Prethyroidectomy voice and swallowing disorders and the possible role of laryngopharyngeal reflux disease

Objectives: The aim of the study was to evaluate voice and swallowing function before thyroid surgery and to explore the possible role of thyroid enlargement and laryngopharyngeal reflux (LPR).

Methods: We conducted a prospective study of patients who underwent hemi- or total thyroidectomy (n = 118) and compared the results with patients of laparoscopic cholecystectomy (n = 110). All subjects underwent videolaryngostroboscopy, filled in subjective evaluations of voice, swallowing and reflux complaints. Acoustic voice analysis (AVA), maximum phonation time (MPT) and perceptual voice evaluation were conducted.

Results: We found no difference in voice quality between study and control group, neither in subjective complaints nor in AVA or perceptual evaluation. We did find indicative signs of minor laryngeal changes in thyroid group. Swallowing Impairment Score (SIS) revealed worse swallowing function in thyroid patients (p = 0.0006). Comparison of Reflux Symptom Index (RSI) scores revealed that thyroid group patients have higher values compared to control group (p = 0.006). Nevertheless, Reflux Finding Score (RFS) showed identical scores in both groups (p = 0.220). In thyroid group there was a strong positive correlation between RSI and SIS (ρ = 0.641), but no correlation between RFS and SIS (ρ = -0.002). In addition, we found a weak positive correlation between thyroid weight and RFS (ρ = 0.379).

Conclusions: Changes in laryngeal area caused by thyroid disorders do not lead to subjective but indicate slight objective disturbances in voice quality. We detected a decline in swallowing quality within thyroid patients. Higher RSI scores and a positive correlation between RFS and thyroid weight, indicate a possible role of thyroid gland in LPR.