An evaluation of Short-term Treatment Outcomes of Cricothyroid Visor Maneuver: A Proof-of-Concept Pilot Study

Abstract

Muscle tension dysphonia (MTD) is used as a clinical and diagnostic descriptive label for a diverse range of vocal fold behaviors caused by increased tension of the (para) laryngeal musculature. These increased tension can occur in the cricothyroid muscle and in the ''visor'' mechanism, contributing to voice problems. The main goal of this study is to determine whether a new method, the cricothyroid visor maneuver (CVM), is an effective method for improving quality and other aspects of the MTD patients' voices. Eighty-eight adult female patients participated in this quasiexperimental study. One group consisted of 30 MTD patients (mean age 28.7 ± 4.95 years) for whom manual circumlaryngeal therapy (MCT) was provided. The other group consisted of 30 MTD patients (mean age 28.9 ± 5.1 years) who received CVM. Also, 28 adult females with MTD (mean age 28.60 ± 4.56 years), who were on the clinic's waiting list, served as a control group and did not receive any treatment. Treatment was provided in a single 30-minute session. Pre- and post-treatment audio recordings of sustained vowels, selected sentences, and connected speech samples were submitted to auditory-perceptual and acoustical analysis to assess the short-term effects of the two treatment programs. Also, perceptions of patients' about their voice quality before and after therapy were assessed by visual analogue scale. Perceptually, Consensus Auditory Perceptual Evaluation of Voice (CAPE-V) ratings improved in all patients with both treatment methods. Acoustically, with CVM, harmonic-to-noise ratio and Cepstral Peak Prominence increased and perturbation (jitter and shimmer) measures decreased and there was not significant change in MCT and control groups. Visual analogue scale showed that feelings of patients improved after therapy in both treatment methods, with higher scores for patients receiving CVM in comparison to the MCT method. These results suggest that CVM can be an effective method for voice rehabilitation in patients with MTD and manipulation of Cricothyroid muscle and ''visor'' mechanism can lead to marked voice improvement.