Transient Horner syndrome following pediatric adenotonsillectomy: Case report of a rare complication

Horner syndrome, a rare complication of pediatric adenotonsillectomy, results from oculosympathetic pathway disruption near the vulnerable superior cervical ganglion. Only 15 cases are documented, highlighting its exceptional rarity but significant clinical relevance. A 7-year-old girl underwent routine adenotonsillectomy for recurrent tonsillitis and sleep-disordered breathing, utilizing cold steel dissection and bipolar cautery for hemostasis. Postoperatively, delayed awakening and oxygen desaturation occurred, followed by the emergence of left-sided ptosis and miosis upon full arousal. Neurological and ophthalmological assessment confirmed a diagnosis of Horner syndrome. The transient nature, with complete resolution of symptoms within three months, suggests a reversible injury mechanism (e.g., neuropraxia, axonotmesis) potentially related to microtrauma, edema, or thermal effects near the superior cervical ganglion, rather than permanent neurotmesis. The absence of anhidrosis localized the injury to the postganglionic segment. While multifactorial, judicious use of thermal energy near the superior pole/posterior pillar and awareness of potential carotid medial deviation are critical to mitigate risk. This case underscores Horner syndrome as a rare, typically transient neural complication of adenotonsillectomy. It reinforces the importance of meticulous surgical technique, particularly cautious energy device application, and the need for postoperative neurological vigilance. Spontaneous recovery is common, but potential for permanent sequelae warrants informed consent discussion.