FRCS (ORL-HNS) · SECTION 1 SBA

External branch superior laryngeal nerve injury

After thyroidectomy, a professional singer has loss of high pitch and vocal fatigue, but both vocal folds abduct and adduct normally. What injury is most likely?

CHOOSE ONE ANSWER

Best of five

  1. A. Recurrent laryngeal nerve transection
  2. B. Hypoglossal nerve palsy
  3. C. External branch of the superior laryngeal nerve injury
  4. D. Glossopharyngeal nerve palsy
  5. E. Facial nerve palsy
ANSWER AND REASONING

C. External branch of the superior laryngeal nerve injury

The external branch supplies cricothyroid, which lengthens the vocal fold for pitch elevation. Routine laryngoscopy may appear normal; specialised voice assessment and laryngeal electromyography can assist.

Why every option is right or wrong

A. Recurrent laryngeal nerve transection: This usually causes impaired vocal-fold mobility.

B. Hypoglossal nerve palsy: This affects tongue movement.

C. External branch of the superior laryngeal nerve injury: The external branch supplies cricothyroid, which lengthens the vocal fold for pitch elevation. Routine laryngoscopy may appear normal; specialised voice assessment and laryngeal electromyography can assist.

D. Glossopharyngeal nerve palsy: This does not selectively eliminate high pitch.

E. Facial nerve palsy: Facial movement is unrelated to cricothyroid tension.

What if the scenario changed?

If the vocal fold were immobile in a paramedian position with breathy dysphonia, recurrent-laryngeal-nerve injury would be more likely.

EDUCATIONAL USE

Independent Clinora educational preparation material; not official JCIE content, an accredited programme, clinical advice, or a substitute for current guidance, local policy and specialist judgement.

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