After thyroid surgery, a patient develops a hoarse, breathy voice with an ineffective cough. Laryngoscopy shows the left vocal cord in the cadaveric (paramedian) position. The nerve most likely injured is:

• A Left external branch of superior laryngeal nerve
• B Left internal branch of superior laryngeal nerve
• C Left ansa cervicalis
• D Left recurrent laryngeal nerve ✓

Explanation

The recurrent laryngeal nerve (RLN) innervates all intrinsic laryngeal muscles EXCEPT the cricothyroid (innervated by the external branch of the superior laryngeal nerve). Injury to the RLN causes the vocal cord to lie in the cadaveric paramedian position — neither fully adducted nor abducted — producing a breathy, weak, dysphonic voice, a weak ('bovine') cough due to incomplete glottic closure, and aspiration risk. The external branch of the SLN injury produces a lower pitch with loss of cricothyroid-mediated tension but normal cord position and much milder voice changes without aspiration.

Reference: Dhingra Diseases of Ear, Nose and Throat, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.