Curriculum · ENT, Ophthalmology, and Dermatology
Vocal cord palsy
What it is
Injury to the vagus or the recurrent laryngeal nerve can cause vocal fold dysfunction or paralysis.
Causes and risk
Unilateral palsy comes from malignancy of the skull base or neck, from iatrogenic injury, of which thyroid neck surgery is the most common, from trauma, and from degenerative and demyelinating neural diseases. Bilateral palsy is also mostly iatrogenic, from neck surgery or tracheal intubation, and otherwise from neurological disorders or rheumatoid arthritis. Before thyroidectomy the risk of recurrent laryngeal nerve injury is put at 1%, and of bilateral nerve injury at 1 in 500.
How it presents
Unilateral vocal cord palsy gives hoarseness, dyspnoea and aspiration; the cough is ineffective, so thin liquids are aspirated. Bilateral vocal cord palsy is the other way about: the voice is usually good, but there is dyspnea and stridor, and no aspiration. After surgery the same split holds, with unilateral nerve injury giving hoarseness and bilateral nerve injury giving airway obstruction. External laryngeal nerve injury changes the voice, and bilateral or unilateral ELN palsy causes loss of the high pitched sound.