Early postoperative vocal function evaluation after thyroidectomy using thyroidectomy related voice questionnaire

Background The objectives of this study were to evaluate a screening method for detecting postoperative vocal cord palsy and lower-pitched voice and to identify how a prethyroidectomy laryngeal disorder affects post-thyroidectomy voice change by using our subjective voice questionnaire. Methods We examined 300 consecutive patients scheduled to undergo thyroidectomies between November 2010 and August 2011. Laryngoscopic examination, thyroidectomy- related voice questionnaire (TVQ) administration, and acoustic and perceptual analyses were performed preoperatively and 2 weeks after thyroidectomy. Results Ninety-eight (32.6 %) patients had a preoperative laryngeal disorder. Postoperatively, 31 (10.3 %) patients had vocal cord palsy and 54 (18 %) had a lower-pitched voice 2 weeks after thyroidectomy. Postoperative TVQs classified 25 (8.4 %) patients as normal and 275 (91.6 %) patients as abnormal, including 79 (26.3 %) mild, 131 (43.6 %) moderate, and 65 (21.6 %) severe cases. Of the patients with vocal cord palsy, 80.6 % belonged to the severe group, and 92.6 % of patients with lower-pitched voices belonged to the moderate and severe groups. Fundamental frequency and speaking fundamental frequency were decreased significantly in women. The most efficient TVQ cutoff values for detecting post-thyroidectomy vocal cord palsy and postoperative lower-pitched voice were 35 (87.1 % sensitivity, 79.9 % specificity) and 25 (75.9 % sensitivity, 56.5 % specificity), respectively. Total TVQ scores increased more in the nonlaryngeal than in the laryngeal disorder group. Conclusions During the early postoperative period, 28.3 % of patients had vocal cord palsy or lower-pitched voices, which could be evaluated using a simple questionnaire. Therefore, early postoperative voice evaluation is important. Patients with nonlaryngeal disorders may be more sensitive than those with laryngeal disorders to laryngeal symptoms.