A Migraine Mystery (You’ll never guess this one…)

You’ve heard it before.  And intuitively, it seems true.

Something starts the migraine chain-reaction.  Ok, maybe we’re not sure exactly how that works.  But then the blood vessels expand and constrict, the inflammation starts.  And as your heart beats and the blood forces its way through your body, it brings on the POUND POUND POUNDING pain of a migraine headache.

But, have you ever really thought about whether that’s actually true?

Throbbing pain is, of course, a typical characteristic of migraine.  It’s one of the ways that we recognize migraine as opposed to other types of headache.  In fact, in the most recent headache classifications from the International Headache Society, in order to be diagnosed as migraine the pain must have at least two of these characteristics:  one-sided pain, pulsating, moderate or severe pain, and aggravated by activity.

But as with so many realities of headache disorders, when researchers actually investigate, they find that the mystery deepens.

For one thing, we have discovered that the constriction and dilation of blood vessels is not always a clear process when it comes to migraine.  Advanced imaging studies are discovering that vasodilation, formerly the cornerstone of migraine research, is not a necessary part of migraine after all.  (See also this study and Vasodilation and Migraine – The fall of a theory)

Although blood vessels are clearly and necessarily a part of our study of migraine, they may not be related in the way we formerly believed.

And that brings us back to that pulsating pain.

What would happen if we did the obvious, and compared the movement of blood through the body, the heart beat, the pulse, with the throbbing?  Well, now we know.  It looks something like this…

Notice anything odd?  That’s right, the pulse and the pulsating pain don’t match.  In this case, the throbbing pain was slower than the pulse.  This was typical.  But even in patients where the rate of the throbbing and the pulse were similar, they went in and out of sync.

This study (On the temporal relationship between throbbing migraine pain and arterial pulse.) and others are sending researchers scrambling to figure out what is actually causing the pulsating pain sensation.  One theory is that it’s something neurological, not directly related to blood flow at all.

Sometimes the most obvious things about migraine are not so clear once we actually check them out.  As you can imagine, the re-thinking of something simple like pulsating pain could have (and is having) huge repercussions when it comes to migraine treatment.

And in this case it’s not just migraine.  The same phenomenon has been found in other pain conditions, including other headache related conditions.

Not knowing something can actually be a benefit – as long as you know that you don’t know.

If you want to investigate this fascinating line of research further, check out:

• A Heads-up on Migraines: What Causes the Throbbing by Dr. Steven A. King
• The Neurobiology of Throbbing Pain (a continuing research project)
• The neurobiology of throbbing pain in migraine by Dr. Andrew H. Ahn
• Is there a relationship between throbbing pain and arterial pulsations? in The Journal of Neuroscience