Migraines and increased stroke risk has been a fairly frequent topic of research and articles over the last few years. In 2004, Etminan et. al.3 pulled together data from 14 previous studies, correlating and analyzing the data to offer a more conclusive overall picture than we'd had before.

In a new article in the American Journal of Medicine, a team led by Dr. Saman Nazarian report on the data they compiled and analyzed from 21 previous studies.1

Background:

"Observational studies, including recent large cohort studies that were unavailable for prior meta-analysis, have suggested an association between migraine headache and ischemic stroke. We performed an updated meta-analysis to quantitatively summarize the strength of association between migraine and ischemic stroke risk."1

Study methods:

  • Researchers searched electronic databases, including MEDLINE and EMBASE, for studies conducted through February, 2009, for human studies published in English.

  • They also searched the:

    • National Library of Medicine's Health Services Research Projects in Progress,
    • National Institute of Health's clinical trials registry,
    • World Health Organization's International Clinical Trials Registry Platform,
    • Cochrane Central Register of Controlled Trials,
    • Open System for Information on Grey Literature in Europe,
    • and the New York Academy of Medicine Grey Literature through February, 2009, for unpublished reports.
  • The studies included in this review included 12 of the 14 studies used by Etminan et. al.3 and nine additional studies.
  • Thirty-five studies were considered with 21 meeting the criteria for this study.
  • The 21 studies included 622,318 participants.

Study results:

"We report the largest meta-analysis to date of the association between migraine and stroke. In this meta-analysis of 21 observational studies of the association of migraine headache and ischemic stroke, migraine was independently associated with a 2-fold increased risk of ischemic stroke."

The association of ischemic stroke and migraine with aura was stronger than the association of ischemic stroke and migraine without aura.

Migraine, stroke risk, and women:

The association between migraine and stroke was strongest in studies of women. However, no direct comparison of effect estimates between men and women could be made as no studies of both men and women presented data separately by sex.

Study conclusion:

"Migraines appear to be independently associated with a 2-fold increased risk of ischemic stroke. Migraine is a potentially modifiable risk factor that can be treated, and stroke risk can be reduced through reduction of other risk factors. Therefore, further study is warranted to assess the effects of migraine control and stroke risk factor reduction on the risk of ischemic stroke in migraineurs."1

In a Reuter's News interview, Dr. Nazarian stated,

"The main thing I would want (people) to take away from this is that if they get migraines, they should address stroke risk factors. They should not smoke and they should watch their blood pressure and have it treated if it is high."2

Summary and comments:

At this point, there are enough studies of this type that there is no question that Migraine is associated with an increased risk of ischemic stroke. It is important, however, to regard this "two-fold increased risk of ischemic stroke" in context and put it in perspective.

Dr. Fred Sheftell's observations from our 2004 interview are as valid today as they were then:

To put all of this into better perspective, I went to Dr. Fred Sheftell, founder and director of the New England Center for Headache in Stamford, Connecticut, and a well known researcher and author in the field.4 He provided the statistics for those without Migraine disease and compared them to those for Migraineurs:

  • "The average stroke prevalence in women in the general population is 9 per 100,000, which represents absolute risk.
  • If patients with migraine have an average of 2.16 times greater risk that's about 20 per 100,000, still a very low absolute risk.
  • On oral contraceptives, the absolute risk is about 75 per 100,000.
  • Of course the greatest risk factor is smoking!!"

Is this something about which we Migraineurs should be concerned? Yes, but let's keep that concern in perspective. It is well worth a conversation with our doctors about these issues:

  • Reviewing our modifiable stroke risk factors including high blood pressure, exercise, smoking, hormonal contraceptives, and proper nutrition.
  • Preventing as many Migraines as possible and treating those we do get quickly and appropriately.
  • If you have any family history of stroke and how that impacts you.

What this study does not indicate is that Migraineurs should panic. As with any disease, we need to know any risks Migraine presents so we are prepared and can do our part to take care of ourselves and try to avoid complications.

When to seek immediate care:

  • As we've said before, if you have the worst headache or Migraine of your life, call your doctor or go to the emergency room. Extreme head pain can be a symptom of a stroke. Even though she was suffering from an aneurysm, Sharon Stone said it best, "If you have the worst headache you've ever had, go to the hospital because by the time you get to the hospital, you're as far gone as you wanna be."
  • If you experience numbness or paralysis that you have not experienced with a Migraine before, call your doctor or go to the emergency room.
  • If you lose consciousness during a Migraine, it hasn't happened to you during previous Migraines, and you haven't discussed it with your doctor, call your doctor or go to the emergency room.
  • If you have a severe, unremitting Migraine for more than 72 hours, it is Status Migrainous, and you should call your doctor or go to the emergency room.
  • Obviously, it's impossible to predict all circumstances under which we might need to call our doctor or go to the emergency room. If your Migraine seems out of control and frightening, it's better to get it checked out and be safe.

Other than emergencies, remember to consult your doctor whenever your Migraine patterns change. Since the symptoms exhibited by Migraine attacks can also be the symptoms of other conditions, it's important to check with our doctors to be sure they are actually Migraine symptoms.


Resources:

1 Spector, June T., MD, MPH; Kahn, Susan R., MD, MSc; Jones, Miranda R., BA; Jayakumar, Monisha, BDS, MPH; Dalal, Deepan, MBBS, MPH; Nazarian, Saman, MD. "Migraine Headache and Ischemic Stroke Risk: An Updated Meta-analysis." The American Journal of Medicine. Available online (pre-publication). May 19, 2010.

2 Norton, Amy. "Study confirms link between migraines and stroke." Reuters Health. June 2, 2010.

3 Etminan, Mahar; Takkouche, Bahi; Isorna, Francisco Caamaño; Samii, Ali. "Risk of ischaemic stroke in people with migraine: systematic review and meta-analysis of observational studies." BMJ, doi:10.1136/bmj.38302.504063.8F. December 13, 2004.

4 Interview with Dr. Fred Sheftell. December, 2004.

Medical review by John Claude Krusz, PhD, MD

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