During total thyroidectomy, the external branch of the superior laryngeal nerve (EBSLN) is at risk of injury while ligating the superior thyroid artery. Injury to this nerve produces which of the following deficits?

• A Paralysis of the ipsilateral vocal cord in the paramedian position
• B Loss of the cough reflex due to loss of sensation above the vocal folds
• C Hypocalcemia due to inadvertent devascularization of the inferior parathyroid glands
• D Difficulty with high-pitched phonation and voice projection, especially in singers ✓

Explanation

The external branch of the superior laryngeal nerve innervates the cricothyroid muscle, which tenses the vocal cords. Injury causes loss of high-pitched voice and reduced vocal projection, which is particularly disabling in professional voice users. The nerve runs with the superior thyroid vessels and is injured when these are ligated too far from the thyroid capsule. Option A describes recurrent laryngeal nerve injury. Option B describes internal branch of superior laryngeal nerve injury. Option C is unrelated to the EBSLN.

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.