Acute epidemic poliomyelitis is a systemic infection in which the most important lesions occur in the central nervous system. Unless the disease process is checked, the meningeal irritation is followed in a short time by manifestations of involvement of the nerve tissue proper. The initial toxic reaction in the cord or brain stem is a hyperemia and edema, resulting in a local increase in pressure. At the site of the local increase in pressure the smaller blood vessels are compressed, and the part of the cord supplied by these vessels becomes anemic. A deficient blood supply means a deficient oxygen supply. The injurious effects of anoxemia take place rapidly in the nerve tissue.1 If the anoxemia is not relieved, injury to the nerve cells will result. In experimentally produced poliomyelitis in monkeys, Flexner and Lewis2 found that "the chief lesion (in the cord) consisted of edema, injection of the vessels