A joint study by US and Irish scientists has revealed the reason why people experience 'brain freeze', and may pave the way for developing new cures for migraine sufferers, reports online science journal, Live Science.
Scientists from Harvard Medical School and the National University of Ireland in Galway enlisted the help of 13 healthy participants for a study on 'brain freeze', or the sharp, unpleasant sensation around the temples after consuming cold foods like ice-cream or frozen beverages.
Previous research had found that migraine suffers were more likely to experience brain freeze than those who didn't, so the researchers put this theory to the test by deliberately inducing brain freeze on participants to further study its cause.
The test subjects were each made to rapidly sip ice water through a straw until they felt the brain freeze sensation, to raise their hand once to signal its onset, and then to raise their hand again after the sensation had dissipated.
During this process, each participant’s brain was monitored using a method similar to ultrasound imaging, where high-frequency sound waves are used to take a look at internal body structures. The findings showed that while the participants were experiencing brain freeze, there was an increase in bloodflow through the anterior cerebral artery in their heads.
The increased flow, and rapid dilation of this artery in the middle of the brain behind the eyes, was directly linked to the pain experienced during brain freeze, which gradually went away as the blood flow returned to normal.
"The brain is one of the relatively important organs in the body, and it needs to be working all the time," study researcher Jorge Serrador, of Harvard Medical School, said in a statement.
"It's fairly sensitive to temperature, so vasodilation [the widening of the blood vessels] might be moving warm blood inside tissue to make sure the brain stays warm."
The researchers believe that the subsequent constriction of the artery in response to brain freeze is a natural self-defence mechanism which quickly reduces pressure in the skull before it reaches levels that are dangerous.
They concluded that if other headaches work in a similar way, new treatments for migraines could be developed, including drugs to prevent the dilation of blood vessels, or ones that mimic the body's natural response to constrict them.
The findings were presented at the Experimental Biology 2012 meeting in San Diego on April 22