Differential Diagnosis for Hoarseness of Voice after Surgery

• Single most likely diagnosis
  • A. Unilateral partial RLN injury: This is the most likely cause because the patient has undergone surgery for a large multinodular goitre, which is a procedure known to risk damaging the recurrent laryngeal nerve (RLN). The RLN controls the movement of the vocal cords, and even partial injury can lead to hoarseness of voice. The fact that indirect laryngoscopy did not show visible pathology of vocal cord movement suggests a functional issue rather than a gross anatomical problem, consistent with nerve injury.
• Other Likely diagnoses
  • D. External laryngeal nerve injury: This nerve controls the cricothyroid muscle, which is involved in voice pitch. Injury to this nerve can result in voice changes, including hoarseness. Given the surgical context, this is a plausible cause.
  • B. Bilateral partial RLN injury: While less common than unilateral injury, bilateral partial injury to the RLN can occur, especially in surgeries involving both sides of the neck, like a large multinodular goitre. This would affect both vocal cords, potentially leading to more severe voice changes.
• Do Not Miss diagnoses
  • Tracheomalacia: Although less directly related to hoarseness, tracheomalacia (softening of the tracheal cartilages) can lead to respiratory symptoms and potentially affect voice quality indirectly. In the context of recent neck surgery, it's crucial to consider conditions that could compromise the airway.
• Rare diagnoses
  • Other rare causes of hoarseness after surgery could include vocal cord paralysis due to other nerve injuries, thyroid cartilage fracture, or hematoma formation affecting vocal cord function. These are less likely but should be considered if other explanations do not fit or if the patient's condition worsens.