Anterior-Posterior and medial compression of the supraglottis: signs of nonorganic dysphoniaor normal postures?

Acoustic, aerodynamic, and vibrational effects of ventricular folds adduction in an ex vivo experiment

Objectives

The excessive adduction of ventricular folds has been observed in patients with dysphonia and professional singers. Whether these changes in the ventricular folds are the cause or just a result of disease progression remains unclear, and their potential pathological and physiological implications are yet to be determined. This study aimed to examine the impact of different degrees of ventricular adduction on acoustics, aerodynamics, and vocal fold vibration.

Methods

The excised models of mild and severe ventricular adduction were established. We recorded the vibration pattern of vocal folds and ventricular folds and measured acoustic metrics, including fundamental frequency (F0), Jitter, Shimmer, harmonic-to-noise ratio (HNR), and sound pressure level (SPL). Furthermore, we evaluated the aerodynamics index through phonation threshold pressure (PTP), phonation instability pressure (PIP), mean flow rate (MFR), phonation threshold flow (PTF), and phonation instability flow (PIF).

Results

Irregular vibrations of the ventricular fold were observed during ventricular adduction. Notably, mild and severe ventricular adduction conditions showed a significant increase in PTP, Shimmer, and Jitter, whereas MFR, PIF, and HNR decreased compared with the control condition.

Conclusions

Ventricular adduction leads to the deterioration of acoustic and aerodynamic parameters. The aperiodic and irregular vibration of the ventricular folds may be responsible for this phenomenon, although further experiments are warranted. Understanding the functioning of ventricular folds can be beneficial in directing the treatment of muscle tension dysphonia and improving voice training techniques.Level of evidence: level 4.

Hyolaryngeal Kinematics in Primary Muscle Tension Dysphonia Determined by Ultrasound

OBJECTIVES

The purpose of this study was to determine hyolaryngeal kinematics during voicing in people with primary muscle tension dysphonia (pMTD) compared with healthy speakers, and to investigate the relationships between hyolaryngeal displacement and self-perceived vocal function.

METHODS

Twenty-six participants, 13 with pMTD and 13 healthy speakers, were assessed using sonography during sustained vowel phonation and rest. Displacement of the hyoid bone and thyroid cartilage was measured from still frames extracted from ultrasound video recordings, with measures normalized to reflect change from rest during voicing for each participant. Vocal function was determined for all participants through self-perceived speaking effort and the Voice Handicap Index-10.

RESULTS

Normalized displacement of the hyoid bone and thyroid cartilage was significantly greater during voicing for participants with pMTD than for the healthy speakers. Weak-to-moderate, nonsignificant relationships between hyoid displacement and vocal function measures were evidenced, whereas moderate-to-strong, significant relationships were found for thyroid displacement and vocal function measures.

CONCLUSIONS

Displacement of the hyoid and elevation of the larynx during phonation appear to be prominent features of pMTD that differentiate the disorder from healthy phonatory kinematics. Ultrasound imaging provides a sensitive, reliable, noninvasive, and feasible method for objectively determining hyolaryngeal kinematics and may be useful for differential diagnosis and determination of treatment outcomes in pMTD.

Laryngeal and Global Somatosensation in Primary Muscle Tension Dysphonia

INTRODUCTION

Primary muscle tension dysphonia (pMTD) is a functional voice disorder that reduces communicative abilities and adversely impacts occupational productivity and quality of life. Patients with pMTD report increased vocal effort, fatigue, discomfort, and odynophonia. Although laryngeal and paralaryngeal muscle tension and hyperfunction are the most commonly proposed mechanisms underlying these symptoms, recent studies suggest pMTD may have more to do with the somatosensory system. However, relationships between voice symptoms and somatosensory mechanisms are poorly understood, creating challenges for mechanistic-based pMTD management. The first objective was to compare laryngeal, paralaryngeal, and global somatosensation between subjects with and without pMTD. The second was to determine relationships between pMTD symptoms and somatosensation.

METHODS

Fifty-two (20 pMTD and 32 control) subjects underwent laryngeal sensory testing with aesthesiometers, as well as peripheral mechanosensory and dynamic temporal summation testing to paralaryngeal and limb regions. Voice symptom severities (vocal effort, fatigue, discomfort, and odynophonia) were collected on 100-mm visual analog scales before and after laryngeal sensory testing. Participants also completed the Central Sensitization Inventory.

RESULTS

Patients with pMTD reported significantly higher laryngeal sensations (P = 0.0072) and voice symptom severities (P < 0.001) compared with the control group, and had significantly more vocal tract discomfort postlaryngeal sensory testing compared with the prelaryngeal sensory testing timepoint (P = 0.0023). However, there were no significant group differences in laryngeal airway protection responses suggestive of peripheral laryngeal hypersensitivities (P = 0.444). There were also no significant group differences on paralaryngeal or global sensitivities (P > 0.05), and no correlations between severity of voice symptoms and perceptual laryngeal sensations or hypersensitivities (P > 0.05).

CONCLUSION

Patients with pMTD perceive more sensitivities in the larynx and feel more sensations related to the voice (vocal effort, fatigue, discomfort, and pain). However, in general, patients with pMTD do not have abnormal peripheral laryngeal hypersensitivities, increased global somatosensation, or heightened central sensitivity. The lack of significant correlations between peripheral laryngeal hypersensitivities and voice symptom severity ratings suggests these outcome variables target distinct mechanistic constructs.

Analysis of Supraglottic Activity during Vocalization in Flamenco Singers

INTRODUCTION

Flamenco is a traditional music originally from Andalusia in southern Spain. Some of the vocal resources used in Flamenco have components of voice distortion and other voice qualities that could sound like hyperfunctional voice productions. The present study aimed at observing supraglottic activity in flamenco singers while engaged in singing at various degrees of pitch and loudness and while engaged in realizing phonatory tasks.

METHODS

A total of eighteen flamenco singers with at least 5 years of voice training were recruited. Flexible endoscopic voice evaluations were recorded and edited to provide samples of different pitches, loudness levels, and phonatory tasks. Sound was removed from video samples. Two blinded laryngologists were asked to assess antero-posterior compression, medial compression, pharyngeal compression, and VLP for every sample, using a visual analog scale.

RESULTS

Significantly higher values were found for medial compression, anterior-posterior compression, VLP and pharyngeal compression during high loudness levels when compared to medium and low loudness. Overall, medial compression was lower than anterior-posterior compression.

CONCLUSION

Supraglottic activity is present in flamenco singing in the four laryngoscopic variables. It seems to be that supraglottic activity increases with loudness level and pitch. This behavior could be a natural and necessary aspect of flamenco singing present during both sustained vowels and song.

Muscle Tension Dysphagia: An Expanded Investigation of Clinical Presentations and Swallowing Kinematics

PURPOSE

This study retrospectively examined patient-reported symptoms, quality of life, and swallowing kinematics in individuals with presumed muscle tension dysphagia (MTDg).

METHOD

Twenty-six individuals met the inclusion criteria. Data were gathered from patient-reported outcome measures (PROs), symptomology, clinician reports of palpation, and hyolaryngeal and hyoid movements measured on a 20-ml thin liquid bolus during videofluoroscopic swallowing studies.

RESULTS

All PROs were outside of typical limits, except for the Voice Handicap Index-10. Mean hyoid excursion was 1.52 cm (SD = 0.46, range: 0.76-2.43), and hyolaryngeal excursion was 0.77 cm (SD = 0.44, range: -0.42-1.68). A minority of participants (4%-19%) demonstrated atypical hyoid and/or hyolaryngeal excursion compared to the available normative reference value sets.

CONCLUSIONS

Individuals demonstrated abnormalities in the clinical evaluation of the areas of palpation and reported perilaryngeal discomfort and symptoms of laryngeal hyperresponsiveness, with a negative impact on their quality of life across various PROs. Atypical hyoid and/or hyolaryngeal excursion during swallowing was rare when compared to available normative reference values. The clinical evaluation of MTDg may be enhanced by including components related to muscle tension and laryngeal hyperresponsiveness in order to differentiate MTDg from idiopathic functional dysphagia and lead the patient to the otolaryngology/speech-language pathology clinic for intervention and management.

Is Surface Electromyography (sEMG) a Useful Tool in Identifying Muscle Tension Dysphonia? An Integrative Review of the Current Evidence

OBJECTIVE

This integrative review aims to determine the quality level of evidence on using surface electromyography (sEMG) as a diagnostic tool in identifying muscle tension dysphonia.

METHOD

Two independent reviewers used one search engine and five databases to identify sEMG studies published between January 1980 and December 2020, using a set of specified search terms related to muscle tension dysphonia. The selected articles were systematically evaluated by two independent raters using a modified critical appraisal of diagnostic evidence (m-CADE) form.

RESULTS

Nine articles that satisfied the inclusion criteria were selected from among 576 studies for evaluation. These nine studies showed varied methodological approaches in sEMG measurements, including electrode configuration and position, tasks used in sEMG data collection, outcome measure, and normalization procedures. Five studies showed relatively high m-CADE scores, which were indicative of "suggestive validity and compelling importance". Two studies were rated as "suggestive validity and importance", while two remaining studies were rated as "less suggestive or equivocal validity and importance".

CONCLUSIONS

The review found a moderate level of evidence that sEMG can be a potentially useful tool with diagnostic value in identifying muscle tension dysphonia. However, evidence is not yet available to determine the diagnostic accuracy of sEMG for muscle tension dysphonia. More studies are needed, and it is recommended that future studies involving sEMG and reference measurements should be undertaken using a blinding procedure in order to control any subjective biases. Details of the population that the sEMG has been tested on should be outlined clearly so that spectrum bias could be eliminated or minimized in the application process. Furthermore, it is suggested that a reliable and valid protocol in collecting sEMG data during speech should be developed to minimize the variability of sEMG measures in assessing muscle activities during speech.

Relative Fundamental Frequency in Individuals with Globus Syndrome and Muscle Tension Dysphagia

OBJECTIVE

Relative fundamental frequency (RFF) has been investigated as an acoustic measure to assess for changes in laryngeal tension. This study aimed to assess RFF in individuals with globus syndrome, individuals with muscle tension dysphagia (MTDg), and individuals with typical voices.

METHODS

RFF values were calculated from the speech acoustics of individuals with globus syndrome (n = 12), individuals with MTDg (n = 12), and age- and sex-matched controls with typical voices (n = 24). An analysis of variance was performed on RFF values to assess the effect of group.

RESULTS

There was no statistically significant effect of group on RFF values, with similar values for individuals with globus syndrome, individuals with MTDg, and control participants.

CONCLUSIONS

These results suggest that individuals with these disorders do not appear to possess paralaryngeal muscle tension in a locus and/or manner that directly impacts voice production.

Quantification of False Vocal Fold Hyperfunction During Quiet Breathing in Muscle Tension Dysphonia

BACKGROUND/OBJECTIVES

False vocal fold (FVF) hyperfunction during phonation is thought to be a diagnostic sign of primary muscle tension dysphonia (pMTD). However, hyperfunctional patterns with phonation are also observed in typical speakers. This study tested the hypothesis that FVF posturing during quiet breathing, as measured by the curvature of FVF, could differentiate patients with pMTD from typical speakers.

METHODS

Laryngoscopic images were collected prospectively in 30 subjects with pMTD and 33 typical speakers. Images were acquired at the end of expiration and maximal inspiration during quiet breathing, during sustained /i/, and during loud phonation before and after a 30-min vocal loading task. The FVF curvature (degree of concavity/convexity) was quantified using a novel curvature index (CI, >0 for hyperfunctional/convex, <0 for "relaxed"/concave) and compared between the two groups.

RESULTS

At end-expiration, the pMTD group adopted a convex FVF contour, whereas the control group adopted a concave FVF contour (mean CI 0.123 [SEM 0.046] vs. -0.093 [SEM 0.030], p = 0.0002) before vocal loading. At maximal inspiration, the pMTD group had a neutral/straight FVF contour, whereas the control group had a concave FVF contour (mean CI 0.012 [SEM 0.038] vs. -0.155 [SEM 0.018], p = 0.0002). There were no statistically significant differences in FVF curvature between groups in either the sustained voiced or loud conditions. Vocal loading did not change any of these relationships.

CONCLUSIONS

A hyperfunctional posture of the FVFs during quiet breathing especially at end-expiration may be more indicative of a hyperfunctional voice disorder than supraglottic constriction during voicing.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:3449-3454, 2023.

Characterization of Primary Muscle Tension Dysphonia Using Acoustic and Aerodynamic Voice Metrics

OBJECTIVES/HYPOTHESIS

The objectives of this study were to (1) identify optimal clusters of 15 standard acoustic and aerodynamic voice metrics recommended by the American Speech-Language-Hearing Association (ASHA) to improve characterization of patients with primary muscle tension dysphonia (pMTD) and (2) identify combinations of these 15 metrics that could differentiate pMTD from other types of voice disorders.

STUDY DESIGN

Retrospective multiparametric METHODS: Random forest modeling, independent t-tests, logistic regression, and affinity propagation clustering were implemented on a retrospective dataset of 15 acoustic and aerodynamic metrics.

RESULTS

Ten percent of patients seen at the New York University (NYU) Voice Center over two years met the study criteria for pMTD (92 out of 983 patients), with 65 patients with pMTD and 701 of non-pMTD patients with complete data across all 15 acoustic and aerodynamic voice metrics. PCA plots and affinity propagation clustering demonstrated substantial overlap between the two groups on these parameters. The highest ranked parameters by level of importance with random forest models-(1) mean airflow during voicing (L/sec), (2) mean SPL during voicing (dB), (3) mean peak air pressure (cmH2O), (4) highest F0 (Hz), and (5) CPP mean vowel (dB)-accounted for only 65% of variance. T-tests showed three of these parameters-(1) CPP mean vowel (dB), (2) highest F0 (Hz), and (3) mean peak air pressure (cmH2O)-were statistically significant; however, the log2-fold change for each parameter was minimal.

CONCLUSION

Computational models and multivariate statistical testing on 15 acoustic and aerodynamic voice metrics were unable to adequately characterize pMTD and determine differences between the two groups (pMTD and non-pMTD). Further validation of these metrics is needed with voice elicitation tasks that target physiological challenges to the vocal system from baseline vocal acoustic and aerodynamic ouput. Future work should also place greater focus on validating metrics of physiological correlates (eg, neuromuscular processes, laryngeal-respiratory kinematics) across the vocal subsystems over traditional vocal output measures (eg, acoustics, aerodynamics) for patients with pMTD.

LEVEL OF EVIDENCE

II.

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.

Clinical Characteristics and Effects of Vocal Demands in Occupational Voice Users With and Without Primary Muscle Tension Dysphonia

OBJECTIVES

The objectives of this study were to (1) compare laryngeal configuration patterns in occupational voice users with and without primary muscle tension dysphonia (pMTD), (2) characterize laryngeal configurations in relation to other clinical metrics (acoustic, perceptual), and (3) determine the effects of vocal demands (load) on these clinical parameters.

METHODS

Thirty subjects (15 pMTD, 15 control) were recruited for the study. Laryngoscopic examinations and voice samples for sustained /i/ were obtained before and after a half hour vocal load task. Subjects rated their vocal effort and discomfort before and after the vocal load. Laryngeal configurations were analyzed subjectively with dichotomous and categorical rating scales and hyper function severity quantified (endolaryngeal area outlets). Overall dysphonia severity and vocal instability of each voice sample was rated on 100mm visual analog scales and cepstral peak prominence (CPP) extracted from each voice sample.

RESULTS

Laryngeal configurations between groups or vocal load condition were not distinguishable with any of the dichotomous, categorical, or quantitative laryngeal metrics. Vocal effort and discomfort ratings were significantly higher in the pMTD group compared to the control group. Vocal load also had significant effects across groups on vocal effort and vocal tract discomfort ratings. Although CPP values fell within the normal range in both groups, CPP was significantly lower in the pMTD group at both pre-load and post-load time points. Auditory-perceptual ratings were also significantly worse in the pMTD group. Vocal load did not have a significant effect on acoustic or auditory-perceptual measures.

CONCLUSION

Similar laryngeal configurations between groups at both pre- and post-vocal load suggests classic patterns of laryngeal "hyperadduction" may occur variably in occupational voice users and may not be indicative of pMTD pathophysiology. Greater vocal effort, discomfort, instability, and perturbation within the vocal system may better define pMTD than laryngeal configuration in occupational voice users with pMTD.

Potential Biophysiological Mechanisms Underlying Vocal Demands and Vocal Fatigue

Patients with complaint of vocal fatigue have perceptual, acoustic, and aerodynamic outcomes that are heterogeneous in nature. One reason may be due to different underlying biophysiological mechanisms that lead to these heterogeneous clinical presentations. Five potential mechanisms are proposed: neuromuscular, metabolic, vocal tissue, afferent, and central neural. Analytical frameworks and study designs to study these mechanisms are also addressed. A better understanding of biophysiological mechanisms of vocal fatigue can improve precision of therapeutic approaches. It can also help shift management from symptom-based to etiology-focused approaches for vocal fatigue.

Collision Pressure and Dissipated Power Dose in a Self-Oscillating Silicone Vocal Fold Model With a Posterior Glottal Opening

PURPOSE

The goal of this study was to experimentally evaluate how compensating for the adverse acoustic effects of a posterior glottal opening (PGO) by increasing subglottal pressure and changing supraglottal compression, as have been associated with vocal hyperfunction, influences the risk of vocal fold (VF) trauma.

METHOD

A self-oscillating synthetic silicone model of the VFs with an airflow bypass that modeled a PGO was investigated in a hemilaryngeal flow facility. The influence of compensatory mechanisms on collision pressure and dissipated collision power was investigated for different PGO areas and supraglottal compression. Compensatory behaviors were mimicked by increasing the subglottal pressure to achieve a target sound pressure level (SPL).

RESULTS

Increasing the subglottal pressure to compensate for decreased SPL due to a PGO produced higher values for both collision pressure and dissipated collision power. Whereas a 10-mm² PGO area produced a 12% increase in the peak collision pressure, the dissipated collision power increased by 122%, mainly due to an increase in the magnitude of the collision velocity. This suggests that the value of peak collision pressure may not fully capture the mechanisms by which phonotrauma occurs. It was also found that an optimal value of supraglottal compression exists that maximizes the radiated SPL, indicating the potential utility of supraglottal compression as a compensatory mechanism.

CONCLUSIONS

Larger PGO areas are expected to increase the risk of phonotrauma due to the concomitant increase in dissipated collision power associated with maintaining SPL. Furthermore, the risk of VF damage may not be fully characterized by only the peak collision pressure.

Integrative Review and Framework of Suggested Mechanisms in Primary Muscle Tension Dysphonia

PURPOSE

Despite the high prevalence of primary muscle tension dysphonia (MTD-1), its underlying mechanisms and their interrelationships have yet to be fully identified. The objectives of this integrative review were (a) to describe and classify the suggested underlying mechanisms for MTD-1, (b) to appraise the empirical evidence supporting each of the proposed mechanisms, and (c) to summarize the information in an integrative model.

METHOD

PubMed, Scopus, and CINAHL were searched for all publications pertaining to muscle tension dysphonia. Papers were retained if they included theoretical or empirical data pertaining to underlying mechanisms of MTD-1. A total of 921 papers initially qualified for screening, of which 100 remained for consideration in this review. Underlying mechanisms of MTD-1 were extracted using a consensus approach.

RESULTS

Seven broad categories of putative mechanisms involved in MTD-1 were identified: psychosocial, autonomic, sensorimotor, respiratory, postural, inflammatory, and neuromuscular. These categories were further divided into 19 subcategories detailed in the body of this review article. Based on the reviewed evidence, our proposed integrative model presents MTD-1 as an idiosyncratic motor adaptation to physiological perturbation or perceived threat. Under this model, physiologically or psychologically aversive stimuli can instigate a series of motor adaptations at multiple levels of the nervous system, ultimately disturbing muscle activation patterns and their biomechanical outcomes. Importantly, these adaptations appear to have the potential to become chronic even after threatening stimuli are withdrawn.

CONCLUSIONS

The proposed model highlights the importance of personalized rehabilitation in MTD-1 treatment. Limitations of the literature are discussed to provide guidance for future research aimed at improving our understanding of MTD-1.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.19586065.

Objective Laryngoscopic Measures From Older Patients With Voice Complaints and Signs of Aging

PURPOSE

The purpose of this study was to use objective measures of glottal gap, bowing, and supraglottic compression from selected images of laryngoscopic examinations from adults over 60 years of age with voice complaints and signs of aging to test current hypotheses on whether degree of severity impacts treatment recommendations and potential follow-through with treatment.

METHOD

Records from 108 individuals 60 years or older with voice complaints and signs of aging were reviewed. Three objective measures (normalized glottal gap area [NGGA], total bowing index, and normalized true vocal fold width) were derived. Each measure was subsequently divided into three categories by severity: absence, small degree, or large degree. Nonparametric statistics tested associations between severity and treatment recommendations as well as potential follow-through.

RESULTS

Noninvasive treatments (observation/voice therapy) were marginally associated with no glottal gap (p = .09). More invasive treatments (injection/bilateral thyroplasty) were associated with glottal gaps being present (p = .026), but bilateral thyroplasty recommendations were not significantly associated with the largest gaps. Treatment modalities were not characterized by specific severity categories for any of the objective measures. No significant differences were found for any of the three objective measures between those who followed through with recommended treatment and those who did not.

DISCUSSION

Results demonstrated some support for current hypotheses on how degrees of severity of objective measures relate to treatment recommendations. Of the three measures, NGGA appears to be more informative regarding treatment recommendations and follow-through, but due to low power, larger sample sizes are needed to confirm clinical relevance.

Strain Elastosonography Measurement in Patients with Primary Muscle Tension Dysphonia Compared with Healthy Speakers: A Pilot Study

OBJECTIVES

The purpose of this study was to investigate real-time elastosonography (RTE) to measure strain of the (para)laryngeal muscles in patients with primary muscle tension dysphonia (MTD) and healthy speakers.

STUDY DESIGN

This is a cross-sectional study.

METHODS

Ten patients with primary MTD (37.8 ± 10.53 years) and 10 healthy speakers (36.9 ± 9.8 years) participated. Participants were diagnosed as MTD patient or healthy via voice history, voice self-assessment, perceptual voice evaluation, laryngeal palpation, and videostroboscopy. Then, RTE was performed to extract strain index (SI) and strain ratio (SR) for all participants. The RTE was utilized for the suprahyoid, thyrohyoid, and the cricothyroid muscles, both in right and left sides during rest, /a/, and /i/ prolongations. To study the effect of group, task, and interactive effect on the SI and SR, two-way repeated-measures analysis of variance was performed.

RESULTS

The effect of group on the SI was significant for the right cricothyroid (P ˂ 0.001). Significant effect of group on the SR obtained for the right suprahyoid, left thyrohyoid, and right cricothyroid (P < 0.05). Moreover, the only muscle whose SR was significantly affected by task was the left suprahyoid (P < 0.05). Compared to healthy speakers, the interactive effect was significantly lower in SI for the left cricothyroid, and higher in SR for both the right suprahyoid and left cricothyroid in patients (P < 0.05).

CONCLUSIONS

The RTE can discriminate patients with primary MTD from healthy subjects in some laryngeal muscles, especially suprahyoid and cricothyroid. It may be regarded as a clinical instrument in the assessment of MTD in future. Further studies with bigger sample size are recommended.

Consecuencias laringoscópicas, electroglotográficas, acústicas y sintomatológicas producidas por la sobrecarga vocal en mujeres con voces sanas y no entrenadas

La sobrecarga es una de las etapas del continuo de carga vocal. Actualmente, se considera que su investigación permite una mejor comprensión de la patología y sintomatología funcional de la voz. El objetivo de este trabajo fue analizar las consecuencias laringoscópicas, electroglotográficas, acústicas y sintomatológicas producidas por la sobrecarga vocal en mujeres con voces sanas y no entrenadas. Se examinó el comportamiento acústico, laringoscópico, electroglotográfico y sintomatológico de 30 mujeres que se sometieron a una tarea de sobrecarga vocal caracterizada por la lectura ininterrumpida de un texto durante 60 minutos, cuya intensidad fluctuó entre los 75 y 85 dB. A nivel laringoscópico, se observó mayor vascularización, aumento de la compresión supraglótica y cambios en la amplitud, simetría y onda mucosa. Acústicamente, se evidenció incremento significativo en la frecuencia fundamental e intensidad vocal. En la electroglotografía, el cociente de cierre y la fase abierta y cerrada disminuyeron significativamente, mientras que a nivel sintomatológico, la totalidad de la muestra expresó al menos un síntoma de fatiga vocal. En conclusión, los hallazgos observados son expresiones de la fatiga del mecanismo tiroaritenoideo y de la inflamación aguda de la cubierta cordal. 

Does More Compression Mean More Pressure? A New Classification for Muscle Tension Dysphonia

Objective The aims of this study were to test the hypothesis that greater supraglottic compression (anteroposterior or lateral) correlates with higher subglottic pressure (SGP) and to develop a classification of muscle tension dysphonia (MTD), based on the degree of supraglottic compression during speech. Method A prospective, cross-sectional study was conducted in a series of 37 consecutive patients diagnosed with MTD with an altered aerodynamic profile characterized by high SGP (more than 90 mmH₂O). Supraglottic anteroposterior and lateral compression were categorized in three grades and assessed during the laryngoscopic examination. All patients completed the Spanish Voice Handicap Index (VHI) questionnaire and completed an acoustic and aerodynamic voice assessment. The relationship between compression grade and VHI with SGP was analyzed. Results More than 90% of patients demonstrated some degree of anteroposterior compression, and 67% had some degree of lateral compression. The mean (SD) SGP was 111.03 (16.7) mmH₂O, and the mean VHI was 27.86 (12.5). The degree of SGP was statistically different in the different grades of anteroposterior compression, and also anteroposterior compression correlated with an SGP (p < .05). The degree of lateral compression was not correlated with SGP. Neither the degree of anteroposterior or lateral compression nor the value of SGP was found to correlate with VHI. Conclusions Because grade of anteroposterior compression correlates with SGP, these grades can be used for diagnosis and follow-up of MTD patients. To this end and on this basis, we propose a new classification for MTD. Unlike the established classification, our proposed one makes it possible to combine different laryngoscopic features, improving the description of the larynx during phonation.

Detection of Muscle Tension Dysphonia Using Eulerian Video Magnification: A Pilot Study

OBJECTIVE

To determine whether Eulerian Video Magnification software is useful in diagnosis of muscle tension dysphonia (MTD).

STUDY DESIGN

Prospective.

METHODS

Adult patients scheduled in a tertiary care laryngology practice for evaluation of dysphonia were recruited between November 2016 and March 2017. Demographic and clinical data were extracted from patient charts. Diagnosis of MTD was confirmed with videostroboscopic and physical exam and by a speech-language pathologist. Eighteen MTD patients were video recorded while at rest and with phonation. Five patients without MTD also were analyzed as controls. Videos were analyzed using Eulerian Video Magnification software (Massachusetts Institute of Technology) to assess change in blood flow at the forehead, infrahyoid muscles, and sternocleidomastoid muscles, while using the values of the background wall as a control value.

RESULTS

Patients with MTD demonstrated little change in perfusion to the infrahyoid muscles of the neck while phonating (+1% ± 55%). Control subjects demonstrated an increase in perfusion to the infrahyoid muscles while phonating (+102% ± 164%), with this change being significant when comparing the two groups (P = 0.04, t = 2.189, df = 21). A change in perfusion of 0% or less to infrahyoid muscles was 75% sensitive and 70% specific for diagnosis of MTD. No differences in perfusion were found between other regions assessed. Patient age and gender did not correlate with any change in perfusion between rest and phonation.

CONCLUSION

Our data suggest that Eulerian Video Magnification can be used in the diagnosis of MTD by focusing on the difference in perfusion to the infrahyoid muscles between rest and phonation.

Aerodynamic Characteristics of Growl Voice and Reinforced Falsetto in Metal Singing

OBJECTIVES

The present study aimed to assess the aerodynamic characteristics of vocally healthy metal singers when producing growl voice or reinforced falsetto.

METHODS

Fifty-four participants (metal singers) were initially enrolled in this study, with 23 meeting the inclusion criteria. Sixteen participants performed growl voice and seven performed reinforced falsetto as a voice resource during metal singing. All participants were asked to undergo rigid laryngeal videostroboscopy to confirm the absence of laryngeal pathology. Then, subjects were aerodynamically assessed while performing growl voice or reinforced falsetto.

RESULTS

Higher glottal airflow rate, sound pressure level, and subglottic pressure (Psub) for growl voice samples compared to vowel production without growl voice (keeping the same fundamental frequency [F0]) were found. Higher Psub, sound pressure level, and glottal resistance for high-pitched reinforced falsetto compared to naïve falsetto (keeping the same F0) were found. No differences for F0 were found for neither growl voice nor reinforced falsetto.

CONCLUSIONS

It seems that growl voice is produced by decreasing vocal folds adduction and increasing Psub, which in turn, promotes an increased airflow rate. Reinforced falsetto is characterized by an increased vocal fold adduction and an increased Psub. A proper resonance strategy in reinforced falsetto and a decreased glottal adduction in growl voice might probably be the factors that contribute to prevent voice problems in singers who use these vocal resources, classically labeled as vocal abuse.

Evaluation of the Supraglottic and Subglottic Activities Including Acoustic Assessment of the Opera-Chant Singers

Opera and chant singers learn to effectively use aerodynamic components by breathing exercises during their education. Aerodynamic components, including subglottic air pressure and airflow, deteriorate in voice disorders. This study aimed to evaluate the changes in aerodynamic parameters and supraglottic structures of men and women with different vocal registers who are in an opera and chant education program. Vocal acoustic characteristics, aerodynamic components, and supraglottic structures were evaluated in 40 opera and chant art branch students. The majority of female students were sopranos, and the male students were baritone or tenor vocalists. The acoustic analyses revealed that the mean fundamental frequency was 152.33 Hz in the males and 218.77 Hz in the females. The estimated mean subglottal pressures were similar in females (14.99 cmH₂O) and in males (14.48 cmH₂O). Estimated mean airflow rates were also similar in both groups. The supraglottic structure compression analyses revealed partial anterior-posterior compressions in 2 tenors and 2 sopranos, and false vocal fold compression in 2 sopranos. Opera music is sung in high-pitched sounds. Attempts to sing high-pitched notes and frequently using register transitions overstrain the vocal structures. This intense muscular effort eventually traumatizes the vocal structures and causes supraglottic activity.

Brain activity during phonation in healthy female singers with supraglottic compression: an fMRI pilot study

This pilot study evaluated the usability of functional magnetic resonance imaging (fMRI) to detect brain activation during phonation in healthy female singers with supraglottic compression. Four healthy female classical singers (mean age: 26 years) participated in the study. All subjects had normal vocal folds and vocal characteristics and showed supraglottic compression. The fMRI experiment was carried out using a block design paradigm. Brain activation during phonation and exhalation was analyzed using Brain Voyager software (Brain Innovation B.V., Maastricht, The Netherlands). An fMRI data analysis showed a significant effect of phonation control in the bilateral pre/postcentral gyrus, and in the frontal, cingulate, superior and middle temporal gyrus, as well as in the parietal lobe, insula, lingual gyrus, cerebellum, thalamus and brainstem. These activation areas are consistent with previous reports using other fMRI protocols. In addition, a significant effect of phonation compared to exhalation control was found in the bilateral superior temporal gyrus, and the pre/postcentral gyrus. This fMRI pilot study allowed to detect a normal pattern of brain activity during phonation in healthy female singers with supraglottic compression using the proposed protocol. However, the pilot study detected problems with the experimental material/procedures that would necessitate refining the fMRI protocol. The phonation tasks were not capable to show brain activation difference between high-pitched and comfortable phonation. Further fMRI studies manipulating vocal parameters during phonation of the vowels /a/ and /i/ may elicit more distinctive hemodynamic response (HDR) activity patterns relative to voice modulation.

Modeling the Pathophysiology of Phonotraumatic Vocal Hyperfunction With a Triangular Glottal Model of the Vocal Folds

PURPOSE

Our goal was to test prevailing assumptions about the underlying biomechanical and aeroacoustic mechanisms associated with phonotraumatic lesions of the vocal folds using a numerical lumped-element model of voice production.

METHOD

A numerical model with a triangular glottis, posterior glottal opening, and arytenoid posturing is proposed. Normal voice is altered by introducing various prephonatory configurations. Potential compensatory mechanisms (increased subglottal pressure, muscle activation, and supraglottal constriction) are adjusted to restore an acoustic target output through a control loop that mimics a simplified version of auditory feedback.

RESULTS

The degree of incomplete glottal closure in both the membranous and posterior portions of the folds consistently leads to a reduction in sound pressure level, fundamental frequency, harmonic richness, and harmonics-to-noise ratio. The compensatory mechanisms lead to significantly increased vocal-fold collision forces, maximum flow-declination rate, and amplitude of unsteady flow, without significantly altering the acoustic output.

CONCLUSION

Modeling provided potentially important insights into the pathophysiology of phonotraumatic vocal hyperfunction by demonstrating that compensatory mechanisms can counteract deterioration in the voice acoustic signal due to incomplete glottal closure, but this also leads to high vocal-fold collision forces (reflected in aerodynamic measures), which significantly increases the risk of developing phonotrauma.

Relative Fundamental Frequency Distinguishes Between Phonotraumatic and Non-Phonotraumatic Vocal Hyperfunction

PURPOSE

The purpose of this article is to examine the ability of an acoustic measure, relative fundamental frequency (RFF), to distinguish between two subtypes of vocal hyperfunction (VH): phonotraumatic (PVH) and non-phonotraumatic (NPVH).

METHOD

RFF values were compared among control individuals with typical voices (N = 49), individuals with PVH (N = 54), and individuals with NPVH (N = 35).

RESULTS

Offset Cycle 10 RFF differed significantly among all 3 groups with values progressively decreasing for controls, individuals with NPVH, and individuals with PVH. Individuals with PVH also had lower Offset Cycles 8 and 9 relative to the other 2 groups and lower RFF values for Offset Cycle 7 relative to controls. There was also a trend for lower Onset Cycle 1 RFF values for the PVH group compared with the NPVH group.

CONCLUSIONS

RFF values were significantly different between controls and individuals with VH and also between the two subtypes of VH. This study adds further support to the notion that the differences between these two subsets of VH may be functional as well as structural.

Adductor Spasmodic Dysphonia versus Muscle Tension Dysphonia: Examining the Diagnostic Value of Recurrent Laryngeal Nerve Lidocaine Block

Objectives:

Differentiating adductor spasmodic dysphonia (ADSD) from muscle tension dysphonia (MTD) can be difficult. This investigation examined the precision of response to unilateral lidocaine block of the recurrent laryngeal nerve (RLN block) as a potential diagnostic test to discriminate ADSD from MTD.

Methods:

Patients with ADSD (n = 23) and MTD (n = 20) were audio-recorded before and during RLN block. The patients completed self-ratings of dysphonia severity, vocal effort, and laryngeal tightness, and blinded listeners completed auditory-perceptual ratings of overall severity, breathiness, and strain of voice samples before and during the block.

Results:

Repeated-measures analysis of variance, with “group” (ADSD/MTD) as the between-subjects variable and “time” (before block/during block) as the within-subjects variable, confirmed significant “time” effects, but no significant “group-by-time” interaction effects, indicating that both disorder groups responded favorably to RLN block, according to patient- and listener-based ratings. Furthermore, low estimates of sensitivity and specificity and weak receiver operating characteristic curves confirmed that a positive response to the RLN block test did not distinguish ADSD from MTD.

Conclusions:

We conclude that RLN block offers little discriminatory value in the differential diagnosis of ADSD versus MTD, and a positive response to RLN block should not be considered confirmatory of ADSD.

Computerized Tomography Measures During and After Artificial Lengthening of the Vocal Tract in Subjects With Voice Disorders

PURPOSE

The present study aimed to observe the effect of two types of tubes on vocal tract bidimensional and tridimensional images.

METHODS

Ten participants with hyperfunctional dysphonia were included. Computerized tomography was performed during production of sustained [a:], followed by sustained phonation into a drinking straw, and then repetition of sustained [a:]. A similar procedure was performed with a stirring straw after 15 minutes of vocal rest. Anatomic distances and area measures were obtained from computerized tomography midsagittal and transversal images. Vocal tract total volume was also calculated.

RESULTS

During tube phonation, increases were measured in the vertical length of the vocal tract, oropharyngeal area, hypopharyngeal area, outlet of the epilaryngeal tube, and inlet to the lower pharynx. Also, the larynx was lower, and more closure was noted between the velum and the nasal passage.

CONCLUSION

Tube phonation causes an increased total vocal tract volume, mostly because of the increased cross-sectional areas in the pharyngeal region. This change is more prominent when the tube offers more airflow resistance (stirring straw) compared with less airflow resistance (drinking straw). Based on our data and previous studies, it seems that vocal tract changes are not dependent on the voice condition (vocally trained, untrained, or disordered voices), but on the exercise itself and the type of instructions given to subjects. Tube phonation is a good option to reach therapeutic goals (eg, wide pharynx and low larynx) without giving biomechanical instructions, but only asking patients to feel easy voice and vibratory sensations.

Functional voice disorders: Clinical presentations and differential diagnosis

In this chapter, an overview of the heterogeneous group of functional voice disorders is given, including the psychogenic voice disorder (PVD) and hyperfunctional or muscle tension voice disorder (MTVD) subgroups. Reference is made to prevalence and demographic data, with empiric evidence for psychosocial factors commonly associated with the onset and maintenance of these disorders. Clinical features that distinguish between the different presentations of PVD and MTVD are described. While there are some shared characteristics, key differences between these two subgroups indicate that PVD more closely resembles the psychogenic movement disorders and a range of other functional neurologic disorders. Assessment procedures and auditory-perceptual features of the voice that distinguish these disorders from the neurologically based voice disorders are discussed, with case examples highlighting ambiguous features that may influence differential diagnosis. The clinical profiles of PVD and MTVD affirm approaches to clinical management by speech-language pathologists that integrate symptomatic behavioral voice therapy with "top-down" models of counseling or psychotherapy. They also support the proposition that PVD may be construed as a subtype of functional neurologic disorders.

Dynamics of phonatory posturing at phonation onset

INTRODUCTION

In speech and singing, the intrinsic laryngeal muscles set the prephonatory posture prior to the onset of phonation. The timing and shape of the prephonatory glottal posture can directly affect the resulting phonation type. We investigated the dynamics of human laryngeal phonatory posturing.

METHODS

Onset of vocal fold adduction to phonation was observed in 27 normal subjects using high-speed video recording. Subjects were asked to utter a variety of phonation types (modal, breathy, pressed, /i/ following sniff). Digital videokymography with concurrent acoustic signal was analyzed to assess the timing of the following: onset of adduction to final phonatory posture (FPT), phonation onset time (POT), and phonatory posture time (PPT). Final phonatory posture time was determined as the moment at which the laryngeal configuration used in phonation was first achieved.

RESULTS

Thirty-three audiovisual recordings met inclusion criteria. Average FPT, PPT, and POT were as follows: 303, 106, and 409 ms for modal; 430, 104, and 534 ms for breathy; 483, 213, and 696 ms for pressed; and 278, 98, and 376 ms for sniff-/i/. The following posturing features were observed: 1) pressed phonation: increased speed of closure just prior to final posture, complete glottal closure, and increased supraglottic hyperactivity; and 2) breathy phonation: decreased speed of closure prior to final posture, increased posterior glottal gap, and increased midmembranous gap.

CONCLUSIONS

Phonation onset latency was shortest for modal and longest for pressed voice. These findings are likely explained by glottal resistance and subglottal pressure requirements.

LEVEL OF EVIDENCE

NA. Laryngoscope, 126:1837-1843, 2016.

Muscle Tension Dysphonia: A Rationale for Symptomatic Subtypes, Expedited Treatment, and Increased Therapy Compliance

This article will briefly identify the variable nature of muscle tension dysphonia (MTD). Causes such as psychogenicity and maladaptive “vocal posture” will be described and questioned. Special Interest Group (SIG) 3 members may benefit from identification of the strengths and weaknesses of an ongoing movement towards a symptomatically generic “MTD.” More specific subtyping of MTD into 9 categories will be proposed, as well as description of associated therapy methods. Increased patient awareness that some subtypes may be self-correctable could simplify intervention, increase compliance, and improve clinician and researcher effectiveness.

Evaluation of voice quality after supraglottic laryngectomy

OBJECTIVE

Supraglottic laryngectomy is a surgical procedure that preserves laryngeal functions. This technique allows extensions including removal of tongue base or 1 arytenoid. We aimed to compare vocal results of supraglottic laryngectomy and extended procedures.

STUDY DESIGN

Cross-sectional study.

SETTING

Tertiary care hospital.

SUBJECTS AND METHODS

Thirty-three males who underwent supraglottic laryngectomy were included in the study. Fifteen patients (45.5%) were applied standard supraglottic laryngectomy (standard supraglottic laryngectomy group). In 11 patients (33.3%), unilateral arytenoid cartilage was totally resected by separation at the cricoarytenoid joint (laterally extended group), and the tongue base was removed in 7 patients (anteriorly extended group) (21.2%). Twenty male smokers constituted control group. Acoustic and aerodynamic voice analyses were performed for the assessment of objective results. Grade, roughness, breathiness, asthenia, and strain scale (GRBAS) scores were analyzed for perceptual assessment. Voice Handicap Index-30 was used to evaluate subjective results.

RESULTS

The comparison of supraglottic laryngectomy group with the control group revealed that the mean maximum phonation time and fundamental frequency were significantly lower in the supraglottic laryngectomy group (P < .001), and the mean jitter, shimmer, and noise-to-harmonics ratio were significantly higher in the supraglottic laryngectomy group (P < .001). Maximum phonation time and fundamental frequency were higher in the standard supraglottic laryngectomy group in comparison to extended groups. Jitter value was also lower in the standard supraglottic laryngectomy group compared to extended groups. Perceptual and subjective analyses revealed no difference among standard supraglottic laryngectomy and extended groups.

CONCLUSION

The results of this study indicate that supraglottic laryngectomy patients have acceptable voice quality, as determined by perceptual and subjective assessment.

Ventricular-fold dynamics in human phonation

PURPOSE

In this study, the authors aimed (a) to provide a classification of the ventricular-fold dynamics during voicing, (b) to study the aerodynamic impact of these motions on vocal-fold vibrations, and (c) to assess whether ventricular-fold oscillations could be sustained by aerodynamic coupling with the vocal folds.

METHOD

A 72-sample database of vocal gestures accompanying different acoustical events comprised high-speed cinematographic, audio, and electroglottographic recordings of 5 subjects. Combining the physiological correlates with a theoretical model of phonation, the vocal-ventricular aerodynamic interactions were investigated.

RESULTS

A ventricular-fold motion is found during (de)crescendos, shout, throat singing, yodel, growls, and glides with transitions between registers. Three main types of dynamics are identified: slow nonoscillatory motion and fast oscillatory motion with aperiodical or periodical vibrations. These patterns accompany a change in voice quality, pitch, and/or intensity. Alterations of glottal-oscillatory amplitude, frequency, and contact were predicted. It is shown that a ventricular oscillation can be initiated and sustained by aerodynamic coupling with the vocal folds.

CONCLUSIONS

Vocal-ventricular aerodynamic interactions can alter, enhance, or suppress vocal-fold vibrations or leave them unchanged, depending on the ventricular-fold dynamics involved. Depending on its variation in time, a similar level of ventricular-fold adduction impacts the glottal vibratory magnitude and contact much differently.

Aerodynamic and acoustic effects of ventricular gap

PURPOSE

Supraglottic compression is frequently observed in individuals with dysphonia. It is commonly interpreted as an indication of excessive circumlaryngeal muscular tension and ventricular medialization. The purpose of this study was to describe the aerodynamic and acoustic impact of varying ventricular medialization in a canine model.

METHODS

Subglottal air pressure, glottal airflow, electroglottograph, acoustic signals, and high-speed video images were recorded in seven excised canine larynges mounted in vitro for laryngeal vibratory experimentation. The degree of gap between the ventricular folds was adjusted and measured using sutures and weights. Data were recorded during phonation when the ventricular gap was narrow, neutral, and large. Glottal resistance was estimated by measures of subglottal pressure and glottal flow.

RESULTS

Glottal resistance increased systematically as ventricular gap became smaller. Wide ventricular gaps were associated with increases in fundamental frequency and decreases in glottal resistance. Sound pressure level did not appear to be impacted by the adjustments in ventricular gap used in this research.

CONCLUSIONS

Increases in supraglottic compression and associated reduced ventricular width may be observed in a variety of disorders that affect voice quality. Ventricular compression may interact with true vocal fold posture and vibration resulting in predictable changes in aerodynamic, physiological, acoustic, and perceptual measures of phonation. The data from this report supports the theory that narrow ventricular gaps may be associated with disordered phonation. In vitro and in vivo human data are needed to further test this association.

The assessment methods of laryngeal muscle activity in muscle tension dysphonia: a review

The purpose of this paper is to review the methods used for the assessment of muscular tension dysphonia (MTD). The MTD is a functional voice disorder associated with abnormal laryngeal muscle activity. Various assessment methods are available in the literature to evaluate the laryngeal hyperfunction. The case history, laryngoscopy, and palpation are clinical methods for the assessment of patients with MTD. Radiography and surface electromyography (EMG) are objective methods to provide physiological information about MTD. Recent studies show that surface EMG can be an effective tool for assessing muscular tension in MTD.

Laryngeal and pharyngeal activity during semioccluded vocal tract postures in subjects diagnosed with hyperfunctional dysphonia

High vertical laryngeal position (VLP), pharyngeal constriction, and laryngeal compression are common features associated with hyperfunctional voice disorders. The present study aimed to observe the effect on these variables of different semioccluded vocal tract postures in 20 subjects diagnosed with hyperfunctional dysphonia. During observation with flexible endoscope, each participant was asked to produce eight different semioccluded exercises: lip trills, hand-over-mouth technique, phonation into four different tubes, and tube phonation into water using two different depth levels. Participants were required to produce each exercise at three loudness levels: habitual, soft, and loud. To determine the VLP, anterior-to-posterior (A-P) compression, and pharyngeal width, a human evaluation test with three blinded laryngologists was conducted. Judges rated the three endoscopic variables using a five-point Likert scale. An intraclass correlation coefficient to assess intrarater and interrater agreement was performed. A multivariate linear regression model considering VLP, pharyngeal width, and A-P laryngeal compression as outcomes and phonatory tasks and intensity levels as predictive variables were carried out. Correlation analysis between variables was also conducted. Results indicate that all variables differ significantly. Therefore, VLP, A-P constriction, and pharyngeal width changed differently throughout the eight semioccluded postures. All semioccluded techniques produced a lower VLP, narrower aryepiglottic opening, and a wider pharynx than resting position. More prominent changes were obtained with a tube into the water and narrow tube into the air. VLP significantly correlated with pharyngeal width and A-P laryngeal compression. Moreover, pharyngeal width significantly correlated with A-P laryngeal compression.

Comparison between palpatory findings of the hyoid position and their acoustic, videostroboscopic, and perceptual attributes in patients with muscle tension dysphonia (with and without organic lesions)

SUMMARY

The direction in which the hyoid is pulled may change as a result of muscle tension dysphonia (MTD). The disposition usually occurs owing to paralaryngeal muscular imbalance (decompensation), which can create laryngeal dysfunction and consequently deteriorating the voice quality. This study aimed at reporting on a comparison between palpatory findings of hyoid position and their acoustic and perceptual and stroboscopic attributes among patients with MTD.

DESIGN

Cross-sectional random triple-blinded study.

METHOD

Palpatory, acoustic, audioperceptual, and stroboscopic findings of 39 patients with MTD were analyzed descriptively and using independent sample t test.

RESULTS

Dominant perceptual vocal characteristic of patients with pulled-up hyoid position was rough and the degrees of jitter and shimmer were higher in patients with pulled-up hyoid position than in patients with pulled-down hyoid position (jitter, P=0.019; shimmer, P=0.004), whereas signal-to-noise (S/N) ratio was lower in patients with pulled-up hyoid position than in pulled-down hyoid patients, but not significantly (S/N ratio, P=0.56). The dominant perceptual characteristic of patients with pulled-up hyoid position was rough voice, whereas that for pulled-down hyoid patients was strained voice. On the other hand, the dominant observable pattern in patients with pulled-up hyoid was MTD type II (lateral constriction), whereas that in patients with pulled-down hyoid was MTD type III (moderate anteroposterior constriction).

CONCLUSION

There is a general congruence between the hyoid pulled direction and its perceptual, acoustic, and videostroboscopic findings in patients with MTD.

Neck surface electromyography as a measure of vocal hyperfunction before and after injection laryngoplasty

OBJECTIVES

The goal of this preliminary study was to determine whether neck surface electromyography (sEMG) is sensitive to possible changes in vocal hyperfunction associated with injection laryngoplasty, particularly with respect to alterations in the degree of vocal hyperfunction.

METHODS

Thirteen individuals undergoing office-based injection laryngoplasty for glottal phonatory insufficiency were prospectively studied with a battery of acoustic, aerodynamic, endoscopic, and anterior neck sEMG assessments before the procedure and approximately 1 week afterward.

RESULTS

Anterior neck sEMG values were not significantly reduced (p < 0.05) after the procedure; however, perceptual ratings of strain and false vocal fold compression were both significantly reduced, reflecting a decrease in vocal hyperfunction.

CONCLUSIONS

The results do not support the use of anterior neck sEMG measures to assess vocal hyperfunction, and place into question the use of some other measures (estimates of anterior-posterior supraglottic compression, quantitative measures of anterior-posterior and false vocal fold supraglottic compression, and acoustic vowel rise times) that have been considered reflective of vocal hyperfunction.

A virtual trajectory model predicts differences in vocal fold kinematics in individuals with vocal hyperfunction

A simple, one degree of freedom virtual trajectory model of vocal fold kinematics was developed to investigate whether kinematic features of vocal fold movement confirm increased muscle stiffness. Model simulations verified that increases in stiffness were associated with changes in kinematic parameters, suggesting that increases in gesture rate would affect kinematic features to a lesser degree in vocal hyperfunction patients given the increased levels of muscle tension they typically employ to phonate. This hypothesis was tested experimentally in individuals with muscle tension dysphonia (MTD; N = 10) and vocal nodules (N = 10) relative to controls with healthy normal voice (N = 10) who were examined with trans-nasal endoscopy during a simple vocal fold abductory-adductory task. Kinematic measures in MTD patients were less affected by increased gesture rate, consistent with the hypothesis that these individuals have elevated typical laryngeal muscle tension. Group comparisons of the difference between medium and fast gesture rates (Mann-Whitney, one-tailed) showed statistically significant differences between the control and MTD individuals on the two kinematic features examined (p<0.05). Results in nodules participants were mixed and are discussed independently. The findings support the potential use of vocal fold kinematics as an objective clinical assay of vocal hyperfunction.

Modifications of vestibular fold shape from respiration to phonation in unilateral vocal fold paralysis

The diversity of vestibular fold (VeF) behavior during phonation, as well as the lack of insight regarding both the anatomy and muscle fiber composition hinder our understanding of their role during phonation. The concave shape of the free margin of VeF appears to be standard, but little is known regarding the variability of this shape. We, therefore, sought to determine the laryngoscopic features related to changes in the free margin of the VeFs during phonation in patients with unilateral vocal fold paralysis. Laryngeal images from 39 patients with unilateral paralysis associated with recurrent laryngeal nerve damage were evaluated with regard to variations in length and shape of the VeFs (concave, straight, or convex) during both respiration and phonation. The VeFs on both the paralyzed and unaffected sides were analyzed during both phonation and respiration resulting in 156 total images. During phonation, all VeFs on the nonparalyzed side were straight or convex, whereas on the paralyzed side, only 20 of the 39 were straight or convex during phonation. During respiration, significant differences in the shape of the nonparalyzed side were observed. During phonation, a nonconcave appearance on the paralyzed side usually correlated with a similar appearance during respiration. VeF length decreased during phonation in 30 nonparalyzed VeFs in contrast to only 13 paralyzed folds. When subjects switched from respiration to phonation, the VeFs were typically nonconcave on the nonparalyzed side. In contrast, on the paralyzed side, nonconcave VeFs were consistent across both tasks. In patients with unilateral vocal fold paralysis, VeF conformation is likely determined from extralaryngeal than intrinsic muscle. These findings have important theoretical considerations for laryngeal treatment.

Development of a modified diagnostic classification system for voice disorders with inter-rater reliability study

Diversity in nomenclature and on-going dilemmas over the conceptual bases for the classification of voice disorders make it virtually impossible for the collation and accurate comparison of evidence-based data across different clinical settings. This has significant implications for treatment outcome studies. The first aim of this study was to develop a modified diagnostic classification system for voice disorders with clearly defined operational guidelines by which we might reliably distinguish voice disorders from one another. The second aim was to establish the face validity and reliability of the system as an effective diagnostic tool for the allocation of patients to different diagnostic groups for clinical and research purposes. After the Diagnostic Classification System for Voice Disorders (DCSVD) had been developed, it was used in an inter-rater reliability study for the independent assessment of 53 new consecutive patients referred to the Voice Analysis Clinics of three tertiary hospitals. There were three raters present for the assessment and diagnostic allocation of each patient. The high levels of inter-rater reliability suggest this may be a robust classification system that has good face validity and even at this early stage, strong construct validity.

Disfonias: relação S/Z e tipos de voz

OBJETIVO: verificar o resultado da relação s/z e do tipo de voz em pacientes com diagnóstico de disfonias orgânico-funcionais (DOF) e disfonias funcionais por uso incorreto da voz (DFUIV), bem como a ocorrência das diferentes patologias dentro das DOF. MÉTODOS: 70 indivíduos, de ambos os sexos, entre cinco e 65 anos de idade, atendidos numa clínica-escola, cadastrados em Banco de Dados, entre 1998 e 2006, com DOF e DFUIV, ambos classificados em três subgrupos: casos em que a relação s/z indicava hipercontração, normalidade, e falta de coaptação das pregas vocais durante a fonação. Os tipos de voz foram classificados conforme a ocorrência em: sem alteração; ruidosa; ruidosa, comprimida e/ou apresentando alteração de f0h; ruidosa e/ou apresentando alteração de f0h; e comprimida. RESULTADOS: ocorrência significativa de DOF e de DOF com nódulos vocais; nas DOF e DFUIV, ocorrência significante de relação s/z normal com tempos isolados de /s/ e /z/ abaixo do normal e voz ruidosa. CONCLUSÕES: O resultado da relação s/z foi estatisticamente significativo a favor da faixa de normalidade estabelecida, tanto nos pacientes com diagnóstico de DOF, quanto naqueles com DFUIV, sendo que, em ambos os grupos de pacientes, a voz ruidosa foi a mais freqüente. Dentro das DOF, os nódulos vocais foram significativamente mais freqüentes do que as demais patologias.