Kristiane Van Lierde

Pathophysiology and Treatment of Muscle Tension Dysphonia: A Review of the Current Knowledge

OBJECTIVE Muscle tension dysphonia (MTD) is a clinical and diagnostic term describing a spectrum of disturbed vocal fold behavior caused by increased tension of the (para)laryngeal musculature. Recent knowledge introduced MTD as a bridge between functional and organic disorders. This review addresses the causal and contributing factors of MTD and evaluates the different treatment options. METHODS We searched MEDLINE (Pubmed, 1950-2009) and CENTRAL (The Cochrane Library, Issue 2, 2009). Studies were included if they reviewed the classification of functional dysphonia or the pathophysiology of MTD. Etiology and pathophysiology of MTD and circumlaryngeal manual therapy (CMT) were obligatory based on reviews and prospective cohort studies because randomized controlled trials (RCTs) are nonexisting. Concerning the treatment options of voice therapy and vocal hygiene, selection was based on RCTs and systematic reviews. RESULTS Etiological factors can be categorized into three new subgroups: (1) psychological and/or personality factors, (2) vocal misuse and abuse, and (3) compensation for underlying disease. The effective treatment options for MTD are (1) indirect therapy: vocal hygiene and patient education; (2) direct therapy: voice therapy and CMT; (3) medical treatment; and (4) surgery for secondary organic lesions. CONCLUSIONS MTD is the pathological condition in which an excessive tension of the (para)laryngeal musculature, caused by a diverse number of etiological factors, leads to a disturbed voice. Etiological factors range from psychological/personality disorders and vocal misuse/abuse to compensatory vocal habits in case of laryngopharyngeal reflux, upper airway infections, and organic lesions. MTD needs to be approached in a multidisciplinary setting where close cooperation between a laryngologist and a speech language pathologist is possible.

The prevalence of laryngeal pathology in a treatment‐seeking population with dysphonia

This article describes the prevalence of laryngeal pathology in a treatment‐seeking population with dysphonia in the Flemish part of Belgium.

Impact of thyroidectomy without laryngeal nerve injury on vocal quality characteristics: An objective multiparameter approach

The main purpose of this study was to determine the impact of thyroidectomy on the subjective and objective vocal quality using the Dysphonia Severity Index. It was hypothesized that objective measures of vocal function and other vocal characteristics would change (temporarily or permanently) from the presurgical to the postsurgical conditions, even with the entire preservation of the laryngeal nerve, due to the surgical approach and other influencing factors.

The Treatment of Muscle Tension Dysphonia: A Comparison of Two Treatment Techniques by Means of an Objective Multiparameter Approach

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 severity 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.

Age‐related patterns of nasal resonance in normal Flemish children and young adults

The main purpose of the present acoustical study was to delineate further the changes in nasal resonance in childhood and young adulthood. An additional objective was to collect reference nasal resonance scores for normal Flemish‐speaking children. Scores were recorded with a Nasometer while 33 children produced sounds and read three standard passages. We compared the nasal resonance data from the children with those of 58 adults that had been obtained in a previous study. Age had a significant effect on three sounds and two texts. The results indicated that young Flemish adults had higher nasal resonance scores than children, particularly when the reading stimuli included nasal consonants for which a co‐ordinated opening and closing function of the velopharyngeal mechanism was required. These results reflect anatomical changes and differences in speech programming associated with growth.

Voice disorders in teachers: occupational risk factors and psycho-emotional factors

Background. Teaching is a high-risk occupation for developing voice disorders. The purpose of this study was to investigate previously described vocal risk factors as well as to identify new risk factors related to both the personal life of the teacher (fluid intake, voice-demanding activities, family history of voice disorders, and children at home) and to environmental factors (temperature changes, chalk use, presence of curtains, carpet, or air-conditioning, acoustics in the classroom, and noise in and outside the classroom). Methods. The study group comprised 994 teachers (response rate 46.6%). All participants completed a questionnaire. Chi-square tests and logistic regression analyses were performed. Results. A total of 51.2% (509/994) of the teachers presented with voice disorders. Women reported more voice disorders compared to men (56.4% versus 40.4%, P < 0.001). Vocal risk factors were a family history of voice disorders (P = 0.005), temperature changes in the classroom (P = 0.017), the number of pupils per classroom (P = 0.001), and noise level inside the classroom (P = 0.001). Teachers with voice disorders presented a higher level of psychological distress (P < 0.001) compared to teachers without voice problems. Conclusion. Voice disorders are frequent among teachers, especially in female teachers. The results of this study emphasize that multiple factors are involved in the development of voice disorders.

The Objective Vocal Quality, Vocal Risk Factors, Vocal Complaints, and Corporal Pain in Dutch Female Students Training to be Speech-Language Pathologists During the 4 Years of Study

The purpose of the present cross-sectional study was to determine the objective vocal quality and the vocal characteristics (vocal risk factors, vocal and corporal complaints) in 197 female students in speech-language pathology during the 4 years of study. The objective vocal quality was measured by means of the Dysphonia Severity Index (DSI). Perceptual voice assessment, the Voice Handicap Index (VHI), questionnaires addressing vocal risks, and vocal and corporal complaints during and/or after voice usage were performed. Speech-language pathology (SLP) students have a borderline vocal quality corresponding to a DSI% of 68. The analysis of variance revealed no significant change of the objective vocal quality between the first bachelor year and the master year. No psychosocial handicapping effect of the voice was observed by means of the VHI total, though there was an effect at the functional VHI level in addition to some vocal complaints. Ninety-three percent of the student SLPs reported the presence of corporal pain during and/or after speaking. In particular, sore throat and headache were mentioned as the prevalent corporal pain symptoms. A longitudinal study of the objective vocal quality of the same subjects during their career as an SLP might provide new insights.

Comparison of the overall intelligibility, articulation, resonance, and voice characteristics between children using cochlear implants and those using bilateral hearing aids: A pilot study

The purpose of this study was to determine and to compare the overall intelligibility, articulation, resonance, and voice characteristics in children using cochlear implants (CI) and children using conventional hearing aids (HA). Nine prelingually deaf children using CI and six children with a prelingual severe hearing loss using HA, were selected to participate. Objective (DSI, nasalance scores) as well as subjective assessment techniques (perceptual evaluations) were used. Both the CI and HA children demonstrated normal vocal quality and resonance but showed the presence of articulation disorders. In the CI children, intelligibility was significantly better compared to the HA children. Significantly more phonetic and phonological disorders were present in the HA children. The results of this study show a poorer intelligibility of the HA children in comparison with the CI children which is probably due to the occurrence of significantly more phonetic and phonological disorders. Future detailed analysis in a larger sample of CI and HA children may help further clarify the issue of speech and voice characteristics and may demonstrate an important prognostic value.

The Impact of Vocal Warm-Up Exercises on the Objective Vocal Quality in Female Students Training to be Speech Language Pathologists

PURPOSE The purpose of this study was to determine the impact of a specific vocal warm-up (WU) program-focused on the improvement of the dynamics of the extrinsic and intrinsic laryngeal muscles-on the objective vocal quality in Dutch female students who are getting trained to be speech language pathologists (SLPs). Hypothetically, one can assume that the objective vocal quality will increase after vocal WU exercises in SLPs in comparison with the matched control group that receives no WU program. METHODS This was a pretest-posttest control group design study, in which 45 female future SLPs were randomly assigned into two groups. The experimental group received a well-defined vocal WU program, whereas the control group took 30 minutes of vocal rest. Objective assessment techniques (aerodynamic, vocal range, acoustic measurements, and Dysphonia Severity Index [DSI]) were used. RESULTS After vocal WU, a significant increased DSI value, increased vocal performance (with lower intensity and higher frequency), and increased fundamental frequency (F₀) were measured. CONCLUSIONS Clinically, there is clear evidence that warming up the vocal mechanism is beneficial to the objective vocal quality and the vocal performance in future SLPs. To what extent the repetition of these vocal WU exercises has the possibility to maintain increased objective vocal quality in these future professional voice users is subject to further research.

Expressive and Receptive Language Characteristics in Three-Year-Old Preterm Children with Extremely Low Birth Weight

Objective: The purpose of this study was to analyze the language characteristics of a group of extremely low birth weight (ELBW) children at 3 years of age and to compare these language results with a sample of full-term children with normal birth weight (FBW). Methods: All children were judged to be free of any major physical, sensorial and neurological impairments and had a mental developmental index of >55 on the Bayley Scales of Infant Development. The Language was tested using the Reynell Developmental Language scales. Results: There was a significant difference between the ELBW group and the FBW group regarding the receptive and all the expressive language characteristics. There was a significant correlation between the mental developmental index and the language scores in the ELBW as well as in the FBW group. Conclusion: According to the analysis of the language characteristics, the logopedic approach to 3-year-old children born with ELBW must be focused on receptive (comprehension of ‘wh’-questions, passive sentences, inferencing skills and spatial prepositions) and expressive (defining words, expressing semantic relations) morphosyntactic abilities and linguistic conceptualization. These communication disorders appear unrelated to neurological or sensorial impairments, but can be partly explained by a decreased general mental functioning.