Analysis of voice changes after thyroidectomy using the thyroidectomy-related voice and symptom questionnaire

After thyroidectomy, many patients suffer from voice problems and vague neck discomfort. The Thyroidectomy-related Voice and Symptom Questionnaire (TVSQ) is a self-administered questionnaire used to evaluate pre- and post-operative vocal status as well as throat and neck discomfort. We investigated voice conditions in thyroidectomy patients using the TVSQ as well as correlations between TVSQ responses and objective voice parameters. Also, we examined whether any clinicopathologic or surgical factors affect phonetic change after thyroidectomy.

We retrospectively reviewed the records of 242 patients who underwent total thyroidectomy to treat papillary carcinoma between January to December of 2019. Of these, we enrolled 232 who exhibited normal vocal cord mobility after surgery. TVSQ responses and acoustic voice analysis results were examined preoperatively and at 1, 3, and 6 months postoperatively. We subclassified patients into favorable and unfavorable TVSQ groups based on the increase in TVSQ score (△TVSQ ≥20) at 1 month postoperatively. We then investigated the difference of acoustic characteristics between two groups and analyzed the correlations between acoustic parameters and various clinical and surgical factors including pathologic results and lymph node status by subgroup.

All acoustic voice parameters except for the noise-to-harmonics ratio were significantly worse at 1 month postoperatively and recovered over time, but the TVSQ score did not recover from the 1-month value until 6 months postoperatively. In the subgroups, among the many clinicopathologic factors examined, advanced N stage (p = 0.002) and high positive total and central-and-lateral-neck lymph node ratios were significantly associated with an increased risk of an unfavorable TVSQ (p = 0.049, 0.027, <0.01, respectively). Among the acoustic parameters, only the changes in TVSQ total score and voice score were correlated with deterioration in jitter and shimmer at 1 month postoperatively. However, the correlations was not statistically significant and had disappeared at 6 months postoperatively.

We figured out that TVSQ was able to capture the negative effects of lymph node status and lymph node dissection on vocal outcomes after thyroidectomy. Although there was a weak correlation between worsened perturbation value and TVSQ changes, no other acoustic analysis parameters were statistically significant correlated with the TVSQ score.