Phonation Threshold Pressure as a Unique Outcome Measure of Phonatory Physiology Changes Following Submucosal Saline Injection for Vocal Fold Scarring

Abstract

Purpose: This study aimed to describe the utility of phonation threshold pressure (PTP) measurement as an additional outcome measure for changes in vocal fold vibration secondary to submucosal saline injection in the case of an individual with idiopathic vocal fold scarring. Method: An 8-week program of voice therapy, followed by submucosal saline infusion, was administered, using multiple outcome measures to assess voice quality, effort, and function in a 38-year-old woman with idiopathic bilateral vocal fold scarring. Transoral rigid video-endoscopy with stroboscopy in conjunction with the Stroboscopy Evaluation Rating Form provided measures of the vibratory characteristics of the vocal folds (amplitude, mucosal wave, nonvibratory portion, edge smoothness, and straightness). Auditory-perceptual measures were obtained using the Consensus Auditory-Perceptual Evaluation of Voice. Acoustic measures included jitter (%local), shimmer (%local), harmonics-to-noise ratio (dB), and Cepstral Spectral Index of Dysphonia. Additionally, PTP was measured 1 day prior to, and 1 month after, saline infusion. Results: Acoustic, auditory-perceptual, and stroboscopic variables suggested minimal change to the vibratory properties of the vocal folds in response to submucosal saline infusion for the treatment of vocal fold scarring. PTP measurements across the patient's frequency range, however, revealed a marked decrease post infusion. This was consistent with the patient's report of improved functioning and her request for repeat saline infusion. Conclusion: These results are consistent with the possibility of using PTP as an independent means of quantifying changes in phonatory physiology across the frequency range in patients with vocal fold scarring. Supplemental Material: https://doi.org/10.23641/asha.21313725