Oxygen treatment of headaches was first mentioned in literature in 1939. Mr. Charles E. Rhein, Linde Air Products Co., reported to Dr. Alvarez at the Mayo Clinic in Rochester, MN the successful treatment of severe "migraine" attacks by breathing pure oxygen. Subsequently, Dr. Alvarez noted that the treatment with 100 percent oxygen at a flow of six to eight liters a minute would often produce relief. Sometimes patients would not be able to obtain relief with this treatment, whereas at other times they would. In 1940, Dr. Alvarez reported the treatment of over 100 persons suffering from headache attacks. They were treated with oxygen with a nasal type of mask and a flow of six to eight liters a minute. He found that 80 percent of "migrainous" headaches were completely or significantly relieved. Dr. Alvarez also found that patients with other types of headaches were often helped through the use of oxygen inhalation and that the prompt institution of therapy had a better chance of resulting in relief than if it was delayed. This work was much less rigorous than that done recently.
