A 2-year-old girl presented with a 2-month history of episodic segmental ovalization of the right pupil, each occurrence following waking up from sleep (Figure 1A). The tadpole pupil would begin to improve after 10 minutes (Figure 1B) and completely resolve after 40 minutes (Figure 1C). She had a history of partial right-sided ptosis at birth with a spontaneous recovery and a residual right miotic pupil. She was otherwise well and had no history of trauma, headaches, or other neurological symptoms. Pharmacological test results after administering topical apraclonidine, 0.5%, an α-adrenergic agonist and safer alternative to cocaine testing, confirmed an underlying Horner syndrome in her right eye (Figure 2). Magnetic resonance imaging excluded any pathology along the sympathetic chain, and the patient was discharged.
Aggarwal K, Hildebrand GD. The Tadpole Pupil. JAMA Neurol. 2017;74(4):481. doi:10.1001/jamaneurol.2016.5981