To the Editor.—I wish to thank Dr. Emanuel Rosen for his comments on our case report and an attempt will be made to clarify the points that are confusing him.
The rapid clinical course with death or amelioration within one or two weeks has been reported by Faberi (Policlinico sez. prat.37:905, 1930), Viets and Warren (New England J. Med.204:475, 1931) and Flexner (Postvaccinal Encephalitis and Allied Conditions, J. A. M. A.94:305 [Feb. 1] 1930), who wrote that an arresting feature of postvaccination encephalitis is its hyperacute course and that protracted cases are exceptions. On reading Perdrau's article (J. Path. & Bact.31:17, 1928), I did not find three types of cases. However, there was a listing of the 3 cases Perdrau used for his studies. Apparently, the case Dr. Rosen mentions is the exception. As an added thought, Perdrau's work was not