Horner Syndrome as a Rare Complication Following Parathyroidectomy: A Case Report

Horner syndrome arises from disruption of the oculosympathetic pathway, presenting with ptosis, miosis, and hemifacial anhidrosis. It is a rare complication following parathyroid surgery. A 64-year-old female developed right upper eyelid ptosis 24 hours after a right superior parathyroidectomy a year earlier. Histopathology confirmed a parathyroid adenoma. Ophthalmological examination revealed right-sided miosis, with delayed pupillary dilation under scotopic conditions. No hemifacial anhidrosis was noted. Diagnosis was confirmed through apraclonidine test. Surgery for reinsertion of the right upper eyelid retractors resolved the ptosis. The anisocoria persisted. This case underscores the importance of recognizing Horner syndrome as a rare complication following parathyroid surgery. General surgeons should be aware of the oculosympathetic pathway’s vulnerability. A comprehensive clinical history and ophthalmological examination are crucial for identifying potentially serious neurological conditions.