The Treatment of Muscle Tension Dysphonia: A Comparison of Two Treatment Techniques by Means of an Objective Multiparameter Approach *,†Kristiane M. Van Lierde, Marc De Bodt, *,†Evelien Dhaeseleer, ‡Floris Wuyts, and *,†Sofie Claeys, *Gent and yAntwerp, Belgium Summary: The purpose of the present study is to measure the effectiveness of two treatment techniques—vocalization with abdominal breath support and manual circumlaryngeal therapy (MCT)—in patients with muscle tension dysphonia (MTD). The vocal quality before and after the two treatment techniques was measured by means of the dysphonia se- verity index (DSI), which is designed to establish an objective and quantitative correlate of the perceived vocal quality. The DSI is based on the weighted combination of the following set of voice measurements: maximum phonation time (MPT), highest frequency, lowest intensity, and jitter. The repeated-measures analysis of variance (ANOVA) revealed a significant difference between the objective overall vocal quality before and after MCT. No significant differences were measured between the objective overall vocal quality before and after vocalization with abdominal breath support. This study showed evidence that MCT is an effective treatment technique for patients with elevated laryngeal position, increased laryngeal muscle tension, and MTD. The precise way in which MCT has an effect on vocal quality has not been addressed in this experiment, but merits study. Further research into this topic could focus on electromyography (EMG) recordings in relation to vocal improvements with larger sample of subjects. Key Words: Muscle tension dysphonia–Voice therapy–Manual circumlaryngeal therapy–Dysphonia severity index. INTRODUCTION The purpose of voice therapy is the improvement of the vocal quality by teaching the patient to use his/her vocal mechanism more efficiently. The voice therapist can use various indirect ap- proaches (vocal hygiene education) and direct voice techniques (by working on breathing, glottic closure, lowering the larynx, and others) to establish a more efficient vocal quality. Although functional voice disorders are the most frequently occurring la- ryngeal pathologies, 1,2 very few data are available to measure the short-term effectiveness of different vocal techniques. Muscle tension dysphonia (MTD) is a functional voice disor- der caused by imbalanced laryngeal or perilaryngeal muscle ac- tivity that can result in vocal fold hyperadduction, constriction, or bowing. 3,4 According to Rubin et al, 5 there are four basic pat- terns that are termed muscle tension patterns (MTPs): type I is glottal, and types II, III, and IV are supraglottal. The etiologic factors for MTD are: inappropriate vocal behavior, gastro- esophageal reflux, psychologic and personality factors that in- crease vocal fold tension. 6 An elevated larynx and hyoid bone owing to increased perilaryngeal muscle tension appeared to predominate in individuals presenting with MTD. In literature, there are few treatment efficacy data for voice disorders, and even fewer examining the relative effects of treatments, such as the effect of laryngeal manual therapy. The primary aim of laryngeal manual therapy is to relax the excessively tensed laryngeal and perilaryngeal musculature, which inhibits normal phonatory function. The term laryngeal manual therapy has been used throughout this study as an um- brella term, which can be used to refer to any manual laryngeal treatment to decrease laryngeal and perilaryngeal tension. To date, there exist two techniques of laryngeal manual therapy: (1) the classic laryngeal manual therapy approach; and (2) the manual circumlaryngeal therapy (MCT) approach. The MCT is based on the laryngeal musculoskeletal reduction approach, as described by Aronson. 7 Mathieson et al 4 described the vari- ations and similarities of the classic laryngeal manual therapy and MCT. The main differences between classic laryngeal man- ual therapy and MCT consist of whether or not palpatory eval- uation is conducted by the clinician before (classic laryngeal manual therapy) or during the procedure (MCT), the active in- tervention is carried out using chiefly both hands (classic laryn- geal manual therapy) or one hand (MCT), and the patient is asked to vocalize after (classic laryngeal manual therapy) or during manual therapy (MCT). A notable distinction between the two techniques is that, whereas MCT addresses a diminished thyrohyoid space by circular massage in this area, classic laryn- geal manual therapy does not. In this study, the effect of MCT in patients with MTD is described. The MCT for the laryngeal area involves kneading the laryngeal musculature (and does not involve laryngeal reposturing maneuvers) in specific loca- tions while observing changes in voice. 8 The specific therapeu- tic approach of MCT in this study is described in the methods. Few studies investigated the impact of these manual laryn- geal therapies on the vocal quality in pretreatment and post- treatment situations, as shown in Table 1. Roy et al 6,8,9 measured the effect of MCT (as described by Aronson 7 ) in several patients with functional dysphonia associated with increased laryngeal muscle tension. Perceptual and acoustical measures of vocal function were used. These vocal measures indicated a significant change in the direction of normal vocal Accepted for publication September 10, 2008. From the *Department of Otorhinolaryngology, Head and Neck Surgery and Speech and Language, University Hospital Gent, Belgium; yDepartment of Otorhinolaryngology, Head and Neck Surgery and Speech and Language, University Hospital Antwerp, Belgium; and the zDepartment of Biomedical Physics, University of Antwerp, Antwerp, Belgium. Address correspondence and reprint requests to Kristiane Van Lierde, Universitair Zie- kenhuis Gent, 2P1, De Pintelaan 185, 9000 Gent, Belgium. E-mail: kristiane.vanlierde@ ugent.be Journal of Voice, Vol. 24, No. 3, pp. 294-301 0892-1997/$36.00 Ó 2010 The Voice Foundation doi:10.1016/j.jvoice.2008.09.003