Hoarseness following a surgical procedure in the neck is MOST likely caused by damage to which nerve?

Correct answer: D. Recurrent laryngeal nerve

• A. The facial nerve supplies muscles of facial expression, not the larynx.
• B. The external branch of the superior laryngeal nerve supplies the cricothyroid muscle; injury causes loss of high-pitch/voice projection and vocal fatigue rather than frank hoarseness.
• C. The hypoglossal nerve supplies the intrinsic and most extrinsic tongue muscles; injury causes tongue deviation toward the affected side, not hoarseness.
• D. CORRECT. The RECURRENT LARYNGEAL NERVE (a branch of the vagus, CN X) supplies ALL intrinsic muscles of the larynx except the cricothyroid, including the posterior cricoarytenoid — the only abductor of the vocal cords. Unilateral injury produces hoarseness and a breathy voice; bilateral injury can cause airway obstruction. It is the nerve classically injured in thyroid surgery because of its course in the tracheoesophageal groove.

Note: Recurrent laryngeal = hoarseness. Superior laryngeal (external) = loss of high notes.