A 32-year-old professional singer undergoes total thyroidectomy for a benign multinodular goitre. Postoperatively her voice is strong at conversational pitch but she cannot sustain high notes and her voice tires quickly. Indirect laryngoscopy shows normal vocal cord mobility bilaterally. Which structure was most likely injured?

• A Internal branch of the superior laryngeal nerve
• B External branch of the superior laryngeal nerve ✓
• C Recurrent laryngeal nerve
• D Hypoglossal nerve

Explanation

The external branch of the superior laryngeal nerve supplies cricothyroid, the muscle that tenses the vocal cords and produces high pitch. Injury causes loss of high-pitched phonation and early voice fatigue with normal cord mobility on laryngoscopy, classically affecting singers. The internal branch is sensory above the cords and causes aspiration risk, not voice change. The recurrent laryngeal nerve would produce cord palsy with a hoarse, breathy voice visible on endoscopy.

Reference: Bailey and Love's Short Practice of Surgery, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.