Permanent iatrogenic vocal cord paralysis after I-131 therapy: a case report and literature review

A patient who underwent I-131 therapy for a solitary toxic thyroid nodule subsequently experienced vocal cord paralysis, a rare complication. The patient was examined because of hoarseness 1 week after treatment. Indirect laryngoscopy at the time confirmed right vocal cord paralysis. When the examination was repeated in 6 months, no improvement was noted; vocal cord paralysis was then declared permanent. Surprisingly, 11 months after the onset of symptoms, the patient observed improvement in her voice. At 14 months, she experienced complete vocal recovery. However, a computed tomography performed after this showed that her right vocal cord paralysis was unresolved. The apparent complete recovery of her voice is believed to be a result of adaptive compensatory mechanisms. Patients who recover from hoarseness after injury to the recurrent laryngeal nerve should have cord function documented by indirect laryngoscopy or other means before the physician performs a procedure that could harm the contralateral nerve, because damage to this nerve could result in devastating consequences.