Efficacy of the voice therapy protocol (VTP) for adult patients with unilateral vocal fold mobility impairment; a feasibility study

Background: Unilateral vocal fold mobility impairment (UVFMI) causes dysphonia and/or dysphagia, which can significantly affect a patient’s ability to communicate and perform regular daily life activities as well as the quality of life. Voice therapy offers a less invasive and more preferential method for patients. However, there are limitations concerning the integration of multiple therapy approaches. Voice therapy exercises with clear methodologies are required to plan and conduct therapy systematically, and frequency would be required for each exercise. Therefore, this study was conducted by applying the protocols of voice therapy in adult patients with unilateral vocal fold mobility impairment. Objective: This feasibility study is a prospective cohort, pre-post single arm, designed to determine whether the voice therapy protocol (VTP) can enhance voice quality in adult patients with unilateral vocal fold mobility impairment (UVFMI) in a pilot study. Materials and methods: All subjects received 12 sessions of voice therapy protocol, with each session conducted weekly for 45 minutes. The voice therapy protocol applied in this study consisted of vocal hygiene education, abdominal breathing exercises, vocal function exercises, pushing exercises, muscle relaxation exercises, and applied resonance voice therapy. The outcomes of protocols for voice therapy were measured before and after treatment using subjective voice assessments (GIRBAS scale) and objective voice assessments (Dr. Speech program and electroglottography-EGG). Results: Cases 2, 7, 10, 11, and 13 improved after receiving VTP. As for other participants, there are still some voice parameters that need to be monitored. Overall, it was found that the participants’ voice parameters were changing within the acceptable range, with MPT, jitter, shimmer, and HNR values significantly different (p<0.05). Conclusion: The findings of this study indicated that the voice therapy protocol was a worthwhile alternative and could be used to develop further treatment guidelines for adult patients with UVFMI at a speech clinic.