It’s
popsicle-o-clock at the Ballard house and everyone is content… until a horrible
shriek reverberates through the home. The perpetrator is three-year-old Holden
and his tribal yell quickly morphs into a plaintative wail of “brain
freeeeeeeeezzzzze.” In a moment, 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 can instead tell her, “vasodilatation of the anterior cerebral
artery.”
This past
April, Jorge Serrador of Harvard Medical School and colleagues
reported the results of a small study suggesting an explanation for the bodily
processes (physiology) involved with brain freeze (known in medicalese as sphenopalatine ganglioneuralgia.) 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 sphenopalatine
ganglioneuralgia? And, you would be absolutely right. However, there is a
bit more to it, 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. So, with
that in mind, let’s get back to the research at hand.
Serrador
and colleagues recruited thirteen healthy adults willing to suffer through
brain freeze in the name of science (and I’m guessing there were other
inducements as well). While researchers monitored the blood flow in their brains
with transcranial Doppler (ultrasound), the volunteers sipped ice water through
straws pressed against their upper palates. Then, they raised their hands to
signal the freeze and thaw of brain freeze. Brain blood flow under these
conditions was then compared with that of 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 in that 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 constricted (tightened) as the volunteers' pain
receded. Now, remember, this was a small study and it’s results have yet to
complete the rigorous peer review process associated with manuscript
publication. Nonetheless, there do seem to be some important implications in
these findings.
1)
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. And, for people
with friends or family members with migraines, this study provides us with a
way to relate to their pain. For some with migraines, the headache must
certainly feel like one long brain freeze. Ouch.
2)
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, as
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 very 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.
3)
Now,
I can turn Holden’s occasional freezathon into a spelling lesson for his
sister. Ok, here we go, let’s try “sphenopalatine
ganglioneuralgia.” S...P...H…
