When the virus of measles attacks the central nervous system the resulting clinical picture has one outstanding characteristic, namely, variability. Results of physical examinations and laboratory tests are so bizarre and inconstant that in respect to them one case has little in common with another, save that all results indicate involvement of the central nervous system. No more specific common denominator is available.
Encephalitis complicating measles has long been known and reported, but in no instance has any considerable series of cases been analyzed by a single observer; consequently, the clinical data have been limited to the observations in small groups of cases. Even terminology has been confused, because the widely varying clinical picture tends to encourage nomenclature descriptive of individual observations. Thus one finds "encephalitis," "encephalomeningitis," "serous meningitis," "paraplegia," "meningoencephalitis" and other terms used in case reports. Because the term encephalitis seems best fitted to the condition in the
PAUL M. HAMILTON, RALPH J. HANNA. ENCEPHALITIS COMPLICATING MEASLESA REPORT ON TWO HUNDRED AND FORTY-ONE CASES COLLECTED FROM THE LITERATURE AND ON FORTY-FOUR ADDITIONAL CASES. Am J Dis Child. 1941;61(3):483–493. doi:10.1001/archpedi.1941.02000090059005