RESEARCHES ON THE PUPILLARY REACTIONS IN EPIDEMIC ENCEPHALITIS

Abstract

In the diagnosis of epidemic encephalitis, the ocular findings are of primary importance. Pupillary changes are receiving increasing attention in the last two years and frequent references have appeared in literature concerning the occurrence of the Argyll Robertson pupil. This sign, which formerly has been considered pathognomonic for neurosyphilis, has lately been reported in chronic alcoholism, injuries, and tumor of the midbrain. In spite of its occasional occurrence in these conditions, its frequent presence in a condition as prevalent as epidemic encephalitis would tend to lessen its diagnostic value to clinicians. In reviewing the pupillary reports in the literature, very frequent mention is found of absent or sluggish light reflexes. There is a surprisingly small number of cases in which a true Argyll Robertson sign was brought out. Among the authors who record cases which they feel certain exhibit an Argyll Robertson sign are Bonhoeffer,¹Economo,²Pette,³