Improving Voice Outcomes After Injury to the Recurrent Laryngeal Nerve

Objectives: The present study aimed to determine the voice outcomes before and after the administration of voice therapy in patients who suffered an injury to the recurrent laryngeal nerve after undergoing thyroidectomy. Methods: The sample consisted of 26 patients (2 males and 24 females) aged between 18 and 80 years (m=55±12) who experienced injury to the recurrent laryngeal nerve following thyroidectomy that was used to treat a thyroid gland disease. Subjective and objective parameters of the voice of the patients as well as its aerodynamic aspects were assessed upon the completion of the surgical procedure and before and after the implementation of voice therapy. Objective voice analysis was performed with the help of computer software viz. “Speech Training for Windows, Version 4.00 - Dr. Speech “and” EZ Voice Plus (TM) v. 2.0;” while GRBAS scale was used for subjective voice assessment. The subjects were followed for two years. The data so collected during this period was analyzed by implementing descriptive statistical parameters, Chi-square test, t-test and Wilcoxon test. Results: Patients with an injury to the recurrent laryngeal nerve were found to have voice alterations in all vocal parameters of subjective voice assessment conducted using the GRBAS Scale. These alterations ranged from moderate to severe degree, which provided a high degree of roughness in the voice. Objective voice assessment parameter analysis showed a decrease in voice pitch, increase in shimmer, decrease in noise-to-harmonics ratio, decrease in maximum phonation time and a decrease in voiceless percentage. Overall, it was observed that there were significant differences in all parameters of subjective and objective voice assessment, before and after vocal therapy, except for variables regarding the noise-to-harmonics ratio and aerodynamic variable of the S/Z ratio, although, the results on these vocal parameters were better after voice therapy. Discussion: Laryngeal symptoms are known to often accompany thyroidectomy procedures. In the present study, it was observed that administration of vocal therapy and teamwork between the doctors and speech therapist significantly affected the patient’s recovery and improvement in the quality of voice after thyroidectomy.