Pupillary abnormalities in congenital neurosyphilis.

Pupils in congenital neurosyphilis differ from the classic Argyll-Robertson pupil in acquired cases, and often tend to be large and unreactive. Constriction to pilocarpine in the reported patient would suggest that peripheral parasympathetic damage is responsible for such pupillary findings. Congenital neurosyphilis should be included among the causes of "tonic" pupil.