A 45-year-old woman undergoes total thyroidectomy for a multinodular goitre. Postoperatively she complains of inability to raise her voice pitch and fatigues easily while speaking, but has no stridor or respiratory distress. Which nerve is most likely injured?
- A External branch of superior laryngeal nerve ✓
- B Recurrent laryngeal nerve, left side
- C Internal branch of superior laryngeal nerve
- D Recurrent laryngeal nerve, bilateral
Correct answer: A. External branch of superior laryngeal nerve
Explanation
The external branch of the superior laryngeal nerve innervates the cricothyroid muscle, which tenses the vocal cords. Injury causes loss of high-pitched phonation and voice fatigue without airway compromise. Recurrent laryngeal nerve injury causes hoarseness and, if bilateral, stridor. Internal branch injury causes aspiration. The presentation here is isolated pitch change, pointing to EBSLN injury.
Reference: Bailey and Love's Short Practice of Surgery, 28th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.