Editing Cold-stimulus headache (section)

==Cause and frequency==
A cold-stimulus headache is thought to be the direct result of the rapid cooling and rewarming of the [[capillaries]] in the [[sinuses]] leading to periods of [[vasoconstriction]] and [[vasodilation]]. A similar, but painless, [[blood vessel]] response causes the face to appear "flushed" after being outside on a cold day. In both instances, the low temperature causes the capillaries in the sinuses to constrict and then experience extreme rebound dilation as they warm up again.<ref name="sa">''Scientific American Mind'', 1555–2284, 2008, Vol. 19, Issue 1. ''"Brain Freeze."'' Andrews, Mark A., Lake Erie College of Osteopathic Medicine.</ref>

In the palate, this dilation is sensed by nearby pain receptors, which then send signals back to the [[brain]] via the [[trigeminal nerve]], one of the major nerves of the facial area. This nerve also senses facial pain, so as the neural signals are conducted the brain interprets the pain as coming from the forehead—the same "[[referred pain]]" phenomenon seen in heart attacks. Brain-freeze pain may last from a few seconds to a few minutes. Research suggests that the same vascular mechanism and nerve implicated in "brain freeze" cause the aura (sensory disturbance) and pulsatile (throbbing pain) phases of [[migraine]]s.<ref name="bmj">{{cite journal |last=Hulihan |first=Joseph |date=1997 |title=Ice cream headache |journal=BMJ |doi=10.1136/bmj.314.7091.1364 |volume=314 |issue=7091 |page=1364|pmid=9161304 |pmc=2126629 }}</ref>

It is possible to have a cold-stimulus headache in both hot and cold weather, contrary to [[List of common misconceptions|popular belief]], because the effect relies upon the temperature of the food being consumed rather than that of the environment.<ref>{{Cite news |last=O’Connor |first=Anahad |date=October 11, 2010 |title=The Claim: 'Brain Freeze' Occurs Only on Warm Days |url=https://www.nytimes.com/2010/10/12/health/12really.html |access-date=June 24, 2024 |work=[[The New York Times]]}}</ref><ref>{{Cite journal |last1=Kaczorowski |first1=Maya |last2=Kaczorowski |first2=Janusz |date=December 21, 2002 |title=Ice cream evoked headaches (ICE-H) study: randomised trial of accelerated versus cautious ice cream eating regimen |journal=[[The BMJ]] |volume=325 |issue=7378 |pages=1445–1446 |doi=10.1136/bmj.325.7378.1445 |pmid=12493658 |pmc=139031 }}</ref> Other causes that may mimic the sensation of cold-stimulus headache include that produced when high speed drilling is performed through the inner table of the skull in people undergoing such a procedure in an awake or sedated state.
[[File:Gray778 Trigeminal.png|thumb|218x218px|The [[trigeminal nerve]], shown in yellow, conducts signals from dilating blood vessels in the [[palate]] to the brain, which interprets the pain as coming from the forehead.{{citation needed|date=August 2021}}]]

===Anterior cerebral artery theory===
Another theory into the cause of cold-stimulus headaches is explained by increased blood flow to the brain through the [[anterior cerebral artery]], which supplies oxygenated blood to most medial portions of the [[frontal lobe]]s and [[superior medial parietal]] lobes. This increase in blood volume and resulting increase in size in this artery is thought to bring on the pain associated with a cold-stimulus headache.{{citation needed|date=August 2021}}

When the anterior cerebral artery constricts, reining in the response to this increased blood volume, the pain disappears. The dilation, then quick constriction, of this blood vessel may be a type of self-defense for the brain.{{citation needed|date=August 2021}}

This inflow of blood cannot be cleared as quickly as it is coming in during the cold-stimulus headache, so the blood flow could raise the pressure inside the skull and induce pain that way. As the [[intracranial pressure]] and temperature in the brain rise the blood vessel contracts, and the pressure in the brain is reduced before reaching dangerous levels.<ref>{{cite web |last=Welsh |first=Jennifer |date=22 April 2012 |title=Cause of Brain Freeze Revealed |publisher=TechMediaNetwork.com |url=http://www.livescience.com/19834-brain-freeze-blood-flow-migraines.html |access-date=2012-04-24}}</ref>