TY - JOUR T1 - Horner’s syndrome and apraclonidine eye drops JF - Practical Neurology JO - Pract Neurol DO - 10.1136/practneurol-2020-002497 VL - 20 IS - 4 SP - practneurol-2020-002497 AU - Edward Margolin AU - Trishal Jeeva-Patel AU - Nicolin Hainc Y1 - 2020/08/01 UR - http://pn.bmj.com/content/20/4/practneurol-2020-002497.abstract N2 - A 62-year-old woman had noticed a droopy right eyelid for 2 weeks. She had a history of stage 2 breast cancer, treated 10 years before with mastectomy, radiotherapy and chemotherapy. She was otherwise healthy and took no medications. On examination, there was mild right upper eyelid ptosis and anisocoria, more pronounced in the dark, with the right pupil smaller than the left. Testing with 0.5% apraclonidine drops reversed the anisocoria (figure 1), and we diagnosed a right Horner’s syndrome.Figure 1 (A) Right pupil is smaller than the left with mild right upper lid ptosis. (B) Forty-five minutes after instillation of 0.5% apraclonidine, there is resolution of ptosis and reversal of anisocoria, with the left pupil now larger than the right.On further questioning, she reported a recent onset of pain along the right lower ribs. Given the previous history of breast cancer, we obtained a dedicated MR scan of the cervical and … ER -