Migraine headaches cause intense, throbbing head pain. These headaches can also make your nerves incredibly sensitive, and even the slightest touch becomes painful. This is called allodynia, which means "other pain." Up to about 80% of people with this condition have allodynia during an attack.
Pain is uncomfortable. But it's meant to be a helpful sensation. It warns your body that you're injured so you can stop doing whatever caused it and treat it if you need to. Allodynia, though, is pain that doesn't serve any purpose.
You also can have allodynia if you have a disease that damages your nerves, like diabetes.
Symptoms
There are three kinds of allodynia:
Static allodynia or tactile allodynia is pain from the pressure of something against your skin. It can be painful to put on a shirt, wear glasses, or put your head on a pillow.
Dynamic allodynia is pain that starts when something rubs lightly against your skin. Things like the touch of a person's hand, running a brush through your hair, or water falling on your head in the shower can trigger it.
Thermal allodynia is pain that comes on in hot or cold temperatures. For instance, breathing in cold air can cause it.
The pain, which ranges from mild to severe, is different for each person.
Causes
Migraine is more than just a headache. It is an overall condition of which the headache is just one symptom. During a migraine, your brain releases chemicals that cause the nerve endings around the brain to send signals to your central nervous system, and that can result in the throbbing head pain you feel.
When those signals keep firing for an hour or so, your nerves become hypersensitive. Even normal signals, like a touch on your scalp or face, can be very painful.
You're more likely to get allodynia if you:
- Get visual auras -- zigzag lines or flashes of light -- with your migraine headaches
- Have more than 15 headaches a month
- Have severe migraine headaches
- Have had migraine headaches for many years
- Have another pain condition, like irritable bowel syndrome, chronic fatigue syndrome, or fibromyalgia
- Have depression or anxiety
- Are female
- Are overweight or obese
- Smoke
Diagnosis
A neurologist -- a doctor who specializes in problems with your brain, spinal cord, and nerves – can help you figure out what's going on. They'll ask about your headaches, sensitivity to touch, and other symptoms. You'll also have a physical exam.
They may suggest one or more of these tests to get more information:
- Blood tests: Are usually not needed unless something else is suspected
- Magnetic resonance imaging (MRI): Are usually not needed unless something else is suspected.
Treatment
You can prevent allodynia by treating migraine symptoms as soon as they start. Some migraine drugs, including triptans, typically don't work for people who have allodynia. Instead, your doctor may give you a shot of a nonsteroidal anti-inflammatory drug (NSAID) called ketorolac or an ergot medication called dihydroergotamine.
Once your headache goes away, the allodynia usually eases up. But some people still have the pain even after the migraine is gone.
What You Can Do
Ask your doctor if you should take medicine to prevent migraine headaches, such as:
- Blood pressure drugs like beta-blockers
- Antidepressants
- Anti-seizure drugs
There are also some devices which can short-circuit the electrical activity in your brain that triggers a migraine and prevent it or halt it:
- SpringTMS or eNeura sTMS
- Cefaly
- gammaCore
Another way to avoid migraines is to have healthy routines. Exercise, get good regular sleep, and practice relaxation techniques like yoga, tai chi, or deep breathing to ease stress.
Fasting and dehydration can both set off migraine headaches. So don't wait too long between meals, and make sure you drink enough water during the day.
