Postoperative hoarseness following neck surgery suggests injury to which nerve?

Correct answer: D. Recurrent laryngeal nerve

• A. The internal laryngeal nerve is SENSORY to the larynx above the vocal cords. Injury abolishes the cough reflex and causes aspiration, but does not cause hoarseness.
• B. Hypoglossal injury affects tongue movement and produces deviation on protrusion, with slurred articulation rather than hoarseness.
• C. Glossopharyngeal injury affects the gag reflex, posterior tongue sensation and taste, and swallowing, but not voice quality.
• D. CORRECT. The recurrent laryngeal nerve, a branch of the vagus, supplies ALL the intrinsic muscles of the larynx except the cricothyroid. Injury paralyses the vocal cord on that side, producing hoarseness. Bilateral injury is an airway emergency because both cords sit in the paramedian position.

Note: The external laryngeal nerve supplies cricothyroid, the tensor of the vocal cords. Injury produces loss of high pitch and vocal fatigue rather than frank hoarseness — classically described as the nerve that ends a singer's career. It is at risk in thyroid surgery because it runs with the superior thyroid artery.