Iatrogenic Horner's syndrome: A cause for diagnostic confusion in the emergency department.

Dear editor, Horner's syndrome (HS) results from interruption of sympathetic nervous supply to the eye and manifests clinically with partial ptosis, miosis and enophthalmos, along with anhidrosis of face on the affected side. [1] HS is not an uncommon finding in patients visiting emergency department (ED), being reported in those with brainstem strokes, myelitis, malignancies of lung and thyroid, dissections of carotid and vertebral arteries, traumatic injury to neck and thorax and cervical or thoracic intervertebral disc herniation. [1] Some of the iatrogenic causes of HS include cervical and upper thoracic sympathectomy, tube thoracostomy, thyroidectomy, carotid surgery/stenting and epidural anesthesia. [1] However, percutaneous internal jugular vein (IJV) central venous catheter (CVC) placement is a rare and underappreciated cause of HS. [2–4] Development of anisocoria in an unconscious patient, as a consequence of this iatrogenic HS, can give rise to diagnostic confusion [3]