Question

Following thyroid surgery, a patient developed hoarseness, weakness, decreased range of pitch or volume, and fatigue after extensive use of the voice. The nerve injured is:

• A. Transverse cutaneous nerve of the neck (C2 and C3)
• B. External branch of the superior laryngeal nerve
• C. Recurrent laryngeal nerve
• D. Cervical sympathetic plexus

Hint:

Think about which nerve controls vocal cord closure, not just pitch.

Answer 1

The Correct Option is C

Step 1: Understanding the Question:
This question describes a patient who develops voice changes after thyroid surgery and asks which nerve is responsible. Thyroidectomy places several nerves at risk because they run close to the thyroid vessels and gland capsule, and different nerve injuries produce different patterns of voice change.

Step 2: Key Concept or Approach:
The recurrent laryngeal nerve (RLN) supplies every intrinsic muscle of the larynx except the cricothyroid and is chiefly responsible for vocal cord movement and glottic closure. It runs close to the inferior thyroid artery and the ligament of Berry, making it the nerve most commonly injured during thyroid surgery. When one RLN is injured, the corresponding vocal cord loses its adductor tone and sits in a paramedian position. The opposite cord tries to compensate by crossing the midline during phonation, but glottic closure stays incomplete. This produces a weak, breathy voice that tires quickly with use, drops in volume, and loses part of its normal pitch range because the patient can no longer generate firm, sustained glottic contact.

Step 3: Working Through the Options:
The transverse cutaneous nerve of the neck (C2, C3) is a purely sensory branch of the cervical plexus supplying skin over the anterior neck; injuring it causes numbness, not any change in voice. The external branch of the superior laryngeal nerve supplies only the cricothyroid muscle, which tenses the vocal cords for high-pitched sound; its injury causes a subtle, often overlooked loss of the upper singing range while the conversational voice usually stays close to normal, a milder pattern than the one described. The cervical sympathetic plexus has nothing to do with phonation; damage to it produces Horner's syndrome (ptosis, miosis, anhidrosis), not hoarseness. The recurrent laryngeal nerve fits the clinical picture because its injury directly impairs cord closure, giving hoarseness, a breathy and weak voice, reduced loudness, a narrowed pitch range, and easy vocal fatigue on prolonged use.

Step 4: Conclusion:
The nerve injured is the recurrent laryngeal nerve.