Migraine

Migraine

By Lori Montgomery MD CCFP

Introduction

Migraine (say: my-greyn) is a very common disorder. About 12% of women (12 out 100) and 6% (6 out 100) of men have migraines. It is by far the most common diagnosis in people who see a doctor for their headaches. The headaches are often very severe. Most people get migraines only every once in a while (episodic migraine). Some people get them nearly every day (chronic migraine). They can happen with or without an aura. An aura is a visual or other neurologic symptom, which happens 20 to 30 minutes before the headache. Not all migraines behave in the exact same way. For that reason, many people are likely given a diagnosis of some other kind of headache, when really they have migraines.

Signs and symptoms

  • throbbing or pulsating pain mostly on one side of the head (although some people have pain on both sides of the head), often felt behind or around the eye
  • pain is moderate to severe
  • pain is worse with exertion (such as climbing stairs)
  • untreated headaches most often last between four and 72 hours
  • nausea and vomiting (throwing up)
  • sensitivity to light, sound, or smell
  • some people experience nasal (nose) congestion or a runny nose with migraine
  • some people have very sensitive skin over the face and scalp during the migraine
  • some people get an aura before the headache start. This may include flashing and/or coloured lights, tunnel vision or blind spots, zig-zags or stripes in the vision, numbness or tingling over a particular part of the body (face and arm, or arm and leg, for example), or trouble speaking. Less than a third of people with migraine get auras, and most people do not get an aura with every single headache. The aura most often happens 20 to 30 minutes before a headache, and often disappears within 15 minutes or so.

Causes

Migraine is a genetic disorder that requires environmental triggers to set it off. That means that even though you have the genetic predisposition to have migraines, if you never encounter a trigger, you may never have a migraine. Genetic predisposition means you are likely to have migraines because of your genes. Genes are the building blocks that determine things like your hair and eye colour. Most migraines have many possible triggers or things that set them off. Triggers include:

  • foods and alcohol
  • weather changes
  • muscle pain
  • lack of sleep
  • low blood sugar

Some of the web sites listed below have more information on triggers.

We are not really sure how a trigger makes a migraine happen. We used to think that dilating and constricting (opening and closing) blood vessels in the brain were the beginning of the story. We still think that the pain of migraine comes from nerves related to these expanding and contracting blood vessels. We now think that there is a also sequence or order of nerves firing in the brain. This makes these blood vessels dilate and constrict in the first place. We still do not know what sets off this cycle of events.

Diagnostic tests

There is a set of criteria used to diagnose migraine, established by the International Headache Society. They include a number of the signs and symptoms listed above. If you meet these criteria, and if your physical exam is normal, there is no need for blood tests, computerized tomography (CT) scans, or magnetic resonance imaging (MRIs) to make the diagnosis. If the physical exam is not normal, you may need other tests to make sure the headache is not caused by something else.

Treatment approach

Cut down on triggers

One of the most important things you can do to treat migraine is to avoid as many triggers as possible. This means paying very close attention to the headaches (most often using a headache diary) until you know for sure what triggers are important for you. For most people, this involves getting regular sleep, eating regular, well-balanced meals, exercising daily, and avoiding highly processed food. Some people will notice other very specific triggers, which can be easy to get rid of.

Some triggers are the kind of thing you can not avoid. Weather changes are one example. But if you can cut down on the number of triggers you are exposed to at the same time, then one of your triggers alone may not set off a headache.

Non-drug therapies

Studies that non-drug therapies can help to reduce pain levels and enhance pain coping. These include:

  • relaxation
  • meditation
  • activity pacing
  • cognitive behavioural therapy

These self-management strategies can help you to improve your function so you can do more and enjoy life more.

Medicines

There are medicines that are specific to migraine, and can be helpful to stop a migraine attack if taken early enough in the course of the headache. These include triptans and ergots. Sometimes, over-the-counter medicines such as anti-inflammatories or acetaminophen, or weak opioids can also stop a headache. However, people with migraine need to be careful not to use any of these medicines on more than 10 days per month, because they can cause you to develop a medication overuse headache, and make migraines happen more often.

Other treatments will depend on how frequently the migraine happens, and how disabling it is. If it happens more than four times per month, it may be worth considering a medicine that you take daily to reduce how often the migraines occur and how intense they are. These medicines will never completely get rid of your migraines (they can not change your genetics!) They can help to make life more manageable. Some of these include:

  • calcium channel blockers (such as verapamil)
  • beta blockers (such as propranolol)
  • tricyclic antidepressants (such as nortriptyline)
  • topiramate
  • valproic acid
  • gabapentin or pregabalin

 Botox (botulinum toxin type A) has been used at times to treat migraine. It is the subject of intense research, and may prove to be useful for some people. It has not been officially approved for use in migraine, but current research appears very promising.

Invasive therapies

There are other, more invasive therapies, which are being studied for extremely severe, disabling daily migraine. They include implantable nerve stimulators and deep brain stimulation. However, there are many possible side effects of these procedures, and there is not enough research evidence yet to recommend them.

For more information

Web sites

American Headache Society
www.achenet.org

Medline Plus (U.S. National Library of Medicine and the National Institutes of Health)
www.nlm.nih.gov/medlineplus/migraine.html

Headache Cooperative of New England
www.hacoop.org

National Headache Foundation
www.headaches.org

Michigan Head-pain and Neurological Institute
www.mhni.com

World Headache Alliance
www.w-h-a.org

Headache Network Canada
www.headachenetwork.ca

National Institute of Neurological Disorders and Stroke
www.ninds.nih.gov

References

Mathew NT et al. Botulinum Toxin Type A (BOTOX®) for the prophylactic treatment of chronic daily headache: A randomized, double-blind, placebo-controlled trial. Headache. 2005;45(4)293-307.
Mathew NT. Antiepileptic drugs in migraine prevention Headache. 2003;41(s1):18-25.

Saper JR, Dodick D, Gladstone JP. Management of chronic daily headache: Challenges in clinical practice. Headache. 2005;45(s1) S74-S85.

Silberstein SD. Efficacy and safety of topiramate for the treatment of chronic migraine: A randomized, double-blind, placebo-controlled trial. Headache. 2007;47(2)170-180.

Saper JR, Dodick D, Gladstone JP. Management of chronic daily headache: Challenges in clinical practice. Headache. 45(s1):S74-S85.