Mimicking Adie's pupils in the early phase of meningeal neurosyphilis

We report on a patient who presented at our hospital with complaints of bilateral pupillary dilatation and abnormal ocular movement. These symptoms gradually worsened over a few months. After subsequent serological and CSF examinations, he was diagnosed with meningeal neurosyphilis. His pupillary abnormality was marked by deficits of the light reflex and accommodation reaction. Pilocarpine tests demonstrated less hypersensitivity in the bilateral pupils, which indicated preganglionic parasympathetic pupillary involvement. The symptoms improved with penicillin injection therapy. This case provides evidence of pupillary parasympathetic denervation associated with meningeal involvement in the early phase of neurosyphilis. It could be distinguished from a classical Adie's tonic pupil caused by postganglionic long‐standing denervation.