Outcome and changing cause of unilateral vocal cord paralysis.

Unilateral vocal cord paralysis (UVCP) is relatively common, and previously, thyroidectomy used to be the leading cause. We retrospectively reviewed 98 cases of UVCP. The left vocal cord was involved in 70% of the cases and the right vocal cord in 30%. The cause was neoplastic in 32%, surgical in 30%, idiopathic in 16%, traumatic in 11%, central in 8%, and infectious in 3% of the cases. Only 4 cases were the result of thyroid surgery. Evaluation consisted of a review of the history, a physical examination, and computerized scanning or magnetic resonance imaging, as needed. The functional recovery rate as related to the cause was as follows: surgery 31%, idiopathic 19%, traumatic 18%, and neoplastic 0%. Thirty-five percent of patients required medialization laryngoplasty or Teflon injection. Lung and skull base tumors and their surgical treatment are the most common causes of UVCP.