, siblings or children - were more likely to have experienced migraine with aura, compared to epileptics with less than two first-degree relatives with epilepsy.
'Our study demonstrates a strong genetic basis for migraine and epilepsy, because the rate of migraine is increased only in people who have close (rather than distant) relatives with epilepsy', said Dr Winawer.
The study included 730 participants, all of whom had epilepsy of unknown cause and had two or more relatives with epilepsy, suggesting that the genetic make-up of the family may have contributed to the presence of the disorder. They were questioned about their medical history, specifically whether they experienced migraines, with or without aura.
Ten percent of participants with no first-degree relatives with epilepsy had migraine with aura, this increased to 11 percent of participants when one first-degree relative also had epilepsy, and 25 percent when two or more first-degree relatives had epilepsy. Including more distant relatives with epilepsy, who were therefore genetically less similar to the participant, did not continue this trend.
These results led the scientists to suggest that there may be a genetic link between epilepsy and migraine with aura. Further work is needed to test whether this association can be backed up with more definitive genetic evidence.
Deputy chief executive of the charity Epilepsy Action, Simon Wigglesworth told the BBC: 'Having a better understanding of the genetic link between epilepsy and other medical conditions can only be a good thing. It means that steps can be taken to improve diagnosis and treatment for people living with epilepsy and co-existing conditions'.
The study was published in the journal Epilepsia.