For the past seventeen years from 1968 to 1984, six hundred and sixty-one patients of recurrent laryngeal nerve (RLN) paralysis were found in our clinic. These patients were 359 males and 302 females from one-month to 94 years in age. In 591 cases, the vocal (cord) was affected unilaterally, 184 cases on the right side, 407 cases on the left side, and 70 cases bilaterally. These cases contain following disorders: 14 cases of central nerve disorder, 64 of cervical tumor, 124 of thyroid operation, 14 of other neck operations, 6 of neck trauma, 55 of tracheal intubation, 99 of chest disease, 41 of chest operation and 240 of idiopathic RLN paralysis. In the cases of tracheal intubation, chest disease and chest operation, the left vocal cord tended to be affected. But in the patients of esophageal carcinoma, the right vocal cord seemed to be more vulnerable. In the case of thyroid operation, RLN paralysis occurred in some cases on both sides and the thyroid operation is the main factor of bilateral RLN paralysis. In the case of idiopathic paralysis the relation between prevalence of influenza and the RLN paralysis was suspected.
