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Migraine Associated With Incomplete Brain Artery Structure

Migraine Associated With Incomplete Brain Artery Structure

A network of arteries in the brain called “the circle of Willis” is more likely to be incomplete in Migraine patients than in non-Migraineurs, according to a study by researchers at the University of Pennsylvania.

Researchers used imaging to examine the brain structures in three groups: a Migraine-free control group, a Migraine with Aura group, and a Migraine without Aura group. Although incomplete circle of Willis, a structure that protects the supply of blood from arteries to the brain, is actually quite common, it was more frequently observed in study subjects with Migraine with Aura and Migraine without Aura than in the Migraine-free control group.

The research team also measured changes in cerebral blood flow to learn more about the possible association between the circle of Willis structural abnormality and cerebral blood flow. Based on their analysis, there is diminished cerebral blood flow in areas supplied by the circle of Willis.

Blood vessels have been thought to play a role in the Migraine process for many years. But as we’ve learned more about Migraine, specific beliefs about that role have changed.

Migraine used to be considered a vascular disorder. Dilation of blood vessels in the head was believed to be responsible for a Migraine attack. It’s now a widely accepted view that the Migraine process is instead initiated by neurons and a cascade of events in the brain. But the changes in cerebral blood flow observed in this study suggest blood vessels are also involved in Migraine in some way we don’t yet understand.

These researchers hypothesize that cerebral blood flow impairment may allow development of a lack of oxygen (ischemia) relative to the excitement of neurons, trigger cortical spreading depression and predispose Migraineurs to stroke and lesions.

Unfortunately, the study had a very small sample size, which significantly limited the research team’s ability to draw many conclusions about circle of Willis and cerebral blood flow. Future research that builds on these findings may give us more information and confirm the hypothesis about the role of cerebral blood flow changes.

This article represents the opinions, thoughts, and experiences of the author; none of this content has been paid for by any advertiser. The team does not recommend or endorse any products or treatments discussed herein. Learn more about how we maintain editorial integrity here.

1. Brett Cucchiara, Ronald L. Wolf, Lidia Nagae, et al. "Migraine with Aura is Associated with an Incomplete Circle of Willis: Results of a Prospective Observational Study." PLoS One 8(7): e71007. doi:10.1371/journal.pone.0071007.


  • Hope
    5 years ago

    Very interesting. I wonder if being born prematurely would affect the Circle of Willis to completely form? Thank you for this informative article. Today is yet another migraine day, I am medicated, praying the severe nausea does not kick in and will attempt going to work. Weather change.

  • Michael
    6 years ago

    Finding this article was wonderful timing as I had just came to the conclusion that the fat in various foods was the activator of my headaches. That and sunlight, both of which affect the amount of blood getting to my brain. Fats, via plugging up capillaries, and sun as a tension producing heat source and eye strain.

    More oxygen to the brain. Problem hopefully solved. Thanks.

  • mjsymonds
    6 years ago

    “These researchers hypothesize that cerebral blood flow impairment may allow development of a lack of oxygen (ischemia) relative to the excitement of neurons, trigger cortical spreading depression and predispose Migraineurs to stroke and lesions.”

    This hypothesis from the article ties into something that happened to me a number of years ago. At a friend’s suggestion, I saw a spiritual healer while in the middle of a migraine and during the session she told me, “Your brain is not getting enough oxygen.” It was the only thing she said to me, and afterwards, I still had the migraine–which didn’t really surprise me, but you know, hope springs eternal…

    Anyway, aside from practicing deep slow breathing during a migraine, I wasn’t quite sure what to do with that information, so I asked her afterward if she could explain it further. First, she asked me what it was she’d told me(!) Because, since she’s always in a trance state during the healing and the messages “come through her but not from her,” she didn’t even remember saying it, so no, she couldn’t explain it any further. Well, that was interesting! But for some reason “your brain isn’t getting enough oxygen” has always stuck in my mind, and I’ve continued to wonder if there would ever be a medical explanation that would make sense of it.

    Well, maybe this is it? But even if that odd experience hadn’t happened to me, I think this is exciting research and I hope more is done in follow-up studies to build on these findings associated with an incomplete circle of Willis and cerebral blood flow changes. Of course, I’d love to know the state of my own brain arteries!

    Thanks, as always, Diana for your clear and detailed articles on the results of the latest migraine studies.

  • nrsrcht
    6 years ago

    I have experienced migraines for about 50+ years and over that time they have changed. For the last 15 or so years I have not been able to sleep on my left side (headache side) and must sleep in an inclined position. I recently was diagnosed with (FMD) Fibro Muscular Dysplasia in the brain. I have bifurcation at the carotid and blood vessels above that are spiral shaped. I certainly am interested in hearing more about this new information.

  • Ellen Schnakenberg
    6 years ago


    Needing to sleep in a raised position can indicate you need some additional testing. Some headache types are orthostatic, which means they respond to positioning up or down. This could be really important for you. Here is some information to read about one of the tests that is usually done on patients who have orthosttic headache issues: and here is one of the conditions associated with the need to sleep in a raised position:


  • mjsymonds
    6 years ago

    nrsrcht – I’m in my 50s now with 45 years of migraine and several years ago I also had to start sleeping in an inclined position or I woke up with a migraine every day. I also find it difficult to sleep on my left (migraine) side. What you say about your diagnosis is very interesting to me. What sort of imaging did you have done? MRI or CT scan with contrast?

  • Vicki
    6 years ago

    Well, this gives the “Whatchoo talkin’ bout Willis?” thing a whole new meaning!! lol

    I hope to hear more about this. Interesting.

  • Ellen Schnakenberg
    6 years ago

    Vicki – Thanks for the LOL moment 🙂 Perfect timing today!!!

  • Diana-Lee author
    6 years ago

    LOL! Yes, I hope there will be more research following up on this study.

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