harles Matthews is the Director of the North Carolina Comprehensive Headache Clinic. A Summa cum Laude graduate of Duke University, he was the 1978 Jefferson Fellow at the University of Virginia Medical School.
H and H- Dr. Matthews, there has been some news recently that researchers found that a genetic abnormality that causes migraine. Could you tell us about that?
Dr Matthews: I think you’re referring to the recent article published in Nature Genetics at the end of August 2010. What made the newspapers was the announcement that a specific genetic abnormality has been found associated with migraine with aura. Although there have been genetic abnormalities associated with the much rarer condition of Familial Hemiplegic Migraine, (FHP), this is the first claim of finding a genetic association with the much more common condition of migraine with aura. To go back a second, migraine with aura means that you have migraines that are preceded or accompanied by visual or other neurological disturbances.
H and H- How common is migraine with aura?
Dr. Matthews : It’s common enough that many of the Health and Healing readers may have it. About 30% of people who have migraine have these more common auras. Most have visual changes such as seeing dark spots or holes in their vision, bright lights, zigzagged lines, or colors. In patients who come to the Headache Clinic, 60% have auras.
H and H: Tell us more about FHP.
Dr. Matthews : In the rare Familial Hemiplegic Migraine (FHM), migraines are associated with stroke-like symptoms of weakness of half the body. We have some patients at the Headache Clinic who have this rare condition.
Sometimes patients with FHP, in addition to migraine, have episodes of coma or epileptic seizures. There have been three genetic abnormalities associated with this condition. Nerve cells are powered somewhat like batteries, and the genetic abnormalities that have been found occur in gene sequences that affect how neurons charge their batteries. The known genetic abnormalities probably account for about half of patients who have these rare, severe types of migraine.
H and H- So, with this new study, have we learned what causes the common migraine with aura?
Dr. Matthews: Gosh, I wish it were than simple. It turns out that God didn’t make us out of parts that work like those of a can opener. He made us out of parts that work more like neighborhoods in a city. So, if one city street closes down, others can open up and take more traffic. If you’re a can opener, one part goes and you stop opening cans. If we were made like a can opener, we wouldn’t be able to learn, adapt, or recover from injury.
When most genetic problems “cause” disease, it’s usually severe progressive childhood illnesses. For those common illnesses that most of us have- migraine, heart disease, common forms of cancer- it’s going to be very hard to make much of a connection with these genetic associations.
H and H- Tell us more about the genetic abnormality they found for common migraine with aura.
Dr. Matthews : This study was done at the Wellcome Trust Sanger Instutute in England. These very diligent researchers studied the genetic sequences of 6000 people with migraine with aura, and compared them to 50,000 people in the general population. This process is called a genome-wide association study. They found that approximately 26% of patients who had migraine with aura had a variant in the genetic sequence that codes for glutamate, which can be thought of as a natural stimulant produced by the brain.
H and H- So, does that mean that people who have migraine with aura are making too much of their own “uppers” in their brains?
Dr. Matthews: I’m glad you said that, not me! Still, that’s actually in my view a deep way to express that. But here’s the interesting part: guess how many people in the normal population had the same genetic variant?
H and H- Ummm...two percent?
Dr. Matthews : No, twenty percent. Remember what I said about being made like neighborhoods in a city? This is more of an “association” than a “cause”.
H and H: Anything else new in genetic studies of migraine?
Dr. Matthews: we have had a number of patients who have migraine with aura, an abnormal thyroid test called “reverse T3”, and severe constipation diagnosed as irritable bowel syndrome. They are often severely fatigued, as if they were hypothyroid, but their usual thyroid tests are normal. They are not “hypothyroid” in any standard sense.
These patients have responded dramatically to thyroid augmentation with a particular form of hormone called T3, with resolution of migraines as well as fatigue and digestive disturbances. We have begun work with researchers in England who are interested in the genetics of thyroid metabolism to see if these patients share the same genetic variant in the sequence that codes for the enzyme that allows the body to use thyroid hormone.
If this research works out as we hope, we will have made somware progress tounderstanding how the whole body- not just the brain- becomes sick when headaches persist over time.
The good news is that, regardless of how the research works out, effective treatment for these patients is available now.
