Purpose: To report the clinical and pharmacological findings of a patient with iatrogenic Horner syndrome (HS) which occurred after thyroid surgery.
Case report: A 29-year-old man was referred to our emergency ward due to anisocoria and unilateral eyelid ptosis reported by the patient immediately after a recent thyroidectomy for a papillary carcinoma. Ophthalmologic examination revealed 3 mm ptosis of the right eyelid. In dim illumination, the right and left pupil size was measured 3 and 6 mm, respectively. In bright illumination, the amount of anisocoria decreased; the near pupillary reaction was intact. Brain and neck magnetic resonance imaging and chest radiography were normal. Pharmacological tests with 10% cocaine, 1% hydroxyamphetamine and 1% phenylephrine localized the interruption of the oculosympathetic pathway with postganglionic third-order neuron involvement. After 6 months of follow-up, no sign of recovery was recorded.
Conclusion: Despite HS could appear to be a rare complication of thyroid surgery, it is of importance for the neck surgeons to be aware that oculosympathetic pathway (OSP) is a potentially vulnerable structure with close anatomical relationship with the thyroid gland, and for the ophthalmologists that HS may occur secondary to neck surgery and taking an accurate history is mandatory.
Keywords: Horner syndrome; Miosis; Ptosis; Thyroid Surgery.