A Clinical Review on 173 Cases of Unilateral Vocal Cord Paralysis

Background and Objectives：Unilateral vocal cord paralysis is a common finding in the practice of otolaryngology. Having an idiopathic cause, requiring surgeries on neck and chest, presenting tumors, trauma and neurological diseases are considered to be its major etiology. We reviewed and compared both domestic and international papers and analyzed the trend of clinical characteristics and causes of unilateral vocal cord palsy in Korean patients. Materials and Method：We reviewed 173 patients who visited the Severance Hospital and the Yong dong Severance Hospital from April, 1995 to December, 2001. They were diagnosed with unilateral vocal cord palsy by reviewing systems, physical examination, radiographic studies, and endoscopy. They were analyzed according to sex, age, cause of vocal cord palsy, condition of the paralyzed vocal cord and treatment methods by a preestablished protocol. Results：The male to female ratio was 1.6：1. Patients in their fifties consisted of 24.3% of the total number of cases, and patients over 60 formed 30.6%, showing that the frequency of unilateral vocal cord palsy increased with age. The paralyzed vocal cord was fixed at paramedian position in 79.8% of the cases. The left vocal cord was paralyzed about twice as much as the right vocal cord. Among the causes of vocal cord palsy, 32.4% of the cases were due to postoperative paralysis, and most of those were developed after thyroid surgery. About 67% of the cases were not related to surgery, of which the causes were most commonly idiopathic, with tumor being the next frequent. In 38.4% of the patients, atrophy of the membranous portion of the paralyzed vocal cord was noted. Rotation of the arytenoid cartilage was seen in 25.3%. Conclusion：Vocal cord paralysis is not only a disease entity in itself, but can be seen as a sign of an underlying disease. Thus, determining the cause of vocal cord paralysis is extremely important. Although the number of cases of vocal cord paralysis due to surgery is now decreasing, those due to trauma or idiopathic causes are rising and paralysis due to tumor is increasing. Consequently, it is necessary to perform a complete and thorough search for the underlying cause of vocal cord paralysis.ope