The occurrence of lesions in the central nervous system as a complication of measles was first indicated by Lucas1 in 1790, when he reported the clinical aspects of a case in which myelitis developed six days after the appearance of the rash. The condition was called "acute disseminated encephalomyelitis" by Westphal2 in 1872. The pathologic changes were accurately described by Barlow and Penrose3 in 1886. Individual cases have occasionally been reported in France, Germany and England during the last century, but in the past few years epidemics of measles have occurred in which the incidence of nervous sequelae is unusually high. During 1926 Neale and Applebaum4 saw eight cases in the state of New York. Greenfield,5 of London, reported having examined material from four cases within three months, in 1928. A report of the pathologic changes in four fatal cases occurring in the spring of