Chronic Migraines: A Tidal Wave of Activity in the BrainFeb 24, 2014
An estimated 36 million people in the U.S. suffer from chronic migraines, an illness for which there are limited medications and no cure. Dr. K.C. Brennan describes a migraine as a tidal wave of activity that turns up the volume of the senses in the brain and debilitates many people. Listen as Dr. Brennan explains how his and others’ research is revealing more about chronic migraines and that he expects new discoveries in the next 10 years.
Recording: Medical news and research from University of Utah physicians and specialists you can use for a happier and healthier life. You're listening to The Scope.
Interviewer: Chronic migraines are a mysterious and debilitating illness that affects an estimated 36 million people in the United States. That's a large number of patients who have a chronic illness for which there is no known treatment or cure.
Dr. K.C. Brennan is an assistant professor of neurology at the University of Utah School of Medicine. He's an expert in treating and researching migraines and he's here today to talk to us about migraines. Dr. Brennan, welcome.
Dr. K.C. Brennan: Thank you for having me.
Interviewer: Would you just quickly explain what a migraine is.
Dr. K.C. Brennan: Imagine a pounding headache, throbbing pain, then imagine that normal light hurts your eyes, sound hurts your ears, normal smells and tastes make you feel nauseous, you're completely incapacitated, that's what a migraine is.
Interviewer: What are the common migraine treatments right now and how well do they work?
Dr. K.C. Brennan: The best medications we have are called the triptan drugs, Imitrex, Maxalt, those are the names of these drugs and you see them advertised. There's been no single medication developed to prevent migraine.
Interviewer: How much do we know about these migraines right now, in terms of what causes them?
Dr. K.C. Brennan: We know that migraine is a pain disorder; it's a disorder where your pain system is activated when it shouldn't be activated. But we also know that migraine is an excitable disorder of the brain, it's the brain firing when it shouldn't be firing.
Migraine is also a disorder of plasticity, plasticity is the ability of the brain to change itself and it's what the brain does when it learns. When you see a chronic migraine patient you realize that their brain has learned to produce pain when it's not supposed to. I think that's a very important way of framing the question of migraine.
Interviewer: At the moment though we really don't know why the brain is doing this.
Dr. K.C. Brennan: We know that your genetics contribute a lot, there is your environment, you know, light and sound can trigger migraines, they sort of set the process off. Stress is a huge trigger of migraines, and release from stress, so not just a kid going into exams but that kid after they're done with exams suddenly stress releases and that's when they get their migraines.
Hormones are a very big part of it so two-thirds of people with migraine are women, only one-third are men, why is that? Well we think it's because of female sex hormones. So there's a lot of factors that can trigger or modulate, they can turn the volume knob up or down or start things off. We do not know the ultimate cause and that's probably because there are many ultimate causes.
Interviewer: Do migraines tend to run in families?
Dr. K.C. Brennan: They do tend to run in families.
Interviewer: What's the current state of research in migraines? How much are we learning and what are the big questions that people are looking at?
Dr. K.C. Brennan: I think there's been a real infusion of strength into the migraine field from two fronts, one is that we're now doing imaging in humans with migraine, so we're able to actually look at the brains of people with migraine. The other area where we've really had an infusion of strength is we're looking at migraine as a pain disorder, how pain works in the brain in general and then what makes migraine unique.
Interviewer: Can you just give us a little bit more in depth detail about what you've discovered and what you're hoping eventually to accomplish.
Dr. K.C. Brennan: What we've done recently is try and look at what this event, cortical spreading depression, which is the event that underlies the aura, what it does to the brain that might contribute to the migraine attack because the aura is something painless.
Interviewer: Yeah, and to be clear, when you talk about a spreading depression, the cortical spreading depression, define that if you would, that's a massive firing of?
Dr. K.C. Brennan: Right, it's got an unfortunate name, spreading depression is a massive wave of activity, it's like a tidal wave in the brain and it spreads out and it doesn't respect boundaries in the brain, it just moves out like a ripple in a pond.
Interviewer: And this itself, the aura itself is not, is it the migraine or is it what pre-stages the migraine?
Dr. K.C. Brennan: It's considered part of a migraine attack for people who have migraine with aura. Now there are people who have migraine without aura and there's fertile debate in our field about whether these are different kinds of migraine or whether they're all the same thing.
Interviewer: Where do you see research going and how much more do you think we will know about migraines 10 years from now?
Dr. K.C. Brennan: I'm optimistic we're going to know a huge amount more and I'm optimistic for a number of reasons. We've got tools to study migraine, in the lab and in the clinic that are just wondrous.
Interviewer: Is there some evolutionary reason that this volume knob might have been turned up?
Dr. K.C. Brennan: One line of thought goes, what goes on in migraine is essentially the sickness response. A person with migraine is very much like a person with a bad flu. When you have a bad flu or when you have meningitis or something like that, you know, all the senses hurt. And this is known as the sickness response that there's an inflammatory everything hurts reaction that goes on that incentivizes the person to get somewhere where they can get better, go to a dark room, lie down, heal up.
It seems like that sickness response gets switched on, that sickness volume knob gets turned up in migraine for reasons that don't make sense. The circuitry that creates migraine exists for a reason but it gets overused in migraine and then it entrains itself it becomes this daily miserable thing.
Recording: We're your daily dose of science, conversation, medicine. This is The Scope, University of Utah Health Sciences Radio.