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.
Harvard Medical School scientists who say they have a better idea of what causes brain freeze, believe that their study could eventually pave the way to more effective treatments for various types of headaches, such as migraine-related ones, or pain caused by brain injuries.