The Progressive Era. During the period known as the Progressive Era (1890s to about 1920) the U.S. government became increasingly activist in both domestic and foreign policy.
One possible link between brain freeze and other headaches is local changes in brain blood flow. If further research confirms all these types of headaches are caused by blood flow changes, new drugs that block widening of the blood vessels - called vasodilation - could improve treatment for sufferers.
This simple fact can be applied to the biological cause of brain freeze as well. Upon contact with ice, the blood vessels in the roof of the mouth begin to constrict, making the vessels in the head to expand, and thus creating a headache. 2) Trigeminal nerve factor: The trigeminal nerve, or cranial nerve 5 (CN5), is responsible for facial sensation.