"Collateral Damage:" Horner's Syndrome Following Excision of a Cervical Vagal Schwannoma.

Horner's syndrome is characterized by triad of blepharoptosis, miosis, and anhydrosis on the lateral part of the face. Incidence of iatrogenic Horner syndrome resulting from neck surgeries has been reported between 10% to 18.5%. Iatrogenic Horner syndrome resulting from excision of cervical vagal nerve schwannoma is uncommon, and has rarely been mentioned in literature. We report a rare case of iatrogenic preganglionic Horner's syndrome resulting from excision of a cervical vagal schwannoma. An 18 years old female presented with the complaints of sudden drooping of right upper lid associated with reduced sweating on right side of face for the past 3 months. There was history of excision of a right cervical vagal schwannoma. Ocular examination revealed mild ptosis, miosis with anisocoria more in scotopic illumination. Photographs of the patient prior to surgery showed no evidence of ptosis. Preoperative Magnetic resonance imaging revealed a mass suggesting a vagal nerve schwanomma. A diagnosis of iatrogenic preganglionic Horner's syndrome was made and the patient was kept under follow up. Horner's syndrome is an uncommon sequelae of cervical vagal schwannoma excision that results from injury of the cervical sympathetic chain intraoperatively and hence should be discussed with the patient during pre-operative counseling.