Methods of Measuring Laryngeal Muscle Tension in Patients with Muscle Tension Dysphonia: A Scoping Review

BACKGROUND

In clinical practice and research relating to Muscle Tension Dysphonia (MTD), several laryngeal muscle tension measurement methods are used to diagnose, to identify specific muscle strengths and deficits, and to measure therapeutic outcomes. The variety and reliability of available measurement methods presents challenges within diagnosis and treatment. The lack of methodical standardization presents a barrier to homogeneous practice in this area. There is a need for a comprehensive scoping review of laryngeal muscle tension measurement methods.

STUDY DESIGN

Scoping review.

OBJECTIVES

(1) To identify current methods of laryngeal muscle measurement which have been developed or tested with people with MTD; and (2) To identify the construct/s measured, reliability, validity, ability to detect change, efficiency and accessibility of identified methods.

METHOD

This scoping review was conducted using the Arksey and O'Malley framework. Studies were identified through searches of 4 major databases. The reviewer independently assessed titles, abstracts, and full-text articles.

RESULTS

Twenty seven papers published from 2000 to 2022 that satisfied the inclusion criteria were selected from 194 studies. The papers showed a variety of approaches with regards to the measurement of laryngeal activity and tension in subjects with MTD. Just over a quarter (25.9%) were reviews of the validity of assessment methods of MTD, including surface electromyography (sEMG), while 22.2% discussed surface electromyography as a measurement of muscle activity in subjects with MTD. 96.3% used a published methodological framework.

CONCLUSIONS

Assessment methods for Primary MTD are multifaceted, including patient history, laryngoscopic examination, and voice-related musculoskeletal features. Potential use of objective measurement methods, including sEMG, Real Time Elastosonography, Magnetic Resonance Imaging was noted. Due to variability in assessment methods and results, there is a need for greater objective practical methodological standardization to ensure accurate diagnosis, appropriate care, and chart patient progress.

Effectiveness of Intensive Voice Therapy Versus Weekly Therapy for Muscle Tension Dysphonia: A Noninferiority Randomised Controlled Trial With Nested Focus Group

OBJECTIVES

To investigate the noninferiority of intensive voice therapy and compare its effects with weekly voice therapy on multidimensional outcomes of voice and well-being, satisfaction, and attendance in people with muscle tension dysphonia (MTD). The study further aimed to explore clinician's perceptions of barriers and enablers to implementation of intensive therapy.

STUDY DESIGN

Noninferiority randomised controlled trial with nested focus group.

METHODS

Twenty adults with MTD were randomised to receive either weekly voice therapy (1 hour per week for 8 weeks) or intensive voice therapy (1 hour, 4 days per week for 2 weeks). Participants were assessed by a blinded assessor twice before treatment, once post treatment and once at 4 weeks follow up on the primary outcome measure VHI and a range of secondary auditory-perceptual, acoustic, and patient (i.e., VoiSS, satisfaction) and clinician reported outcome measures (i.e., AusTOMs, attendance rates). Five Speech Language Pathologists also participated in a focus group to explore barriers and enablers to implementing intensive therapy, with questions and analyses guided by the Theoretical Domains Framework.

RESULTS

While noninferiority for the primary outcome measure VHI was not confirmed, secondary outcome measures revealed comparable within group clinically important improvements for VoiSS and the AusTOMs, as well as selected acoustic and auditory-perceptual measures for both groups. A trend of more improvements being maintained in the intensive group was identified. Comparably high satisfaction and attendance was also found between groups. Clinicians reported more enablers than barriers to providing intensive therapy which included beliefs that it led to greater progression and consolidation of patient learning, was supported by the local context and was associated with positive emotions. Barriers related to difficulties with booking and scheduling and the belief that intensive therapy was not for all patients.

CONCLUSIONS

While the current study was likely underpowered to establish non-inferiority of intensive therapy, secondary outcomes suggested that intensive therapy may produce comparable benefits to voice, wellbeing, satisfaction and attendance compared to weekly therapy and may be a viable therapy option for individuals with MTD. When implementing intensive therapy, clinicians should consider patient's preferences and availability, as well as systems which allow for flexible booking and therapy provision for patients. Clear recommendations for future research including the use of a larger sample and telehealth are also provided.

Injection laryngoplasty as adjunct treatment method for muscle tension dysphonia: Preliminary findings

Objectives

This study examined the effectiveness of injection laryngoplasty (IL) in muscle tension dysphonia (MTD) patients who did not fully respond to voice therapy. It was hypothesized that IL would improve voice quality and voice‐related quality of life measures in MTD.

Methods

A retrospective review was conducted on 37 patients with a primary diagnosis of MTD who underwent IL following a suboptimal response to voice therapy (mean age = 43.0 years; standard deviation [SD] = 13.4; range = 23 to 71). Outcome measures included laryngoscopic signs of supraglottic constriction, Voice Handicap Index‐10 (VHI‐10) scores, maximal phonation time, vowel fundamental frequency (F0), standard deviation of F0 (F0SD), harmonics‐to‐noise ratio (HNR), and smoothed cepstral peak prominence. These were compared between baseline and within 3 months following the IL procedure.

Results

There was significant decrease in supraglottic constriction. Mean (SD) of VHI‐10 scores decreased from 25.4 (5.7) at baseline to 15.3 (9.3) following IL. This improvement in VHI‐10 was observed in patients with and without baseline glottal insufficiency (GI). Mean (SD) of HNR (decibels) increased from 21.1 (5.4) at baseline to 22.8 (4.3) after IL. Only patients with GI demonstrated a significant improvement in HNR from baseline to post‐IL. No statistically significant differences in other acoustic measures were observed.

Conclusions

IL resulted in positive changes in voice‐related quality of life in MTD patients with and without GI. Acoustically, only those with GI demonstrated an increase in HNR following IL. Further studies are needed to examine the effects of IL in MTD.

Level of Evidence

4 Laryngoscope, 130:980–985, 2020