There were about 145 cases of epidemic encephalitis in the neurological and medical services at the Mount Sinai Hospital during the epidemics of this disease in 1919 and 1920. A great many of these patients left the hospital soon after the acute infection had subsided, showing some residual symptoms and signs of the disease. After a number of months had elapsed, we felt that it would be of interest to reexamine these patients in order to determine what, if any, changes were still present. With this object in view, this follow-up study was undertaken. Altogether eighty-nine patients were reexamined, and these examinations comprise the basis for this report.
In order to be reasonably certain that none of the symptoms or residual signs found at this reexamination were still part of the acute stage of the disease, at least six months were allowed to elapse before a patient was reexamined. The