Magnets Mitigate Migraine
Chris - Also in the news this week, researchers have shown that you can knock migraines on the head with a magnet. Dr. Richard Lipton is a neurologist at the Albert Einstein College of Medicine. He's based in New York and he is with us now. Hello, Richard.
Richard - Hi, there.
Chris - Welcome to the Naked Scientists. You've worked on migraines but many people may not understand exactly what a migraine is. So could you first of all tell us what a migraine really is, medically speaking?
Richard - Sure. So migraine is a specific headache disorder that's characterised by pain that's usually one-sided, usually throbbing, often associated with a visual display called an aura, but always associated with something other than just pain, sometimes aura, sometimes nausea, sometimes sensitivity to light or sound.
Chris - And what do we think is going on in the brain to trigger these, initially, visual effects and then this throbbing pulsing headache that makes people do other things like retire into a dark room and sometimes unfortunately experience nausea?
Richard - Well for migraine with aura, which was what my study was about, there's a lot of evidence that what's going on in the brain is an event called cortical spreading depression. And in cortical spreading depression, which you can also produce very easily in experimental animals, you have a wave of excitation followed by a wave of inhibition marches slowly forward over the surface of the brain. As it marches, if it's in visual cortex, it produces spots of light, the zigzag lines, and then the inhibition produces a greying out of vision which is sometimes called the scotoma.
Chris - And then people get the pain, but why do they experience pain?
Richard - The link between aura and pain probably has to do with the fact that there are pain sensitive fibres in the membranes that surround the brain, referred to as the meninges, and the aura itself directly activates these pain sensitive fibres in the brain which are parts of a nerve called the trigeminal nerve and that is likely how aura initiates pain in migraine.
Chris - So in your study, you were asking, can a pulse of magnetism alter the outcome of someone seeing initially these auras. Does it prevent them going on to get a headache?
Richard - Well, the method we used is called transcranial magnetic stimulation. It's a method that's been around for 30 years. The idea is that if you apply a powerful magnet to the surface of the skull, the magnetic field penetrates through the skull into the brain and induces a small amount of current flow and depending on where you do it and when you do it, that can have either diagnostic or therapeutic applications.
Chris - So how many people did you enrol in your study and what were the outcomes?
Richard - So here, the idea was to use a magnetic pulse to induce a current during the aura of migraine with the idea that if you induce the current flow, you would disrupt that march of electrical activity and possibly prevent or dramatically reduce pain. So we ended up randomizing about 200 people, 160 of whom we ended up treating either with the real magnetic device or with a sham device that vibrated and clicked, but did not deliver a magnetic field. And we found that of the people who got the real device, 40% were pain-free 2 hours later and remained pain-free at 24 and 48 hours, so most of them. Whereas only 20% did that well when they were treated with the sham device and that's a result comparable to what you see with the best as available medical therapy.
Chris - Speaking of which, I've got an email here from Seraphina Anderson who says, "Why don't normal pain killers like paracetamol or ibuprofen work when you get a migraine?"
Richard - Well sometimes they do and you know, and like every condition, there's a broad spectrum of severity. So, ibuprofen and paracetamol may work if you treat the migraine very early. If you wait and wonder if you need to treat, oral medications become less effective because migraine also affects the gut and you may not absorb the medication as well. For people who don't do well with over-the-counter medications, there's certainly a wide range of prescription drug options that are very effective. So I'm certainly not saying this is the only way to treat migraine.
Chris - Given how common it is, very large numbers of people suffer with migraines, is your method safe, to your knowledge, and therefore, what's the next step? Will we be seeing magnetic stimulators on the shelves of pharmacy shops so people can go and get one if they regularly suffer migraines?
Richard - My hope is that the answer is yes. So in the UK, 18% of women, 6% of men have migraine so it's an extraordinarily common disorder in the UK, in the US and Western Europe or really around the world. Yes, the hope is that this will receive regulatory approval as a medical device and that it will become available to people who want to use it. There is a portable device - For most of its 30-year history, TMS was given with a large 70-pound device that cost perhaps $25 to $30,000 that was kept in doctor's offices and used by medical personnel. We studied a portable device that weighs about 3 pounds. It's about the size of a hair dryer and the intention is that people will take the device home and when they get a headache, they'll have an alternative to reaching for either an over-the-counter or prescription medication.
Chris - Let's hope so. Thank you very much. Richard Lipton, who's at Albert Einstein College of Medicine and that research, if you want to read up a little bit more about it, it's in the April edition of the Lancet Neurology.