For the past nine years we have had at the research laboratory of the health department of New York City a meningitis division, the function of the members of which is to see in consultation all kinds of meningeal conditions for differential diagnosis and treatment. In this connection we have seen over 1,000 cases of meningitis of various kinds, 600 or more cases of poliomyelitis and over 700 cases of meningism with various diseases, besides small numbers of cases of numerous other conditions, so that we have had a fairly good background for the study of a new type of meningeal or cerebral disease.
Last October, as a member of the research laboratory of the health department of New York City, I began to see a new type of disease. The majority of these patients gave a history of influenza followed in a varying length of time by headache, drowsiness