Everyone loves summer with its long days, blazing sun and ice-cold drinks – all too often accompanied with the head-splitting pains associated with so-called ‘brain freeze’. The culprits range from ice-creams and milkshakes to chilled drinks, all having the same effect of leaving you feeling like you’ve been poked in the brain by a large sharp object. Suffering from brain freeze is not uncommon so you’re not alone. In fact approximately 40-80% of the population experience brain-freeze at some point in their life.

The scientific name for this is Sphenopalatine ganglioneuralgia which literally means nerve pain of the sphenopalatine ganglion, the nerve found at the roof of your mouth.

Brain freeze is characterised by sharp stabbing pains in the head, particularly across the forehead and temples, associated with the quick consumption of cold food or drinks. Although the sensation can be extremely painful, the pain normally fades quickly. So what causes this mysterious and painful phenomenon?

Although it is certainly not caused by our brains actually freezing, some scientists have suggested that the pain may indeed be linked to a decrease in brain temperature. One particular study from Japan found that during bouts of brain freeze, brought about by consuming a large volume of ice, the temperature of patients heads (taken from the ear) actually dropped in accordance with the cold stimuli, suggesting that brain temperature also decreased.

So what aspect of brain ‘cooling’ causes the pain associated with brain freeze? A pioneering study carried out by Jorge Serrador at Harvard Medical School may have found the answer. The study monitored blood flow to the brain in 13 volunteers as they sipped ice cold water (directed, with a straw, at the roof of their mouths). When brain freeze was induced volunteers were asked to raise their hands as a signal, then raising them again once the pain subsided.

It was found that one of the brains major suppliers of oxygenated blood, the anterior cerebral artery, dilated (increased in size) whilst drinking the iced water. This lead to an increase in blood flow to the brain and was regularly followed by pain. Interestingly, as the cerebral artery shrunk back to its original size, restoring regular blood flow, the symptoms associated with brain freeze subsided. Serrador concluded that the increase in blood flow and therefore size of the cerebral artery was responsible for the pain associated with brain freeze. Specifically, he speculated that the pain may be brought about by an increase in cranial pressure caused by the increased blood flow.

The brain is one of our most delicate and sensitive organs; extremely sensitive to changes in temperature. It is possible that brain-freeze may be a defence mechanism, protecting our brains from large fluctuations in temperature. If the ganglion, in the roof of the mouth, detects extreme cold it causes an increase in blood flow to the brain, which is important to keep it warm. As more blood flows into the brain, the pressure inside the skull increases causing pain. The blood vessel then constricts again to reduce the pressure.

It’s also interesting to note that migraine sufferers are actually more likely to experience brain-freeze than those who don’t suffer from migraines. Indicating that the two may share a common mechanism.

So, that’s a quick run-through of the science behind what is actually happening to your body during brain freeze. So next time you’re in the pub and someone tells you they have brain freeze, you can astound them with your knowledge of the science behind it!

Post by: Sam Lawrence