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Art Taught Scientists About Migraine’s Pathophysiology

Well before the use of MRI and fMRIs, drawings of visual auras gave researchers an indication of what happens in the brain at the onset of a migraine. These artistic representations – the most helpful of which were drawn by scientists who have migraine with aura – have led to crucial discoveries about the pathophysiology of migraine.

The most notable discovery is of the involvement of cortical spreading depression, now understood to be a key component of how migraine spreads through the brain. (Maggie Koerth-Baker’s elegant description of cortical spreading depression is “…electrical stimulation and depression moving through the cerebral cortex. Think about it like a wave, with a crest where electrical impulses are stronger than normal, followed by a trough where they are lower than normal.”)

An academic paper exploring the connection between drawings of visual auras and migraine research developments was published in the journal Brain in 2007. I learned about that paper when Boing Boing reported on it this week. Both are worth a read, though the Boing Boing article is much easier to get through.

This is a fascinating investigation even for those of us who don’t have visual auras. I love the idea artistic representations created by migraineurs played a pivotal role in understanding migraine.

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Why Women Have More Migraines Than Men

Three times as many women have migraine as do men. That translates to 18% to 25% of women worldwide. A new study shows that this discrepancy might be because women’s brains are faster to activate the cascading waves of activity thought to cause migraine pain and other migraine symptoms.

The strength of the stimulus required to trigger these waves of activity, called cortical spreading depression (CSD), was two to three times higher for men than for women. This excitability indicates that women’s propensity toward migraine is linked to more than just menstrual cycle.

I have the mental ability of a three-year-old today. See A Woman’s Brain Wired for More Migraines? from CBS/WebMD and Why Women Get More Migraines Than Men, a UCLA press release, for details.

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Reinterpreting Study on Migraine & Brain Damage

Headache specialist Dr. Christina Peterson‘s comment on Migraines Linked With Brain Damage points out that one study never reveals absolute truth. Nor are articles written for the general public usually preceeded by the analysis necessary to critically evaluate research findings. As Dr. Peterson writes, it is “distressing and somewhat irresponsible that every finding in the medical literature becomes a sound bite for the media.”

“For anyone who thinks the information presented here is condescending–please note that most of what Kerrie has put forward here has been written by journalists, and
not by medical experts
. It has been paraphrased from the original medical studies. I personally find it distressing and somewhat irresponsible that every finding in the medical literature becomes a sound bite for the media.

“It is the unfortunate fact that not every study can be taken as absolute gospel truth. This is why we call our ideas “hypotheses,” and we set up studies to test our hypotheses. Generally speaking, we consider them to be working hypotheses until newer ideas are discovered to expand our understanding of the concept. And even then, we are not
fully comfortable until new findings are confirmed by several studies.

“A good chunk of what we are taught in the early part of medical school is how to interpret studies in the medical literature–how to analyze the validity of study design, how to be certain the statistical analysis was done correctly, and how to tell if a given study actually measured anything that matters.

“There are a number of issues presented here. White matter lesions (those white spots on MRI scans that some migraineurs get) may or may not reflect anything to do with brain damage. We do not know yet. However, there was a paper presented this past week in Boston at the Academy of Neurology meeting that suggests not. But I would want to see
further confirmation before I would be certain about anything. White matter lesions, however, are unlikely to cause cognitive damage, as it is the gray matter that does the thinking.

In the study that suggests “older” migraine sufferers have no cognitive decline–this was determined by conducting a 10 minute test called the Mini-Mental Status Exam, which is not particularly rigorous testing. Genetic material was also collected for a test called APOE4, which has been associated with Alzheimer’s. However, very recent research conducted at Yale has demonstrated that the APOE4 genetic allele is associated with psychosis in Alzheimer’s, and not with cognitive decline or loss of function. (The migraine researchers could not have known that when they began their study some years ago.)

“In Boston, I saw microscopy pictures of blood vessels, brain cells, and receptors specially stained to show what happens during cortical spreading depression. This was research done at Harvard-MIT. It was fairly clear that there is oxygen loss in the cellular areas in between the capillaries during cortical spreading depression (CSD). Does this
cause cognitive loss? We don’t know.
The type of researcher who looks at cellular and subcellular structures is generally not the same type of researcher who studies cognitive responses in a whole person.

“Research can be excruciatingly slow. We have, for example, known about CSD since the 1930s, but it took time before it was proven to be associated with migraine, and even longer before we have been able to more clearly understand its significance. We are only now learning exactly what happens chemically during CSD.

“The take-home message is that not everyone with migraine is the same, and that, NO–it’s NOT JUST A HEADACHE!