Dr. Ballard is an associate emergency physician at Kaiser-Permanente in San Rafael, CA, and the chair of the CREST ED Research Network. His writing credits include co-authorship with Angela Ballard of the award-winning travel narrative A Blistered Kind of Love: One Couple's Trial by Trail (Mountaineers Books, 2003) and authorship of The Bullet's Yaw (IUniverse, 2007). Dr. Ballard writes a biweekly-medical column for the Marin Independent Journal, which he posts on his blog: http://incisionanddrainage.blogspot.com.
It's popsicle-o-clock at the Ballard house, and everyone is content — until a horrible shriek reverberates through the house. The perpetrator is 3-year-old Holden and histribal yell quickly morphs into a plaintive wail of “brain freeeeeeeeezzzzze.” The pain (for all of us) recedes, and our daughter, removing her hands from her ears, asks, “Dad, what causes brain freeze?”
Until recently I would have answered, “Popsicles,” but now, thanks to new evidence, I caninstead tell her, “vasodilatation of the anterior cerebral artery.”
This past April, Jorge Serrador, MD, of Harvard Medical School and colleagues reported the results of a small study suggesting an explanation for the physiology involved with brain freeze (known in medicalese as sphenopalatineganglioneuralgia.) Now, I know what you might be thinking, with autism unexplained and cancer uncured, aren't there greater priorities for medical research than a painful yet benign experience like sphenopalatineganglioneuralgia? You are absolutely right.
There is a bit more to it,however, and some have long posited that the physiology of brain freeze might be related to that of other (less temporary) conditions such as post-traumatic and migraine headaches. In fact, prior studies have suggested that migraine sufferers are more likely than other folks to experience brain freeze.
Serrador and colleagues recruited 13 healthy adults willing to suffer through brain freeze in the name of science (and I'm guessing there were other inducements as well). Researchers used transcranial Doppler to monitor the blood flow in the brains of the volunteers sipping ice water through straws pressed against their upper palates. They raised their hands to signal the freeze and thaw of brain freeze. Brain blood flow under these conditions was then compared with the same volunteers sipping warm water.
The results of the study were presented at the Experimental Biology 2012 conference in San Diego, and were notable because the researchers observed that one particular artery, the anterior cerebral artery, dilated rapidly and flooded the brain with blood in conjunction with the freeze sensation. Soon after this vasodilatation occurred, the same vessel constrictedas the volunteers' pain receded. Now, remember, this was a small study and its results have yet to complete the rigorous peer-review process. Nonetheless, there do seem to be some important implications in these findings.
Migraine headaches. These are thought to be caused by abnormal dilation of arteries in the brain, and many existing treatments attempt to modulate this process. These results then support this concept and may lead to greater focus on migraine treatments that prevent dilation in the first place. This study provides us with a way to relate to the pain of our friends and family members with migraines. A migraine must certainly feel like one long brain freeze. Ouch.
The suddenness of sensation matters. We've all heard about the frog that will jump out of a pot of boiling water but will stay in a tub slowly brought from ambient temperature to a boil. One of the aspects of brain freeze that makes it so uncomfortable is the rapidity and severity of its onset. This principle is worth keeping in mind for other situations. Take, for example, removing a bandage. The conventional wisdom is that pulling it off quickly is better; it gets the pain over and done with. But some researchers, such as Dan Ariely, the author of the fascinating book Predictably Irrational, contend the opposite; the quicker the pain the more severe the pain and thus the greater the overall discomfort. So perhaps slowly removing a Band-Aid is actually more comfortable than yanking it right on off. That's a topic to be exposed more thoroughly some other time.
Now, I can turn Holden's occasional freezathon into a spelling lesson for his sister. Ok, here we go, let's try sphenopalatineganglioneuralgia. S...P...H….
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