Teaching Video NeuroImages: Disorder of sweat, tonic pupil, and areflexia: Ross syndrome

A 40-year-old man presented with a 10-year history of excessive sweating on the right side, progressing to absence of sweat, rough skin, heat intolerance, and blurred vision. Examination showed anhidrosis (right side), diffuse areflexia, and Adie tonic pupils. Starch iodine test showed absence of sweating (figure). Pupillary reflex was poor (video 1). Skin biopsy was unremarkable. Ross syndrome was diagnosed.