FE Modelling of the Fluid-Structure-Acoustic Interaction for the Vocal Folds Self-Oscillation

NASA Astrophysics Data System (ADS)

Švancara, Pavel; Horáček, J.; Hrůza, V.

The flow induced self-oscillation of the human vocal folds in interaction with acoustic processes in the simplified vocal tract model was explored by three-dimensional (3D) finite element (FE) model. Developed FE model includes vocal folds pretension before phonation, large deformations of the vocal fold tissue, vocal folds contact, fluid-structure interaction, morphing the fluid mesh according the vocal folds motion (Arbitrary Lagrangian-Eulerian approach), unsteady viscous compressible airflow described by the Navier-Stokes equations and airflow separation during the glottis closure. Iterative partitioned approach is used for modelling the fluid-structure interaction. Computed results prove that the developed model can be used for simulation of the vocal folds self-oscillation and resulting acoustic waves. The developed model enables to numerically simulate an influence of some pathological changes in the vocal fold tissue on the voice production.

Shear properties of vocal fold mucosal tissues and their effect on vocal fold oscillation

NASA Astrophysics Data System (ADS)

Chan, Roger Wai Kai

Viscoelastic shear properties of vocal fold mucosal tissues and phonosurgical biomaterials were measured with a parallel-plate rotational rheometer. Elastic, viscous and damping properties were quantified as a function of frequency (0.01 Hz to 15 Hz) for human vocal fold mucosal tissues (N = 15), implantable biomaterials commonly used in the treatment of vocal fold paralysis (Teflon, gelatin, and collagen) (the non-mucosal group), and biomaterials currently or potentially useful in the treatment of vocal fold mucosal defects (adipose tissue or fat, hyaluronic acid, and fibronectin) (the mucosal group). It was found that intersubject differences as large as an order of magnitude were often observed for the shear properties of vocal fold mucosal tissues, part of which may be age- and gender-related. Shear properties of the non-mucosal group biomaterials were often much higher than those of the mucosal group biomaterials, which were relatively close to the shear properties of mucosal tissues. Viscoelastic and rheological modeling showed that shear properties of human vocal fold mucosa may be described by a quasi-linear viscoelastic theory and a statistical network theory, based upon which extrapolations to audio frequencies were possible. A theory of small-amplitude vocal fold oscillation was revisited to describe the effects of tissue shear properties on vocal fold oscillation and phonation threshold pressure, a measure of the 'ease' of phonation and an objective indication of vocal function. It was found that phonation threshold pressure is directly related to the viscous shear modulus or the 'effective damping modulus', a concept proposed to quantify the effective amount of damping in vocal fold oscillation. The mucosal group biomaterials were incorporated into the artificial vocal fold mucosa of a physical model in order to empirically assess their effects on phonation threshold pressure. Results showed that higher threshold pressures were consistently observed

Numerical Simulation of the Self-Oscillations of the Vocal Folds and of the Resulting Acoustic Phenomena in the Vocal Tract

NASA Astrophysics Data System (ADS)

Švancara, P.; Horáček, J.; Švec, J. G.

The study presents a three-dimensional (3D) finite element (FE) model of the flow-induced self-oscillation of the human vocal folds in interaction with acoustics of simplified vocal tract models. The 3D vocal tract models of the acoustic spaces shaped for simulation of phonation of Czech vowels [a:], [i:] and [u:] were created by converting the data from the magnetic resonance images (MRI). For modelling of the fluid-structure interaction, explicit coupling scheme with separated solvers for fluid and structure domain was utilized. The FE model comprises vocal folds pretension before starting phonation, large deformations of the vocal fold tissue, vocal-fold collisions, fluid-structure interaction, morphing the fluid mesh according to the vocal-fold motion (Arbitrary Lagrangian-Eulerian approach), unsteady viscous compressible airflow described by the Navier-Stokes equations and airflow separation. The developed FE model enables to study the relationship between flow-induced vibrations of the vocal folds and acoustic wave propagation in the vocal tract and can also be used to simulate for example pathological changes in the vocal fold tissue and their influence on the voice production.

Vocal Fold Epithelial Barrier in Health and Injury A Research Review

PubMed Central

Levendoski, Elizabeth Erickson; Leydon, Ciara; Thibeault, Susan L.

2015-01-01

Purpose Vocal fold epithelium is composed of layers of individual epithelial cells joined by junctional complexes constituting a unique interface with the external environment. This barrier provides structural stability to the vocal folds and protects underlying connective tissue from injury while being nearly continuously exposed to potentially hazardous insults including environmental or systemic-based irritants such as pollutants and reflux, surgical procedures, and vibratory trauma. Small disruptions in the epithelial barrier may have a large impact on susceptibility to injury and overall vocal health. The purpose of this article is to provide a broad-based review of our current knowledge of the vocal fold epithelial barrier. Methods A comprehensive review of the literature was conducted. Details of the structure of the vocal fold epithelial barrier are presented and evaluated in the context of function in injury and pathology. The importance of the epithelial-associated vocal fold mucus barrier is also introduced. Results/Conclusions Information presented in this review is valuable for clinicians and researchers as it highlights the importance of this understudied portion of the vocal folds to overall vocal health and disease. Prevention and treatment of injury to the epithelial barrier is a significant area awaiting further investigation. PMID:24686981

Computation of the three-dimensional medial surface dynamics of the vocal folds.

PubMed

Döllinger, Michael; Berry, David A

2006-01-01

To increase our understanding of pathological and healthy voice production, quantitative measurement of the medial surface dynamics of the vocal folds is significant, albeit rarely performed because of the inaccessibility of the vocal folds. Using an excised hemilarynx methodology, a new calibration technique, herein referred to as the linear approximate (LA) method, was introduced to compute the three-dimensional coordinates of fleshpoints along the entire medial surface of the vocal fold. The results were compared with results from the direct linear transform. An associated error estimation was presented, demonstrating the improved accuracy of the new method. A test on real data was reported including computation of quantitative measurements of vocal fold dynamics.

A case of bilateral vocal fold mucosal bridges, bilateral trans-vocal fold type III sulci vocales, and an intracordal polyp.

PubMed

Tan, Melin; Pitman, Michael J

2011-07-01

We present a patient with a novel finding of bilateral mucosal bridges, bilateral type III trans-vocal fold sulci vocales, and a vocal fold polyp. Although sulci and mucosal bridges occur in the vocal folds, it is rare to find multiples of these lesions in a single patient, and it is even more uncommon when they occur in conjunction with a vocal fold polyp. To our knowledge, this is the first description of a vocal fold polyp in combination with multiple vocal fold bridges and multiple type III sulci vocales in a single patient. To describe and visually present the diagnosis and treatment of a patient with an intracordal polyp, bilateral mucosal bridges, as well as bilateral type III trans-vocal fold sulci vocales. Presentation of a set of high definition intraoperative photos displaying the extent of the vocal fold lesions and the resection of the intracordal polyp. This patient presented with only 6 months of significant dysphonia. It was felt that the recent change in voice was because of the polyp and not the bridges or sulci vocales. Considering the patient's presentation and the possible morbidity of resection of mucosal bridges and sulci, only the polyp was excised. Postoperatively, the patient's voice returned to his acceptable mild baseline dysphonia, and the benefit has persisted 6 months postoperatively. The combination of bilateral mucosal bridges, bilateral type III sulcus vocalis, and an intracordal polyp in one patient is rare if not novel. Treatment of the polyp alone returned the patient's voice to his lifelong baseline of mild dysphonia. Copyright © 2011 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

Tissue Engineering-based Therapeutic Strategies for Vocal Fold Repair and Regeneration

PubMed Central

Li, Linqing; Stiadle, Jeanna M.; Lau, Hang K.; Zerdoum, Aidan B.; Jia, Xinqiao; L.Thibeault, Susan; Kiick, Kristi L.

2016-01-01

Vocal folds are soft laryngeal connective tissues with distinct layered structures and complex multicomponent matrix compositions that endow phonatory and respiratory functions. This delicate tissue is easily damaged by various environmental factors and pathological conditions, altering vocal biomechanics and causing debilitating vocal disorders that detrimentally affect the daily lives of suffering individuals. Modern techniques and advanced knowledge of regenerative medicine have led to a deeper understanding of the microstructure, microphysiology, and micropathophysiology of vocal fold tissues. State-of-the-art materials ranging from extracecullar-matrix (ECM)-derived biomaterials to synthetic polymer scaffolds have been proposed for the prevention and treatment of voice disorders including vocal fold scarring and fibrosis. This review intends to provide a thorough overview of current achievements in the field of vocal fold tissue engineering, including the fabrication of injectable biomaterials to mimic in vitro cell microenvironments, novel designs of bioreactors that capture in vivo tissue biomechanics, and establishment of various animal models to characterize the in vivo biocompatibility of these materials. The combination of polymeric scaffolds, cell transplantation, biomechanical stimulation, and delivery of antifibrotic growth factors will lead to successful restoration of functional vocal folds and improved vocal recovery in animal models, facilitating the application of these materials and related methodologies in clinical practice. PMID:27619243

“Finding a Voice”: Imaging Features after Phonosurgical Procedures for Vocal Fold Paralysis

PubMed Central

Vachha, B.A.; Ginat, D.T.; Mallur, P.; Cunnane, M.; Moonis, G.

2017-01-01

SUMMARY Altered communication (hoarseness, dysphonia, and breathy voice) that can result from vocal fold paralysis, secondary to numerous etiologies, may be amenable to surgical restoration. In this article, both traditional and cutting-edge phonosurgical procedures targeting the symptoms resulting from vocal fold paralysis are reviewed, with emphasis on the characteristic imaging appearances of various injectable materials, implants, and augmentation procedures used in the treatment of vocal fold paralysis. In addition, complications of injection laryngoplasty and medialization laryngoplasty are illustrated. Familiarity with the expected imaging changes following treatment of vocal fold paralysis may prevent the misinterpretation of posttreatment changes as pathology. Identifying common complications related to injection laryngoplasty and localization of displaced implants is crucial in determining specific management in patients who have undergone phonosurgical procedures for the management of vocal fold paralysis. PMID:27173367

Insights Into the Role of Collagen in Vocal Fold Health and Disease.

PubMed

Tang, Sharon S; Mohad, Vidisha; Gowda, Madhu; Thibeault, Susan L

2017-09-01

As one of the key fibrous proteins in the extracellular matrix, collagen plays a significant role in the structural and biomechanical characteristics of the vocal fold. Anchored fibrils of collagen create secure structural regions within the vocal folds and are strong enough to sustain vibratory impact and stretch during phonation. This contributes tensile strength, density, and organization to the vocal folds and influences health and pathogenesis. This review offers a comprehensive summary for a current understanding of collagen within normal vocal fold tissues throughout the life span as well as vocal pathology and wound repair. Further, collagen's molecular structure and biosynthesis are discussed. Finally, collagen alterations in tissue injury and repair and the incorporation of collagen-based biomaterials as a method of treating voice disorders are reviewed. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

An optical flow-based state-space model of the vocal folds.

PubMed

Granados, Alba; Brunskog, Jonas

2017-06-01

High-speed movies of the vocal fold vibration are valuable data to reveal vocal fold features for voice pathology diagnosis. This work presents a suitable Bayesian model and a purely theoretical discussion for further development of a framework for continuum biomechanical features estimation. A linear and Gaussian nonstationary state-space model is proposed and thoroughly discussed. The evolution model is based on a self-sustained three-dimensional finite element model of the vocal folds, and the observation model involves a dense optical flow algorithm. The results show that the method is able to capture different deformation patterns between the computed optical flow and the finite element deformation, controlled by the choice of the model tissue parameters.

Functional assessment of the ex vivo vocal folds through biomechanical testing: A review

PubMed Central

Dion, Gregory R.; Jeswani, Seema; Roof, Scott; Fritz, Mark; Coelho, Paulo; Sobieraj, Michael; Amin, Milan R.; Branski, Ryan C.

2016-01-01

The human vocal folds are complex structures made up of distinct layers that vary in cellular and extracellular composition. The mechanical properties of vocal fold tissue are fundamental to the study of both the acoustics and biomechanics of voice production. To date, quantitative methods have been applied to characterize the vocal fold tissue in both normal and pathologic conditions. This review describes, summarizes, and discusses the most commonly employed methods for vocal fold biomechanical testing. Force-elongation, torsional parallel plate rheometry, simple-shear parallel plate rheometry, linear skin rheometry, and indentation are the most frequently employed biomechanical tests for vocal fold tissues and each provide material properties data that can be used to compare native tissue verses diseased for treated tissue. Force-elongation testing is clinically useful, as it allows for functional unit testing, while rheometry provides physiologically relevant shear data, and nanoindentation permits micrometer scale testing across different areas of the vocal fold as well as whole organ testing. Thoughtful selection of the testing technique during experimental design to evaluate a hypothesis is important to optimizing biomechanical testing of vocal fold tissues. PMID:27127075

Glottal aerodynamics in compliant, life-sized vocal fold models

NASA Astrophysics Data System (ADS)

McPhail, Michael; Dowell, Grant; Krane, Michael

2013-11-01

This talk presents high-speed PIV measurements in compliant, life-sized models of the vocal folds. A clearer understanding of the fluid-structure interaction of voiced speech, how it produces sound, and how it varies with pathology is required to improve clinical diagnosis and treatment of vocal disorders. Physical models of the vocal folds can answer questions regarding the fundamental physics of speech, as well as the ability of clinical measures to detect the presence and extent of disorder. Flow fields were recorded in the supraglottal region of the models to estimate terms in the equations of fluid motion, and their relative importance. Experiments were conducted over a range of driving pressures with flow rates, given by a ball flowmeter, and subglottal pressures, given by a micro-manometer, reported for each case. Imaging of vocal fold motion, vector fields showing glottal jet behavior, and terms estimated by control volume analysis will be presented. The use of these results for a comparison with clinical measures, and for the estimation of aeroacoustic source strengths will be discussed. Acknowledge support from NIH R01 DC005642.

Current treatment of vocal fold scarring.

PubMed

Hirano, Shigeru

2005-06-01

Vocal fold scarring still remains a therapeutic challenge, with the most problematic issue being the histologic changes that are primarily responsible for altering the viscoelasticity of the vocal fold mucosa. Optimal treatment for vocal fold scarring has not yet been established. To restore or regenerate damaged vocal folds, it is important to investigate the changes to the layer structure of the lamina propria. Tissue engineering and regenerative medicine may provide new strategies for the prevention and treatment of vocal fold scarring. Recent developments in this field are reviewed in the present article. Histologic studies have revealed that hyaluronic acid, fibronectin, decorin, and various other extracellular matrix components, as well as collagen, may contribute to determining the vibratory properties of the vocal fold mucosa. Changes of these molecules are thought to affect the viscoelasticity of the scarred vocal folds. Based on such histologic findings, innovative approaches have been developed, including administration of hyaluronic acid into injured or scarred vocal folds. Other strategies that have recently shown advances include growth factor therapy and cell therapy using stem cells or mature fibroblasts. The effects of these new treatments have not fully been confirmed clinically, but there seems to be great therapeutic potential in such regenerative medical strategies. Recent research has revealed the detailed histologic and rheologic changes related to vocal fold scarring. Based on these findings, various new therapeutic strategies have been developed in animal models using tissue engineering and regenerative medicine. However, no clinical trials have been performed, and more studies are necessary to establish the optimum modality.

Using Trial Vocal Fold Injection to Select Vocal Fold Scar Patients Who May Benefit From More Durable Augmentation.

PubMed

Carroll, Thomas L; Dezube, Aaron; Bauman, Laura A; Mallur, Pavan S

2018-02-01

Clinical indications for vocal fold injection augmentation (VFI) are expanding. Prior studies demonstrate the benefit of trial VFI for select causes of glottic insufficiency. No studies have examined trial VFI for glottic insufficiency resulting from true vocal fold (TVF) scar. Retrospective chart review of patients who underwent trial VFI for a dominant pathology of TVF scar causing dysphonia. Patients who subsequently underwent durable augmentation were identified. The primary study outcome was the difference in Voice Handicap Index-10 (VHI-10) score from pretrial VFI to post-durable augmentation. Twenty-eight patients underwent trial VFI for TVF scar, 22 of whom reported a positive response. Fifteen of 22 subjects who underwent durable augmentation had viable data for analysis. Mean VHI-10 improved from 26.9 to 18.6 ( P < .05), for a delta VHI-10 of 8.3, or 30.9% improvement. Twelve of the 15 (80%) showed a clinically significant improvement (delta VHI-10 >5). A trial VFI is a potentially useful, low-risk procedure that appears to help the patient and clinician identify when global augmentation might improve the voice when vocal fold scar is present. Patients who reported successful trial VFI often demonstrated significant improvement in their VHI-10 after subsequent durable augmentation.

[Temperament of children with vocal fold nodules].

PubMed

Wei, Youhua; Wang, Zhinan; Xu, Zhongqiang; Chen, Ping; Hao, Lili

2009-11-01

To examine the temperament of children with vocal fold nodules. To compare the temperament dimension and temperamental types of 42 children with vocal fold nodules with 46 vocally normal children, using Chinese children's Temperament Problem Screening system (CCTPSs). The children with vocal fold nodules differed significantly from the comparison group in their temperament dimension's adaptability, intensity of reaction, mood value, persistency and temperamental types. There are more difficult and slow-to-warm-up children in patients with vocal fold nodules than vocally normal children.

Vocal Dose Measures: Quantifying Accumulated Vibration Exposure in Vocal Fold Tissues

PubMed Central

Titze, Ingo R.; Švec, Jan G.; Popolo, Peter S.

2011-01-01

To measure the exposure to self-induced tissue vibration in speech, three vocal doses were defined and described: distance dose, which accumulates the distance that tissue particles of the vocal folds travel in an oscillatory trajectory; energy dissipation dose, which accumulates the total amount of heat dissipated over a unit volume of vocal fold tissues; and time dose, which accumulates the total phonation time. These doses were compared to a previously used vocal dose measure, the vocal loading index, which accumulates the number of vibration cycles of the vocal folds. Empirical rules for viscosity and vocal fold deformation were used to calculate all the doses from the fundamental frequency (F0) and sound pressure level (SPL) values of speech. Six participants were asked to read in normal, monotone, and exaggerated speech and the doses associated with these vocalizations were calculated. The results showed that large F0 and SPL variations in speech affected the dose measures, suggesting that accumulation of phonation time alone is insufficient. The vibration exposure of the vocal folds in normal speech was related to the industrial limits for hand-transmitted vibration, in which the safe distance dose was derived to be about 500 m. This limit was found rather low for vocalization; it was related to a comparable time dose of about 17 min of continuous vocalization, or about 35 min of continuous reading with normal breathing and unvoiced segments. The voicing pauses in normal speech and dialogue effectively prolong the safe time dose. The derived safety limits for vocalization will likely require refinement based on a more detailed knowledge of the differences in hand and vocal fold tissue morphology and their response to vibrational stress, and on the effect of recovery of the vocal fold tissue during voicing pauses. PMID:12959470

Vocal dose measures: quantifying accumulated vibration exposure in vocal fold tissues.

PubMed

Titze, Ingo R; Svec, Jan G; Popolo, Peter S

2003-08-01

To measure the exposure to self-induced tissue vibration in speech, three vocal doses were defined and described: distance dose, which accumulates the distance that tissue particles of the vocal folds travel in an oscillatory trajectory; energy dissipation dose, which accumulates the total amount of heat dissipated over a unit volume of vocal fold tissues; and time dose, which accumulates the total phonation time. These doses were compared to a previously used vocal dose measure, the vocal loading index, which accumulates the number of vibration cycles of the vocal folds. Empirical rules for viscosity and vocal fold deformation were used to calculate all the doses from the fundamental frequency (F0) and sound pressure level (SPL) values of speech. Six participants were asked to read in normal, monotone, and exaggerated speech and the doses associated with these vocalizations were calculated. The results showed that large F0 and SPL variations in speech affected the dose measures, suggesting that accumulation of phonation time alone is insufficient. The vibration exposure of the vocal folds in normal speech was related to the industrial limits for hand-transmitted vibration, in which the safe distance dose was derived to be about 500 m. This limit was found rather low for vocalization; it was related to a comparable time dose of about 17 min of continuous vocalization, or about 35 min of continuous reading with normal breathing and unvoiced segments. The voicing pauses in normal speech and dialogue effectively prolong the safe time dose. The derived safety limits for vocalization will likely require refinement based on a more detailed knowledge of the differences in hand and vocal fold tissue morphology and their response to vibrational stress, and on the effect of recovery of the vocal fold tissue during voicing pauses.

Repairing the vibratory vocal fold.

PubMed

Long, Jennifer L

2018-01-01

A vibratory vocal fold replacement would introduce a new treatment paradigm for structural vocal fold diseases such as scarring and lamina propria loss. This work implants a tissue-engineered replacement for vocal fold lamina propria and epithelium in rabbits and compares histology and function to injured controls and orthotopic transplants. Hypotheses were that the cell-based implant would engraft and control the wound response, reducing fibrosis and restoring vibration. Translational research. Rabbit adipose-derived mesenchymal stem cells (ASC) were embedded within a three-dimensional fibrin gel, forming the cell-based outer vocal fold replacement (COVR). Sixteen rabbits underwent unilateral resection of vocal fold epithelium and lamina propria, as well as reconstruction with one of three treatments: fibrin glue alone with healing by secondary intention, replantation of autologous resected vocal fold cover, or COVR implantation. After 4 weeks, larynges were examined histologically and with phonation. Fifteen rabbits survived. All tissues incorporated well after implantation. After 1 month, both graft types improved histology and vibration relative to injured controls. Extracellular matrix (ECM) of the replanted mucosa was disrupted, and ECM of the COVR implants remained immature. Immune reaction was evident when male cells were implanted into female rabbits. Best histologic and short-term vibratory outcomes were achieved with COVR implants containing male cells implanted into male rabbits. Vocal fold cover replacement with a stem cell-based tissue-engineered construct is feasible and beneficial in acute rabbit implantation. Wound-modifying behavior of the COVR implant is judged to be an important factor in preventing fibrosis. NA. Laryngoscope, 128:153-159, 2018. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

Vocal fold paralysis secondary to phonotrauma.

PubMed

Klein, Travis A L; Gaziano, Joy E; Ridley, Marion B

2014-01-01

A unique case of acute onset vocal fold paralysis secondary to phonotrauma is presented. The cause was forceful vocalization by a drill instructor on a firearm range. Imaging studies revealed extensive intralaryngeal and retropharyngeal hemorrhage. Laryngoscopy showed a complete left vocal fold paralysis. Relative voice rest was recommended, and the patient regained normal vocal fold mobility and function after approximately 12 weeks. Copyright © 2014 The Voice Foundation. All rights reserved.

Pulsed dye laser-induced inflammatory response and extracellular matrix turnover in rat vocal folds and vocal fold fibroblasts.

PubMed

Lin, Ya; Yamashita, Masaru; Zhang, Jingxian; Ling, Changying; Welham, Nathan V

2009-10-01

Disruption of the vocal fold extracellular matrix (ECM) can induce a profound and refractory dysphonia. Pulsed dye laser (PDL) irradiation has shown early promise as a treatment modality for disordered ECM in patients with chronic vocal fold scar; however, there are limited data addressing the mechanism by which this laser energy might induce cellular and extracellular changes in vocal fold tissues. In this study, we examined the inflammatory and ECM modulating effects of PDL irradiation on normal vocal fold tissues and cultured vocal fold fibroblasts (VFFs). We evaluated the effects of 585 nm PDL irradiation on inflammatory cytokine and collagen/collagenase gene transcription in normal rat vocal folds in vivo (3-168 hours following delivery of approximately 39.46 J/cm(2) fluence) and VFFs in vitro (3-72 hours following delivery of 4.82 or 9.64 J/cm(2) fluence). We also examined morphological vocal fold tissue changes 3 hours, 1 week, and 1 month post-irradiation. PDL irradiation altered inflammatory cytokine and procollagen/collagenase expression at the transcript level, both in vitro and in vivo. Additionally, PDL irradiation induced an inflammatory repair process in vivo that was completed by 1 month with preservation of normal tissue morphology. PDL irradiation can modulate ECM turnover in phenotypically normal vocal folds. Additional work is required to determine if these findings extend to disordered ECM, such as is seen in vocal fold scar. Lasers Surg. Med. 41:585-594, 2009. (c) 2009 Wiley-Liss, Inc.

Vocal Fold Surface Hydration: A review

PubMed Central

Leydon, Ciara; Sivasankar, Mahalakshmi; Falciglia, Danielle Lodewyck; Atkins, Christopher; Fisher, Kimberly V.

2009-01-01

Vocal fold surface liquid homeostasis contributes to optimal vocal physiology. In this paper we review emerging evidence that vocal fold surface liquid is maintained in part by salt and water fluxes across the epithelium. Based on recent immunolocalization and electrophysiological findings, we describe a transcellular pathway as one mechanism for regulating superficial vocal fold hydration. We propose that the pathway includes the sodium-potassium pump, sodium-potassium-chloride cotransporter, epithelial sodium channels, cystic fibrosis transmembrane regulator chloride channels, and aquaporin water channels. By integrating knowledge of the regulating mechanisms underlying ion and fluid transport with observations from hydration challenges and treatments using in vitro and in vivo studies, we provide a theoretical basis for understanding how environmental and behavioral challenges and clinical interventions may modify vocal fold surface liquid composition. We present converging evidence that clinical protocols directed at facilitating vocal fold epithelial ion and fluid transport may benefit healthy speakers, those with voice disorders, and those at risk for voice disorders. PMID:19111440

Stochastic mechanical model of vocal folds for producing jitter and for identifying pathologies through real voices.

PubMed

Cataldo, E; Soize, C

2018-06-06

Jitter, in voice production applications, is a random phenomenon characterized by the deviation of the glottal cycle length with respect to a mean value. Its study can help in identifying pathologies related to the vocal folds according to the values obtained through the different ways to measure it. This paper aims to propose a stochastic model, considering three control parameters, to generate jitter based on a deterministic one-mass model for the dynamics of the vocal folds and to identify parameters from the stochastic model taking into account real voice signals experimentally obtained. To solve the corresponding stochastic inverse problem, the cost function used is based on the distance between probability density functions of the random variables associated with the fundamental frequencies obtained by the experimental voices and the simulated ones, and also on the distance between features extracted from the voice signals, simulated and experimental, to calculate jitter. The results obtained show that the model proposed is valid and some samples of voices are synthesized considering the identified parameters for normal and pathological cases. The strategy adopted is also a novelty and mainly because a solution was obtained. In addition to the use of three parameters to construct the model of jitter, it is the discussion of a parameter related to the bandwidth of the power spectral density function of the stochastic process to measure the quality of the signal generated. A study about the influence of all the main parameters is also performed. The identification of the parameters of the model considering pathological cases is maybe of all novelties introduced by the paper the most interesting. Copyright © 2018 Elsevier Ltd. All rights reserved.

Viscoelasticity of rabbit vocal folds after injection augmentation.

PubMed

Dahlqvist, Ake; Gärskog, Ola; Laurent, Claude; Hertegård, Stellan; Ambrosio, Luigi; Borzacchiello, Assunta

2004-01-01

Vocal fold function is related to the viscoelasticity of the vocal fold tissue. Augmentation substances used for injection treatment of voice insufficiency may alter the viscoelastic properties of vocal folds and their vibratory capacity. The objective was to compare the mechanical properties (viscoelasticity) of various injectable substances and the viscoelasticity of rabbit vocal folds, 6 months after injection with one of these substances. Animal model. Cross-linked collagen (Zyplast), double cross-linked hyaluronan (hylan B gel), dextranomers in hyaluronan (DHIA), and polytetrafluoroethylene (Teflon) were injected into rabbit vocal folds. Six months after the injection, the animals were killed and the right- and left-side vocal folds were removed. Dynamic viscosity of the injected substances and the vocal folds was measured with a Bohlin parallel-plate rheometer during small-amplitude oscillation. All injected vocal folds showed a decreasing dynamic viscosity with increasing frequency. Hylan B gel and DiHA showed the lowest dynamic viscosity values, and vocal folds injected with these substances also showed the lowest dynamic viscosity (similar to noninjected control samples). Teflon (and vocal folds injected with Teflon) showed the highest dynamic viscosity values, followed by the collagen samples. Substances with low viscoelasticity alter the mechanical properties of the vocal fold to a lesser degree than substances with a high viscoelasticity. The data indicated that hylan B gel and DiHA render the most natural viscoelastic properties to the vocal folds. These substances seem to be appropriate for preserving or restoring the vibratory capacity of the vocal folds when glottal insufficiency is treated with augmentative injections.

Viscoelastic properties of rabbit vocal folds after augmentation.

PubMed

Hertegård, Stellan; Dahlqvist, Ake; Laurent, Claude; Borzacchiello, Assunta; Ambrosio, Luigi

2003-03-01

Vocal fold function is closely related to tissue viscoelasticity. Augmentation substances may alter the viscoelastic properties of vocal fold tissues and hence their vibratory capacity. We sought to investigate the viscoelastic properties of rabbit vocal folds in vitro after injections of various augmentation substances. Polytetrafluoroethylene (Teflon), cross-linked collagen (Zyplast), and cross-linked hyaluronan, hylan b gel (Hylaform) were injected into the lamina propria and the thyroarytenoid muscle of rabbit vocal folds. Dynamic viscosity of the injected vocal fold as a function of frequency was measured with a Bohlin parallel-plate rheometer during small-amplitude oscillation. All injected vocal folds showed a decreasing dynamic viscosity with increasing frequency. Vocal fold samples injected with hylan b gel showed the lowest dynamic viscosity, quite close to noninjected control samples. Vocal folds injected with polytetrafluoroethylene showed the highest dynamic viscosity followed by the collagen samples. The data indicated that hylan b gel in short-term renders the most natural viscoelastic properties to the vocal fold among the substances tested. This is of importance to restore/preserve the vibratory capacity of the vocal folds when glottal insufficiency is treated with injections.

Automated measurement of vocal fold vibratory asymmetry from high-speed videoendoscopy recordings.

PubMed

Mehta, Daryush D; Deliyski, Dimitar D; Quatieri, Thomas F; Hillman, Robert E

2011-02-01

In prior work, a manually derived measure of vocal fold vibratory phase asymmetry correlated to varying degrees with visual judgments made from laryngeal high-speed videoendoscopy (HSV) recordings. This investigation extended this work by establishing an automated HSV-based framework to quantify 3 categories of vocal fold vibratory asymmetry. HSV-based analysis provided for cycle-to-cycle estimates of left-right phase asymmetry, left-right amplitude asymmetry, and axis shift during glottal closure for 52 speakers with no vocal pathology producing comfortable and pressed phonation. An initial cross-validation of the automated left-right phase asymmetry measure was performed by correlating the measure with other objective and subjective assessments of phase asymmetry. Vocal fold vibratory asymmetry was exhibited to a similar extent in both comfortable and pressed phonations. The automated measure of left-right phase asymmetry strongly correlated with manually derived measures and moderately correlated with visual-perceptual ratings. Correlations with the visual-perceptual ratings remained relatively consistent as the automated measure was derived from kymograms taken at different glottal locations. An automated HSV-based framework for the quantification of vocal fold vibratory asymmetry was developed and initially validated. This framework serves as a platform for investigating relationships between vocal fold tissue motion and acoustic measures of voice function.

Quantitative Analysis of Vocal Fold Vibration in Vocal Fold Paralysis With the Use of High-speed Digital Imaging.

PubMed

Yamauchi, Akihito; Yokonishi, Hisayuki; Imagawa, Hiroshi; Sakakibara, Ken-Ichi; Nito, Takaharu; Tayama, Niro

2016-11-01

The goal of this work was to objectively elucidate the vibratory characteristics of vocal fold paralysis (VFP) using high-speed digital imaging (HSDI). HSDI was performed in 29 vocally healthy subjects (12 women and 17 men) and in 107 patients with VFP (40 women and 67 men). Then, the HSDI data were evaluated by visual-perceptual rating, single-line kymography, multiline kymography, laryngotopography, and glottal area waveform analysis. Patients with VFP compared with vocally healthy subjects revealed more frequent incomplete glottal closure, greater asymmetry in amplitude, mucosal wave, frequency, and phase, as well as larger open quotient, smaller speed index, larger maximal and minimal glottal area, and smaller glottal area difference. Paralyzed vocal folds in VFP revealed reduced mucosal wave than nonparalyzed vocal folds in VFP or in intact vocal folds in vocally healthy subjects. HSDI was effective in documenting the characteristics of vocal fold vibrations in patients with VFP and in exploring the vibratory disturbance for estimating the severity of dysphonia. Copyright © 2016 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Vocal fold hemorrhage: factors predicting recurrence.

PubMed

Lennon, Christen J; Murry, Thomas; Sulica, Lucian

2014-01-01

Vocal fold hemorrhage is an acute phonotraumatic injury treated with voice rest; recurrence is a generally accepted indication for surgical intervention. This study aims to identify factors predictive of recurrence based on outcomes of a large clinical series. Retrospective cohort. Retrospective review of cases of vocal fold hemorrhage presenting to a university laryngology service. Demographic information was compiled. Videostroboscopic exams were evaluated for hemorrhage extent, presence of varix, mucosal lesion, and/or vocal fold paresis. Vocal fold hemorrhage recurrence was the main outcome measure. Follow-up telephone survey was used to complement clinical data. Forty-seven instances of vocal fold hemorrhage were evaluated (25M:22F; 32 professional voice users). Twelve of the 47 (26%) patients experienced recurrence. Only the presence of varix demonstrated significant association with recurrence (P = 0.0089) on multivariate logistic regression. Vocal fold hemorrhage recurred in approximately 26% of patients. Varix was a predictor of recurrence, with 48% of those with varix experiencing recurrence. Monitoring, behavioral management and/or surgical intervention may be indicated to treat patients with such characteristics. © 2013 The American Laryngological, Rhinological and Otological Society, Inc.

Irregular vocal fold dynamics incited by asymmetric fluid loading in a model of recurrent laryngeal nerve paralysis

NASA Astrophysics Data System (ADS)

Sommer, David; Erath, Byron D.; Zanartu, Matias; Peterson, Sean D.

2011-11-01

Voiced speech is produced by dynamic fluid-structure interactions in the larynx. Traditionally, reduced order models of speech have relied upon simplified inviscid flow solvers to prescribe the fluid loadings that drive vocal fold motion, neglecting viscous flow effects that occur naturally in voiced speech. Viscous phenomena, such as skewing of the intraglottal jet, have the most pronounced effect on voiced speech in cases of vocal fold paralysis where one vocal fold loses some, or all, muscular control. The impact of asymmetric intraglottal flow in pathological speech is captured in a reduced order two-mass model of speech by coupling a boundary-layer estimation of the asymmetric pressures with asymmetric tissue parameters that are representative of recurrent laryngeal nerve paralysis. Nonlinear analysis identifies the emergence of irregular and chaotic vocal fold dynamics at values representative of pathological speech conditions.

Sarcoidosis Presenting as Bilateral Vocal Fold Immobility.

PubMed

Hintze, Justin M; Gnagi, Sharon H; Lott, David G

2018-05-01

Bilateral true vocal fold paralysis is rarely attributable to inflammatory diseases. Sarcoidosis is a rare but important etiology of bilateral true vocal fold paralysis by compressive lymphadenopathy, granulomatous infiltration, and neural involvement. We describe the first reported case of sarcoidosis presenting as bilateral vocal fold immobility caused by direct fixation by granulomatous infiltration severe enough to necessitate tracheostomy insertion. In addition, we discuss the presentation, the pathophysiology, and the treatment of this disease with a review of the literature of previously reported cases of sarcoidosis-related vocal fold immobility. Sarcoidosis should therefore be an important consideration for the otolaryngologist's differential diagnosis of true vocal fold immobility. Copyright © 2018 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

[Basic research on vocal fold dynamics: three-dimensional vibration analysis of human and canine larynges].

PubMed

Döllinger, M; Rosanowski, F; Eysholdt, U; Lohscheller, J

2008-12-01

The understanding of normal and pathological vocal fold dynamics is the basis for a pathophysiological motivated voice therapy. Crucial vocal fold dynamics concerning voice production occur at the medial part of the vocal fold which is seen as the most critical region of mucosal wave propagation. Due to the limited size of the larynx the possibilities of laryngeal imaging by endoscopic techniques are limited. This work describes an experimental set-up that enables quantification of the entire medial and superior vocal fold surface using excised human and in vivo canine larynges. The data obtained enable analysis of vocal fold deflections, velocities, and mucosal wave propagation. The reciprocal dependencies can be examined and different areas of vocal fold dynamics located. The vertical components obscured in clinical endoscopy can be visualized. This is not negligible. In particular it is shown that the vertical deflection, which cannot be observed by clinical examination, plays an important part in the dynamics and therefore cannot be omitted for therapeutic procedures. The theoretically assumed entrainment and influence of the two main vibration modes enabling normal phonation is confirmed.

Classification for animal vocal fold surgery: resection margins impact histological outcomes of vocal fold injury.

PubMed

Imaizumi, Mitsuyoshi; Thibeault, Susan L; Leydon, Ciara

2014-11-01

Extent of vocal fold injury impacts the nature and timing of wound healing and voice outcomes. However, depth and extent of the lesion created to study wound healing in animal models vary across studies, likely contributing to different outcomes. Our goal was to create a surgery classification system to enable comparison of postoperative outcomes across animal vocal fold wound-healing studies. Prospective, controlled animal study. Rats underwent one of three types of unilateral vocal fold surgeries classified by depth and length of resection. The surgeries were: for subepithelial injury, resection of epithelium and superficial layer of the lamina propria at the midmembranous portion of the vocal fold; for transmucosal injury, resection of epithelium and lamina propria; and for transmuscular injury, resection of epithelium, lamina propria, and superficial portion of the vocalis muscle. Wound healing was evaluated histologically at various time points up to 35 days postinjury. Complete healing occurred by 14 days postsurgery for subepithelial injury, and by day 35 for transmucosal injury. Injury remained present at day 35 for transmuscular injury. Timing and completeness of healing varied by extent and depth of resection. Scarless healing occurred rapidly following subepithelial injury, whereas scarring was observed at 5 weeks after transmuscular injury. The proposed classification system may facilitate comparison of surgical outcomes across vocal fold wound-healing studies. N/A. © 2014 The American Laryngological, Rhinological and Otological Society, Inc.

Modeling the biomechanical influence of epilaryngeal stricture on the vocal folds: a low-dimensional model of vocal-ventricular fold coupling.

PubMed

Moisik, Scott R; Esling, John H

2014-04-01

PURPOSE Physiological and phonetic studies suggest that, at moderate levels of epilaryngeal stricture, the ventricular folds impinge upon the vocal folds and influence their dynamical behavior, which is thought to be responsible for constricted laryngeal sounds. In this work, the authors examine this hypothesis through biomechanical modeling. METHOD The dynamical response of a low-dimensional, lumped-element model of the vocal folds under the influence of vocal-ventricular fold coupling was evaluated. The model was assessed for F0 and cover-mass phase difference. Case studies of simulations of different constricted phonation types and of glottal stop illustrate various additional aspects of model performance. RESULTS Simulated vocal-ventricular fold coupling lowers F0 and perturbs the mucosal wave. It also appears to reinforce irregular patterns of oscillation, and it can enhance laryngeal closure in glottal stop production. CONCLUSION The effects of simulated vocal-ventricular fold coupling are consistent with sounds, such as creaky voice, harsh voice, and glottal stop, that have been observed to involve epilaryngeal stricture and apparent contact between the vocal folds and ventricular folds. This supports the view that vocal-ventricular fold coupling is important in the vibratory dynamics of such sounds and, furthermore, suggests that these sounds may intrinsically require epilaryngeal stricture.

Dysphonia and vocal fold telangiectasia in hereditary hemorrhagic telangiectasia.

PubMed

Chang, Joseph; Yung, Katherine C

2014-11-01

This case report is the first documentation of dysphonia and vocal fold telangiectasia as a complication of hereditary hemorrhagic telangiectasia (HHT). Case report of a 40-year-old man with HHT presenting with 2 years of worsening hoarseness. Hoarseness corresponded with a period of anticoagulation. Endoscopy revealed vocal fold scarring, vocal fold telangiectasias, and plica ventricular is suggestive of previous submucosal vocal fold hemorrhage and subsequent counterproductive compensation with ventricular phonation. Hereditary hemorrhagic telangiectasia may present as dysphonia with vocal fold telangiectasias and place patients at risk of vocal fold hemorrhage. © The Author(s) 2014.

Microvascular lesions of the true vocal fold.

PubMed

Postma, G N; Courey, M S; Ossoff, R H

1998-06-01

Microvascular lesions, also called varices or capillary ectasias, in contrast to vocal fold polyps with telangiectatic vessels, are relatively small lesions arising from the microcirculation of the vocal fold. Varices are most commonly seen in female professional vocalists and may be secondary to repetitive trauma, hormonal variations, or repeated inflammation. Microvascular lesions may either be asymptomatic or cause frank dysphonia by interrupting the normal vibratory pattern, mass, or closure of the vocal folds. They may also lead to vocal fold hemorrhage, scarring, or polyp formation. Laryngovideostroboscopy is the key in determining the functional significance of vocal fold varices. Management of patients with a varix includes medical therapy, speech therapy, and occasionally surgical vaporization. Indications for surgery are recurrent hemorrhage, enlargement of the varix, development of a mass in conjunction with the varix or hemorrhage, and unacceptable dysphonia after maximal medical and speech therapy due to a functionally significant varix.

Dependence of phonation threshold pressure on vocal tract acoustics and vocal fold tissue mechanics.

PubMed

Chan, Roger W; Titze, Ingo R

2006-04-01

Analytical and computer simulation studies have shown that the acoustic impedance of the vocal tract as well as the viscoelastic properties of vocal fold tissues are critical for determining the dynamics and the energy transfer mechanism of vocal fold oscillation. In the present study, a linear, small-amplitude oscillation theory was revised by taking into account the propagation of a mucosal wave and the inertive reactance (inertance) of the supraglottal vocal tract as the major energy transfer mechanisms for flow-induced self-oscillation of the vocal fold. Specifically, analytical results predicted that phonation threshold pressure (Pth) increases with the viscous shear properties of the vocal fold, but decreases with vocal tract inertance. This theory was empirically tested using a physical model of the larynx, where biological materials (fat, hyaluronic acid, and fibronectin) were implanted into the vocal fold cover to investigate the effect of vocal fold tissue viscoelasticity on Pth. A uniform-tube supraglottal vocal tract was also introduced to examine the effect of vocal tract inertance on Pth. Results showed that Pth decreased with the inertive impedance of the vocal tract and increased with the viscous shear modulus (G") or dynamic viscosity (eta') of the vocal fold cover, consistent with theoretical predictions. These findings supported the potential biomechanical benefits of hyaluronic acid as a surgical bioimplant for repairing voice disorders involving the superficial layer of the lamina propria, such as scarring, sulcus vocalis, atrophy, and Reinke's edema.

Interstitial protein alterations in rabbit vocal fold with scar.

PubMed

Thibeault, Susan L; Bless, Diane M; Gray, Steven D

2003-09-01

Fibrous and interstitial proteins compose the extracellular matrix of the vocal fold lamina propria and account for its biomechanic properties. Vocal fold scarring is characterized by altered biomechanical properties, which create dysphonia. Although alterations of the fibrous proteins have been confirmed in the rabbit vocal fold scar, interstitial proteins, which are known to be important in wound repair, have not been investigated to date. Using a rabbit model, interstitial proteins decorin, fibromodulin, and fibronectin were examined immunohistologically, two months postinduction of vocal fold scar by means of forcep biopsy. Significantly decreased decorin and fibromodulin with significantly increased fibronectin characterized scarred vocal fold tissue. The implications of altered interstitial proteins levels and their affect on the fibrous proteins will be discussed in relation to increased vocal fold stiffness and viscosity, which characterizes vocal fold scar.

Vocal exercise may attenuate acute vocal fold inflammation

PubMed Central

Abbott, Katherine Verdolini; Li, Nicole Y.K.; Branski, Ryan C.; Rosen, Clark A.; Grillo, Elizabeth; Steinhauer, Kimberly; Hebda, Patricia A.

2012-01-01

Objectives/Hypotheses The objective was to assess the utility of selected “resonant voice” exercises for the reduction of acute vocal fold inflammation. The hypothesis was that relatively large-amplitude, low-impact exercises associated with resonant voice would reduce inflammation more than spontaneous speech and possibly more than voice rest. Study Design The study design was prospective, randomized, double-blind. Methods Nine vocally healthy adults underwent a 1-hr vocal loading procedure, followed by randomization to (a) a spontaneous speech condition, (b) a vocal rest condition, or (c) a resonant voice exercise condition. Treatments were monitored in clinic for 4 hr, and continued extra-clinically until the next morning. At baseline, immediately following loading, after the 4-hr in-clinic treatment, and 24 hr post baseline, secretions were suctioned from the vocal folds bilaterally and submitted to enzyme-linked immunosorbent assay (ELISA) to estimate concentrations of key markers of tissue injury and inflammation: IL-1β, IL-6, IL-8, TNF-α, MMP-8, and IL-10. Results Complete data sets were obtained for 3 markers -- IL-1β, IL-6, and MMP-8 -- for one subject in each treatment condition. For those markers, results were poorest at 24-hr follow-up in the spontaneous speech condition, sharply improved in the voice rest condition, and best in the resonant voice condition. Average results for all markers, for all responsive subjects with normal baseline mediator concentrations, revealed an almost identical pattern. Conclusions Some forms of tissue mobilization may be useful to attenuate acute vocal fold inflammation. PMID:23177745

Biomechanical effects of hydration in vocal fold tissues.

PubMed

Chan, Roger W; Tayama, Niro

2002-05-01

It has often been hypothesized, with little empirical support, that vocal fold hydration affects voice production by mediating changes in vocal fold tissue rheology. To test this hypothesis, we attempted in this study to quantify the effects of hydration on the viscoelastic shear properties of vocal fold tissues in vitro. Osmotic changes in hydration (dehydration and rehydration) of 5 excised canine larynges were induced by sequential incubation of the tissues in isotonic, hypertonic, and hypotonic solutions. Elastic shear modulus (G'), dynamic viscosity eta' and the damping ratio zeta of the vocal fold mucosa (lamina propria) were measured as a function of frequency (0.01 to 15 Hz) with a torsional rheometer. Vocal fold tissue stiffness (G') and viscosity (eta) increased significantly (by 4 to 7 times) with the osmotically induced dehydration, whereas they decreased by 22% to 38% on the induced rehydration. Damping ratio (zeta) also increased with dehydration and decreased with rehydration, but the detected differences were not statistically significant at all frequencies. These findings support the long-standing hypothesis that hydration affects vocal fold vibration by altering tissue rheologic (or viscoelastic) properties. Our results demonstrated the biomechanical importance of hydration in vocal fold tissues and suggested that hydration approaches may potentially improve the biomechanics of phonation in vocal fold lesions involving disordered fluid balance.

Reinke Edema: Watch For Vocal Fold Cysts.

PubMed

Tüzüner, Arzu; Demirci, Sule; Yavanoglu, Ahmet; Kurkcuoglu, Melih; Arslan, Necmi

2015-06-01

Reinke edema is one of the common cause of dysphonia middle-aged population, and severe thickening of vocal folds require surgical treatment. Smoking plays a major role on etiology. Vocal fold cysts are also benign lesions and vocal trauma blamed for acquired cysts. We would like to present 3 cases with vocal fold cyst related with Reinke edema. First case had a subepidermal epidermoid cyst with Reinke edema, which could be easily observed before surgery during laryngostroboscopy. Second case had a mucous retention cyst into the edematous Reinke tissue, which was detected during surgical intervention, and third case had a epidermoid cyst that occurred 2 months after before microlaryngeal operation regarding Reinke edema reduction. These 3 cases revealed that surgical management of Reinke edema needs a careful dissection and close follow-up after surgery for presence of vocal fold cysts.

Adipose-Derived Mesenchymal Stem Cells in the Regeneration of Vocal Folds: A Study on a Chronic Vocal Fold Scar

PubMed Central

Vassiliki, Kalodimou; Irini, Messini; Nikolaos, Psychalakis; Karampela, Eleftheria; Apostolos, Papalois

2016-01-01

Background. The aim of the study was to assess the histological effects of autologous infusion of adipose-derived stem cells (ADSC) on a chronic vocal fold scar in a rabbit model as compared to an untreated scar as well as in injection of hyaluronic acid. Study Design. Animal experiment. Method. We used 74 New Zealand rabbits. Sixteen of them were used as control/normal group. We created a bilateral vocal fold wound in the remaining 58 rabbits. After 18 months we separated our population into three groups. The first group served as control/scarred group. The second one was injected with hyaluronic acid in the vocal folds, and the third received an autologous adipose-derived stem cell infusion in the scarred vocal folds (ADSC group). We measured the variation of thickness of the lamina propria of the vocal folds and analyzed histopathologic changes in each group after three months. Results. The thickness of the lamina propria was significantly reduced in the group that received the ADSC injection, as compared to the normal/scarred group. The collagen deposition, the hyaluronic acid, the elastin levels, and the organization of elastic fibers tend to return to normal after the injection of ADSC. Conclusions. Autologous injection of adipose-derived stem cells on a vocal fold chronic scar enhanced the healing of the vocal folds and the reduction of the scar tissue, even when compared to other treatments. PMID:26933440

Side population cells in the human vocal fold.

PubMed

Yamashita, Masaru; Hirano, Shigeru; Kanemaru, Shin-ichi; Tsuji, Shunichiro; Suehiro, Atsushi; Ito, Juichi

2007-11-01

The regenerative processes of the vocal fold, or the existence of stem cells in the folds, are unknown. Side population (SP) cells are defined as cells that have the ability to exclude the DNA binding dye, Hoechst 33342. They are regarded as a cell population enriched with stem cells and can be isolated from non-SP cells by a fluorescence-activated cell sorter. This study was designed to determine whether SP cells exist in the human vocal fold, as a first step in elucidating the regenerative mechanisms of the vocal fold. Seven human excised larynges were used in this study. Two were used for fluorescence-activated cell sorter analysis, and 5 were subjected to immunohistochemical analysis with antibodies against an adenosine triphosphate binding cassette transporter family member, ABCG2, which is expressed in SP cells. The number of SP cells in the human vocal fold was about 0.2% of the total number of cells. ABCG2-positive cells were identified in both the epithelium and subepithelial tissue throughout the entire vocal fold. This preliminary study demonstrated the existence of SP cells in the human vocal fold. Further studies are warranted to clarify how these cells work in the vocal fold, particularly in the regenerative process.

A Rat Excised Larynx Model of Vocal Fold Scar

ERIC Educational Resources Information Center

Welham, Nathan V.; Montequin, Douglas W.; Tateya, Ichiro; Tateya, Tomoko; Choi, Seong Hee; Bless, Diane M.

2009-01-01

Purpose: To develop and evaluate a rat excised larynx model for the measurement of acoustic, aerodynamic, and vocal fold vibratory changes resulting from vocal fold scar. Method: Twenty-four 4-month-old male Sprague-Dawley rats were assigned to 1 of 4 experimental groups: chronic vocal fold scar, chronic vocal fold scar treated with 100-ng basic…

Determining the etiology of mild vocal fold hypomobility.

PubMed

Heman-Ackah, Yolanda D; Batory, Mark

2003-12-01

The prevalence of mild vocal fold hypomobility is unknown. In a study by Heman-Ackah et al, vocal fold hypomobility in a population of singing teachers was found to be associated more frequently with vocal complaints than was the presence of vocal fold masses. The etiology of mild vocal fold hypomobility has not been previously explored. In the present study, a retrospective chart review was performed of 134 patients who presented to a tertiary laryngology referral center over a 6-month period for evaluation of vocal complaints. Of the 134 patients, 61 (46%) were found to have mild vocal referring otolaryngologist. Imaging studies and laboratory tests to evaluate for structural, metabolic, and infectious causes of the decreased mobility had been ordered. Forty-nine patients completed the work-up. Of these, 41 out of 49 (84%) were found to have imaging or laboratory findings that could explain the hypomobility. Thyroid abnormalities were found to be associated with vocal fold hypomobility in 21 out of 49 (43%) of those with a complete evaluation. Other causes of vocal fold hypomobility included idiopathic (8 of 49, 16%), viral neuritis (5 of 49, 10%), central nervous system abnormality (4 of 49, 8%), neural tumor (3 of 49, 6%), joint dysfunction (3 of 49, 6%), iatrogenic nerve injury (2 of 49, 4%), myopathy (2 of 49, 4%), and noniatrogenic traumatic nerve injury (1 of 49, 2%), This study shows that unilateral vocal fold hypomobility often is associated with a physiologic process, and a complete investigation to determine the etiology is warranted in all cases.

Cause of vocal fold scar.

PubMed

Allen, Jacqui

2010-12-01

The prolonged debilitation, loss of income, and decrement in quality of life caused by vocal fold scar is exacerbated by our inability to successfully treat this difficult problem. As technology focuses on developing innovative treatments, we need to fully appreciate and understand the mechanisms giving rise to glottal scar, on both a macroscopic and microscopic level. This review examines recent literature pertaining to the gross and molecular mechanisms which give rise to vocal fold scar. Mechanisms of vocal fold scar production have been examined in both macroscopic and microscopic detail. Trauma and injury involving any aspect of the lamina propria, particularly the deeper layers, may result in epithelial tethering and scar formation. At the molecular level, early inflammatory cytokines activate and recruit fibroblasts which then drive the fibrotic cascade. Transforming growth factor-β enhances fibrosis and is balanced by tissue matrix metalloproteinases and hepatocyte growth factor activity. Molecular signaling offers novel opportunities to intervene in scar formation. New work investigating the cause of vocal fold scar identifies complex molecular processes leading to fibrosis in the lamina propria. Improved mechanistic understanding offers insight into prevention strategies and possible targets for antifibrotic therapies that may help prevent or treat this debilitating condition.

Influence of the ventricular folds on a voice source with specified vocal fold motion1

PubMed Central

McGowan, Richard S.; Howe, Michael S.

2010-01-01

The unsteady drag on the vocal folds is the major source of sound during voiced speech. The drag force is caused by vortex shedding from the vocal folds. The influence of the ventricular folds (i.e., the “false” vocal folds that protrude into the vocal tract a short distance downstream of the glottis) on the drag and the voice source are examined in this paper by means of a theoretical model involving vortex sheets in a two-dimensional geometry. The effect of the ventricular folds on the output acoustic pressure is found to be small when the movement of the vocal folds is prescribed. It is argued that the effect remains small when fluid-structure interactions account for vocal fold movement. These conclusions can be justified mathematically when the characteristic time scale for change in the velocity of the glottal jet is large compared to the time it takes for a vortex disturbance to be convected through the vocal fold and ventricular fold region. PMID:20329852

A portable high-speed camera system for vocal fold examinations.

PubMed

Hertegård, Stellan; Larsson, Hans

2014-11-01

In this article, we present a new portable low-cost system for high-speed examinations of the vocal folds. Analysis of glottal vibratory parameters from the high-speed recordings is compared with videostroboscopic recordings. The high-speed system is built around a Fastec 1 monochrome camera, which is used with newly developed software, High-Speed Studio (HSS). The HSS has options for video/image recording, contains a database, and has a set of analysis options. The Fastec/HSS system has been used clinically since 2011 in more than 2000 patient examinations and recordings. The Fastec 1 camera has sufficient time resolution (≥4000 frames/s) and light sensitivity (ISO 3200) to produce images for detailed analyses of parameters pertinent to vocal fold function. The camera can be used with both rigid and flexible endoscopes. The HSS software includes options for analyses of glottal vibrations, such as kymogram, phase asymmetry, glottal area variation, open and closed phase, and angle of vocal fold abduction. It can also be used for separate analysis of the left and vocal fold movements, including maximum speed during opening and closing, a parameter possibly related to vocal fold elasticity. A blinded analysis of 32 patients with various voice disorders examined with both the Fastec/HSS system and videostroboscopy showed that the high-speed recordings were significantly better for the analysis of glottal parameters (eg, mucosal wave and vibration asymmetry). The monochrome high-speed system can be used in daily clinical work within normal clinical time limits for patient examinations. A detailed analysis can be made of voice disorders and laryngeal pathology at a relatively low cost. Copyright © 2014 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Amplitude of Glottal Mucosal Wave After Vocal Fold Microflap With or Without Fibrin Glue.

PubMed

González-Herranz, Ramón; Amarillo, Elizabeth; Hernández-García, Estefanía; Montojo Woodeson, José; Plaza-Mayor, Guillermo

2017-05-01

The vocal fold microflap technique is the ideal to remove benign vocal fold pathology. Our objective is to compare the amplitudes of the mucosal wave before and after the closure of microflap defect with fibrin glue, and when microflap is left to heal by secondary intention. The present study is a retrospective series, including 32 patients treated by intracordal phonosurgery, with closure of the microflap either with fibrin glue or by healing by secondary intention. They all had both preoperative and 6-month postoperative track records to allow voice analysis, a subjective Voice Handicap Index 10 (VHI-10), and a good image quality strobe. After selecting the patients was found that the mean overall preoperative VHI-10 was 26.6, and improved up to 10.5 after surgery, a statistical differences (P = 0.03). When comparing both groups, with or without fibrin glue, fibrin glue did not improved results in VHI-10. On the contrary, there was a significant difference in the improvement of the open glottal phase after surgery (P = 0.03), showing a much higher improvement when fibrin glue was used. The use of fibrin glue after a vocal fold microflap for advanced pathology, such as sulcus vocalis in pocket, vergeture, or vocal fold scar, increases the amplitude of the mucosal wave of the vocal folds, but does not improve the VHI-10 results in our cohort of female patients. So far, patient-reported outcome shows that healing by secondary intention continues to provide excellent voice results. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Experimental analysis of the characteristics of artificial vocal folds.

PubMed

Misun, Vojtech; Svancara, Pavel; Vasek, Martin

2011-05-01

Specialized literature presents a number of models describing the function of the vocal folds. In most of those models, an emphasis is placed on the air flowing through the glottis and, further, on the effect of the parameters of the air alone (its mass, speed, and so forth). The article focuses on the constructional definition of artificial vocal folds and their experimental analysis. The analysis is conducted for voiced source voice phonation and for the changing mean value of the subglottal pressure. The article further deals with the analysis of the pressure of the airflow through the vocal folds, which is cut (separated) into individual pulses by the vibrating vocal folds. The analysis results show that air pulse characteristics are relevant to voice generation, as they are produced by the flowing air and vibrating vocal folds. A number of artificial vocal folds have been constructed to date, and the aforementioned view of their phonation is confirmed by their analysis. The experiments have confirmed that man is able to consciously affect only two parameters of the source voice, that is, its fundamental frequency and voice intensity. The main forces acting on the vocal folds during phonation are as follows: subglottal air pressure and elastic and inertia forces of the vocal folds' structure. The correctness of the function of the artificial vocal folds is documented by the experimental verification of the spectra of several types of artificial vocal folds. Copyright © 2011 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

Mechanical properties of the vocal fold. Stress-strain studies.

PubMed

Haji, T; Mori, K; Omori, K; Isshiki, N

1992-01-01

The viscoelasticity of the vocal and ventricular folds was experimentally assessed by analyzing the stress-strain relationships obtained using a newly developed measuring system. The degree of stiffness of the mid-membranous portion of the vocal fold was less than that near the anterior commissure or the vocal process. The ventricular fold was much less stiff and significantly more viscous than the vocal fold. At the membranous portion of the vocal fold, the degree of stiffness was less and that of viscosity greater at 2 mm above and below the free margin than at the free margin itself.

Voice rest after vocal fold surgery: current practice and evidence.

PubMed

Coombs, A C; Carswell, A J; Tierney, P A

2013-08-01

Voice rest is commonly recommended after vocal fold surgery, but there is a lack of evidence base and no standard protocol. The aim of this study was to establish common practice regarding voice rest following vocal fold surgery. An online survey was circulated via e-mail invitation to members of the ENT UK Expert Panel between October and November 2011. The survey revealed that 86.5 per cent of respondents agreed that 'complete voice rest' means no sound production at all, but there was variability in how 'relative voice rest' was defined. There was no dominant type of voice rest routinely recommended after surgery for laryngeal papillomatosis or intermediate pathologies. There was considerable variability in the duration of voice rest recommended, with no statistically significant, most popular response (except for malignant lesions). Surgeons with less than 10 years of experience were more likely to recommend fewer days of voice rest. There is a lack of consistency in advice given to patients after vocal fold surgery, in terms of both type and length of voice rest. This may arise from an absence of robust evidence on which to base practice.

Histopathologic investigations of the unphonated human child vocal fold mucosa.

PubMed

Sato, Kiminori; Umeno, Hirohito; Nakashima, Tadashi; Nonaka, Satoshi; Harabuchi, Yasuaki

2012-01-01

Vocal fold stellate cells (VFSCs) in the maculae flavae (MFe) located at both ends of the vocal fold mucosa are inferred to be involved in the metabolism of extracellular matrices. MFe are also considered to be an important structure in the growth and development of the human vocal fold mucosa. Tension caused by phonation (vocal fold vibration) is hypothesized to stimulate VFSCs to accelerate production of extracellular matrices. Human child vocal fold mucosae unphonated since birth were investigated histologically. Histologic analysis of human child vocal fold mucosa. Vocal fold mucosae, which have remained unphonated since birth, of two children (7 and 12 years old) with cerebral palsy were investigated by light and electron microscopy and compared with normal subjects. Vocal fold mucosae and MFe were hypoplastic and rudimentary and did not have a vocal ligament, Reinke's space, or the layered structure. The lamina propria appeared as a uniform structure. Some VFSCs in the MFe showed degeneration and not many vesicles were present at the periphery of the cytoplasm. The VFSCs synthesized fewer extracellular matrices, such as fibrous protein and glycosaminoglycan. The VFSCs appeared to have decreased activity. Vocal fold vibration (phonation) after birth is an important factor in the growth and development of the human vocal fold mucosa. Copyright © 2012 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

The impact of intraglottal vortices on vocal fold dynamics

NASA Astrophysics Data System (ADS)

Erath, Byron; Pirnia, Alireza; Peterson, Sean

2016-11-01

During voiced speech a critical pressure is produced in the lungs that separates the vocal folds and creates a passage (the glottis) for airflow. As air passes through the vocal folds the resulting aerodynamic loading, coupled with the tissue properties of the vocal folds, produces self-sustained oscillations. Throughout each cycle a complex flow field develops, characterized by a plethora of viscous flow phenomena. Air passing through the glottis creates a jet, with periodically-shed vortices developing due to flow separation and the Kelvin-Helmholtz instability in the shear layer. These vortices have been hypothesized to be a crucial mechanism for producing vocal fold vibrations. In this study the effect of vortices on the vocal fold dynamics is investigated experimentally by passing a vortex ring over a flexible beam with the same non-dimensional mechanical properties as the vocal folds. Synchronized particle image velocimetry data are acquired in tandem with the beam dynamics. The resulting impact of the vortex ring loading on vocal fold dynamics is discussed in detail. This work was supported by the National Science Foundation Grant CBET #1511761.

Insights into the role of elastin in vocal fold health and disease

PubMed Central

Moore, Jaime

2011-01-01

Elastic fibers are large, complex and surprisingly poorly understood extracellular matrix (ECM) macromolecules. The elastin fiber, generated from a single human gene - elastin (ELN), is a self assembling integral protein that endows critical mechanic proprieties to elastic tissues and organs such as the skin, lungs, and arteries. The biology of elastic fibers is complex because they have multiple components, a tightly regulated developmental deposition, a multi-step hierarchical assembly and unique biomechanical functions. Elastin is present in vocal folds, where it plays a pivotal role in the quality of phonation. This review article provides an overview of the genesis of elastin and its wide- ranging structure and function. Specific distribution within the vocal fold lamina propria across the lifespan in normal and pathological states and its contribution to vocal fold biomechanics will be examined. Elastin and elastin-derived molecules are increasingly investigated for their application in tissue engineering. The properties of various elastin– based materials will be discussed and their current and future applications evaluated. A new level of understanding of the biomechanical properties of vocal fold elastin composites and their molecular basis should lead to new strategies for elastic fiber repair and regeneration in aging and disease. PMID:21708449

A Computational Study of Vocal Fold Dehydration During Phonation.

PubMed

Wu, Liang; Zhang, Zhaoyan

2017-12-01

While vocal fold dehydration is often considered an important factor contributing to vocal fatigue, it still remains unclear whether vocal fold vibration alone is able to induce severe dehydration that has a noticeable effect on phonation and perceived vocal effort. A three-dimensional model was developed to investigate vocal fold systemic dehydration and surface dehydration during phonation. Based on the linear poroelastic theory, the model considered water resupply from blood vessels through the lateral boundary, water movement within the vocal folds, water exchange between the vocal folds and the surface liquid layer through the epithelium, and surface fluid accumulation and discharge to the glottal airway. Parametric studies were conducted to investigate water loss within the vocal folds and from the surface after a 5-min sustained phonation under different permeability and vibration conditions. The results showed that the dehydration generally increased with increasing vibration amplitude, increasing epithelial permeability, and reduced water resupply. With adequate water resupply, a large-amplitude vibration can induce an overall systemic dehydration as high as 3%. The distribution of water loss within the vocal folds was non-uniform, and a local dehydration higher than 5% was observed even under conditions of a low overall systemic dehydration (<1%). Such high level of water loss may severely affect tissue properties, muscular functions, and phonations characteristics. In contrast, water loss of the surface liquid layer was generally an order of magnitude higher than water loss inside the vocal folds, indicating that the surface dehydration level is likely not a good indicator of the systemic dehydration.

The importance of hyaluronic acid in vocal fold biomechanics.

PubMed

Chan, R W; Gray, S D; Titze, I R

2001-06-01

This study examined the influence of hyaluronic acid (HA) on the biomechanical properties of the human vocal fold cover (the superficial layer of the lamina propria). Vocal fold tissues were freshly excised from 5 adult male cadavers and were treated with bovine testicular hyaluronidase to selectively remove HA from the lamina propria extracellular matrix (ECM). Linear viscoelastic shear properties (elastic shear modulus and dynamic viscosity) of the tissue samples before and after enzymatic treatment were quantified as a function of frequency (0.01 to 15 Hz) by a parallel-plate rotational rheometer at 37 degrees C. On removing HA from the vocal fold ECM, the elastic shear modulus (G' ) or stiffness of the vocal fold cover decreased by an average of around 35%, while the dynamic viscosity (eta') increased by 70% at higher frequencies (>1 Hz). The results suggested that HA plays an important role in determining the biomechanical properties of the vocal fold cover. As a highly hydrated glycosaminoglycan in the vocal fold ECM, it likely contributes to the maintenance of an optimal tissue viscosity that may facilitate phonation, and an optimal tissue stiffness that may be important for vocal fundamental frequency control. HA has been proposed as a potential bioimplant for the surgical repair of vocal fold ECM defects (eg, vocal fold scarring and sulcus vocalis). Our results suggested that such clinical use may be potentially optimal for voice production from a biomechanical perspective.

What can vortices tell us about vocal fold vibration and voice production.

PubMed

Khosla, Sid; Murugappan, Shanmugam; Gutmark, Ephraim

2008-06-01

Much clinical research on laryngeal airflow has assumed that airflow is unidirectional. This review will summarize what additional knowledge can be obtained about vocal fold vibration and voice production by studying rotational motion, or vortices, in laryngeal airflow. Recent work suggests two types of vortices that may strongly contribute to voice quality. The first kind forms just above the vocal folds during glottal closing, and is formed by flow separation in the glottis; these flow separation vortices significantly contribute to rapid closing of the glottis, and hence, to producing loudness and high frequency harmonics in the acoustic spectrum. The second is a group of highly three-dimensional and coherent supraglottal vortices, which can produce sound by interaction with structures in the vocal tract. Present work is also described that suggests that certain laryngeal pathologies, such as asymmetric vocal fold tension, will significantly modify both types of vortices, with adverse impact on sound production: decreased rate of glottal closure, increased broadband noise, and a decreased signal to noise ratio. Recent research supports the hypothesis that glottal airflow contains certain vortical structures that significantly contribute to voice quality.

Vascular lesions of the vocal fold.

PubMed

Gökcan, Kürşat Mustafa; Dursun, Gürsel

2009-04-01

The aim of the study was to present symptoms, laryngological findings, clinical course, management modalities, and consequences of vascular lesions of vocal fold. This study examined 162 patients, the majority professional voice users, with vascular lesions regarding their presenting symptoms, laryngological findings, clinical courses and treatment results. The most common complaint was sudden hoarseness with hemorrhagic polyp. Microlaryngoscopic surgery was performed in 108 cases and the main indication of surgery was the presence of vocal fold mass or development of vocal polyp during clinical course. Cold microsurgery was utilized for removal of vocal fold masses and feeding vessels cauterized using low power, pulsed CO(2) laser. Acoustic analysis of patients revealed a significant improvement of jitter, shimmer and harmonics/noise ratio values after treatment. Depending on our clinical findings, we propose treatment algorithm where voice rest and behavioral therapy is the integral part and indications of surgery are individualized for each patient.

Histopathologic study of human vocal fold mucosa unphonated over a decade.

PubMed

Sato, Kiminori; Umeno, Hirohito; Ono, Takeharu; Nakashima, Tadashi

2011-12-01

Mechanotransduction caused by vocal fold vibration could possibly be an important factor in the maintenance of extracellular matrices and layered structure of the human adult vocal fold mucosa as a vibrating tissue after the layered structure has been completed. Vocal fold stellate cells (VFSCs) in the human maculae flavae of the vocal fold mucosa are inferred to be involved in the metabolism of extracellular matrices of the vocal fold mucosa. Maculae flavae are also considered to be an important structure in the growth and development of the human vocal fold mucosa. Tension caused by phonation (vocal fold vibration) is hypothesized to stimulate the VFSCs to accelerate production of extracellular matrices. A human adult vocal fold mucosa unphonated over a decade was investigated histopathologically. Vocal fold mucosa unphonated for 11 years and 2 months of a 64-year-old male with cerebral hemorrhage was investigated by light and electron microscopy. The vocal fold mucosae (including maculae flavae) were atrophic. The vocal fold mucosa did not have a vocal ligament, Reinke's space or a layered structure. The lamina propria appeared as a uniform structure. Morphologically, the VFSCs synthesized fewer extracellular matrices, such as fibrous protein and glycosaminoglycan. Consequently, VFSCs appeared to decrease their level of activity.

Diagnostic and therapeutic pitfalls in benign vocal fold diseases

PubMed Central

Bohlender, Jörg

2013-01-01

More than half of patients presenting with hoarseness show benign vocal fold changes. The clinician should be familiar with the anatomy, physiology and functional aspects of voice disorders and also the modern diagnostic and therapeutic possibilities in order to ensure an optimal and patient specific management. This review article focuses on the diagnostic and therapeutic limitations and difficulties of treatment of benign vocal fold tumors, the management and prevention of scarred vocal folds and the issue of unilateral vocal fold paresis. PMID:24403969

Paediatric vocal fold paralysis.

PubMed

Garcia-Lopez, Isabel; Peñorrocha-Teres, Julio; Perez-Ortin, Magdalena; Cerpa, Mauricio; Rabanal, Ignacio; Gavilan, Javier

2013-01-01

Vocal fold paralysis (VFP) is a relatively common cause of stridor and dysphonia in the paediatric population. This report summarises our experience with VFP in the paediatric age group. All patients presenting with vocal fold paralysis over a 12-month period were included. Medical charts were revised retrospectively. The diagnosis was performed by flexible endoscopic examination. The cases were evaluated with respect to aetiology of the paralysis, presenting symptoms, delay in diagnosis, affected side, vocal fold position, need for surgical treatment and outcome. The presenting symptoms were stridor and dysphonia. Iatrogenic causes formed the largest group, followed by idiopathic, neurological and obstetric VFP. Unilateral paralysis was found in most cases. The median value for delay in diagnosis was 1 month and it was significantly higher in the iatrogenic group. Surgical treatment was not necessary in most part of cases. The diagnosis of VFP may be suspected based on the patient's symptoms and confirmed by flexible endoscopy. Infants who develop stridor or dysphonia following a surgical procedure have to be examined without delay. The surgeon has to keep in mind that there is a possibility of late spontaneous recovery or compensation. Copyright © 2012 Elsevier España, S.L. All rights reserved.

Vocal Fold Mucus Aggregation in Persons with Voice Disorders

PubMed Central

Bonilha, Heather Shaw; White, Lisa; Kuckhahn, Kelsey; Gerlach, Terri Treman; Deliyski, Dimitar D.

2012-01-01

Mucus aggregation on the vocal folds is a common finding from laryngeal endoscopy. Patients with voice disorders report the presence of mucus aggregation. Patients also report that mucus aggregation causes them to clear their throat, a behavior believed to be harmful to vocal fold mucosa. Even though clinicians and patients report and discuss mucus aggregation, we have a limited understanding of mucus aggregation in persons with voice disorders. The primary goal of this study was to provide an initial assessment of the presence and features of mucus aggregation in persons with voice disorders. The secondary goal of this study was to determine if there are differences in mucus aggregation between persons with and without voice disorders. To address these goals, four features of mucus aggregation were judged from laryngeal endoscopy recordings from 54 speakers with voice disorders and compared to judgments of these same features in persons without voice disorders. The results from this study showed: (1) 100% of dysphonic speakers had visible mucus aggregation on their vocal folds. (2) Persons with hyperfunctional voice disorders had different mucus characteristics than persons with hypofunctional voice disorders (p=0.002). (3) Dysphonic speakers did not differ in frequency of mucus identified on the vocal folds than non-dysphonic speakers. However, the two groups had different mucus characteristics (p=0.001). Future studies are warranted to determine if these differences in mucus aggregation between persons with and without voice disorders relate to specific aspects of laryngeal pathology or patient characteristics, such as age and gender. Once we understand these relationships, we may be able to use this information to improve our diagnosis and treatment of patients with atypical laryngeal mucus aggregation. PMID:22510352

Intraoperative handheld probe for 3D imaging of pediatric benign vocal fold lesions using optical coherence tomography (Conference Presentation)

NASA Astrophysics Data System (ADS)

Benboujja, Fouzi; Garcia, Jordan; Beaudette, Kathy; Strupler, Mathias; Hartnick, Christopher J.; Boudoux, Caroline

2016-02-01

Excessive and repetitive force applied on vocal fold tissue can induce benign vocal fold lesions. Children affected suffer from chronic hoarseness. In this instance, the vibratory ability of the folds, a complex layered microanatomy, becomes impaired. Histological findings have shown that lesions produce a remodeling of sup-epithelial vocal fold layers. However, our understanding of lesion features and development is still limited. Indeed, conventional imaging techniques do not allow a non-invasive assessment of sub-epithelial integrity of the vocal fold. Furthermore, it remains challenging to differentiate these sub-epithelial lesions (such as bilateral nodules, polyps and cysts) from a clinical perspective, as their outer surfaces are relatively similar. As treatment strategy differs for each lesion type, it is critical to efficiently differentiate sub-epithelial alterations involved in benign lesions. In this study, we developed an optical coherence tomography (OCT) based handheld probe suitable for pediatric laryngological imaging. The probe allows for rapid three-dimensional imaging of vocal fold lesions. The system is adapted to allow for high-resolution intra-operative imaging. We imaged 20 patients undergoing direct laryngoscopy during which we looked at different benign pediatric pathologies such as bilateral nodules, cysts and laryngeal papillomatosis and compared them to healthy tissue. We qualitatively and quantitatively characterized laryngeal pathologies and demonstrated the added advantage of using 3D OCT imaging for lesion discrimination and margin assessment. OCT evaluation of the integrity of the vocal cord could yield to a better pediatric management of laryngeal diseases.

[Surgery of benign vocal fold lesions].

PubMed

Olthoff, A

2016-09-01

Surgical treatment of benign vocal fold lesions can be indicated for clinical or functional reasons. The principles of phonosurgery have to be maintained in either case. The appropriate phonosurgical technique depends on the type of vocal fold lesion. Depending on the findings, phonosurgery aims to maintain or improve voice quality. The evaluation of clinical and functional results includes indirect laryngoscopy, videostroboscopy, and voice analysis.

Multidimensional assessment of vocal changes in benign vocal fold lesions after voice therapy.

PubMed

Schindler, Antonio; Mozzanica, Francesco; Maruzzi, Patrizia; Atac, Murat; De Cristofaro, Valeria; Ottaviani, Francesco

2013-06-01

To evaluate through a multidimensional protocol voice changes after voice therapy in patients with benign vocal fold lesions. 65 consecutive patients affected by benign vocal fold lesions were enrolled. Depending on videolaryngostroboscopy the patients were divided into 3 groups: 23 patients with Reinke's oedema, 22 patients with vocal fold cysts and 20 patients with gelatinous polyp. Each subject received 10 voice therapy sessions and was evaluated, before and after voice therapy, through a multidimensional protocol including videolaryngostroboscopy, perception, acoustics, aerodynamics and self-rating by the patient. Data were compared using Wilcoxon signed-rank test. Kruskal-Wallis test was used to analyse the mean variation difference between the three groups of patients. Mann-Whitney test was used for post hoc analysis. Only in 11 cases videolaryngostroboscopy revealed an improvement of the initial pathology. However a significant improvement was observed in perceptual, acoustic and self-assessment ratings in the 3 groups of patients. In particular the parameters of G, R and A of the GIRBAS scale, and the noise to harmonic ratio, Jitter and shimmer scores improved after rehabilitation. A significant improvement of all the parameters of Voice Handicap Index after rehabilitation treatment was found. No significant difference among the three groups of patients was visible, except for self-assessment ratings. Voice therapy may provide a significant improvement in perceptual, acoustic and self-assessed voice quality in patients with benign glottal lesions. Utilization of voice therapy may allow some patients to avoid surgical intervention. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Vocal fold contact patterns based on normal modes of vibration.

PubMed

Smith, Simeon L; Titze, Ingo R

2018-05-17

The fluid-structure interaction and energy transfer from respiratory airflow to self-sustained vocal fold oscillation continues to be a topic of interest in vocal fold research. Vocal fold vibration is driven by pressures on the vocal fold surface, which are determined by the shape of the glottis and the contact between vocal folds. Characterization of three-dimensional glottal shapes and contact patterns can lead to increased understanding of normal and abnormal physiology of the voice, as well as to development of improved vocal fold models, but a large inventory of shapes has not been directly studied previously. This study aimed to take an initial step toward characterizing vocal fold contact patterns systematically. Vocal fold motion and contact was modeled based on normal mode vibration, as it has been shown that vocal fold vibration can be almost entirely described by only the few lowest order vibrational modes. Symmetric and asymmetric combinations of the four lowest normal modes of vibration were superimposed on left and right vocal fold medial surfaces, for each of three prephonatory glottal configurations, according to a surface wave approach. Contact patterns were generated from the interaction of modal shapes at 16 normalized phases during the vibratory cycle. Eight major contact patterns were identified and characterized by the shape of the flow channel, with the following descriptors assigned: convergent, divergent, convergent-divergent, uniform, split, merged, island, and multichannel. Each of the contact patterns and its variation are described, and future work and applications are discussed. Copyright © 2018 Elsevier Ltd. All rights reserved.

The Effect of Surface Electrical Stimulation on Vocal Fold Position

PubMed Central

Humbert, Ianessa A.; Poletto, Christopher J.; Saxon, Keith G.; Kearney, Pamela R.; Ludlow, Christy L.

2008-01-01

Objectives/Hypothesis Closure of the true and false vocal folds is a normal part of airway protection during swallowing. Individuals with reduced or delayed true vocal fold closure can be at risk for aspiration and benefit from intervention to ameliorate the problem. Surface electrical stimulation is currently used during therapy for dysphagia, despite limited knowledge of its physiological effects. Design Prospective single effects study. Methods The immediate physiological effect of surface stimulation on true vocal fold angle was examined at rest in 27 healthy adults using ten different electrode placements on the submental and neck regions. Fiberoptic nasolaryngoscopic recordings during passive inspiration were used to measure change in true vocal fold angle with stimulation. Results Vocal fold angles changed only to a small extent during two electrode placements (p ≤ 0.05). When two sets of electrodes were placed vertically on the neck the mean true vocal fold abduction was 2.4 degrees; while horizontal placements of electrodes in the submental region produced a mean adduction of 2.8 degrees (p=0.03). Conclusions Surface electrical stimulation to the submental and neck regions does not produce immediate true vocal fold adduction adequate for airway protection during swallowing and one position may produce a slight increase in true vocal fold opening. PMID:18043496

Vocalization Subsystem Responses to a Temporarily Induced Unilateral Vocal Fold Paralysis

ERIC Educational Resources Information Center

Croake, Daniel J.; Andreatta, Richard D.; Stemple, Joseph C.

2018-01-01

Purpose: The purpose of this study is to quantify the interactions of the 3 vocalization subsystems of respiration, phonation, and resonance before, during, and after a perturbation to the larynx (temporarily induced unilateral vocal fold paralysis) in 10 vocally healthy participants. Using dynamic systems theory as a guide, we hypothesized that…

Adapted to Roar: Functional Morphology of Tiger and Lion Vocal Folds

PubMed Central

Klemuk, Sarah A.; Riede, Tobias; Walsh, Edward J.; Titze, Ingo R.

2011-01-01

Vocal production requires active control of the respiratory system, larynx and vocal tract. Vocal sounds in mammals are produced by flow-induced vocal fold oscillation, which requires vocal fold tissue that can sustain the mechanical stress during phonation. Our understanding of the relationship between morphology and vocal function of vocal folds is very limited. Here we tested the hypothesis that vocal fold morphology and viscoelastic properties allow a prediction of fundamental frequency range of sounds that can be produced, and minimal lung pressure necessary to initiate phonation. We tested the hypothesis in lions and tigers who are well-known for producing low frequency and very loud roaring sounds that expose vocal folds to large stresses. In histological sections, we found that the Panthera vocal fold lamina propria consists of a lateral region with adipocytes embedded in a network of collagen and elastin fibers and hyaluronan. There is also a medial region that contains only fibrous proteins and hyaluronan but no fat cells. Young's moduli range between 10 and 2000 kPa for strains up to 60%. Shear moduli ranged between 0.1 and 2 kPa and differed between layers. Biomechanical and morphological data were used to make predictions of fundamental frequency and subglottal pressure ranges. Such predictions agreed well with measurements from natural phonation and phonation of excised larynges, respectively. We assume that fat shapes Panthera vocal folds into an advantageous geometry for phonation and it protects vocal folds. Its primary function is probably not to increase vocal fold mass as suggested previously. The large square-shaped Panthera vocal fold eases phonation onset and thereby extends the dynamic range of the voice. PMID:22073246

Histological changes in vocal fold growth and aging.

PubMed

Kuhn, Maggie A

2014-12-01

Sophisticated descriptions of the highly specialized vocal fold microarchitecture have been available for over three decades, but how this anatomy evolves with growth and aging remains an area of active investigation and, at times, a source of controversy. As our aging population expands and interest in pediatric voice disorders blossoms, it is timely to consider our contemporary understanding of evolving vocal fold histology and its implications for voice production. Novel applications of existing and emerging biotechnology, development of animal models and skillful use of human specimens have afforded greater insights into the histologic vocal fold changes seen throughout the lifespan in health and disease. Burgeoning knowledge has laid the foundation for more comprehensive models of vocal fold histology and has led to the development of innovative therapies for challenging voice disorders.

Material parameter computation for multi-layered vocal fold models.

PubMed

Schmidt, Bastian; Stingl, Michael; Leugering, Günter; Berry, David A; Döllinger, Michael

2011-04-01

Today, the prevention and treatment of voice disorders is an ever-increasing health concern. Since many occupations rely on verbal communication, vocal health is necessary just to maintain one's livelihood. Commonly applied models to study vocal fold vibrations and air flow distributions are self sustained physical models of the larynx composed of artificial silicone vocal folds. Choosing appropriate mechanical parameters for these vocal fold models while considering simplifications due to manufacturing restrictions is difficult but crucial for achieving realistic behavior. In the present work, a combination of experimental and numerical approaches to compute material parameters for synthetic vocal fold models is presented. The material parameters are derived from deformation behaviors of excised human larynges. The resulting deformations are used as reference displacements for a tracking functional to be optimized. Material optimization was applied to three-dimensional vocal fold models based on isotropic and transverse-isotropic material laws, considering both a layered model with homogeneous material properties on each layer and an inhomogeneous model. The best results exhibited a transversal-isotropic inhomogeneous (i.e., not producible) model. For the homogeneous model (three layers), the transversal-isotropic material parameters were also computed for each layer yielding deformations similar to the measured human vocal fold deformations.

Permeability of canine vocal fold lamina propria.

PubMed

Meyer, Jacob P; Kvit, Anton A; Devine, Erin E; Jiang, Jack

2015-04-01

Determine the permeability of excised canine vocal fold lamina propria. Basic science. Vocal folds were excised from canine larynges and mounted within a device to measure the flow of 0.9% saline through the tissue over time. The resultant fluid volume displaced over time was then used in a variation of Darcy's law to calculate the permeability of the tissue. Permeability was found through each anatomical plane of the vocal fold, with five samples per plane. Permeability was also found for lamina propria stretched to 10%, 20%, and 30% of its initial length to determine the effects of tensile strain on permeability, with five samples per level of strain. Permeability was found to be 1.40 × 10(-13) m(3) s/kg through the sagittal plane, 1.00 × 10(-13) m(3) s/kg through the coronal plane, and 4.02 × 10(-13) m(3) s/kg through the axial plane. It was significantly greater through the axial plane than both the sagittal (P = .025) and coronal (P = .009) planes. Permeability under strain through the sagittal plane was found to be 1.94 × 10(-13) m(3) s/kg under 10% strain, 3.35 × 10(-13) m(3) s/kg under 20% strain, and 4.80 × 10(-13) m(3) s/kg under 30% strain. The permeability significantly increased after 20% strain (P < .05). Permeability in canine vocal fold lamina propria was found to be increased along the anterior-posterior axis, following the length of the vocal folds. This may influence fluid distribution within the lamina propria during and after vibration. Similarly, permeability increased after 20% strain was imposed on the lamina propria, and may influence vocal fold dynamics during certain phonation tasks. NA Laryngoscope, 125:941-945, 2015. © 2014 The American Laryngological, Rhinological and Otological Society, Inc.

Botulinum toxin in the treatment of vocal fold nodules.

PubMed

Allen, Jacqui E; Belafsky, Peter C

2009-12-01

Promising new techniques in the management of vocal fold nodules have been developed in the past 2 years. Simultaneously, the therapeutic use of botulinum toxin has rapidly expanded. This review explores the use of botulinum toxin in treatment of vocal nodules and summarizes current therapeutic concepts. New microsurgical instruments and techniques, refinements in laser technology, radiosurgical excision and steroid intralesional injections are all promising new techniques in the management of vocal nodules. Botulinum toxin-induced 'voice rest' is a new technique we have employed in patients with recalcitrant nodules. Successful resolution of nodules is possible with this technique, without the risk of vocal fold scarring inherent in dissection/excision techniques. Botulinum toxin usage is exponentially increasing, and large-scale, long-term studies demonstrate its safety profile. Targeted vocal fold temporary paralysis induced by botulinum toxin injection is a new, well tolerated and efficacious treatment in patients with persistent vocal fold nodules.

Vocal fold submucosal infusion technique in phonomicrosurgery.

PubMed

Kass, E S; Hillman, R E; Zeitels, S M

1996-05-01

Phonomicrosurgery is optimized by maximally preserving the vocal fold's layered microstructure (laminae propriae). The technique of submucosal infusion of saline and epinephrine into the superficial lamina propria (SLP) was examined to delineate how, when, and why it was helpful toward this surgical goal. A retrospective review revealed that the submucosal infusion technique was used to enhance the surgery in 75 of 152 vocal fold procedures that were performed over the last 2 years. The vocal fold epithelium was noted to be adherent to the vocal ligament in 29 of the 75 cases: 19 from previous surgical scarring, 4 from cancer, 3 from sulcus vocalis, 2 from chronic hemorrhage, and 1 from radiotherapy. The submucosal infusion technique was most helpful when the vocal fold epithelium required resection and/or when extensive dissection in the SLP was necessary. The infusion enhanced the surgery by vasoconstriction of the microvasculature in the SLP, which improved visualization during cold-instrument tangential dissection. Improved visualization facilitated maximal preservation of the SLP, which is necessary for optimal pliability of the overlying epithelium. The infusion also improved the placement of incisions at the perimeter of benign, premalignant, and malignant lesions, and thereby helped preserve epithelium uninvolved by the disorder.

Vocal fold tissue failure: preliminary data and constitutive modeling.

PubMed

Chan, Roger W; Siegmund, Thomas

2004-08-01

In human voice production (phonation), linear small-amplitude vocal fold oscillation occurs only under restricted conditions. Physiologically, phonation more often involves large-amplitude oscillation associated with tissue stresses and strains beyond their linear viscoelastic limits, particularly in the lamina propria extracellular matrix (ECM). This study reports some preliminary measurements of tissue deformation and failure response of the vocal fold ECM under large-strain shear The primary goal was to formulate and test a novel constitutive model for vocal fold tissue failure, based on a standard-linear cohesive-zone (SL-CZ) approach. Tissue specimens of the sheep vocal fold mucosa were subjected to torsional deformation in vitro, at constant strain rates corresponding to twist rates of 0.01, 0.1, and 1.0 rad/s. The vocal fold ECM demonstrated nonlinear stress-strain and rate-dependent failure response with a failure strain as low as 0.40 rad. A finite-element implementation of the SL-CZ model was capable of capturing the rate dependence in these preliminary data, demonstrating the model's potential for describing tissue failure. Further studies with additional tissue specimens and model improvements are needed to better understand vocal fold tissue failure.

Homeostasis of Hyaluronic Acid in Normal and Scarred Vocal Folds

PubMed Central

Tateya, Ichiro; Tateya, Tomoko; Watanuki, Makoto; Bless, Diane M.

2015-01-01

Summary Objectives/Hypothesis Vocal fold scarring is one of the most challenging laryngeal disorders to treat. Hyaluronic acid (HA) is the main component of lamina propria, and it plays an important role in proper vocal fold vibration and is also thought to be important in fetal wound healing without scarring. Although several animal models of vocal fold scarring have been reported, little is known about the way in which HA is maintained in vocal folds. The purpose of this study was to clarify the homeostasis of HA by examining the expression of hyaluronan synthase (Has) and hyaluronidase (Hyal), which produce and digest HA, respectively. Study Design Experimental prospective animal study. Methods Vocal fold stripping was performed on 38 Sprague-Dawley rats. Vocal fold tissue was collected at five time points (3 days–2 months). Expression of HA was examined by immunohistochemistry, and messenger RNA (mRNA) expression of Has and Hyal was examined by real-time polymerase chain reaction and in-situ hybridization. Results In scarred vocal folds, expression of Has1 and Has2 increased at day 3 together with expression of HA and returned to normal at 2 weeks. At 2 months, Has3 and Hyal3 mRNA showed higher expressions than normal. Conclusions Expression patterns of Has and Hyal genes differed between normal, acute-scarred, and chronic-scarred vocal folds, indicating the distinct roles of each enzyme in maintaining HA. Continuous upregulation of Has genes in the acute phase may be necessary to achieve scarless healing of vocal folds. PMID:25499520

Histologic and rheologic characterization of vocal fold scarring.

PubMed

Thibeault, Susan L; Gray, Steven D; Bless, Diane M; Chan, Roger W; Ford, Charles N

2002-03-01

Scarring of the vocal fold causes considerable dysphonia and presents significant treatment challenges. A rabbit model was developed to investigate the histologic ultrastructure and rheologic properties of the scarred vocal fold lamina propria. Eleven rabbit larynges were scarred by means of forcep biopsy. Sixty days postoperatively, the rabbits were sacrificed and their vocal folds were harvested. Histological analysis of the scarred and normal lamina propria was completed for collagen, procollagen, elastin, and hyaluronic acid. Linear viscoelastic shear properties of the tissues were also measured, including elastic shear modulus and dynamic viscosity. Compared to normal vocal fold lamina propria, scarred tissues demonstrated significantly less collagen, an increase in procollagen, and a decrease in elastin. Rheologically, both elastic shear modulus and dynamic viscosity were significantly higher for the scarred tissues. Increased stiffness and viscosity do not appear to result from an increase in collagen, but rather appear to be related to the presence of new, disorganized collagen scaffolding. Results are interpreted in terms of the possible role of interstitial proteins in the etiology of increased stiffness and viscosity, which requires further investigation. This animal model should allow for systematic future investigations of vocal fold scarring and its treatment.

Behavioral Voice Therapy in School-Age Children with Vocal Fold Nodules. EBP Briefs. Volume 6, Issue 5

ERIC Educational Resources Information Center

Watts, Christopher R.

2012-01-01

Does behavioral voice therapy effectively improve voice quality and eliminate or reduce the size of vocal fold pathology in school-age children who have vocal nodules? An evidence-based practice intervention review was conducted to answer this research question. The following resources were searched: Cumulative Index to Nursing and Allied Health…

[3D visualization and analysis of vocal fold dynamics].

PubMed

Bohr, C; Döllinger, M; Kniesburges, S; Traxdorf, M

2016-04-01

Visual investigation methods of the larynx mainly allow for the two-dimensional presentation of the three-dimensional structures of the vocal fold dynamics. The vertical component of the vocal fold dynamics is often neglected, yielding a loss of information. The latest studies show that the vertical dynamic components are in the range of the medio-lateral dynamics and play a significant role within the phonation process. This work presents a method for future 3D reconstruction and visualization of endoscopically recorded vocal fold dynamics. The setup contains a high-speed camera (HSC) and a laser projection system (LPS). The LPS projects a regular grid on the vocal fold surfaces and in combination with the HSC allows a three-dimensional reconstruction of the vocal fold surface. Hence, quantitative information on displacements and velocities can be provided. The applicability of the method is presented for one ex-vivo human larynx, one ex-vivo porcine larynx and one synthetic silicone larynx. The setup introduced allows the reconstruction of the entire visible vocal fold surfaces for each oscillation status. This enables a detailed analysis of the three dimensional dynamics (i. e. displacements, velocities, accelerations) of the vocal folds. The next goal is the miniaturization of the LPS to allow clinical in-vivo analysis in humans. We anticipate new insight on dependencies between 3D dynamic behavior and the quality of the acoustic outcome for healthy and disordered phonation.

Wavelet analysis of hemispheroid flow separation toward understanding human vocal fold pathologies

NASA Astrophysics Data System (ADS)

Plesniak, Daniel H.; Carr, Ian A.; Bulusu, Kartik V.; Plesniak, Michael W.

2014-11-01

Physiological flows observed in human vocal fold pathologies, such as polyps and nodules, can be modeled by flow over a wall-mounted protuberance. The experimental investigation of flow separation over a surface-mounted hemispheroid was performed using particle image velocimetry (PIV) and measurements of surface pressure in a low-speed wind tunnel. This study builds on the hypothesis that the signatures of vortical structures associated with flow separation are imprinted on the surface pressure distributions. Wavelet decomposition methods in one- and two-dimensions were utilized to elucidate the flow behavior. First, a complex Gaussian wavelet was used for the reconstruction of surface pressure time series from static pressure measurements acquired from ports upstream, downstream, and on the surface of the hemispheroid. This was followed by the application of a novel continuous wavelet transform algorithm (PIVlet 1.2) using a 2D-Ricker wavelet for coherent structure detection on instantaneous PIV-data. The goal of this study is to correlate phase shifts in surface pressure with Strouhal numbers associated with the vortex shedding. Ultimately, the wavelet-based analytical framework will be aimed at addressing pulsatile flows. This material is based in part upon work supported by the National Science Foundation under Grant Number CBET-1236351, and GW Center for Biomimetics and Bioinspired Engineering (COBRE).

High-speed imaging of vocal fold vibrations and larynx movements within vocalizations of different vowels.

PubMed

Maurer, D; Hess, M; Gross, M

1996-12-01

Theoretic investigations of the "source-filter" model have indicated a pronounced acoustic interaction of glottal source and vocal tract. Empirical investigations of formant pattern variations apart from changes in vowel identity have demonstrated a direct relationship between the fundamental frequency and the patterns. As a consequence of both findings, independence of phonation and articulation may be limited in the speech process. Within the present study, possible interdependence of phonation and phoneme was investigated: vocal fold vibrations and larynx position for vocalizations of different vowels in a healthy man and woman were examined by high-speed light-intensified digital imaging. We found 1) different movements of the vocal folds for vocalizations of different vowel identities within one speaker and at similar fundamental frequency, and 2) constant larynx position within vocalization of one vowel identity, but different positions for vocalizations of different vowel identities. A possible relationship between the vocal fold vibrations and the phoneme is discussed.

Mechanomimetic hydrogels for vocal fold lamina propria regeneration.

PubMed

Kutty, Jaishankar K; Webb, Ken

2009-01-01

Vocal fold injury commonly leads to reduced vocal quality due to scarring-induced alterations in matrix composition and tissue biomechanics. The long-term hypothesis motivating our work is that rapid restoration of phonation and the associated dynamic mechanical environment will reduce scarring and promote regenerative healing. Toward this end, the objective of this study was to develop mechanomimetic, degradable hydrogels approximating the viscoelastic properties of the vocal ligament and mucosa that may be photopolymerized in situ to restore structural integrity to vocal fold tissues. The tensile and rheological properties of hydrogels (targeting the vocal ligament and mucosa, respectively) were varied as a function of macromer concentration. PEG diacrylate-based hydrogels exhibited linear stress-strain response and elastic modulus consistent with the properties of the vocal ligament at low strains (0-15%), but did not replicate the non-linear behavior observed in native tissue at higher strains. Methacrylated hyaluronic acid hydrogels displayed dynamic viscosity consistent with native vocal mucosa, while elastic shear moduli values were several-fold higher. Cell culture studies indicated that both hydrogels supported spreading, proliferation and collagen/proteoglycan matrix deposition by encapsulated fibroblasts throughout the 3D network.

Microstructural and mechanical characterization of scarred vocal folds.

PubMed

Heris, Hossein K; Miri, Amir K; Ghattamaneni, Nageswara R; Li, Nicole Y K; Thibeault, Susan L; Wiseman, Paul W; Mongeau, Luc

2015-02-26

The goal of this study was to characterize the vocal folds microstructure and elasticity using nonlinear laser scanning microscopy and atomic force microscopy-based indentation, respectively. As a pilot study, the vocal folds of fourteen rats were unilaterally injured by full removal of lamina propria; the uninjured folds of the same animals served as controls. The area fraction of collagen fibrils was found to be greater in scarred tissues two months after injury than the uninjured controls. A novel mathematical model was also proposed to relate collagen concentration and tissue bulk modulus. This work presents a first step towards systematic investigation of microstructural and mechanical characteristics in scarred vocal fold tissue. Copyright © 2015 Elsevier Ltd. All rights reserved.

Vocal fold motion outcome based on excellent prognosis with laryngeal electromyography.

PubMed

Smith, Libby J; Rosen, Clark A; Munin, Michael C

2016-10-01

As laryngeal electromyography (LEMG) becomes more refined, accurate predictions of vocal fold motion recovery are possible. Focus has been on outcomes for patients with poor prognosis for vocal fold motion recovery. Limited information is available regarding the expected rate of purposeful vocal fold motion recovery when there is good to normal motor recruitment, no signs of denervation, and no signs of synkinetic activity with LEMG, termed excellent prognosis. The objective of this study is to determine the rate of vocal fold motion recovery with excellent prognosis findings on LEMG after acute recurrent laryngeal nerve injury. Retrospective review. Patients undergoing a standardized LEMG protocol, consisting of qualitative (evaluation of motor recruitment, motor unit configuration, detection of fibrillations, presence of synkinesis) and quantitative (turns analysis) measurements were evaluated for purposeful vocal-fold motion recovery, calculated after at least 6 months since onset of injury. Twenty-three patients who underwent LEMG for acute vocal fold paralysis met the inclusion criteria of excellent prognosis. Eighteen patients (78.3%) recovered vocal fold motion, as determined by flexible laryngoscopy. Nearly 80% of patients determined to have excellent prognosis for vocal fold motion recovery experienced return of vocal fold motion. This information will help clinicians not only counsel their patients on expectations but will also help guide treatment. 4. Laryngoscope, 126:2310-2314, 2016. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

Vocal fold ion transport and mucin expression following acrolein exposure

PubMed Central

Levendoski, Elizabeth Erickson; Sivasankar, M. Preeti

2014-01-01

The vocal fold epithelium is exposed to inhaled particulates including pollutants during breathing in everyday environments. Yet, our understanding of the effects of pollutants on vocal fold epithelial function is extremely limited. The objective of this study was to investigate the effect of the pollutant acrolein on two vocal fold epithelial mechanisms: ion transport and mucin synthesis. These mechanisms were chosen as each plays a critical role in vocal defense and in maintaining surface hydration which is necessary for optimal voice production. Healthy, native porcine vocal folds (N=85) were excised and exposed to an acrolein or sham challenge. A 60 minute acrolein, but not sham challenge significantly reduced ion transport and inhibited cyclic adenosine monophosphate-dependent increases in ion transport. Decreases in ion transport were associated with reduced sodium absorption. Within the same timeline, no significant acrolein-induced changes in mucin gene or protein expression were observed. These results improve our understanding of the effects of acrolein on key vocal fold epithelial functions and inform the development of future investigations that seek to elucidate the impact of a wide range of pollutant exposures on vocal fold health. PMID:24648011

Synthetic, multi-layer, self-oscillating vocal fold model fabrication.

PubMed

Murray, Preston R; Thomson, Scott L

2011-12-02

Sound for the human voice is produced via flow-induced vocal fold vibration. The vocal folds consist of several layers of tissue, each with differing material properties. Normal voice production relies on healthy tissue and vocal folds, and occurs as a result of complex coupling between aerodynamic, structural dynamic, and acoustic physical phenomena. Voice disorders affect up to 7.5 million annually in the United States alone and often result in significant financial, social, and other quality-of-life difficulties. Understanding the physics of voice production has the potential to significantly benefit voice care, including clinical prevention, diagnosis, and treatment of voice disorders. Existing methods for studying voice production include in vivo experimentation using human and animal subjects, in vitro experimentation using excised larynges and synthetic models, and computational modeling. Owing to hazardous and difficult instrument access, in vivo experiments are severely limited in scope. Excised larynx experiments have the benefit of anatomical and some physiological realism, but parametric studies involving geometric and material property variables are limited. Further, they are typically only able to be vibrated for relatively short periods of time (typically on the order of minutes). Overcoming some of the limitations of excised larynx experiments, synthetic vocal fold models are emerging as a complementary tool for studying voice production. Synthetic models can be fabricated with systematic changes to geometry and material properties, allowing for the study of healthy and unhealthy human phonatory aerodynamics, structural dynamics, and acoustics. For example, they have been used to study left-right vocal fold asymmetry, clinical instrument development, laryngeal aerodynamics, vocal fold contact pressure, and subglottal acoustics (a more comprehensive list can be found in Kniesburges et al.) Existing synthetic vocal fold models, however, have either

Trends in Utilization of Vocal Fold Injection Procedures.

PubMed

Rosow, David E

2015-11-01

Office-based vocal fold injections have become increasingly popular over the past 15 years. Examination of trends in procedure coding for vocal fold injections in the United States from 2000 to 2012 was undertaken to see if they reflect this shift. The US Part B Medicare claims database was queried from 2000 through 2012 for multiple Current Procedural Terminology codes. Over the period studied, the number of nonoperative laryngoscopic injections (31513, 31570) and operative medialization laryngoplasties (31588) remained constant. Operative vocal fold injection (31571) demonstrated marked linear growth over the 12-year study period, from 744 procedures in 2000 to 4788 in 2012-an increase >640%. The dramatic increased incidence in the use of code 31571 reflects an increasing share of vocal fold injections being performed in the operating room and not in an office setting, running counter to the prevailing trend toward awake, office-based injection procedures. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2015.

Effect of artificially lengthened vocal tract on vocal fold oscillation's fundamental frequency.

PubMed

Hanamitsu, Masakazu; Kataoka, Hideyuki

2004-06-01

The fundamental frequency of vocal fold oscillation (F(0)) is controlled by laryngeal mechanics and aerodynamic properties. F(0) change per unit change of transglottal pressure (dF/dP) using a shutter valve has been studied and found to have nonlinear, V-shaped relationship with F(0). On the other hand, the vocal tract is also known to affect vocal fold oscillation. This study examined the effect of artificially lengthened vocal tract length on dF/dP. dF/dP was measured in six men using two mouthpieces of different lengths. The dF/dP graph for the longer vocal tract was shifted leftward relative to the shorter one. Using the one-mass model, the nadir of the "V" on the dF/dP graph was strongly influenced by the resonance around the first formant frequency. However, a more precise model is needed to account for the effects of viscosity and turbulence.

Nonlinear laser scanning microscopy of human vocal folds.

PubMed

Miri, Amir K; Tripathy, Umakanta; Mongeau, Luc; Wiseman, Paul W

2012-02-01

The purpose of this work was to apply nonlinear laser scanning microscopy (NLSM) for visualizing the morphology of extracellular matrix proteins within human vocal folds. This technique may potentially assist clinicians in making rapid diagnoses of vocal fold tissue disease or damage. Microstructural characterization based on NLSM provides valuable information for better understanding molecular mechanisms and tissue structure. Experimental, ex vivo human vocal fold. A custom-built multimodal nonlinear laser scanning microscope was used to scan fibrillar proteins in three 4% formaldehyde-fixed cadaveric samples. Collagen and elastin, key extracellular matrix proteins in the vocal fold lamina propria, were imaged by two nonlinear microscopy modalities: second harmonic generation (SHG) and two-photon fluorescence (TPF), respectively. An experimental protocol was introduced to characterize the geometrical properties of the imaged fibrous proteins. NLSM revealed the biomorphology of the human vocal fold fibrous proteins. No photobleaching was observed for the incident laser power of ∼60 mW before the excitation objective. Types I and III fibrillar collagen were imaged without label in the tissue by intrinsic SHG. Imaging while rotating the incident laser light-polarization direction confirmed a helical shape for the collagen fibers. The amplitude, periodicity, and overall orientation were then computed for the helically distributed collagen network. The elastin network was simultaneously imaged via TPF and found to have a basket-like structure. In some regions, particularly close to the epithelium, colocalization of both extracellular matrix components were observed. A benchmark study is presented for quantitative real-time, ex vivo, NLSM imaging of the extracellular macromolecules in human vocal fold lamina propria. The results are promising for clinical applications. Copyright © 2011 The American Laryngological, Rhinological, and Otological Society, Inc.

Learning to detect vocal hyperfunction from ambulatory neck-surface acceleration features: initial results for vocal fold nodules.

PubMed

Ghassemi, Marzyeh; Van Stan, Jarrad H; Mehta, Daryush D; Zañartu, Matías; Cheyne, Harold A; Hillman, Robert E; Guttag, John V

2014-06-01

Voice disorders are medical conditions that often result from vocal abuse/misuse which is referred to generically as vocal hyperfunction. Standard voice assessment approaches cannot accurately determine the actual nature, prevalence, and pathological impact of hyperfunctional vocal behaviors because such behaviors can vary greatly across the course of an individual's typical day and may not be clearly demonstrated during a brief clinical encounter. Thus, it would be clinically valuable to develop noninvasive ambulatory measures that can reliably differentiate vocal hyperfunction from normal patterns of vocal behavior. As an initial step toward this goal we used an accelerometer taped to the neck surface to provide a continuous, noninvasive acceleration signal designed to capture some aspects of vocal behavior related to vocal cord nodules, a common manifestation of vocal hyperfunction. We gathered data from 12 female adult patients diagnosed with vocal fold nodules and 12 control speakers matched for age and occupation. We derived features from weeklong neck-surface acceleration recordings by using distributions of sound pressure level and fundamental frequency over 5-min windows of the acceleration signal and normalized these features so that intersubject comparisons were meaningful. We then used supervised machine learning to show that the two groups exhibit distinct vocal behaviors that can be detected using the acceleration signal. We were able to correctly classify 22 of the 24 subjects, suggesting that in the future measures of the acceleration signal could be used to detect patients with the types of aberrant vocal behaviors that are associated with hyperfunctional voice disorders.

The role of finite displacements in vocal fold modeling.

PubMed

Chang, Siyuan; Tian, Fang-Bao; Luo, Haoxiang; Doyle, James F; Rousseau, Bernard

2013-11-01

Human vocal folds experience flow-induced vibrations during phonation. In previous computational models, the vocal fold dynamics has been treated with linear elasticity theory in which both the strain and the displacement of the tissue are assumed to be infinitesimal (referred to as model I). The effect of the nonlinear strain, or geometric nonlinearity, caused by finite displacements is yet not clear. In this work, a two-dimensional model is used to study the effect of geometric nonlinearity (referred to as model II) on the vocal fold and the airflow. The result shows that even though the deformation is under 1 mm, i.e., less than 10% of the size of the vocal fold, the geometric nonlinear effect is still significant. Specifically, model I underpredicts the gap width, the flow rate, and the impact stress on the medial surfaces as compared to model II. The study further shows that the differences are caused by the contact mechanics and, more importantly, the fluid-structure interaction that magnifies the error from the small-displacement assumption. The results suggest that using the large-displacement formulation in a computational model would be more appropriate for accurate simulations of the vocal fold dynamics.

Arytenoid and posterior vocal fold surgery for bilateral vocal fold immobility.

PubMed

Young, VyVy N; Rosen, Clark A

2011-12-01

Many procedures exist to address the airway restriction often seen with bilateral vocal fold immobility. We review the most recent studies involving arytenoid and/or posterior vocal fold surgery to provide an update on the issues related to these procedures. Specific focus is placed on selection of the surgical approach and operative side, use of adjunctive therapies, and outcome measures including decannulation rate, revision and complication rate, and postoperative results. Ten studies were identified between 2004 and 2011. Modifications to the orginal transverse cordotomy and medial arytenoidectomy techniques continue to be investigated to seek improvement in dyspnea symptoms with minimal decline in voice and/or swallowing function. Decannulation rates for these approaches are high. Postoperative dysphagia appears to be less commonly observed but requires continued study. The use of mitomycin-C in these procedures has been poorly studied to date. Both transverse cordotomy and medial arytenoidectomy procedures result in high success rates. However, many questions related to these procedures remain unanswered, particularly with respect to preoperative and postoperative evaluations of voice quality, swallowing function, and pulmonary status. There is need for rigorous prospective clinical studies to address these many issues further.

Measurement of flow separation in a human vocal folds model

NASA Astrophysics Data System (ADS)

Šidlof, Petr; Doaré, Olivier; Cadot, Olivier; Chaigne, Antoine

2011-07-01

The paper provides experimental data on flow separation from a model of the human vocal folds. Data were measured on a four times scaled physical model, where one vocal fold was fixed and the other oscillated due to fluid-structure interaction. The vocal folds were fabricated from silicone rubber and placed on elastic support in the wall of a transparent wind tunnel. A PIV system was used to visualize the flow fields immediately downstream of the glottis and to measure the velocity fields. From the visualizations, the position of the flow separation point was evaluated using a semiautomatic procedure and plotted for different airflow velocities. The separation point position was quantified relative to the orifice width separately for the left and right vocal folds to account for flow asymmetry. The results indicate that the flow separation point remains close to the narrowest cross-section during most of the vocal fold vibration cycle, but moves significantly further downstream shortly prior to and after glottal closure.

Rheometric properties of canine vocal fold tissues: Variation with anatomic location

PubMed Central

Kimura, Miwako; Mau, Ted; Chan, Roger W.

2010-01-01

Objective To evaluate the in vitro rheometric properties of the canine vocal fold lamina propria and muscle at phonatory frequencies, and their changes with anatomic location. Methods Six canine larynges were harvested immediately postmortem. Viscoelastic shear properties of anterior, middle, and posterior portions of the vocal fold cover (lamina propria) as well as those of the medial thyroarytenoid (TA) muscle (vocalis muscle) were quantified by a linear, controlled-strain simple-shear rheometer. Measurements of elastic shear modulus (G’) and dynamic viscosity (η’) of the specimens were conducted with small-amplitude sinusoidal shear deformation over a frequency range of 1 Hz to 250 Hz. Results All specimens showed similar frequency dependence of the viscoelastic functions, with G’ gradually increasing with frequency and η’ decreasing with frequency monotonically. G’ and η’ of the canine vocalis muscle were significantly higher than those of the canine vocal fold cover, and η’ of the canine vocal fold cover was significantly higher than that of the human vocal fold cover. There were no significant differences in G’ and in η’ between different portions of the canine vocal fold cover. Conclusion These preliminary data based on the canine model suggested that the vocalis muscle, while in a relaxed state in vitro, is significantly stiffer and more viscous than the vocal fold cover during vibration at phonatory frequencies. For large-amplitude vocal fold vibration involving the medial portion of the TA muscle, such distinct differences in viscoelastic properties of different layers of the vocal fold should be taken into account in multi-layered biomechanical models of phonation. PMID:21035291

Quantification of Vocal Fold Vibration in Various Laryngeal Disorders Using High-Speed Digital Imaging.

PubMed

Yamauchi, Akihito; Yokonishi, Hisayuki; Imagawa, Hiroshi; Sakakibara, Ken-Ichi; Nito, Takaharu; Tayama, Niro; Yamasoba, Tatsuya

2016-03-01

To quantify vibratory characteristics of various laryngeal disorders seen by high-speed digital imaging (HSDI). HSDI was performed on 78 patients with various laryngeal disorders (20 with polyp, 16 with carcinoma, 13 with leukoplakia, 6 with vocal fold nodule, and 33 with others) and 29 vocally healthy subjects. Obtained data were quantitatively evaluated by frame-by-frame analysis, laryngotopography, digital kymography, and glottal area waveform. Overall, patients with laryngeal pathologies showed greater asymmetry in amplitude, mucosal wave and phase, smaller mucosal wave, and poorer glottal closure than vocally healthy subjects. Furthermore, disease-specific vibratory disturbances that generally agreed with the findings in the literature were quantified: comparing polyp with nodule, differences were noted in longitudinal phase difference, amplitude, and mucosal wave. In comparison with leukoplakia and cancer, nonvibrating area was more frequently noted in cancer. The HSDI analysis of various voice disorders using multiple methods can help phonosurgeons to properly diagnose various laryngeal pathologies and to estimate the degree of their vocal disturbances. Copyright © 2016 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Tissue-Engineered Vocal Fold Mucosa Implantation in Rabbits.

PubMed

Shiba, Travis L; Hardy, Jordan; Luegmair, Georg; Zhang, Zhaoyan; Long, Jennifer L

2016-04-01

To assess phonatory function and wound healing of a tissue-engineered vocal fold mucosa (TE-VFM) in rabbits. An "artificial" vocal fold would be valuable for reconstructing refractory scars and resection defects, particularly one that uses readily available autologous cells and scaffold. This work implants a candidate TE-VFM after resecting native epithelium and lamina propria in rabbits. Prospective animal study. Research laboratory. Rabbit adipose-derived stem cells were isolated and cultured in three-dimensional fibrin scaffolds to form TE-VFM. Eight rabbits underwent laryngofissure, unilateral European Laryngologic Society type 2 cordectomy, and immediate reconstruction with TE-VFM. After 4 weeks, larynges were excised, phonated, and examined by histology. Uniform TE-VFM implants were created, with rabbit mesenchymal cells populated throughout fibrin hydrogels. Rabbits recovered uneventfully after implantation. Phonation was achieved in all, with mucosal waves evident at the implant site. Histology after 4 weeks showed resorbed fibrin matrix, continuous epithelium, and mildly increased collagen relative to contralateral unoperated vocal folds. Elastic fiber appearance was highly variable. Inflammatory cell infiltrate was limited to animals receiving sex-mismatched implants. TE-VFMs were successfully implanted into 8 rabbits, with minor evidence of scar formation and immune reaction. Vibration was preserved 4 weeks after resecting and reconstructing the complete vocal fold cover layer. Further studies will investigate the mechanism and durability of improvement. TE-VFM with autologous cells is a promising new approach for vocal fold reconstruction. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2016.

Vocal fold hemorrhage associated with coumadin therapy in an opera singer.

PubMed

Neely, J L; Rosen, C

2000-06-01

Vocal fold hemorrhage can represent a disastrous and potentially career ending injury to a singer or professional voice user. The risk factors of vocal fold hemorrhage, including laryngeal trauma, phonotrauma, aspirin and nonsteroidal antiinflammatories, and hormonal imbalances are well known. We present a case of an opera singer who developed recurrent vocal fold hemorrhage associated with coumadin anticoagulation therapy. This case highlights the importance of the risk of vocal fold hemorrhage to professional singers and professional voice users and offers an alternative to long-term coumadin therapy in this select population.

Relationship Between Laryngeal Electromyography and Video Laryngostroboscopy in Vocal Fold Paralysis.

PubMed

Maamary, Joel A; Cole, Ian; Darveniza, Paul; Pemberton, Cecilia; Brake, Helen Mary; Tisch, Stephen

2017-09-01

The objective of this study was to better define the relationship of laryngeal electromyography and video laryngostroboscopy in the diagnosis of vocal fold paralysis. Retrospective diagnostic cohort study with cross-sectional data analysis METHODS: Data were obtained from 57 patients with unilateral vocal fold paralysis who attended a large tertiary voice referral center. Electromyographic findings were classified according to recurrent laryngeal nerve, superior laryngeal nerve, and high vagal/combined lesions. Video laryngostroboscopy recordings were classified according to the position of the immobile fold into median, paramedian, lateral, and a foreshortened/hooded vocal fold. The position of the paralyzed vocal fold was then analyzed according to the lesion as determined by electromyography. The recurrent laryngeal nerve was affected in the majority of cases with left-sided lesions more common than right. Vocal fold position differed between recurrent laryngeal and combined vagal lesions. Recurrent laryngeal nerve lesions were more commonly associated with a laterally displaced immobile fold. No fold position was suggestive of a combined vagal lesion. The inter-rater reliability for determining fold position was high. Laryngeal electromyography is useful in diagnosing neuromuscular dysfunction of the larynx and best practice recommends its continued implementation along with laryngostroboscopy. While recurrent laryngeal nerve lesions are more likely to present with a lateral vocal fold, this does not occur in all cases. Such findings indicate that further unknown mechanisms contribute to fold position in unilateral paralysis. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Viscoelastic measurements after vocal fold scarring in rabbits--short-term results after hyaluronan injection.

PubMed

Hertegård, S; Dahlqvist, A; Goodyer, E

2006-07-01

The scarring model resulted in significant damage and elevated viscoelasticity of the lamina propria. Hyaluronan preparations may alter viscoelasticity in scarred rabbit vocal folds. Vocal fold scarring results in stiffness of the lamina propria and severe voice problems. The aims of this study were to examine the degree of scarring achieved in the experiment and to measure the viscoelastic properties after injection of hyaluronan in rabbit vocal folds. Twenty-two vocal folds from 15 New Zealand rabbits were scarred, 8 vocal folds were controls. After 8 weeks 12 of the scarred vocal folds received injections with 2 types of cross-linked hyaluronan products and 10 scarred folds were injected with saline. After 11 more weeks the animals were sacrificed. After dissection, 15 vocal folds were frozen for viscoelastic measurements, whereas 14 vocal folds were prepared and stained. Measurements were made of the lamina propria thickness. Viscoelasticity was measured on intact vocal folds with a linear skin rheometer (LSR) adapted to laryngeal measurements. Measurements on the digitized slides showed a thickened lamina propria in the scarred samples as compared with the normal vocal folds (p<0.05). The viscoelastic analysis showed a tendency to stiffening of the scarred vocal folds as compared with the normal controls (p=0.05). There was large variation in stiffness between the two injected hyaluronan products.

Collagen Content Limits Optical Coherence Tomography Image Depth in Porcine Vocal Fold Tissue.

PubMed

Garcia, Jordan A; Benboujja, Fouzi; Beaudette, Kathy; Rogers, Derek; Maurer, Rie; Boudoux, Caroline; Hartnick, Christopher J

2016-11-01

Vocal fold scarring, a condition defined by increased collagen content, is challenging to treat without a method of noninvasively assessing vocal fold structure in vivo. The goal of this study was to observe the effects of vocal fold collagen content on optical coherence tomography imaging to develop a quantifiable marker of disease. Excised specimen study. Massachusetts Eye and Ear Infirmary. Porcine vocal folds were injected with collagenase to remove collagen from the lamina propria. Optical coherence tomography imaging was performed preinjection and at 0, 45, 90, and 180 minutes postinjection. Mean pixel intensity (or image brightness) was extracted from images of collagenase- and control-treated hemilarynges. Texture analysis of the lamina propria at each injection site was performed to extract image contrast. Two-factor repeated measure analysis of variance and t tests were used to determine statistical significance. Picrosirius red staining was performed to confirm collagenase activity. Mean pixel intensity was higher at injection sites of collagenase-treated vocal folds than control vocal folds (P < .0001). Fold change in image contrast was significantly increased in collagenase-treated vocal folds than control vocal folds (P = .002). Picrosirius red staining in control specimens revealed collagen fibrils most prominent in the subepithelium and above the thyroarytenoid muscle. Specimens treated with collagenase exhibited a loss of these structures. Collagen removal from vocal fold tissue increases image brightness of underlying structures. This inverse relationship may be useful in treating vocal fold scarring in patients. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2016.

Vocal Fold Mucus Aggregation in Persons with Voice Disorders

ERIC Educational Resources Information Center

Bonilha, Heather Shaw; White, Lisa; Kuckhahn, Kelsey; Gerlach, Terri Treman; Deliyski, Dimitar D.

2012-01-01

Mucus aggregation on the vocal folds is a common finding from laryngeal endoscopy. Patients with voice disorders report the presence of mucus aggregation. Patients also report that mucus aggregation causes them to clear their throat, a behavior believed to be harmful to vocal fold mucosa. Even though clinicians and patients report and discuss…

Laboratory Evaluation of Vocal Fold Paralysis and Paresis.

PubMed

White, Michelle; Meenan, Kirsten; Patel, Tirth; Jaworek, Aaron; Sataloff, Robert T

2017-03-01

This study aimed to assess the value of comprehensive laboratory evaluation in patients with vocal fold paralysis or paresis. This is a retrospective chart review. Records of 231 patients with vocal fold paralysis or paresis were reviewed to determine whether there is a significant increase in the number of abnormal test results compared with rates of abnormal results for these tests in the general population and whether testing resulted in clinically important diagnosis. Laboratory data were collected from charts from initial visits from 2010 to 2014 and compared with national data. When controlled for age and sex, white blood cell count was found to have a significantly higher rate of abnormal test results (P < 0.001) in patients with vocal fold paralysis or paresis than the general population. Although hemoglobin, thyroid-stimulating hormone, and thyroid antibody tests were more likely to be abnormal in our patient population, the trend was not statistically significant. Further, the prevalence of syphilis and myasthenia gravis was found to be higher in these subjects than their respective national prevalences, and the incidence of Lyme disease was found to be higher than the national prevalence of Lyme disease. Several patients were diagnosed with medically important conditions such as diabetes, thyroid dysfunction, syphilis, myasthenia gravis, and Lyme disease based on these tests. This study suggests that comprehensive testing of patients with vocal fold movement disorders results in diagnoses that would be missed without a comprehensive evaluation, some of which are important medically, although their causal relationship to vocal fold paralysis or paresis was not investigated or established. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Vibrational dynamics of vocal folds using nonlinear normal modes.

PubMed

Pinheiro, Alan P; Kerschen, Gaëtan

2013-08-01

Many previous works involving physical models, excised and in vivo larynges have pointed out nonlinear vibration in vocal folds during voice production. Moreover, theoretical studies involving mechanical modeling of these folds have tried to gain a profound understanding of the observed nonlinear phenomena. In this context, the present work uses the nonlinear normal mode theory to investigate the nonlinear modal behavior of 16 subjects using a two-mass mechanical modeling of the vocal folds. The free response of the conservative system at different energy levels is considered to assess the impact of the structural nonlinearity of the vocal fold tissues. The results show very interesting and complex nonlinear phenomena including frequency-energy dependence, subharmonic regimes and, in some cases, modal interactions, entrainment and bifurcations. Copyright © 2012 IPEM. Published by Elsevier Ltd. All rights reserved.

Characterization of chronic vocal fold scarring in a rabbit model.

PubMed

Rousseau, Bernard; Hirano, Shigeru; Chan, Roger W; Welham, Nathan V; Thibeault, Susan L; Ford, Charles N; Bless, Diane M

2004-03-01

The purpose of the current study was to assess the histologic and rheologic properties of the scarred vocal fold lamina propria during a chronic phase of wound repair in a rabbit model. Eighteen rabbit larynges were scarred using a procedure that involved stripping the vocal fold lamina propria down to the thyroarytenoid muscle, using 3-mm microforceps. The approximate dimension of injury to the vocal fold was 3 x 1.5 x 0.5 mm [length x width x depth]. At 6 months postoperatively, histologic analysis of the scarred and control lamina propria in eight of these rabbits was completed for collagen, procollagen, elastin, and hyaluronic acid. Compared with control samples, scarred tissue samples revealed fragmented and disorganized elastin fibers. Additionally, collagen was significantly increased, organized, and formed thick bundles in the scarred vocal fold lamina propria. Measurements of the viscoelastic shear properties of the scarred and control lamina propria in the remaining 10 rabbits revealed increased elastic shear modulus (G') in 8 of 10 scarred samples and increased dynamic viscosity (eta') in 9 of 10 scarred samples. Although rheologic differences were not statistically significant, they revealed that on average, scarred samples were stiffer and more viscous than the normal controls. Histologic data are interpreted as indicating that by 6 months postinjury, the scarred rabbit vocal fold has reached a mature phase of wound repair, characterized by an increased, organized, and thick bundle collagen matrix. Rheologic data are interpreted as providing support for the potential role of increased, thick bundle collagen, and a disorganized elastin network on shear stiffness and dynamic viscosity in the chronic vocal fold scar. Based on these results, a 6-month postoperative time frame is proposed for future studies of chronic vocal fold scarring using the rabbit animal model.

Laryngeal Electromyography for Prognosis of Vocal Fold Paralysis.

PubMed

Pardo-Maza, Adriana; García-Lopez, Isabel; Santiago-Pérez, Susana; Gavilán, Javier

2017-01-01

This study aimed to determine the value of laryngeal electromyography in the prognosis of vocal fold paralysis. This is a retrospective descriptive study. This study included 80 patients diagnosed with unilateral or bilateral vocal fold paralysis on flexible laryngoscopy between 2002 and 2014 in a tertiary medical center. Laryngeal electromyography using a standardized protocol was performed; the outcome measures were classified and analyzed into two groups according to the degree of injury. Group 1 included patients with mild to moderate injury, and group 2 included patients with severe to complete injury. Prognosis was correlated with vocal fold motion recovery status with a minimum of 6 months of follow-up since the symptoms onset using positive and negative predictive values. Sixty patients showed acute or chronic recurrent laryngeal neuropathy in laryngeal electromyography. Twelve of 41 patients included in group 1 recovered motion, and 30 of 35 patients included in group 2 did not recover, resulting in 88.2% of positive predictive value and 35.7% of negative predictive value. Our data confirm that laryngeal electromyography is a useful clinical tool in predicting poor recovery in patients with vocal fold paralysis. It allows identification of candidates for early intervention. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Protective Effect of Astaxanthin on Vocal Fold Injury and Inflammation Due to Vocal Loading: A Clinical Trial.

PubMed

Kaneko, Mami; Kishimoto, Yo; Suzuki, Ryo; Kawai, Yoshitaka; Tateya, Ichiro; Hirano, Shigeru

2017-05-01

Professional voice users, such as singers and teachers, are at greater risk of developing vocal fold injury from excessive use of voice; thus, protection of the vocal fold is essential. One of the most important factors that aggravates injury is the production of reactive oxygen species at the wound site. The purpose of the current study was to assess the effect of astaxanthin, a strong antioxidant, on the protection of the vocal fold from injury and inflammation due to vocal loading. This study is an institutional review board-approved human clinical trial. Ten male subjects underwent a 60-minute vocal loading session and received vocal assessments prior to, immediately after, and 30 minutes postvocal loading (AST(-) status). All subjects were then prescribed 24 mg/day of astaxanthin for 28 days, after which they received the same vocal task and assessments (AST(+) status). Phonatory parameters were compared between both groups. Aerodynamic assessment, acoustic analysis, and GRBAS scale (grade, roughness, breathiness, asthenia, and strain) were significantly worse in the AST(-) status immediately after vocal loading, but improved by 30 minutes after loading. In contrast, none of the phonatory parameters in the AST(+) status were statistically worse, even when measured immediately after vocal loading. No allergic responses or adverse effects were observed after administration of astaxanthin. The current results suggest that astaxanthin can protect the vocal fold from injury and inflammation caused by vocal loading possibly through the regulation of oxidative stress. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Viscosities of implantable biomaterials in vocal fold augmentation surgery.

PubMed

Chan, R W; Titze, I R

1998-05-01

Vocal fold vibration depends critically on the viscoelasticity of vocal fold tissues. For instance, phonation threshold pressure, a measure of the "ease" of phonation, has been shown to be directly related to the viscosity of the vibrating mucosa. Various implantable biomaterials have been used in vocal fold augmentation surgery, with implantation sites sometimes close to or inside the mucosa. Yet their viscosities or other mechanical properties are seldom known. This study attempts to provide data on viscosities of commonly used phonosurgical biomaterials. Using a parallel-plate rotational rheometer, oscillatory shear experiments were performed on implantable polytetrafluoroethylene (Teflon or Polytef; Mentor Inc., Hingham, MA), collagen (Zyderm; Collagen Corp., Palo Alto, CA), glutaraldehyde crosslinked (GAX) collagen (Phonagel or Zyplast; Collagen Corp.), absorbable gelatin (Gelfoam; Upjohn Co., Kalamazoo, MI), and human abdominal subcutaneous fat. Samples of human vocal fold mucosal tissues were also tested. Under sinusoidal oscillatory shear at 10 Hz and at 37 degrees C, the dynamic viscosity was 116 Pascal-seconds (Pa-s) for polytetrafluoroethylene, 21 Pa-s for gelatin, 8-13 Pa-s for the two types of collagen, 3 Pa-s for fat, and 1 to 3 Pa-s for vocal fold mucosa. Results extrapolated to 100 Hz also show similar differences among the biomaterials, but all values are an order of magnitude lower because of the typical inverse frequency relation (shear thinning effect) for polymeric and biologic materials. The data suggest that the use of fat for vocal fold augmentation may be more conducive to the "ease" of phonation because of its relatively low viscosity, which is closest to physiologic levels. This implication is probably the most relevant in predicting initial outcome of the postoperative voice before there is any significant assimilation (e.g., resorption and fibrosis) of the implanted biomaterial.

Endoscopic vocal fold injection using a 25-gauge butterfly needle.

PubMed

Buchanan, M A; Riffat, F; Palme, C E

2016-04-01

To describe a useful technique for infiltrating a bulking agent using a butterfly needle, as part of a transoral endoscopic vocal fold medialisation procedure. This paper describes the procedure of grasping the needle with phonosurgery forceps and administering the injectate to the vocal fold through careful application of the syringe plunger via a length of rubber tubing from outside the mouth. This procedure is performed routinely in our institution without complication. The advantages of this technique are discussed. This is a safe and easy method of injecting into a vocal fold.

Shortening of the front vibrating part of the vocal folds in phonation.

PubMed

Pesák, J; Jindra, P

2005-01-01

We have tried to make use of the opportunity of repeated observations through the analysis of the recorded movements of the phonating vocal folds by means of the phonating vocal folds through indirect videolaryngostroboscopic technique. The results of our investigation correspond, among others, with Hála and Sovák's diagrammatic description of continual and gradual changes in the vibration of the vocal folds in an uninterrupted sequence of tones of the human voice. In the initial chapter mention has been made of Hála and Honty's works and of Pressmann's work dealing with the described behaviour of the glottis when phonating high-pitched tones. The conclusions analogous to our findings have also been described by means of stereoscopically measuring the length of the phonating vocal folds. In conclusion, by measuring the distances between the anterior commissure and the junction between the membranous part of the vocal fold and vocal process of the arytenoid and the anterior commissure to the posterior nodal point of the vibrating part of the vocal folds we have verified the correctness of the findings published by Czermak, Hála and Honty, Pressmann, and Sovák, who pointed out the phenomenon of the shortening of the front vibrating part of the vocal folds in phonating high-pitched tones of the human voice. Copyright 2005 S. Karger AG, Basel.

Cyclic Adenosine Monophosphate Regulation of Ion Transport in Porcine Vocal Fold Mucosae

PubMed Central

Sivasankar, Mahalakshmi; Nofziger, Charity; Blazer-Yost, Bonnie

2012-01-01

Objectives/Hypothesis Cyclic adenosine monophosphate (cAMP) is an important biological molecule that regulates ion transport and inflammatory responses in epithelial tissue. The present study examined whether the adenylyl cyclase activator, forskolin, would increase cAMP concentration in porcine vocal fold mucosa and whether the effects of increased cAMP would be manifested as a functional increase in transepithelial ion transport. Additionally, changes in cAMP concentrations following exposure to an inflammatory mediator, tumor necrosis factor-α (TNFα) were investigated. Study Design In vitro experimental design with matched treatment and control groups. Methods Porcine vocal fold mucosae (N = 30) and tracheal mucosae (N = 20) were exposed to forskolin, TNFα, or vehicle (dimethyl sulfoxide) treatment. cAMP concentrations were determined with enzyme-linked immunosorbent assay. Ion transport was measured using electrophysiological techniques. Results Thirty minute exposure to forskolin significantly increased cAMP concentration and ion transport in porcine vocal fold and tracheal mucosae. However, 30-minute and 2-hour exposure to TNFα did not significantly alter cAMP concentration. Conclusions We demonstrate that forskolin-sensitive adenylyl cyclase is present in vocal fold mucosa, and further, that the product, cAMP increases vocal fold ion transport. The results presented here contribute to our understanding of the intracellular mechanisms underlying vocal fold ion transport. As ion transport is important for maintaining superficial vocal fold hydration, data demonstrating forskolin-stimulated ion transport in vocal fold mucosa suggest opportunities for developing pharmacological treatments that increase surface hydration. PMID:18596479

Management of vocal fold scar with autologous fat implantation: perceptual results.

PubMed

Neuenschwander, M C; Sataloff, R T; Abaza, M M; Hawkshaw, M J; Reiter, D; Spiegel, J R

2001-06-01

Vocal fold scar disrupts the mucosal wave and interferes with glottic closure. Treatment involves a multidisciplinary approach that includes voice therapy, medical management, and sometimes surgery. We reviewed the records of the first eight patients who underwent autologous fat implantation for vocal fold scar. Information on the etiology of scar, physical findings, and prior interventions were collected. Videotapes of videostroboscopic findings and perceptual voice ratings [Grade, Roughness, Breathiness, Asthenia, Strain (GRBAS)] were randomized and analyzed independently by four blinded observers. Etiology of scar included mass excision (7), vocal fold stripping (3), congenital sulcus (2), and hemorrhage (1). Prior surgical procedures performed included thyroplasty (1), autologous fat injection (9), excision of scar (2), and lysis of adhesions (2). Strobovideolaryngoscopy: Statistically significant improvement was found in glottic closure, mucosal wave, and stiffness (P = 0.05). Perceptual ratings (GRBAS): Statistically significant improvement was found in all five parameters, including overall Grade, Roughness, Breathiness, Asthenia, and Strain (P = 0.05). Patients appear to have improved vocal fold function and quality of voice after autologous fat implantation in the vocal fold. Autologous fat implantation is an important adjunctive procedure in the management of vocal fold scar, and a useful addition to the armamentarium of the experienced phonomicrosurgeon.

Acute vocal fold hemorrhage caught on video during office exam.

PubMed

Carroll, Thomas L; Smith, Libby J

2009-03-01

This article presents a unique video of a laryngeal exam during which a vocal fold hemorrhage occurs. This patient had likely been suffering from intermittent vocal fold hemorrhages for the last decade due to a persistent vascular lesion and an underlying chronic cough.

Ectasias and varices of the vocal fold: clearing the striking zone.

PubMed

Hochman, I; Sataloff, R T; Hillman, R E; Zeitels, S M

1999-01-01

Vascular malformations such as ectasias and varices (Es and Vs) are frequently encountered in patients who present with recurrent vocal fold hemorrhage and/or other traumatic vocal fold lesions. This study examined Es and Vs with regard to their anatomic presentation, phonomicrosurgical management, and treatment outcome. Forty-two patients (39 of them singers) were treated for a total of 87 Es and Vs: 67 of 87 (77%) were on the superior surface of the vocal fold and 20 of 87 (23%) were on the medial surface of the vocal fold. Eighty-three percent were located in the middle musculomembranous region (the striking zone), where the greatest aerodynamically induced shearing stresses occur during phonation. Treatment was performed with carbon dioxide laser cauterization (13 patients), or a new technique utilizing cold instrument excision by means of epithelial cordotomies (23 patients), while a combined approach was employed in 6 patients. Comparisons of preoperative and postoperative stroboscopy revealed improvement or no significant change in all patients in whom the cold instrument technique was used, and increased epithelial stiffness was noted in 4 of 19 patients in whom the carbon dioxide laser was used. Clearing the striking zone appears to have halted further hemorrhages by removing the the fragile Es and Vs from this injury-prone region of the vocal fold. Interpretations of stroboscopic examinations were directed at providing new insights into the biomechanical forces of vocal fold vibration that probably contribute to the genesis of Es and Vs in the vocal folds.

Paradigms and progress in vocal fold restoration.

PubMed

Ford, Charles N

2008-09-01

Science advances occur through orderly steps, puzzle-solving leaps, or divergences from the accepted disciplinary matrix that occasionally result in a revolutionary paradigm shift. Key advances must overcome bias, criticism, and rejection. Examples in biological science include use of embryonic stem cells, recognition of Helicobacter pylori in the etiology of ulcer disease, and the evolution of species. Our work in vocal fold restoration reflects these patterns. We progressed through phases of tissue replacement with fillers and biological implants, to current efforts at vocal fold regeneration through tissue engineering, and face challenges of a new "systems biology" paradigm embracing genomics and proteomics.

Vocal fold immobility: a longitudinal analysis of etiology over 20 years.

PubMed

Rosenthal, Laura H Swibel; Benninger, Michael S; Deeb, Robert H

2007-10-01

To determine the current etiology of vocal fold immobility, identify changing trends over the last 20 years, and compare results to historical reports. The present study is a retrospective analysis of all patients seen within a tertiary care institution between 1996 and 2005 with vocal fold immobility. The results were combined with a previous study of patients within the same institution from 1985 through 1995. Results were compared to the literature. The medical records of all patients assigned a primary or additional diagnostic code for vocal cord paralysis were obtained from the electronic database. Eight hundred twenty-seven patients were available for analysis (435 from the most recent cohort), which is substantially larger than any reported series to date. Vocal fold immobility was most commonly associated with a surgical procedure (37%). Nonthyroid surgeries (66%), such as anterior cervical approaches to the spine and carotid endarterectomies, have surpassed thyroid surgery (33%) as the most common iatrogenic causes. These data represent a change from historical figures in which extralaryngeal malignancies were considered the major cause of unilateral immobility. Thyroidectomy continues to cause the majority (80%) of iatrogenic bilateral vocal fold immobility and 30% of all bilateral immobility. This 20-year longitudinal assessment revealed that the etiology of unilateral vocal fold immobility has changed such that there has been a shift from extralaryngeal malignancies to nonthyroid surgical procedures as the major cause. Thyroid surgery remains the most common cause of bilateral vocal fold immobility.

Modulating Phonation Through Alteration of Vocal Fold Medial Surface Contour

PubMed Central

Mau, Ted; Muhlestein, Joseph; Callahan, Sean; Chan, Roger W.

2012-01-01

Objectives 1. To test whether alteration of the vocal fold medial surface contour can improve phonation. 2. To demonstrate that implant material properties affect vibration even when implant is deep to the vocal fold lamina propria. Study Design Induced phonation of excised human larynges. Methods Thirteen larynges were harvested within 24 hours post-mortem. Phonation threshold pressure (PTP) and flow (PTF) were measured before and after vocal fold injections using either calcium hydroxylapatite (CaHA) or hyaluronic acid (HA). Small-volume injections (median 0.0625 mL) were targeted to the infero-medial aspect of the thyroarytenoid (TA) muscle. Implant locations were assessed histologically. Results The effect of implantation on PTP was material-dependent. CaHA tended to increase PTP, whereas HA tended to decrease PTP (Wilcoxon test P = 0.00013 for onset). In contrast, the effect of implantation on PTF was similar, with both materials tending to decrease PTF (P = 0.16 for onset). Histology confirmed implant presence in the inferior half of the vocal fold vertical thickness. Conclusions Taken together, these data suggested the implants may have altered the vocal fold medial surface contour, potentially resulting in a less convergent or more rectangular glottal geometry as a means to improve phonation. An implant with a closer viscoelastic match to vocal fold cover is desirable for this purpose, as material properties can affect vibration even when the implant is not placed within the lamina propria. This result is consistent with theoretical predictions and implies greater need for surgical precision in implant placement and care in material selection. PMID:22865592

[Vascular lesions of vocal folds--part 1: horizontal vascular lesions].

PubMed

Voigt-Zimmermann, S; Arens, C

2014-12-01

In recent decades, the endoscopic methods and technologies for laryngeal examination have improved so much that not only epithelial changes, but also vascular changes are recognizable at earlier stages. When comparing newer and older literature, the associated increasingly differentiated descriptions of such visible vascular changes of the vocal folds lead to terminological blurring and shifts of meaning. This complicates the technical-scientific discourse. The aim of the present work is a theoretical and conceptual clarification of early vascular changes of vocal folds. Horizontal changes of benigne vascular diseases, e. g. vessel ectasia, meander, increasing number and branching of vessels, change of direction may develop in to manifest vascular lesions, like varicosis, polyps and in case of ruptures to haemorrhages of vocal folds. These beginning and reversible vascular changes, when early detected and discussed basing on etiological knowledge, may lead to more differentiated prognostic statements and adequate therapeutic decisions, e. g. phonosurgery, functional voice therapy, voice hygiene and voice rest. Vertical vascular changes, like vessel loops, occur primarily in laryngeal papilloma, pre-cancerous and cancerous changes of the vocal folds. Already in small cancerous lesions of the vocal folds the vascular architecture is completely destroyed. © Georg Thieme Verlag KG Stuttgart · New York.

Towards endoscopic ultrafast laser microsurgery of vocal folds

NASA Astrophysics Data System (ADS)

Hoy, Christopher L.; Everett, W. Neil; Yildirim, Murat; Kobler, James; Zeitels, Steven M.; Ben-Yakar, Adela

2012-03-01

Vocal fold scarring is a predominant cause of voice disorders yet lacks a reliable treatment method. The injection of soft biomaterials to improve mechanical compliance of the vocal folds has emerged as a promising treatment. Here, we study the use of precise femtosecond laser microsurgery to ablate subsurface voids, with a goal of eventually creating a plane in dense subepithelial scar tissue into which biomaterials can be injected for their improved localization. Specifically, we demonstrate the ablation of small subepithelial voids in porcine vocal fold tissue up to 120 µm below the surface such that larger voids in the active area of vocal fold mucosa (~3×10 mm2) can eventually be ablated in about 3 min. We use sub-µJ, 776-nm pulses from a compact femtosecond fiber laser system operating at a 500-kHz repetition rate. The use of relatively high repetition rates, with a small number of overlapping pulses, is critical to achieving ablation in a very short time while still avoiding significant heat deposition. Additionally, we use the same laser for nonlinear optical imaging to provide visual feedback of tissue structure and to confirm successful ablation. The ablation parameters, including pulse duration, pulse energy, spot size, and scanning speed, are comparable to the specifications in our recently developed miniaturized femtosecond laser surgery probes, illustrating the feasibility of developing an ultrafast laser surgical instrument.

Modeling coupled aerodynamics and vocal fold dynamics using immersed boundary methods.

PubMed

Duncan, Comer; Zhai, Guangnian; Scherer, Ronald

2006-11-01

The penalty immersed boundary (PIB) method, originally introduced by Peskin (1972) to model the function of the mammalian heart, is tested as a fluid-structure interaction model of the closely coupled dynamics of the vocal folds and aerodynamics in phonation. Two-dimensional vocal folds are simulated with material properties chosen to result in self-oscillation and volume flows in physiological frequency ranges. Properties of the glottal flow field, including vorticity, are studied in conjunction with the dynamic vocal fold motion. The results of using the PIB method to model self-oscillating vocal folds for the case of 8 cm H20 as the transglottal pressure gradient are described. The volume flow at 8 cm H20, the transglottal pressure, and vortex dynamics associated with the self-oscillating model are shown. Volume flow is also given for 2, 4, and 12 cm H2O, illustrating the robustness of the model to a range of transglottal pressures. The results indicate that the PIB method applied to modeling phonation has good potential for the study of the interdependence of aerodynamics and vocal fold motion.

Viscoelastic and histologic properties in scarred rabbit vocal folds after mesenchymal stem cell injection.

PubMed

Hertegård, S; Cedervall, J; Svensson, B; Forsberg, K; Maurer, F H J; Vidovska, D; Olivius, P; Ahrlund-Richter, L; Le Blanc, K

2006-07-01

The aim of this study was to analyze the short-term viscoelastic and histologic properties of scarred rabbit vocal folds after injection of human mesenchymal stem cells (MSC) as well as the degree of MSC survival. Because MSCs are antiinflammatory and regenerate mesenchymal tissues, can MSC injection reduce vocal fold scarring after injury? Twelve vocal folds from 10 New Zealand rabbits were scarred by a localized resection and injected with human MSC or saline. Eight vocal folds were left as controls. After 4 weeks, 10 larynges were stained for histology and evaluation of the lamina propria thickness. Collagen type I content was analyzed from six rabbits. MSC survival was analyzed by fluorescent in situ hybridization staining from three rabbits. Viscoelasticity for 10 vocal folds was analyzed in a parallel-plate rheometer. The rheometry on fresh-frozen samples showed decreased dynamic viscosity and lower elastic modulus (P<.01) in the scarred samples injected with MSC as compared with the untreated scarred group. Normal controls had lower dynamic viscosity and elastic modulus as compared with the scarred untreated and treated vocal folds (P<.01). Histologic analysis showed a higher content of collagen type 1 in the scarred samples as compared with the normal vocal folds and with the scarred folds treated with MSC. MSCs remained in all samples analyzed. The treated scarred vocal folds showed persistent MSC. Injection of scarred rabbit vocal folds with MSC rendered improved viscoelastic parameters and less signs of scarring expressed as collagen content in comparison to the untreated scarred vocal folds.

Flow fields and acoustics in a unilateral scarred vocal fold model.

PubMed

Murugappan, Shanmugam; Khosla, Sid; Casper, Keith; Oren, Liran; Gutmark, Ephraim

2009-01-01

From prior work in an excised canine larynx model, it has been shown that intraglottal vortices form between the vocal folds during the latter part of closing. It has also been shown that the vortices generate a negative pressure between the folds, producing a suction force that causes sudden, rapid closing of the folds. This rapid closing will produce increased loudness and increased higher harmonics. We used a unilateral scarred excised canine larynx model to determine whether the intraglottal vortices and resulting acoustics were changed, compared to those of normal larynges. Acoustic, flow field, and high-speed imaging measurements from 5 normal and 5 unilaterally scarred canine larynges are presented in this report. Scarring was produced by complete resection of the vocal fold mucosa and superficial layer of the lamina propria on the right vocal fold only. Two months later, these dogs were painlessly sacrificed, and testing was done on the excised larynges during phonation. High-speed video imaging was then used to measure vocal fold displacement during different phases. Particle image velocimetry and acoustic measurements were used to describe possible acoustic effects of the vortices. A higher phonation threshold was required to excite the motion of the vocal fold in scarred larynges. As the subglottal pressure increased, the strength of the vortices and the higher harmonics both consistently increased. However, it was seen that increasing the maximum displacement of the scarred fold did not consistently increase the higher harmonics. The improvements that result from increasing subglottal pressure may be due to a combination of increasing the strength of the intraglottal vortices and increasing the maximum displacement of the vocal fold; however, the data in this study suggest that the vortices play a much more important role. The current study indicates that higher subglottal pressures may excite higher harmonics and improve loudness for patients with

Construction and Characterization of a Novel Vocal Fold Bioreactor

PubMed Central

Zerdoum, Aidan B.; Tong, Zhixiang; Bachman, Brendan; Jia, Xinqiao

2014-01-01

In vitro engineering of mechanically active tissues requires the presentation of physiologically relevant mechanical conditions to cultured cells. To emulate the dynamic environment of vocal folds, a novel vocal fold bioreactor capable of producing vibratory stimulations at fundamental phonation frequencies is constructed and characterized. The device is composed of a function generator, a power amplifier, a speaker selector and parallel vibration chambers. Individual vibration chambers are created by sandwiching a custom-made silicone membrane between a pair of acrylic blocks. The silicone membrane not only serves as the bottom of the chamber but also provides a mechanism for securing the cell-laden scaffold. Vibration signals, generated by a speaker mounted underneath the bottom acrylic block, are transmitted to the membrane aerodynamically by the oscillating air. Eight identical vibration modules, fixed on two stationary metal bars, are housed in an anti-humidity chamber for long-term operation in a cell culture incubator. The vibration characteristics of the vocal fold bioreactor are analyzed non-destructively using a Laser Doppler Vibrometer (LDV). The utility of the dynamic culture device is demonstrated by culturing cellular constructs in the presence of 200-Hz sinusoidal vibrations with a mid-membrane displacement of 40 µm. Mesenchymal stem cells cultured in the bioreactor respond to the vibratory signals by altering the synthesis and degradation of vocal fold-relevant, extracellular matrix components. The novel bioreactor system presented herein offers an excellent in vitro platform for studying vibration-induced mechanotransduction and for the engineering of functional vocal fold tissues. PMID:25145349

Construction and characterization of a novel vocal fold bioreactor.

PubMed

Zerdoum, Aidan B; Tong, Zhixiang; Bachman, Brendan; Jia, Xinqiao

2014-08-01

In vitro engineering of mechanically active tissues requires the presentation of physiologically relevant mechanical conditions to cultured cells. To emulate the dynamic environment of vocal folds, a novel vocal fold bioreactor capable of producing vibratory stimulations at fundamental phonation frequencies is constructed and characterized. The device is composed of a function generator, a power amplifier, a speaker selector and parallel vibration chambers. Individual vibration chambers are created by sandwiching a custom-made silicone membrane between a pair of acrylic blocks. The silicone membrane not only serves as the bottom of the chamber but also provides a mechanism for securing the cell-laden scaffold. Vibration signals, generated by a speaker mounted underneath the bottom acrylic block, are transmitted to the membrane aerodynamically by the oscillating air. Eight identical vibration modules, fixed on two stationary metal bars, are housed in an anti-humidity chamber for long-term operation in a cell culture incubator. The vibration characteristics of the vocal fold bioreactor are analyzed non-destructively using a Laser Doppler Vibrometer (LDV). The utility of the dynamic culture device is demonstrated by culturing cellular constructs in the presence of 200-Hz sinusoidal vibrations with a mid-membrane displacement of 40 µm. Mesenchymal stem cells cultured in the bioreactor respond to the vibratory signals by altering the synthesis and degradation of vocal fold-relevant, extracellular matrix components. The novel bioreactor system presented herein offers an excellent in vitro platform for studying vibration-induced mechanotransduction and for the engineering of functional vocal fold tissues.

Visualizing Collagen Network Within Human and Rhesus Monkey Vocal Folds Using Polarized Light Microscopy

PubMed Central

Julias, Margaret; Riede, Tobias; Cook, Douglas

2014-01-01

Objectives Collagen fiber content and orientation affect the viscoelastic properties of the vocal folds, determining oscillation characteristics during speech and other vocalization. The investigation and reconstruction of the collagen network in vocal folds remains a challenge, because the collagen network requires at least micron-scale resolution. In this study, we used polarized light microscopy to investigate the distribution and alignment of collagen fibers within the vocal folds. Methods Data were collected in sections of human and rhesus monkey (Macaca mulatta) vocal folds cut at 3 different angles and stained with picrosirius red. Results Statistically significant differences were found between different section angles, implying that more than one section angle is required to capture the network’s complexity. In the human vocal folds, the collagen fiber distribution continuously varied across the lamina propria (medial to lateral). Distinct differences in birefringence distribution were observed between the species. For the human vocal folds, high birefringence was observed near the thyroarytenoid muscle and near the epithelium. However, in the rhesus monkey vocal folds, high birefringence was observed near the epithelium, and lower birefringence was seen near the thyroarytenoid muscle. Conclusions The differences between the collagen networks in human and rhesus monkey vocal folds provide a morphological basis for differences in viscoelastic properties between species. PMID:23534129

Optoreflectometry determination of the resonance properties of a vocal fold.

PubMed

Garrel, Renaud; Nicollas, Richard; Giovanni, Antoine; Ouaknine, Maurice

2007-09-01

A new method of measuring the resonance properties of a vocal fold using electromagnetic excitation and laser optoreflectometry for response monitoring is described. Two resonance peaks were experimentally identified with one magnet stuck on the vocal fold at frequencies F0(1m)=54.7 Hz and F0'(1m)=35.8 Hz. The addition of a second magnet allowed calculation of the actual viscoelastic properties of the vocal fold: F0=71.8 Hz; quality factor Q=8.03; mass m=0.057 g; stiffness k=11.6 Nm; and damping zeta=0.0032 Nm(-1). A numerical simulation of a two-layered model verified the experimental data.

Evaluation of Synthetic Self-Oscillating Models of the Vocal Folds

NASA Astrophysics Data System (ADS)

Hubler, Elizabeth P.; Weiland, Kelley S.; Hancock, Adrienne B.; Plesniak, Michael W.

2013-11-01

Approximately 30% of people will suffer from a voice disorder at some point in their lives. The probability doubles for those who rely heavily on their voice, such as teachers and singers. Synthetic vocal fold (VF) models are fabricated and evaluated experimentally in a vocal tract simulator to replicate physiological conditions. Pressure measurements are acquired along the vocal tract and high-speed images are captured at varying flow rates during VF oscillation to facilitate understanding of the characteristics of healthy and damaged VFs. The images are analyzed using a videokymography line-scan technique that has been used to examine VF motion and mucosal wave dynamics in vivo. Clinically relevant parameters calculated from the volume-velocity output of a circumferentially-vented mask (Rothenberg mask) are compared to patient data. This study integrates speech science with engineering and flow physics to overcome current limitations of synthetic VF models to properly replicate normal phonation in order to advance the understanding of resulting flow features, progression of pathological conditions, and medical techniques. Supported by the GW Institute for Biomedical Engineering (GWIBE) and GW Center for Biomimetics and Bioinspired Engineering (COBRE).

Modified arytenoid adduction for cancer-related unilateral vocal fold paralysis.

PubMed

Shi, J; Chen, S; Chen, D; Wang, W; Xia, S; Zheng, H

2011-02-01

(1) To evaluate the efficacy of modified arytenoid adduction in the management of patients with symptomatic cancer-related unilateral vocal fold paralysis, and (2) to assess the impact of this treatment on patients' quality of life. Forty-two patients with cancer-related unilateral vocal fold paralysis underwent modified arytenoid adduction between February 2001 and December 2008. Of these, 37 patients were enrolled in this retrospective study (one patient died of primary disease and four were lost to follow up). Laryngostroboscopy was performed to evaluate vocal fold orientation and mobility. Pre- and post-operative assessment of subjective and objective voice, aerodynamic parameters, and quality of life were also undertaken, and aspiration was subjectively rated. Laryngostroboscopic findings indicated a significant post-operative improvement in vocal fold posterior glottal closure and vertical gap. Significant improvements in voice quality, aerodynamic parameters and quality of life were noted three months post-operatively in all patients (p < 0.01). The overall success rate for swallowing rehabilitation was 94.6 per cent (35/37). Subjective aspiration ratings decreased significantly post-operatively, compared with pre-operative values (p < 0.01). No major complication occurred in any patient, except for dyspnoea in one patient. Modified arytenoid adduction is an effective and reliable medialisation technique which can restore satisfactory voice quality, prevent aspiration and lead to a better quality of life for patients with cancer-related unilateral vocal fold paralysis.

Biomechanics of fundamental frequency regulation: Constitutive modeling of the vocal fold lamina propria.

PubMed

Chan, Roger W; Siegmund, Thomas; Zhang, Kai

2009-12-01

Accurate characterization of biomechanical characteristics of the vocal fold is critical for understanding the regulation of vocal fundamental frequency (F(0)), which depends on the active control of the intrinsic laryngeal muscles as well as the passive biomechanical response of the vocal fold lamina propria. Specifically, the tissue stress-strain response and viscoelastic properties under cyclic tensile deformation are relevant, when the vocal folds are subjected to length and tension changes due to posturing. This paper describes a constitutive modeling approach quantifying the relationship between vocal fold stress and strain (or stretch), and establishes predictions of F(0) with the string model of phonation based on the constitutive parameters. Results indicated that transient and time-dependent changes in F(0), including global declinations in declarative sentences, as well as local F(0) overshoots and undershoots, can be partially attributed to the time-dependent viscoplastic response of the vocal fold cover.

Oral and vocal fold diadochokinesis in dysphonic women.

PubMed

Louzada, Talita; Beraldinelle, Roberta; Berretin-Felix, Giédre; Brasolotto, Alcione Ghedini

2011-01-01

The evaluation of oral and vocal fold diadochokinesis (DDK) in individuals with voice disorders may contribute to the understanding of factors that affect the balanced vocal production. Scientific studies that make use of this assessment tool support the knowledge advance of this area, reflecting the development of more appropriate therapeutic planning. To compare the results of oral and vocal fold DDK in dysphonic women and in women without vocal disorders. For this study, 28 voice recordings of women from 19 to 54 years old, diagnosed with dysphonia and submitted to a voice assessment from speech pathologist and otorhinolaryngologist, were used. The control group included 30 nondysphonic women evaluated in prior research from normal adults. The analysis parameters like number and duration of emissions, as well as the regularity of the repetition of syllables "pa", "ta", "ka" and the vowels "a" and "i," were provided by the Advanced Motor Speech Profile program (MSP) Model-5141, version-2.5.2 (KayPentax). The DDK sequence "pataka" was analyzed quantitatively through the Sound Forge 7.0 program, as well as manually with the audio-visual help of sound waves. Average values of oral and vocal fold DDK dysphonic and nondysphonic women were compared using the "t Student" test and were considered significant when p<0.05. The findings showed no significant differences between populations; however, the coefficient of variation of period (CvP) and jitter of period (JittP) average of the "ka," "a" and "i" emissions, respectively, were higher in dysphonic women (CvP=10.42%, 12.79%, 12.05%; JittP=2.05%, 6.05%, 3.63%) compared to the control group (CvP=8.86%; 10.95%, 11.20%; JittP=1.82%, 2.98%, 3.15%). Although the results do not indicate any difficulties in oral and laryngeal motor control in the dysphonic group, the largest instability in vocal fold DDK in the experimental group should be considered, and studies of this ability in individuals with communication disorders must

Oral and vocal fold diadochokinesis in dysphonic women

PubMed Central

LOUZADA, Talita; BERALDINELLE, Roberta; BERRETIN-FELIX, Giédre; BRASOLOTTO, Alcione Ghedini

2011-01-01

The evaluation of oral and vocal fold diadochokinesis (DDK) in individuals with voice disorders may contribute to the understanding of factors that affect the balanced vocal production. Scientific studies that make use of this assessment tool support the knowledge advance of this area, reflecting the development of more appropriate therapeutic planning. Objective To compare the results of oral and vocal fold DDK in dysphonic women and in women without vocal disorders. Material and methods For this study, 28 voice recordings of women from 19 to 54 years old, diagnosed with dysphonia and submitted to a voice assessment from speech pathologist and otorhinolaryngologist, were used. The control group included 30 nondysphonic women evaluated in prior research from normal adults. The analysis parameters like number and duration of emissions, as well as the regularity of the repetition of syllables "pa", "ta", "ka" and the vowels "a" and "i," were provided by the Advanced Motor Speech Profile program (MSP) Model-5141, version-2.5.2 (KayPentax). The DDK sequence "pataka" was analyzed quantitatively through the Sound Forge 7.0 program, as well as manually with the audio-visual help of sound waves. Average values of oral and vocal fold DDK dysphonic and nondysphonic women were compared using the "t Student" test and were considered significant when p<0.05. Results The findings showed no significant differences between populations; however, the coefficient of variation of period (CvP) and jitter of period (JittP) average of the "ka," "a" and "i" emissions, respectively, were higher in dysphonic women (CvP=10.42%, 12.79%, 12.05%; JittP=2.05%, 6.05%, 3.63%) compared to the control group (CvP=8.86%; 10.95%, 11.20%; JittP=1.82%, 2.98%, 3.15%). Conclusion Although the results do not indicate any difficulties in oral and laryngeal motor control in the dysphonic group, the largest instability in vocal fold DDK in the experimental group should be considered, and studies of this

Role for ion transport in porcine vocal fold epithelial defense to acid challenge.

PubMed

Erickson-Levendoski, Elizabeth; Sivasankar, M Preeti

2012-02-01

The vocal fold epithelium is routinely exposed to gastric contents, including acid and pepsin, during laryngopharyngeal reflux events. The epithelium may possess intrinsic defenses to reflux. The first objective of the current study was to examine whether vocal fold epithelial ion transport is one potential mechanism of defense to gastric contents. The second objective was to determine whether ion transport in response to gastric contents is associated with the secretion of bicarbonate. Prospective design in excised porcine larynges. Laboratory. Porcine vocal folds (N = 56) were exposed on the luminal surface to acid, pepsin, or sham challenges. Ion transport at baseline and following challenge exposure was measured using electrophysiological techniques. To examine specific ion transport mechanisms, vocal folds were pretreated with either a sodium channel blocker or bicarbonate channel blocker. Within 60 seconds of acid but not pepsin exposure, there was a significant increase in ion transport. This rapid increase in ion transport was transient and related to bicarbonate secretion. The current data suggest that porcine vocal folds immediately increase bicarbonate secretion following exposure to acid. Bicarbonate secretion may act to neutralize acid. These findings contribute to the identification of the mechanisms underlying vocal fold defense to reflux and offer implications for the development of treatments for reflux-induced vocal fold injury.

Quantitative Study for the Surface Dehydration of Vocal Folds Based on High-Speed Imaging.

PubMed

Li, Lin; Zhang, Yu; Maytag, Allison L; Jiang, Jack J

2015-07-01

From the perspective of the glottal area and mucosal wave, quantitatively estimate the differences of vocal fold on laryngeal activity during phonation at three different dehydration levels. Controlled three sets of tests. A dehydration experiment for 10 excised canine larynges was conducted at 16 cm H2O. According to the dehydration cycle time (H), dehydration levels were divided into three degrees (0% H, 50% H, 75% H). The glottal area and mucosal wave under three dehydration levels were extracted from high-speed images and digital videokymography (DKG) image sequences. Direct and non-direct amplitude components were derived from glottal areas. The amplitude and frequency of mucosal wave were calculated from DKG image sequences. These parameters in condition of three dehydration levels were compared for statistical analysis. The results showed a significant difference in direct (P = 0.001; P = 0.005) and non-direct (P = 0.005; P = 0.016) components of glottal areas between every two different dehydration levels. Considering the right-upper, right-lower, left-upper, and left-lower of vocal fold, the amplitudes of mucosal waves consistently decreased with increasing of dehydration levels. But, there was no significant difference in frequency. Surface dehydration could give rise to complex variation of vocal fold on tissues and vibratory mechanism, which should need analyzing from multiple perspectives. The results suggested that the combination of glottal area and mucosal wave could be better to research the change of vocal fold at different dehydrations. It would become a better crucial research tool for the clinical treatment of dehydration-induced laryngeal pathologies. Copyright © 2015 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

A new approach to geometrical measurements in an animal model of vocal fold scar.

PubMed

Jabbour, Noel; Krishna, Priya D; Osborne, James; Rosen, Clark A

2009-01-01

A standard method for quantifying the geometric properties of vocal folds has not been widely adopted. An ideal method of geometrical measurement should effectively quantify the dimensions of the medial vibratory portion of the vocal fold, should be easily performed, should yield consistent results, and should be readily available at little to no cost. We have developed a new approach for geometrical measurements to meet these goals. The objective of this study is to describe this new approach and to assess its effectiveness in a canine model of vocal fold scar. One hundred thirty-five mid-membranous coronal sections of vocal folds from 10 canines (five with unilateral surgical scarring) were examined by light microscopy; digital images were captured. ImageJ was used to measure a variety of described parameters. Comparison between scarred vocal folds and control vocal folds was made. At least 20% of the slides for each vocal fold were randomly selected (n=42) for repeat measurements of interrater and intrarater reliability. A statistically significant difference between scarred and control vocal folds was obtained for horizontal distance (P<0.001), vertical distance (P=0.005), area (P<0.001), mean optical density (OD) (P<0.001), and OD at defined points along the length of the vocal fold (P< or =0.009). Reliability calculations for intrarater and interrater measurements ranged from r=0.845 to r=0.994 and from r=0.734 to r=0.976, respectively. The proposed approach for geometrical measurements meets the intended objectives in a canine model of vocal fold scar. Future work is needed to apply this approach to other model systems.

Hyaluronic acid (with fibronectin) as a bioimplant for the vocal fold mucosa.

PubMed

Chan, R W; Titze, I R

1999-07-01

To measure the viscoelastic shear properties of hyaluronic acid, with and without fibronectin, and to compare them with those of the human vocal fold mucosa and other phonosurgical biomaterials. Viscoelastic shear properties of various implantable biomaterials (Teflon, gelatin, collagen, fat, hyaluronic acid, and hyaluronic acid with fibronectin) were measured with a parallel-plate rotational rheometer. Elastic and viscous shear properties were quantified as a function of oscillation frequency (0.01-15 Hz) at 37 degrees C. The shear properties of hyaluronic acid were relatively close to those of human vocal fold mucosal tissues reported previously. Hyaluronic acid at specific concentrations (0.5%-1%), with or without fibronectin, was found to exhibit viscous shear properties (viscous shear modulus and dynamic viscosity) similar to those of the average male and female vocal fold mucosa. According to a theory that establishes the effects of tissue shear properties on vocal fold oscillation, phonation threshold pressure (a measure of the ease of phonation) is directly related to the viscous shear modulus of the vibrating vocal fold mucosa. Therefore, our findings suggest that hyaluronic acid, either by itself or mixed with fibronectin, may be a potentially optimal bioimplant for the surgical management of vocal fold mucosal defects and lamina propria deficiencies (e.g., scarring) from a biomechanical standpoint.

Biosimulation of inflammation and healing in surgically injured vocal folds.

PubMed

Li, Nicole Y K; Vodovotz, Yoram; Hebda, Patricia A; Abbott, Katherine Verdolini

2010-06-01

The pathogenesis of vocal fold scarring is complex and remains to be deciphered. The current study is part of research endeavors aimed at applying systems biology approaches to address the complex biological processes involved in the pathogenesis of vocal fold scarring and other lesions affecting the larynx. We developed a computational agent-based model (ABM) to quantitatively characterize multiple cellular and molecular interactions involved in inflammation and healing in vocal fold mucosa after surgical trauma. The ABM was calibrated with empirical data on inflammatory mediators (eg, tumor necrosis factor) and extracellular matrix components (eg, hyaluronan) from published studies on surgical vocal fold injury in the rat population. The simulation results reproduced and predicted trajectories seen in the empirical data from the animals. Moreover, the ABM studies suggested that hyaluronan fragments might be the clinical surrogate of tissue damage, a key variable that in these simulations both is enhanced by and further induces inflammation. A relatively simple ABM such as the one reported in this study can provide new understanding of laryngeal wound healing and generate working hypotheses for further wet-lab studies.

Preservation of viscoelastic properties of rabbit vocal folds after implantation of hyaluronic Acid-based biomaterials.

PubMed

Choi, Jeong-Seok; Kim, Nahn Ju; Klemuk, Sarah; Jang, Yun Ho; Park, In Suh; Ahn, Kyung Hyun; Lim, Jae-Yol; Kim, Young-Mo

2012-09-01

To compare the rheological characteristics of structurally different hyaluronic acid (HA)-based biomaterials that are presently used for phonosurgery and to investigate their influence on the viscoelastic properties of vocal folds after implantation in an in vivo rabbit model. In vitro and in vivo rheometric investigation. Experimental laboratory, Inha and Seoul National Universities. Viscoelastic shear properties of 3 HA-based biomaterials (Rofilan, Restylane, and Reviderm) were measured with a strain-controlled rheometer. These biomaterials were injected into the deep layers of rabbit vocal folds, and viscoelastic moduli of the injected vocal folds were determined 2 months after the injection. The vocal fold specimens were observed using a light microscope and a transmission electron microscope. All HA-based biomaterials showed similar levels of shear viscosity, which were slightly higher than that of human vocal folds reported in previous studies. Compared with noninjected control vocal folds, there were no significant differences in the magnitudes of both elastic shear modulus (G') and viscous modulus (G") of injected vocal folds among all of the materials. Light microscopic images showed that all materials were observed in the deep layers of vocal folds and electron scanning images revealed that injected HA particles were homogeneously distributed in regions of collagenous fibers. HA-based biomaterials could preserve the viscoelastic properties of the vocal folds, when they were injected into vocal folds in an in vivo rabbit model. However, further studies on the influence of the biomaterials on the viscoelasticity of human vocal folds in ECM surroundings are still needed.

Adipose stromal cells improve healing of vocal fold scar: Morphological and functional evidences.

PubMed

de Bonnecaze, Guillaume; Chaput, Benoit; Woisard, Virginie; Uro-Coste, Emmanuelle; Swider, Pascal; Vergez, Sebastien; Serrano, Elie; Casteilla, Louis; Planat-Benard, Valerie

2016-08-01

Adipose derived stromal cells (ASCs) are abundant and easy to prepare. Such cells may be useful for treating severe vocal disturbance caused by acute vocal fold scars. Prospective animal experiments with controls. Twenty New-Zealand white rabbits were used in the present study. We evaluated vocal fold healing, with or without injection of autologous ASCs, after acute scarring. A defined lesion was created and the ASCs were immediately injected. Vocal fold regeneration was evaluated histomorphometrically and via viscoelastic analysis using an electrodynamic shaker. Six weeks after ASC injection, vocal folds exhibited significantly less inflammation than control folds (P < 0.005). In addition, hypertrophy of the lamina propria and fibrosis were significantly reduced upon ASC injection (P < 0.02). The decrease in viscoelastic parameters was less important in the ASC injected group compared to the noninjected group (P = 0.08). Injection of autologous ASCs improved vocal fold healing in our preclinical model. Further studies are needed, but this method may be useful in humans. NA. Laryngoscope, 126:E278-E285, 2016. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

Effects of long-acting beta adrenergic agonists on vocal fold ion transport.

PubMed

Sivasankar, Mahalakshmi; Blazer-Yost, Bonnie

2009-03-01

Inhaled medications prescribed for the hypersensitive airway typically combine corticosteroids and long-acting beta2 adrenergic agonists (LABAs). The phonatory side effects of these combination treatments are widely recognized. However, there is limited understanding of the physiological changes induced by these medications that underlie the phonatory side effects. The objective of this study was to investigate the distinct effects of corticosteroids and LABAs on vocal fold mucosal physiology. Understanding the physiological changes to the vocal folds after corticosteroid and LABA treatments is necessary to prevent the prevalent vocal decrement associated with these medications. Experimental in vitro design with treatment and control groups. Native porcine vocal fold mucosae (N = 38) were exposed to corticosteroid or LABA treatments. Ion transport was measured continuously at baseline and after treatment. To quantify the nature of ion transport, vocal folds were also treated with chloride and sodium channel inhibitors. Corticosteroid treatment did not alter ion transport. Conversely, exposure to LABAs significantly increased ion transport. This increase in ion transport was transient, observed immediately after treatment in all tissue and associated with increased chloride secretion. The distinct effects of corticosteroids and LABAs on vocal fold physiology have not been examined to date. This study demonstrates that short-term treatment with LABAs, but not corticosteroids, significantly increases ion transport. These findings suggest that one underlying physiological mechanism for phonatory changes associated with inhaled treatments may be related to acute alterations in vocal fold ion transport and surface hydration.

Bilateral Vocal Fold Medialization: A Treatment for Abductor Spasmodic Dysphonia.

PubMed

Dewan, Karuna; Berke, Gerald S

2017-11-10

Abductor spasmodic dysphonia, a difficult-to-treat laryngologic condition, is characterized by spasms causing the vocal folds to remain abducted despite efforts to adduct them during phonation. Traditional treatment for abductor spasmodic dysphonia-botulinum toxin injection into the posterior cricoarytenoid muscle-can be both technically challenging and uncomfortable. Due to the difficulty of needle placement, it is often unsuccessful. The purpose of this investigation is to present a previously undescribed treatment for abductor spasmodic dysphonia-bilateral vocal fold medialization. A retrospective case review of all cases of abductor spasmodic dysphonia treated in a tertiary care laryngology practice with bilateral vocal fold medialization over a 10-year period was performed. The Voice Handicap Index and the Voice-Related Quality of Life surveys were utilized to assess patient satisfaction with voice outcome. Six patients with abductor spasmodic dysphonia treated with bilateral vocal fold medialization were identified. Disease severity ranged from mild to severe. All six patients reported statistically significant improvement in nearly all Voice Handicap Index and Voice-Related Quality of Life parameters. They reported fewer voice breaks and greater ease of communication. Results were noted immediately and symptoms continue to be well controlled for many years following medialization. Bilateral vocal fold medialization is a safe and effective treatment for abductor spasmodic dysphonia. It is performed under local anesthesia and provides phonation improvement in the short and long term. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Role for Ion Transport in Porcine Vocal Fold Epithelial Defense to Acid Challenge

PubMed Central

Erickson-Levendoski, Elizabeth; Sivasankar, M. Preeti

2012-01-01

Objective The vocal fold epithelium is routinely exposed to gastric contents, including acid and pepsin, during laryngopharyngeal reflux events. The epithelium may possess intrinsic defenses to reflux. The first objective of the current study was to examine whether vocal fold epithelial ion transport is one potential mechanism of defense to gastric contents. The second objective was to determine whether ion transport in response to gastric contents is associated with the secretion of bicarbonate. Study Design Prospective design in excised porcine larynges. Setting Laboratory. Subjects and Methods Porcine vocal folds (N = 56) were exposed on the luminal surface to acid, pepsin, or sham challenges. Ion transport at baseline and following challenge exposure was measured using electrophysiological techniques. To examine specific ion transport mechanisms, vocal folds were pretreated with either a sodium channel blocker or bicarbonate channel blocker. Results Within 60 seconds of acid but not pepsin exposure, there was a significant increase in ion transport. This rapid increase in ion transport was transient and related to bicarbonate secretion. Conclusion The current data suggest that porcine vocal folds immediately increase bicarbonate secretion following exposure to acid. Bicarbonate secretion may act to neutralize acid. These findings contribute to the identification of the mechanisms underlying vocal fold defense to reflux and offer implications for the development of treatments for reflux-induced vocal fold injury. PMID:22086905

Characteristics of phonation onset in a two-layer vocal fold model.

PubMed

Zhang, Zhaoyan

2009-02-01

Characteristics of phonation onset were investigated in a two-layer body-cover continuum model of the vocal folds as a function of the biomechanical and geometric properties of the vocal folds. The analysis showed that an increase in either the body or cover stiffness generally increased the phonation threshold pressure and phonation onset frequency, although the effectiveness of varying body or cover stiffness as a pitch control mechanism varied depending on the body-cover stiffness ratio. Increasing body-cover stiffness ratio reduced the vibration amplitude of the body layer, and the vocal fold motion was gradually restricted to the medial surface, resulting in more effective flow modulation and higher sound production efficiency. The fluid-structure interaction induced synchronization of more than one group of eigenmodes so that two or more eigenmodes may be simultaneously destabilized toward phonation onset. At certain conditions, a slight change in vocal fold stiffness or geometry may cause phonation onset to occur as eigenmode synchronization due to a different pair of eigenmodes, leading to sudden changes in phonation onset frequency, vocal fold vibration pattern, and sound production efficiency. Although observed in a linear stability analysis, a similar mechanism may also play a role in register changes at finite-amplitude oscillations.

Vocal fold pseudocyst: results of 46 cases undergoing a uniform treatment algorithm.

PubMed

Estes, Christine; Sulica, Lucian

2014-05-01

To describe treatment results and identify predictors of the need for surgical intervention in patients with vocal fold pseudocyst. Retrospective cohort study with longitudinal followup via survey. Clinical records were reviewed for demographic information, VHI-10 score, and degree of severity of dysphonia. Videostroboscopic examinations were evaluated for presence of vocal fold pseudocyst, along with additional clinical variables, including laterality, reactive lesion, paresis, varix, and hemorrhage. Follow-up surveys were sent to all participants to evaluate current VHI-10 score and degree of vocal limitation. Results were analyzed to determine predictors of surgery and recurrence of pathology. Forty-six patients (41F:5M) with pseudocyst (40 unilateral: 6 bilateral) were reviewed. Twenty-three (50%) had reactive lesions, nineteen (41%) had paresis by clinical criteria, 10 (22%) had varices, and 6 (13%) had hemorrhage on examination. All underwent initial behavioral management (2-12 sessions of voice therapy; mean of 8 sessions). Seventeen (37%) eventually required surgical intervention. No demographic or clinical variables proved predictive of surgical intervention. Follow-up surveys were completed by 63% of patients, and 79% agreed with the statement that they were not professionally limited by their voices. This experience supports behavioral management as an initial intervention in patients with pseudocyst, sufficient by itself to restore vocal function in approximately two out of three patients. Neither initial severity nor any of the studied clinical findings predicted the need for surgery. The large majority of patients with pseudocyst are able to be treated effectively without impact in their professional function. © 2013 The American Laryngological, Rhinological and Otological Society, Inc.

Therapeutic potential of gel-based injectables for vocal fold regeneration

PubMed Central

Bartlett, Rebecca S.; Thibeault, Susan L.; Prestwich, Glenn D.

2012-01-01

Vocal folds are anatomically and biomechanically unique, thus complicating the design and implementation of tissue engineering strategies for repair and regeneration. Integration of an enhanced understanding of tissue biomechanics, wound healing dynamics and innovative gel-based therapeutics has generated enthusiasm for the notion that an efficacious treatment for vocal fold scarring could be clinically attainable within several years. Fibroblast phenotype and gene expression are mediated by the three-dimensional mechanical and chemical microenvironment at an injury site. Thus, therapeutic approaches need to coordinate spatial and temporal aspects of the wound healing response in an injured vocal tissue to achieve an optimal clinical outcome. Successful gel-based injectables for vocal fold scarring will require a keen understanding of how the native inflammatory response sets into motion the later extracellular matrix remodeling, which in turn will determine the ultimate biomechanical properties of the tissue. We present an overview of the challenges associated with this translation as well as the proposed gel-based injectable solutions. PMID:22456756

Vocal Fold Epithelial Barrier in Health and Injury: A Research Review

ERIC Educational Resources Information Center

Levendoski, Elizabeth Erickson; Leydon, Ciara; Thibeault, Susan L.

2014-01-01

Purpose: Vocal fold epithelium is composed of layers of individual epithelial cells joined by junctional complexes constituting a unique interface with the external environment. This barrier provides structural stability to the vocal folds and protects underlying connective tissue from injury while being nearly continuously exposed to potentially…

Biosimulation of Inflammation and Healing in Surgically Injured Vocal Folds

PubMed Central

Li, Nicole Y. K.; Vodovotz, Yoram; Hebda, Patricia A.; Abbott, Katherine Verdolini

2010-01-01

Objectives The pathogenesis of vocal fold scarring is complex and remains to be deciphered. The current study is part of research endeavors aimed at applying systems biology approaches to address the complex biological processes involved in the pathogenesis of vocal fold scarring and other lesions affecting the larynx. Methods We developed a computational agent-based model (ABM) to quantitatively characterize multiple cellular and molecular interactions involved in inflammation and healing in vocal fold mucosa after surgical trauma. The ABM was calibrated with empirical data on inflammatory mediators (eg, tumor necrosis factor) and extracellular matrix components (eg, hyaluronan) from published studies on surgical vocal fold injury in the rat population. Results The simulation results reproduced and predicted trajectories seen in the empirical data from the animals. Moreover, the ABM studies suggested that hyaluronan fragments might be the clinical surrogate of tissue damage, a key variable that in these simulations both is enhanced by and further induces inflammation. Conclusions A relatively simple ABM such as the one reported in this study can provide new understanding of laryngeal wound healing and generate working hypotheses for further wet-lab studies. PMID:20583741

Modeling the Biomechanical Influence of Epilaryngeal Stricture on the Vocal Folds: A Low-Dimensional Model of Vocal-Ventricular Fold Coupling

ERIC Educational Resources Information Center

Moisik, Scott R.; Esling, John H.

2014-01-01

Purpose: Physiological and phonetic studies suggest that, at moderate levels of epilaryngeal stricture, the ventricular folds impinge upon the vocal folds and influence their dynamical behavior, which is thought to be responsible for constricted laryngeal sounds. In this work, the authors examine this hypothesis through biomechanical modeling.…

Non-invasive In vivo measurement of the shear modulus of human vocal fold tissue

PubMed Central

Kazemirad, Siavash; Bakhshaee, Hani; Mongeau, Luc; Kost, Karen

2014-01-01

Voice is the essential part of singing and speech communication. Voice disorders significantly affect the quality of life. The viscoelastic mechanical properties of the vocal fold mucosa determine the characteristics of the vocal folds oscillations, and thereby voice quality. In the present study, a non-invasive method was developed to determine the shear modulus of human vocal fold tissue in vivo via measurements of the mucosal wave propagation speed during phonation. Images of four human subjects’ vocal folds were captured using high speed digital imaging (HSDI) and magnetic resonance imaging (MRI) for different phonation pitches, specifically fundamental frequencies between 110 to 440 Hz. The MRI images were used to obtain the morphometric dimensions of each subject's vocal folds in order to determine the pixel size in the high-speed images. The mucosal wave propagation speed was determined for each subject and at each pitch value using an automated image processing algorithm. The transverse shear modulus of the vocal fold mucosa was then calculated from a surface (Rayleigh) wave propagation dispersion equation using the measured wave speeds. It was found that the mucosal wave propagation speed and therefore the shear modulus of the vocal fold tissue were generally greater at higher pitches. The results were in good agreement with those from other studies obtained via in vitro measurements, thereby supporting the validity of the proposed measurement method. This method offers the potential for in vivo clinical assessments of vocal folds viscoelasticity from HSDI. PMID:24433668

Multi-parameter analysis of titanium vocal fold medializing implant in an excised larynx model

PubMed Central

Witt, Rachel E.; Hoffman, Matthew R.; Friedrich, Gerhard; Rieves, Adam L.; Schoepke, Benjamin J.; Jiang, Jack J.

2010-01-01

Objective Evaluate the efficacy of the titanium vocal fold medializing implant (TVFMI) for the treatment of unilateral vocal fold paralysis (UVFP) based on acoustic, aerodynamic, and mucosal wave measurements in an excised larynx setup. Methods Measurements were recorded on eight excised canine larynges with simulated UVFP before and after medialization with the TVFMI. Results Phonation threshold flow (PTF) and phonation threshold power (PTW) decreased significantly after medialization (p<0.001; p=0.008). Phonation threshold pressure (PTP) also decreased, but this difference was not significant (p=0.081). Percent jitter and percent shimmer decreased significantly after medialization (p=0.005; p=0.034). Signal to noise ratio (SNR) increased significantly (p=0.05). Differences in mucosal wave characteristics were discernable, but not significant. Phase difference between the normal and paralyzed vocal fold and amplitude of the paralyzed vocal fold decreased (p=0.15; p=0.78). Glottal gap decreased significantly (p=0.004). Conclusions The TVFMI was effective in achieving vocal fold medialization, improving vocal aerodynamic and acoustic characteristics of phonation significantly and mucosal wave characteristics discernibly. This study provides objective, quantitative support for the use of the TVFMI in improving vocal function in patients with unilateral vocal fold paralysis. PMID:20336924

A rabbit vocal fold laser scarring model for testing lamina propria tissue engineering therapies

PubMed Central

Mau, Ted; Du, Mindy; Xu, Chet C.

2015-01-01

Objectives/Hypothesis To develop a vocal fold scarring model using an ablative laser in the rabbit as a platform for testing bioengineered therapies for missing or damaged lamina propria. Study Design Prospective controlled animal study. Methods An optimal laser energy level was first determined by assessing the depths of vocal fold injury created by a Holmium:YAG laser at various energy levels on fresh cadaveric rabbit larynges. The selected energy level was then used to create controlled unilateral injuries in vocal folds of New Zealand white rabbits, with the contralateral folds serving as uninjured controls. After 4 weeks, the larynges were harvested and subjected to excised-larynx phonation with high-speed imaging and immunohistochemical staining for collagen types I and III, elastin, and hyaluronic acid (HA) with quantitative histological analysis. Results 1.8 joules produced full-thickness injury of the lamina propria without extensive muscle injury. After 4 weeks, the injured vocal folds vibrated with reduced amplitude (P = 0.036) in excised-larynx phonation compared to normal vocal folds. The injured vocal folds contained a higher relative density of collagen type I (P = 0.004), higher elastin (P = 0.022), and lower HA (P = 0.030) compared to normal controls. Collagen type III was unchanged. Conclusions With its potential for higher precision of injury, this laser vocal fold scarring model may serve as an alternative to scarring produced by cold instruments for studying the effects of vocal fold lamina propria bioengineered therapies. Level of Evidence N/A. PMID:24715695

Modeling viscous dissipation during vocal fold contact: the influence of tissue viscosity and thickness with implications for hydration.

PubMed

Erath, Byron D; Zañartu, Matías; Peterson, Sean D

2017-06-01

The mechanics of vocal fold contact during phonation is known to play a crucial role in both normal and pathological speech production, though the underlying physics is not well understood. Herein, a viscoelastic model of the stresses during vocal fold contact is developed. This model assumes the cover to be a poroelastic structure wherein interstitial fluid translocates in response to mechanical squeezing. The maximum interstitial fluid pressure is found to generally increase with decreasing viscous dissipation and/or decreasing tissue elasticity. A global minimum in the total contact stress, comprising interstitial fluid pressure and elastic stress in the tissue, is observed over the studied dimensionless parameter range. Interestingly, physiologically reasonable estimates for the governing parameters fall within this global minimum region. The model is validated against prior experimental and computational work, wherein the predicted contact stress magnitude and impact duration agree well with published results. Lastly, observations of the potential relationship between vocal fold hydration and increased risk of tissue damage are discussed based upon model predictions of stress as functions of cover layer thickness and viscosity.

Time-Varying Vocal Folds Vibration Detection Using a 24 GHz Portable Auditory Radar.

PubMed

Hong, Hong; Zhao, Heng; Peng, Zhengyu; Li, Hui; Gu, Chen; Li, Changzhi; Zhu, Xiaohua

2016-07-28

Time-varying vocal folds vibration information is of crucial importance in speech processing, and the traditional devices to acquire speech signals are easily smeared by the high background noise and voice interference. In this paper, we present a non-acoustic way to capture the human vocal folds vibration using a 24-GHz portable auditory radar. Since the vocal folds vibration only reaches several millimeters, the high operating frequency and the 4 × 4 array antennas are applied to achieve the high sensitivity. The Variational Mode Decomposition (VMD) based algorithm is proposed to decompose the radar-detected auditory signal into a sequence of intrinsic modes firstly, and then, extract the time-varying vocal folds vibration frequency from the corresponding mode. Feasibility demonstration, evaluation, and comparison are conducted with tonal and non-tonal languages, and the low relative errors show a high consistency between the radar-detected auditory time-varying vocal folds vibration and acoustic fundamental frequency, except that the auditory radar significantly improves the frequency-resolving power.

Restructuring the vocal fold lamina propria with endoscopic microdissection.

PubMed

Bartlett, Rebecca S; Hoffman, Henry T; Dailey, Seth H; Bock, Jonathan M; Klemuk, Sarah A; Askeland, Ryan W; Ahlrichs-Hanson, Jan S; Heaford, Andrew C; Thibeault, Susan L

2013-11-01

The purposes of this preclinical study were to investigate histologic and rheologic outcomes of Microendoscopy of Reinke's space (MERS)-guided minithyrotomy and to assess its instrumentation. Human cadaveric and in vivo animal study. Three human cadaveric larynges were treated with MERS-guided placement of Radiesse VoiceGel and immediately evaluated histologically for biomaterial location. In the second part of this investigation, two scarred porcine larynges were treated with MERS-guided placement of HyStem-VF and rheologically evaluated 6 weeks later. Student t tests determined differences in viscoelastic properties of treated/untreated vocal folds. Sialendoscopes and microendoscopes were subjectively compared for their visualization capacity. MERS imaged the subepithelial area and vocal ligament, guiding both tissue dissection and biomaterial positioning. Sialendoscopes provided adequate visualization and feature incorporated working channels. Enhanced image clarity was created in a gas-filled rather than saline-filled environment, per rater judgment. Histological analysis revealed desirable biomaterial positioning with MERS. Per rheological analysis, viscoelastic properties of the MERS-treated porcine vocal folds compared to uninjured vocal folds 6 weeks following treatment did not statistically differ. MERS-guided laryngoplasty using sialendoscopes yielded satisfactory biomaterial positioning in the short-term and normalized rheologic tissue properties in the long-term, contributing to proof of concept for MERS in the treatment of scarring. Strengths of MERS include direct, real-time visualization of Reinke's space and an ability to manipulate surgical instruments parallel to the vocal fold edge while maintaining an intact epithelium. Future work will explore the clinical utility of MERS for addressing scarring, sulcus vocalis, and other intracordal processes. Copyright © 2013 The American Laryngological, Rhinological and Otological Society, Inc.

Symptomatic unilateral vocal fold paralysis following cardiothoracic surgery.

PubMed

Puccinelli, Cassandra; Modzeski, Mara C; Orbelo, Diana; Ekbom, Dale C

Unilateral vocal fold paralysis (UVFP) is a complication associated with cardiothoracic procedures that presents clinically as dysphonia and/or dysphagia with or without aspiration. The literature lacks both data on recovery of mobility and consensus on best management. Herein, our goals are to 1) Identify cardiothoracic procedures associated with symptomatic UVFP at our institution; 2) Review timing and nature of laryngology diagnosis and management; 3) Report spontaneous recovery rate of vocal fold mobility. Retrospective case series at single tertiary referral center between 2002 and 2015. 141 patients were included who underwent laryngology interventions (micronized acellular dermis injection laryngoplasty and/or type 1 thyroplasty) to treat symptomatic UVFP diagnosed subsequent to cardiothoracic surgery. Pulmonary procedures were most often associated with UVFP (n=50/141; 35.5%). 87.2% had left-sided paralysis (n=123/141). Median time to diagnosis was 42days (x¯=114±348). Over time, UVFP was diagnosed progressively earlier after cardiothoracic surgery. 63.4% of patients (n=95/141) underwent injection laryngoplasty as their initial intervention with median time from diagnosis to injection of 11days (x¯=29.6±54). 41.1% (n=58/141) ultimately underwent type 1 thyroplasty at a median of 232.5days (x¯=367±510.2) after cardiothoracic surgery. 10.2% (n=9/88) of those with adequate follow-up recovered full vocal fold mobility. Many cardiothoracic procedures are associated with symptomatic UVFP, predominantly left-sided. Our data showed poor recovery of vocal fold mobility relative to other studies. Early diagnosis and potential surgical medialization is important in the care of these patients. Copyright © 2017 Elsevier Inc. All rights reserved.

Aeroelastic Model of Vocal-Fold Vibrating Element for Studying the Phonation Threshold

NASA Astrophysics Data System (ADS)

Horáček, J.; Švec, J. G.

2002-10-01

An original theoretical model for vibration onset of the vocal folds in the air-flow coming from the human subglottal tract is designed, which allows studying the influence of the physical properties of the vocal folds (e.g., geometrical shape, mass, viscosity) on their vibration characteristics (such as the natural frequencies, mode shapes of vibration and the thresholds of instability). The mathematical model of the vocal fold is designed as a simplified dynamic system of two degrees of freedom (rotation and translation) vibrating on an elastic foundation in the wall of a channel conveying air. An approximate unsteady one-dimensional flow theory for the inviscid incompressible fluid is presented for the phonatory air-flow. A generally defined shape of the vocal-fold surface is considered for expressing the unsteady aerodynamic forces in the glottis. The parameters of the mechanical part of the model, i.e., the mass, stiffness and damping matrices, are related to the geometry and material density of the vocal folds as well as to the fundamental natural frequency and damping known from experiments. The coupled numerical solution yields the vibration characteristics (natural frequencies, damping and mode shapes of vibration), including the instability thresholds of the aeroelastic system. The vibration characteristics obtained from the coupled numerical solution of the system appear to be in reasonable qualitative agreement with the physiological data and clinical observations. The model is particularly suitable for studying the phonation threshold, i.e., the onset of vibration of the vocal folds.

Permanent medialization of the paralyzed vocal fold utilizing botulinum toxin and Gelfoam.

PubMed

Rontal, Eugene; Rontal, Michael

2003-09-01

The clinical picture of a paralyzed vocal fold often has the same appearance as a subluxated arytenoid, with anterior and medial displacement of the arytenoid and a foreshortened and lax vocal fold. Previous work by the authors has shown that a subluxated arytenoid may be permanently repositioned by reduction and selective injection of the intrinsic laryngeal musculature with botulinum toxin. The injection changes the forces within the larynx, allowing the arytenoid to be brought back to proper position on the cricoid cartilage. This concept has been extended to the paralyzed vocal fold. It has been noted that even a clinically paralyzed vocal fold has voluntary motor units that may still act on the arytenoid through residual action from the interarytenoid and synkinesis. These forces are significant enough to manipulate the arytenoid and, thus, the vocal fold, into its correct, adducted position. In this paper, the arytenoid is mobilized to free any fibrosis. The thyroarytenoid and lateral cricoarytenoid muscles are then injected to prevent any forward synkinetic pull on the arytenoid. Next, a Gelfoam injection medializes the vocal fold to create glottic closure. This rebalancing sufficiently positions the arytenoid, so that valvular function is permanently restored. In the ten patients studied for over 1 year, there was a 90% success rate as measured by videostroboscopy, phonation time, and V-RQOL analysis. There were no untoward complications. All the materials used are nonpermanent. The procedure does not limit other techniques from being performed at a later time.

Effects of mucosal loading on vocal fold vibration

NASA Astrophysics Data System (ADS)

Tao, Chao; Jiang, Jack J.

2009-06-01

A chain model was proposed in this study to examine the effects of mucosal loading on vocal fold vibration. Mucosal loading was defined as the loading caused by the interaction between the vocal folds and the surrounding tissue. In the proposed model, the vocal folds and the surrounding tissue were represented by a series of oscillators connected by a coupling spring. The lumped masses, springs, and dampers of the oscillators modeled the tissue properties of mass, stiffness, and viscosity, respectively. The coupling spring exemplified the tissue interactions. By numerically solving this chain model, the effects of mucosal loading on the phonation threshold pressure, phonation instability pressure, and energy distribution in a voice production system were studied. It was found that when mucosal loading is small, phonation threshold pressure increases with the damping constant Rr, the mass constant Rm, and the coupling constant Rμ of mucosal loading but decreases with the stiffness constant Rk. Phonation instability pressure is also related to mucosal loading. It was found that phonation instability pressure increases with the coupling constant Rμ but decreases with the stiffness constant Rk of mucosal loading. Therefore, it was concluded that mucosal loading directly affects voice production.

Effect of growth factors on hyaluronan production by canine vocal fold fibroblasts.

PubMed

Hirano, Shigeru; Bless, Diane M; Heisey, Dennis; Ford, Charles N

2003-07-01

Hyaluronan (HYA) is considered to be a crucial factor in scarless wound healing and in maintaining tissue viscosity of the vocal fold lamina propria. In this study focusing on the effects of growth factors, we examined how HYA is produced and controlled in canine cultured vocal fold fibroblasts. Fibroblasts were taken from the lamina propria of the vocal folds of 8 dogs and cultured with and without growth factors. The production of HYA in the supernatant culture was quantitatively examined by enzyme-linked immunosorbent assay. Hepatocyte growth factor, epidermal growth factor, basic fibroblast growth factor, and transforming growth factor beta1 all stimulated HYA synthesis from vocal fold fibroblasts. These effects differed with the concentration of growth factors and the incubation period. We also examined how frequently the growth factors had to be administered in order to maintain appropriate levels of HYA. A single administration was sufficient to maintain appropriate HYA levels for at least 7 days. The present studies have demonstrated positive effects of growth factors in stimulating HYA production. Further in vivo study is needed to clarify the usefulness of these growth factors in the management of vocal fold scarring.

Material and shape optimization for multi-layered vocal fold models using transient loadings.

PubMed

Schmidt, Bastian; Leugering, Günter; Stingl, Michael; Hüttner, Björn; Agaimy, Abbas; Döllinger, Michael

2013-08-01

Commonly applied models to study vocal fold vibrations in combination with air flow distributions are self-sustained physical models of the larynx consisting of artificial silicone vocal folds. Choosing appropriate mechanical parameters and layer geometries for these vocal fold models while considering simplifications due to manufacturing restrictions is difficult but crucial for achieving realistic behavior. In earlier work by Schmidt et al. [J. Acoust. Soc. Am. 129, 2168-2180 (2011)], the authors presented an approach in which material parameters of a static numerical vocal fold model were optimized to achieve an agreement of the displacement field with data retrieved from hemilarynx experiments. This method is now generalized to a fully transient setting. Moreover in addition to the material parameters, the extended approach is capable of finding optimized layer geometries. Depending on chosen material restriction, significant modifications of the reference geometry are predicted. The additional flexibility in the design space leads to a significantly more realistic deformation behavior. At the same time, the predicted biomechanical and geometrical results are still feasible for manufacturing physical vocal fold models consisting of several silicone layers. As a consequence, the proposed combined experimental and numerical method is suited to guide the construction of physical vocal fold models.

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

PubMed Central

Galindo, Gabriel E.; Peterson, Sean D.; Erath, Byron D.; Castro, Christian; Hillman, Robert E.

2017-01-01

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. PMID:28837719

Anatomical study of minor alterations in neonate vocal folds.

PubMed

Silva, Adriano Rezende; Machado, Almiro José; Crespo, Agrício Nubiato

2014-01-01

Minor structural alterations of the vocal fold cover are frequent causes of voice abnormalities. They may be difficult to diagnose, and are expressed in different manners. Cases of intracordal cysts, sulcus vocalis, mucosal bridge, and laryngeal micro-diaphragm form the group of minor structural alterations of the vocal fold cover investigated in the present study. The etiopathogenesis and epidemiology of these alterations are poorly known. To evaluate the existence and anatomical characterization of minor structural alterations in the vocal folds of newborns. 56 larynxes excised from neonates of both genders were studied. They were examined fresh, or defrosted after conservation via freezing, under a microscope at magnifications of 25× and 40×. The vocal folds were inspected and palpated by two examiners, with the aim of finding minor structural alterations similar to those described classically, and other undetermined minor structural alterations. Larynges presenting abnormalities were submitted to histological examination. Six cases of abnormalities were found in different larynges: one (1.79%) compatible with a sulcus vocalis and five (8.93%) compatible with a laryngeal micro-diaphragm. No cases of cysts or mucosal bridges were found. The observed abnormalities had characteristics similar to those described in other age groups. Abnormalities similar to sulcus vocalis or micro-diaphragm may be present at birth. Copyright © 2014 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

In Vivo Measurement of Pediatric Vocal Fold Motion Using Structured Light Laser Projection

PubMed Central

Patel, Rita R.; Donohue, Kevin D.; Lau, Daniel; Unnikrishnan, Harikrishnan

2013-01-01

Summary Objective The aim of the study was to present the development of a miniature structured light laser projection endoscope and to quantify vocal fold length and vibratory features related to impact stress of the pediatric glottis using high-speed imaging. Study Design The custom-developed laser projection system consists of a green laser with a 4-mm diameter optics module at the tip of the endoscope, projecting 20 vertical laser lines on the glottis. Measurements of absolute phonatory vocal fold length, membranous vocal fold length, peak amplitude, amplitude-to-length ratio, average closing velocity, and impact velocity were obtained in five children (6–9 years), two adult male and three adult female participants without voice disorders, and one child (10 years) with bilateral vocal fold nodules during modal phonation. Results Independent measurements made on the glottal length of a vocal fold phantom demonstrated a 0.13 mm bias error with a standard deviation of 0.23 mm, indicating adequate precision and accuracy for measuring vocal fold structures and displacement. First, in vivo measurements of amplitude-to-length ratio, peak closing velocity, and impact velocity during phonation in pediatric population and a child with vocal fold nodules are reported. Conclusion The proposed laser projection system can be used to obtain in vivo measurements of absolute length and vibratory features in children and adults. Children have large amplitude-to-length ratio compared with typically developing adults, whereas nodules result in larger peak amplitude, amplitude-to-length ratio, average closing velocity, and impact velocity compared with typically developing children. PMID:23809569

[Vascular Lesions of Vocal Folds - Part 2: Perpendicular Vascular Lesions].

PubMed

Arens, C; Glanz, H; Voigt-Zimmermann, S

2015-11-01

The present work aims at a systematic pathogenetic description of perpendicular vascular changes in the vocal folds. Unlike longitudinal vascular changes, like ectasia and meander, perpendicular vascular changes can be observed in bening lesions. They predominantly occur as typical vascular loops in exophytic lesions, especially in recurrent respiratory papillomatosis (RRP), pre-cancerous and cancerous diseases of the larynx and vocal folds. Neoangiogenesis is caused by an epithelial growth stimulus in the early phase of cancerous genesis. In RRP the VVC impress by a single, long vessel loop with a narrow angle turning point in the each single papilla of the papilloma. In pre- and cancerous lesions the vascular loop is located directly underneath the epithelium. During progressive tumor growth, vascular loops develop an increasingly irregular, convoluted, spirally shape. The arrangement of the vascular loops is primarily still symmetrical. In the preliminary stage of tumor development occurs by neoangiogenesis to a microvascular compression. In advanced vocal fold carcinoma the regular vascular vocal fold structure is destroyed. The various stages of tumor growth are also characterized by typical primary epithelial and secondary connective tissue changes. The characteristic triad of vascular, epithelial and connective tissue changes therefore plays an important role in differential diagnosis. © Georg Thieme Verlag KG Stuttgart · New York.

Jugular vein phlebectasia in paediatric patients with vocal fold nodules.

PubMed

Liu, Xiang; Sun, Chang-zhi; Zou, Hua; Luo, Ren-zhong

2013-08-01

Jugular vein phlebectasia (JVP) may often be overlooked in clinical practice and the management for JVP include surgery and a conservative approach. We have studied the relationship between JVP and vocal fold nodules in paediatric patients as well as the effects of treatment. Twenty-three cases of paediatric vocal fold nodules with JVP were studied. All patients received voice therapy. After 6 months of treatment, hoarseness, neck appearance (subjective evaluation) and the degree of dilation of the jugular vein detected by Doppler ultrasonography were analysed. The follow-up period was 6 to 84 months. The hoarseness disappeared or lessened noticeably after treatment for 1-4 months. The neck masses also lessened (pre vs. post: 2.58 ± 0.40 vs. 1.60 ± 0.19) after treatment for 1-4 months. The visual analogue score of the post-treatment symptoms decreased significantly compared with pre-treatment (p <0.05). The degree of dilation of the post-treatment jugular vein also decreased significantly (p <0.05). Paediatric vocal fold nodules may be related to JVP. Voice changes may also be observed in cases of paediatric JVP. Voice therapy may offer another conservative treatment option for JVP accompanied by vocal fold nodules, and it may offer better results than simple observation of JVP.

Empirical Measurements of Biomechanical Anisotropy of the Human Vocal Fold Lamina Propria

PubMed Central

Kelleher, Jordan E.; Siegmund, Thomas; Du, Mindy; Naseri, Elhum; Chan, Roger W.

2013-01-01

The vocal folds are known to be mechanically anisotropic due to the microstructural arrangement of fibrous proteins such as collagen and elastin in the lamina propria. Even though this has been known for many years, the biomechanical anisotropic properties have rarely been experimentally studied. We propose that an indentation procedure can be used with uniaxial tension in order to obtain an estimate of the biomechanical anisotropy within a single specimen. Experiments were performed on the lamina propria of three male and three female human vocal folds dissected from excised larynges. Two experiments were conducted: each specimen was subjected to cyclic uniaxial tensile loading in the longitudinal (i.e. anterior-posterior) direction, and then to cyclic indentation loading in the transverse (i.e. medial-lateral) direction. The indentation experiment was modeled as contact on a transversely isotropic half-space using the Barnett-Lothe tensors. The longitudinal elastic modulus EL was computed from the tensile test, and the transverse elastic modulus ET and longitudinal shear modulus GL were obtained by inverse analysis of the indentation force-displacement response. It was discovered that the average of EL/ET was 14 for the vocal ligament and 39 for the vocal fold cover specimens. Also, the average of EL/GL, a parameter important for models of phonation, was 28 for the vocal ligament and 54 for the vocal fold cover specimens. These measurements of anisotropy could contribute to more accurate models of fundamental frequency regulation and provide potentially better insights into the mechanics of vocal fold vibration. PMID:22886592

Quantification of change in vocal fold tissue stiffness relative to depth of artificial damage.

PubMed

Rohlfs, Anna-Katharina; Schmolke, Sebastian; Clauditz, Till; Hess, Markus; Müller, Frank; Püschel, Klaus; Roemer, Frank W; Schumacher, Udo; Goodyer, Eric

2017-10-01

To quantify changes in the biomechanical properties of human excised vocal folds with defined artificial damage. The linear skin rheometer (LSR) was used to obtain a series of rheological measurements of shear modulus from the surface of 30 human cadaver vocal folds. The tissue samples were initially measured in a native condition and then following varying intensities of thermal damage. Histological examination of each vocal fold was used to determine the depth of artificial alteration. The measured changes in stiffness were correlated with the depth of cell damage. For vocal folds in a pre-damage state the shear modulus values ranged from 537 Pa to 1,651 Pa (female) and from 583 Pa to 1,193 Pa (male). With increasing depth of damage from the intermediate layer of the lamina propria (LP), tissue stiffness increased consistently (compared with native values) following application of thermal damage to the vocal folds. The measurement showed an increase of tissue stiffness when the depth of tissue damage was extending from the intermediate LP layer downwards. Changes in the elastic characteristics of human vocal fold tissue following damage at defined depths were demonstrated in an in vitro experiment. In future, reproducible in vivo measurements of elastic vocal fold tissue alterations may enable phonosurgeons to infer the extent of subepithelial damage from changes in surface elasticity.

Mesenchymal Stem Cell Therapy for the Treatment of Vocal Fold Scarring: A Systematic Review of Preclinical Studies

PubMed Central

Wingstrand, Vibe Lindeblad; Jensen, David H.; Bork, Kristian; Sebbesen, Lars; Balle, Jesper; Fischer-Nielsen, Anne; von Buchwald, Christian

2016-01-01

Objectives Therapy with mesenchymal stem cells exhibits potential for the development of novel interventions for many diseases and injuries. The use of mesenchymal stem cells in regenerative therapy for vocal fold scarring exhibited promising results to reduce stiffness and enhance the biomechanical properties of injured vocal folds. This study evaluated the biomechanical effects of mesenchymal stem cell therapy for the treatment of vocal fold scarring. Data Sources PubMed, Embase, the Cochrane Library and Google Scholar were searched. Methods Controlled studies that assessed the biomechanical effects of mesenchymal stem cell therapy for the treatment of vocal fold scarring were included. Primary outcomes were viscoelastic properties and mucosal wave amplitude. Results Seven preclinical animal studies (n = 152 single vocal folds) were eligible for inclusion. Evaluation of viscoelastic parameters revealed a decreased dynamic viscosity (η’) and elastic modulus (G’), i.e., decreased resistance and stiffness, in scarred vocal folds treated with mesenchymal stem cells compared to non-treated scarred vocal folds. Mucosal wave amplitude was increased in scarred vocal folds treated with mesenchymal stem cells vs. non-treated scarred vocal folds. Conclusion The results from these studies suggest an increased regenerative effect of therapy with mesenchymal stem cells for scarred vocal folds and are encouraging for further clinical studies. PMID:27631373

Mesenchymal Stem Cell Therapy for the Treatment of Vocal Fold Scarring: A Systematic Review of Preclinical Studies.

PubMed

Wingstrand, Vibe Lindeblad; Grønhøj Larsen, Christian; Jensen, David H; Bork, Kristian; Sebbesen, Lars; Balle, Jesper; Fischer-Nielsen, Anne; von Buchwald, Christian

2016-01-01

Therapy with mesenchymal stem cells exhibits potential for the development of novel interventions for many diseases and injuries. The use of mesenchymal stem cells in regenerative therapy for vocal fold scarring exhibited promising results to reduce stiffness and enhance the biomechanical properties of injured vocal folds. This study evaluated the biomechanical effects of mesenchymal stem cell therapy for the treatment of vocal fold scarring. PubMed, Embase, the Cochrane Library and Google Scholar were searched. Controlled studies that assessed the biomechanical effects of mesenchymal stem cell therapy for the treatment of vocal fold scarring were included. Primary outcomes were viscoelastic properties and mucosal wave amplitude. Seven preclinical animal studies (n = 152 single vocal folds) were eligible for inclusion. Evaluation of viscoelastic parameters revealed a decreased dynamic viscosity (η') and elastic modulus (G'), i.e., decreased resistance and stiffness, in scarred vocal folds treated with mesenchymal stem cells compared to non-treated scarred vocal folds. Mucosal wave amplitude was increased in scarred vocal folds treated with mesenchymal stem cells vs. non-treated scarred vocal folds. The results from these studies suggest an increased regenerative effect of therapy with mesenchymal stem cells for scarred vocal folds and are encouraging for further clinical studies.

Nonlinear viscoelastic characterization of human vocal fold tissues under large-amplitude oscillatory shear (LAOS)

PubMed Central

Chan, Roger W.

2018-01-01

Viscoelastic shear properties of human vocal fold tissues were previously quantified by the shear moduli (G′ and G″). Yet these small-strain linear measures were unable to describe any nonlinear tissue behavior. This study attempted to characterize the nonlinear viscoelastic response of the vocal fold lamina propria under large-amplitude oscillatory shear (LAOS) with a stress decomposition approach. Human vocal fold cover and vocal ligament specimens from eight subjects were subjected to LAOS rheometric testing with a simple-shear rheometer. The empirical total stress response was decomposed into elastic and viscous stress components, based on odd-integer harmonic decomposition approach with Fourier transform. Nonlinear viscoelastic measures derived from the decomposition were plotted in Pipkin space and as rheological fingerprints to observe the onset of nonlinearity and the type of nonlinear behavior. Results showed that both the vocal fold cover and the vocal ligament experienced intercycle strain softening, intracycle strain stiffening, as well as shear thinning both intercycle and intracycle. The vocal ligament appeared to demonstrate an earlier onset of nonlinearity at phonatory frequencies, and higher sensitivity to changes in frequency and strain. In summary, the stress decomposition approach provided much better insights into the nonlinear viscoelastic behavior of the vocal fold lamina propria than the traditional linear measures. PMID:29780189

Nonlinear viscoelastic characterization of human vocal fold tissues under large-amplitude oscillatory shear (LAOS).

PubMed

Chan, Roger W

2018-05-01

Viscoelastic shear properties of human vocal fold tissues were previously quantified by the shear moduli ( G' and G″ ). Yet these small-strain linear measures were unable to describe any nonlinear tissue behavior. This study attempted to characterize the nonlinear viscoelastic response of the vocal fold lamina propria under large-amplitude oscillatory shear (LAOS) with a stress decomposition approach. Human vocal fold cover and vocal ligament specimens from eight subjects were subjected to LAOS rheometric testing with a simple-shear rheometer. The empirical total stress response was decomposed into elastic and viscous stress components, based on odd-integer harmonic decomposition approach with Fourier transform. Nonlinear viscoelastic measures derived from the decomposition were plotted in Pipkin space and as rheological fingerprints to observe the onset of nonlinearity and the type of nonlinear behavior. Results showed that both the vocal fold cover and the vocal ligament experienced intercycle strain softening, intracycle strain stiffening, as well as shear thinning both intercycle and intracycle. The vocal ligament appeared to demonstrate an earlier onset of nonlinearity at phonatory frequencies, and higher sensitivity to changes in frequency and strain. In summary, the stress decomposition approach provided much better insights into the nonlinear viscoelastic behavior of the vocal fold lamina propria than the traditional linear measures.

Time-Varying Vocal Folds Vibration Detection Using a 24 GHz Portable Auditory Radar

PubMed Central

Hong, Hong; Zhao, Heng; Peng, Zhengyu; Li, Hui; Gu, Chen; Li, Changzhi; Zhu, Xiaohua

2016-01-01

Time-varying vocal folds vibration information is of crucial importance in speech processing, and the traditional devices to acquire speech signals are easily smeared by the high background noise and voice interference. In this paper, we present a non-acoustic way to capture the human vocal folds vibration using a 24-GHz portable auditory radar. Since the vocal folds vibration only reaches several millimeters, the high operating frequency and the 4 × 4 array antennas are applied to achieve the high sensitivity. The Variational Mode Decomposition (VMD) based algorithm is proposed to decompose the radar-detected auditory signal into a sequence of intrinsic modes firstly, and then, extract the time-varying vocal folds vibration frequency from the corresponding mode. Feasibility demonstration, evaluation, and comparison are conducted with tonal and non-tonal languages, and the low relative errors show a high consistency between the radar-detected auditory time-varying vocal folds vibration and acoustic fundamental frequency, except that the auditory radar significantly improves the frequency-resolving power. PMID:27483261

Characterization of vocal fold scar formation, prophylaxis, and treatment using animal models.

PubMed

Bless, Diane M; Welham, Nathan V

2010-12-01

To review recent literature on animal models used to study the pathogenesis, detection, prevention, and treatment of vocal fold scarring. Animal work is critical to studying vocal fold scarring because it is the only way to conduct systematic research on the biomechanical properties of the layered structure of the vocal fold lamina propria, and therefore develop reliable prevention and treatment strategies for this complex clinical problem. During the period of review, critical anatomic, physiologic, and wound healing characteristics, which may serve as the bases for selection of a certain species to help answer a specific question, have been described in mouse, rat, rabbit, ferret, and canine models. A number of different strategies for prophylaxis and chronic scar treatment in animals show promise for clinical application. The pathways of scar formation and methods for quantifying treatment-induced change have become better defined. Recent animal vocal fold scarring studies have enriched and confirmed earlier work indicating that restoring pliability to the scarred vocal fold mucosa is challenging but achievable. Differences between animal models and differences in outcome measurements across studies necessitate considering each study individually to obtain guidance for future research. With increased standardization of measurement techniques it may be possible to make more inter-study comparisons.

Evaluation of the Grafted Fascia in the Vocal Fold of Dogs: A Histologic Study.

PubMed

Carvalho, Eduardo G B; Pauna, Henrique F; Machado, Almiro J; Nicola, Ester M D; Altemani, Albina M A M; Crespo, Agrício N

2017-09-01

There is no consensus on the ideal graft for medialization surgery of the vocal folds in the literature. One of the most favorable proposals is the use of autologous fascia, which seems limited by the lack of information regarding the integration of grafted tissue. Our study aims to evaluate the degree of fully engrafted fascia integration in the vocal fold lamina propria of dogs. Fourteen adult mongrel dogs that underwent intravenous general anesthesia were selected and kept under spontaneous ventilation. A fascia lata fragment of 4 cm 2 was obtained from the right leg of each dog. The dogs underwent laryngoscopy; a 3 mm incision was made in the vocal process, next to the vestibular process, and the fascia was grafted into the right vocal fold. The left vocal fold was used as a control. The animals were divided into two groups: group A, evaluated after 2 months of the procedure, and group B, evaluated after 6 months of the procedure. Histologic analysis was made semiquantitatively regarding the presence of inflammatory reaction, fibrosis, and neovascularization. Our final studied group comprised 12 dogs. Microscopic examination of the larynx revealed the absence of any detectable inflammation in the incision site. The lamina propria of the grafted vocal fold showed identifiable compact, thick, and eosinophilic collagen bands. The surrounding tissue showed thin collagen bands with some organization, similar to the contralateral vocal fold. The grafted fascia integrates into the vocal fold lamina propria and seems not to cause inflammatory reaction response. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Measurement of the viscoelastic properties of the vocal folds.

PubMed

Wiikmann, Christian; da Silva, Marcelo Alves; Arêas, Elizabeth Pinheiro Gomes; Tsuji, Domingos Hiroshi; Sennes, Luiz Ubirajara

2009-06-01

Studies of the viscoelastic properties of the vocal folds are normally performed with rheometers that use parallel plates whose interplate space is usually arbitrarily assigned a fixed value. In tissues subject to variation of thickness between samples, fixed gaps could result in different compressions, compromising the comparison among them. We performed an experimental study to determine whether different compressions can lead to different results in measurements of dynamic viscosity (DV) of vocal fold samples. We measured the DV of vocal fold samples of 10 larynges of cadavers under 3 different compression levels, corresponding to 0.2, 0.5, and 10 N on an 8-mm-diameter parallel-plate rheometer. The DV directly varied with compression. We observed statistically significant differences between the results of 0.2 and 10 N (p = 0.0396) and 0.5 and 10 N (p = 0.0442). The study demonstrated that the level of compression influences the DV measure and suggests that a defined compression level should be used in rheometric studies of biological tissues.

Effects of mucosal loading on vocal fold vibration.

PubMed

Tao, Chao; Jiang, Jack J

2009-06-01

A chain model was proposed in this study to examine the effects of mucosal loading on vocal fold vibration. Mucosal loading was defined as the loading caused by the interaction between the vocal folds and the surrounding tissue. In the proposed model, the vocal folds and the surrounding tissue were represented by a series of oscillators connected by a coupling spring. The lumped masses, springs, and dampers of the oscillators modeled the tissue properties of mass, stiffness, and viscosity, respectively. The coupling spring exemplified the tissue interactions. By numerically solving this chain model, the effects of mucosal loading on the phonation threshold pressure, phonation instability pressure, and energy distribution in a voice production system were studied. It was found that when mucosal loading is small, phonation threshold pressure increases with the damping constant R(r), the mass constant R(m), and the coupling constant R(mu) of mucosal loading but decreases with the stiffness constant R(k). Phonation instability pressure is also related to mucosal loading. It was found that phonation instability pressure increases with the coupling constant R(mu) but decreases with the stiffness constant R(k) of mucosal loading. Therefore, it was concluded that mucosal loading directly affects voice production.

Vocal fold fixation caused by penetration of a high-velocity steel projectile.

PubMed

Guo, Chau-Shiang; Ho, Chi-Kung; Hsu, Ruey-Fen

2014-01-01

Vocal fold fixation as a result of trauma caused by a foreign body is rare. We report a unique case of vocal fold fixation caused by traumatic penetration of a shard of steel in a 31-year-old steelworker. While the patient was at work, an airborne projectile suddenly pierced his neck and entered his larynx, causing progressive hoarseness and dyspnea. Flexible laryngoscopy detected no obvious foreign body, but it did reveal that the right vocal fold had become immobile. Computed tomography revealed that a 2.5-cm sliver of steel had become impacted in the right cricoarytenoid joint, which made the arytenoid cartilage unable to rotate. An emergency tracheostomy was performed with local anesthesia to construct a functioning airway, and then rigid laryngoscopy was performed with general anesthesia. The foreign body was removed with the assistance of a microscope and microscissors. Postoperatively, the patient immediately regained control of his right vocal fold, and he experienced no permanent injury.

Effects of poroelastic coefficients on normal vibration modes in vocal-fold tissues.

PubMed

Tao, Chao; Liu, Xiaojun

2011-02-01

The vocal-fold tissue is treated as a transversally isotropic fluid-saturated porous material. Effects of poroelastic coefficients on eigenfrequencies and eigenmodes of the vocal-fold vibration are investigated using the Ritz method. The study demonstrates that the often-used elastic model is only a particular case of the poroelastic model with an infinite fluid-solid mass coupling parameter. The elastic model may be considered appropriate for the vocal-fold tissue when the absolute value of the fluid-solid mass coupling parameter is larger than 10(5) kg/m(3). Otherwise, the poroelastic model may be more accurate. The degree of compressibility of the vocal tissue can also been described by the poroelastic coefficients. Finally, it is revealed that the liquid and solid components in a poroelastic model could have different modal shapes when the coupling between them is weak. The mode decoupling could cause desynchronization and irregular vibration of the folds.

Videostrobolaryngoscopy of mucus layer during vocal fold vibration in patients with laryngeal tension-fatigue syndrome.

PubMed

Hsiao, Tzu-Yu; Liu, Chia-Ming; Lin, Kai-Nan

2002-06-01

The mucus layer on the vocal folds was examined by videostrobolaryngoscopy in patients with laryngeal tension-fatigue syndrome, a chronic functional dysphonia due to vocal abuse and misuse. Besides the findings in previous reports (such as abnormal glottal closure, phase or amplitude asymmetry, and the irregular mucosal wave), the vocal folds during vibration had an uneven mucus surface. The occurrence of an uneven mucus layer on vocal folds was significantly greater in subjects with this voice disorder (83% or 250 of 301 patients in this series) than in those without voice disorders (18.5% or 5 of 27). The increase of mucus viscosity, mucus aggregation, and the formation of rough surfaces on the vocal folds alter the mechanical properties that contribute to vibration of the cover of the vocal folds, and thereby worsen the symptoms of dysphonia in patients with laryngeal tension-fatigue syndrome.

Experimental and Theoretical Investigations of Phonation Threshold Pressure as a Function of Vocal Fold Elongation

PubMed Central

Tao, Chao; Regner, Michael F.; Zhang, Yu; Jiang, Jack J.

2014-01-01

Summary The relationship between the vocal fold elongation and the phonation threshold pressure (PTP) was experimentally and theoretically investigated. The PTP values of seventeen excised canine larynges with 0% to 15% bilateral vocal fold elongations in 5% elongation steps were measured using an excised larynx phonation system. It was found that twelve larynges exhibited a monotonic relationship between PTP and elongation; in these larynges, the 0% elongation condition had the lowest PTP. Five larynges exhibited a PTP minimum at 5% elongation. To provide a theoretical explanation of these phenomena, a two-mass model was modified to simulate vibration of the elongated vocal folds. Two pairs of longitudinal springs were used to represent the longitudinal elastin in the vocal folds. This model showed that when the vocal folds were elongated, the increased longitudinal tension would increase the PTP value and the increased vocal fold length would decrease the PTP value. The antagonistic effects contributed by these two factors were found to be able to cause either a monotonic or a non-monotonic relationship between PTP and elongation, which were consistent with experimental observations. Because PTP describes the ease of phonation, this study suggests that there may exist a nonzero optimal vocal fold elongation for the greatest ease for phonation in some larynges. PMID:25530744

Retention of Human-Induced Pluripotent Stem Cells (hiPS) With Injectable HA Hydrogels for Vocal Fold Engineering.

PubMed

Imaizumi, Mitsuyoshi; Li-Jessen, Nicole Y K; Sato, Yuka; Yang, David T; Thibeault, Susan L

2017-04-01

One prospective treatment option for vocal fold scarring is regeneration with an engineered scaffold containing induced pluripotent stem cells (iPS). In the present study, we investigated the feasibility of utilizing an injectable hyaluronic acid (HA) scaffold encapsulated with human-iPS cell (hiPS) for regeneration of vocal folds. Thirty athymic nude rats underwent unilateral vocal fold injury. Contralateral vocal folds served as uninjured controls. Hyaluronic acid hydrogel scaffold, HA hydrogel scaffold containing hiPS, and HA hydrogel scaffold containing hiPS with epidermal growth factor (EGF) were injected in both vocal folds immediately after surgery. One and 2 weeks after injection, larynges were excised for histology, immunohistochemistry, and fluorescence in situ hybridization (FISH). Presence of HA hydrogel was confirmed in vocal folds 1 and 2 weeks post injection. The FISH analysis confirmed the presence and viability of hiPS in the injected vocal folds. Histological results demonstrated that vocal folds injected with HA hydrogel scaffold containing EGF demonstrated less fibrosis than those with HA hydrogel only. Human-iPS survived in injured rat vocal folds. The HA hydrogel with hiPS and EGF ameliorated the fibrotic response. Additional work is necessary to optimize hiPS differentiation and further confirm the safety of hiPS for clinical applications.

[Case-control survey on risk factors of benign vocal fold lesions].

PubMed

Huang, Dong-Yan; Yang, Wei-Yan; Yu, Ping; He, Yao; Han, Dong-Yi

2008-02-01

To investigate the risk factors that may relate with benign vocal fold lesions including vocal fold nodule, vocal fold polyp, chronic laryngitis and Reinke's edema In present series, 321 cases who were performed laryngoscope were invited to participate the survey. Among them 168 cases with benign vocal fold lesions composed the case group. Another 153 cases with normal larynx composed the control group. Each case were undertook the same questionnaire. Logistic regression analysis was preformed to investigate the possible risk factors. The result demonstrated the occurring of benign vocal fold lesions positively correlated to five factors, including occupation, work or residence environment noise, alcohol-consuming, voice-using hours per day and abuse of voice. Occupations with intensive voice-use were more vulnerable to developing these disorders. Occurring risk of occupations type II with moderate voice-use was 1.934 times than that of occupations type I with lesser voice-use (OR = 1.934). And risk of occupations type III with upper voice-use was 2.633 times than that of type I. Risk raised 1.302 times with each more hour of voice use per day. OR of the following factors of voice abuse, environment noise, alcohol-consuming was 4.744, 2.115 and 2.177, respectively. The result suggested that people should abstain from alcohol, lowering the environment noise, prevent overuse and abuse of voice in order to decrease the prevalence of these disorders, which is especially important for the professional voice users, e. g. teachers or managers. The essential therapy for these disorders is to correct bad phonation habits.

Altered vocal fold kinematics in synthetic self-oscillating models that employ adipose tissue as a lateral boundary condition.

NASA Astrophysics Data System (ADS)

Saidi, Hiba; Erath, Byron D.

2015-11-01

The vocal folds play a major role in human communication by initiating voiced sound production. During voiced speech, the vocal folds are set into sustained vibrations. Synthetic self-oscillating vocal fold models are regularly employed to gain insight into flow-structure interactions governing the phonation process. Commonly, a fixed boundary condition is applied to the lateral, anterior, and posterior sides of the synthetic vocal fold models. However, physiological observations reveal the presence of adipose tissue on the lateral surface between the thyroid cartilage and the vocal folds. The goal of this study is to investigate the influence of including this substrate layer of adipose tissue on the dynamics of phonation. For a more realistic representation of the human vocal folds, synthetic multi-layer vocal fold models have been fabricated and tested while including a soft lateral layer representative of adipose tissue. Phonation parameters have been collected and are compared to those of the standard vocal fold models. Results show that vocal fold kinematics are affected by adding the adipose tissue layer as a new boundary condition.

Effects of dehydration on the viscoelastic properties of vocal folds in large deformations.

PubMed

Miri, Amir K; Barthelat, François; Mongeau, Luc

2012-11-01

Dehydration may alter vocal fold viscoelastic properties, thereby hampering phonation. The effects of water loss induced by an osmotic pressure potential on vocal fold tissue viscoelastic properties were investigated. Porcine vocal folds were dehydrated by immersion in a hypertonic solution, and quasi-static and low-frequency dynamic traction tests were performed for elongations of up to 50%. Digital image correlation was used to determine local strains from surface deformations. The elastic modulus and the loss factor were then determined for normal and dehydrated tissues. An eight-chain hyperelastic model was used to describe the observed nonlinear stress-stretch behavior. Contrary to the expectations, the mass history indicated that the tissue absorbed water during cyclic extension when submerged in a hypertonic solution. During loading history, the elastic modulus was increased for dehydrated tissues as a function of strain. The response of dehydrated tissues was much less affected when the load was released. This observation suggests that hydration should be considered in micromechanical models of the vocal folds. The internal hysteresis, which is often linked to phonation effort, increased significantly with water loss. The effects of dehydration on the viscoelastic properties of vocal fold tissue were quantified in a systematic way. A better understanding of the role of hydration on the mechanical properties of vocal fold tissue may help to establish objective dehydration and phonotrauma criteria. Copyright © 2012 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

Performance of a reduced-order FSI model for flow-induced vocal fold vibration

NASA Astrophysics Data System (ADS)

Chang, Siyuan; Luo, Haoxiang; Luo's lab Team

2016-11-01

Vocal fold vibration during speech production involves a three-dimensional unsteady glottal jet flow and three-dimensional nonlinear tissue mechanics. A full 3D fluid-structure interaction (FSI) model is computationally expensive even though it provides most accurate information about the system. On the other hand, an efficient reduced-order FSI model is useful for fast simulation and analysis of the vocal fold dynamics, which is often needed in procedures such as optimization and parameter estimation. In this work, we study the performance of a reduced-order model as compared with the corresponding full 3D model in terms of its accuracy in predicting the vibration frequency and deformation mode. In the reduced-order model, we use a 1D flow model coupled with a 3D tissue model. Two different hyperelastic tissue behaviors are assumed. In addition, the vocal fold thickness and subglottal pressure are varied for systematic comparison. The result shows that the reduced-order model provides consistent predictions as the full 3D model across different tissue material assumptions and subglottal pressures. However, the vocal fold thickness has most effect on the model accuracy, especially when the vocal fold is thin. Supported by the NSF.

Influence of Left-Right Asymmetries on Voice Quality in Simulated Paramedian Vocal Fold Paralysis

ERIC Educational Resources Information Center

Samlan, Robin A.; Story, Brad H.

2017-01-01

Purpose: The purpose of this study was to determine the vocal fold structural and vibratory symmetries that are important to vocal function and voice quality in a simulated paramedian vocal fold paralysis. Method: A computational kinematic speech production model was used to simulate an exemplar "voice" on the basis of asymmetric…

Bilateral Vocal Fold Paralysis After Surgery Immediately in Adult Patient With Chiari Malformation.

PubMed

Chen, Yan; Yue, Jianhong; Yuan, Weixiu

2016-06-01

The authors report the case of a 50-year-old woman with a bilateral vocal fold paralysis after foramen magnum decompression and resection of partial cerebellar tonsil for Chiari malformation. The possible mechanisms of postoperative bilateral vocal fold paralysis are discussed.

Pipette aspiration applied to the characterization of nonhomogeneous, transversely isotropic materials used for vocal fold modeling.

PubMed

Weiß, S; Thomson, S L; Lerch, R; Döllinger, M; Sutor, A

2013-01-01

The etiology and treatment of voice disorders are still not completely understood. Since the vibratory characteristics of vocal folds are strongly influenced by both anatomy and mechanical material properties, measurement methods to analyze the material behavior of vocal fold tissue are required. Due to the limited life time of real tissue in the laboratory, synthetic models are often used to study vocal fold vibrations. In this paper we focus on two topics related to synthetic and real vocal fold materials. First, because certain tissues within the human vocal folds are transversely isotropic, a fabrication process for introducing this characteristic in commonly used vocal fold modeling materials is presented. Second, the pipette aspiration technique is applied to the characterization of these materials. By measuring the displacement profiles of stretched specimens that exhibit varying degrees of transverse isotropy, it is shown that local anisotropy can be quantified using a parameter describing the deviation from an axisymmetric profile. The potential for this technique to characterize homogeneous, anisotropic materials, including soft biological tissues such as those found in the human vocal folds, is supplemented by a computational study. Copyright © 2012 Elsevier Ltd. All rights reserved.

Quantitative Study of Vibrational Symmetry of Injured Vocal Folds via Digital Kymography in Excised Canine Larynges

ERIC Educational Resources Information Center

Krausert, Christopher R.; Ying, Di; Zhang, Yu; Jiang, Jack J.

2011-01-01

Purpose: Digital kymography and vocal fold curve fitting are blended with detailed symmetry analysis of kymograms to provide a comprehensive characterization of the vibratory properties of injured vocal folds. Method: Vocal fold vibration of 12 excised canine larynges was recorded under uninjured, unilaterally injured, and bilaterally injured…

Life Experience of Patients With Unilateral Vocal Fold Paralysis.

PubMed

Francis, David O; Sherman, Ariel E; Hovis, Kristen L; Bonnet, Kemberlee; Schlundt, David; Garrett, C Gaelyn; Davies, Louise

2018-05-01

Clinicians and patients benefit when they have a clear understanding of how medical conditions influence patients' life experiences. Patients' perspectives on life with unilateral vocal fold paralysis have not been well described. To promote patient-centered care by characterizing the patient experiences of living with unilateral vocal fold paralysis. This study used mixed methods: surveys using the voice and dysphagia handicap indexes (VHI and DHI) and semistructured interviews with adults with unilateral vocal cord paralysis recruited from a tertiary voice center. Recorded interviews were transcribed, coded using a hierarchical coding system, and analyzed using an iterative inductive-deductive approach. Symptom domains of the patient experience. In 36 patients (26 [72%] were female, and the median age and interquartile range [IQR] were 63 years [48-68 years]; median interview duration, 42 minutes), median VHI and DHI scores were 96 (IQR, 77-108) and 55.5 (IQR, 35-89) at the time of interviews, respectively. Frustration, isolation, fear, and altered self-identity were primary themes permeating patients' experiences. Frustrations related to limitations in communication, employment, and the medical system. Sources of fear included a loss of control, fear of further dysfunction or permanent disability, concern for health consequences (eg, aspiration pneumonia), and/or an inability to call for help in emergency situations. These experiences were modified by the following factors: resilience, self-efficacy, perceived sense of control, and social support systems. Effects of unilateral vocal fold paralysis extend beyond impaired voice and other somatic symptoms. Awareness of the extent to which these patients experience frustration, isolation, fear, and altered self-identity is important. A patient-centered approach to optimizing unilateral vocal fold paralysis treatment is enhanced by an understanding of both the physical dimension of this condition and how patients

Change to earlier surgical interventions: contemporary management of unilateral vocal fold paralysis.

PubMed

Costello, Declan

2015-06-01

The management of unilateral vocal fold paralysis has undergone significant changes in the last 2 decades. This has largely been made possible by advances in endoscope technology and new injectable materials. This article will cover the main changes in management of patients with unilateral vocal fold paralysis and summarize the recent literature in relation to early intervention in this group. Several recent studies have suggested that early vocal fold injection medialization reduces the likelihood of needing open laryngeal framework surgery in future. Early injection medialization appears to give good long-term results with few complications and minimizes the need for future laryngeal framework surgery. It should be considered in centres wherein the equipment and trained staff are available.

A budget of energy transfer in a sustained vocal folds vibration in glottis

NASA Astrophysics Data System (ADS)

Zhang, Lucy; Yang, Jubiao; Krane, Michael

2016-11-01

A set of force and energy balance equations using the control volume approach is derived based on the first principles of physics for a sustained vocal folds vibration in glottis. The control volume analysis is done for compressible airflow in a moving and deforming control volume in the vicinity of the vocal folds. The interaction between laryngeal airflow and vocal folds are successfully simulated using the modified Immersed Finite Element Method (mIFEM), a fully coupled approach to simulate fluid-structure interactions. Detailed mathematical terms are separated out for deeper physical understanding and utilization of mechanical energy is quantified with the derived equation. The results show that majority of energy input is consumed for driving laryngeal airflow, while a smaller portion is for compensating viscous losses in and sustaining the vibration of the vocal folds. We acknowledge the funding support of NIH 2R01DC005642-10A1.

Benign Rolandic epilepsy presenting like paradoxical vocal fold motion.

PubMed

Gross, Jennifer H; Bertrand, Mary; Hirose, Keiko

2017-11-01

Paradoxical vocal fold motion (PVFM) is characterized by vocal fold adduction during respiration. Benign Rolandic epilepsy (BRE) is the most common childhood epilepsy and can cause oropharyngolaryngeal or facial manifestations. A 9-year-old male presented with intermittent apnea lasting 30-60 seconds and presumed PVFM. The patient's physical and fiberoptic exam were normal. He was admitted and found to have episodes of oxygen desaturation, neck twitching, and tongue burning. An EEG revealed focal epilepsy. After starting anti-epileptic medications, he had resolution of symptoms. Our patient was eventually diagnosed with BRE, a focal onset epilepsy that can mimic primary otolaryngologic disease. Copyright © 2017 Elsevier B.V. All rights reserved.

Spatio-temporal analysis of irregular vocal fold oscillations: Biphonation due to desynchronization of spatial modes

NASA Astrophysics Data System (ADS)

Neubauer, Jürgen; Mergell, Patrick; Eysholdt, Ulrich; Herzel, Hanspeter

2001-12-01

This report is on direct observation and modal analysis of irregular spatio-temporal vibration patterns of vocal fold pathologies in vivo. The observed oscillation patterns are described quantitatively with multiline kymograms, spectral analysis, and spatio-temporal plots. The complex spatio-temporal vibration patterns are decomposed by empirical orthogonal functions into independent vibratory modes. It is shown quantitatively that biphonation can be induced either by left-right asymmetry or by desynchronized anterior-posterior vibratory modes, and the term ``AP (anterior-posterior) biphonation'' is introduced. The presented phonation examples show that for normal phonation the first two modes sufficiently explain the glottal dynamics. The spatio-temporal oscillation pattern associated with biphonation due to left-right asymmetry can be explained by the first three modes. Higher-order modes are required to describe the pattern for biphonation induced by anterior-posterior vibrations. Spatial irregularity is quantified by an entropy measure, which is significantly higher for irregular phonation than for normal phonation. Two asymmetry measures are introduced: the left-right asymmetry and the anterior-posterior asymmetry, as the ratios of the fundamental frequencies of left and right vocal fold and of anterior-posterior modes, respectively. These quantities clearly differentiate between left-right biphonation and anterior-posterior biphonation. This paper proposes methods to analyze quantitatively irregular vocal fold contour patterns in vivo and complements previous findings of desynchronization of vibration modes in computer modes and in in vitro experiments.

Current Treatment Options for Bilateral Vocal Fold Paralysis: A State-of-the-Art Review

PubMed Central

Li, Yike; Garrett, Gaelyn; Zealear, David

2017-01-01

Vocal fold paralysis (VFP) refers to neurological causes of reduced or absent movement of one or both vocal folds. Bilateral VFP (BVFP) is characterized by inspiratory dyspnea due to narrowing of the airway at the glottic level with both vocal folds assuming a paramedian position. The primary objective of intervention for BVFP is to relieve patients’ dyspnea. Common clinical options for management include tracheostomy, arytenoidectomy and cordotomy. Other options that have been used with varying success include reinnervation techniques and botulinum toxin (Botox) injections into the vocal fold adductors. More recently, research has focused on neuromodulation, laryngeal pacing, gene therapy, and stem cell therapy. These newer approaches have the potential advantage of avoiding damage to the voicing mechanism of the larynx with an added goal of restoring some physiologic movement of the affected vocal folds. However, clinical data are scarce for these new treatment options (i.e., reinnervation and pacing), so more investigative work is needed. These areas of research are expected to provide dramatic improvements in the treatment of BVFP. PMID:28669149

Pathogenesis of vocal fold nodules: new insights from a modelling approach.

PubMed

Dejonckere, Philippe H; Kob, Malte

2009-01-01

To give new insights into the pathogenesis of vocal fold nodules: (a) why the female/male ratio is so extreme, (b) how an hourglass-shaped vibration pattern - eliciting a localized microtrauma - originates, and (c) what the roles of muscular tension imbalance and of behavioral aspects are. Simulations with a 3-dimensional computer model of the vibrating vocal folds. (1) A slightly incomplete dorsal vocal fold adduction is a first condition for inducing an hourglass vibration pattern. (2) A limited collision zone is only possible with a small degree of curving of the rest position of the vocal fold edges in their ventral portion. This is an anatomical characteristic of the adult female larynx. Muscular fatigue and resulting hypotonia seem to enhance this curving. (3) If both these conditions are fulfilled, a sufficient vibration amplitude is required to achieve a localized impact. (4) This third condition can be obtained by an increased subglottal pressure and/or by a decrease in active stress of the tension forces between the neighboring vocalis masses. These last aspects incorporate muscular tension imbalance (dyskinesia) and behavioral aspects in the modelling process. Decrease in active stress is a possible effect of fatigue, and increase in subglottal pressure a result of effort compensation. Copyright 2009 S. Karger AG, Basel.

Human Adipose Tissue Derived Extracellular Matrix and Methylcellulose Hydrogels Augments and Regenerates the Paralyzed Vocal Fold

PubMed Central

Kim, Eun Na; Sung, Myung Whun; Kwon, Tack-Kyun; Cho, Yong Woo; Kwon, Seong Keun

2016-01-01

Vocal fold paralysis results from various etiologies and can induce voice changes, swallowing complications, and issues with aspiration. Vocal fold paralysis is typically managed using injection laryngoplasty with fat or synthetic polymers. Injection with autologous fat has shown excellent biocompatibility. However, it has several disadvantages such as unpredictable resorption rate, morbidities associated with liposuction procedure which has to be done in operating room under general anesthesia. Human adipose-derived extracellular matrix (ECM) grafts have been reported to form new adipose tissue and have greater biostability than autologous fat graft. Here, we present an injectable hydrogel that is constructed from adipose tissue derived soluble extracellular matrix (sECM) and methylcellulose (MC) for use in vocal fold augmentation. Human sECM derived from adipose tissue was extracted using two major steps—ECM was isolated from human adipose tissue and was subsequently solubilized. Injectable sECM/MC hydrogels were prepared by blending of sECM and MC. Sustained vocal fold augmentation and symmetric vocal fold vibration were accomplished by the sECM/MC hydrogel in paralyzed vocal fold which were confirmed by laryngoscope, histology and a high-speed imaging system. There were increased number of collagen fibers and fatty granules at the injection site without significant inflammation or fibrosis. Overall, these results indicate that the sECM/MC hydrogel can enhance vocal function in paralyzed vocal folds without early resorption and has potential as a promising material for injection laryngoplasty for stable vocal fold augmentation which can overcome the shortcomings of autologous fat such as unpredictable duration and morbidity associated with the fat harvest. PMID:27768757

Intraoperative laryngeal electromyography in children with vocal fold immobility: a simplified technique.

PubMed

Scott, Andrew R; Chong, Peter Siao Tick; Randolph, Gregory W; Hartnick, Christopher J

2008-01-01

The primary objective of this study was to determine whether a simplified technique for intraoperative laryngeal electromyography was feasible using standard nerve integrity monitoring electrodes and audiovisual digital recording equipment. Our secondary objective was to determine if laryngeal electromyography data provided any additional information that significantly influenced patient management. Between February 2006 and February 2007, 10 children referred to our institution with vocal fold immobility underwent intraoperative laryngeal electromyography of the thyroarytenoid muscles. A retrospective chart review of these 10 patients was performed after institutional review board approval. Standard nerve integrity monitoring electrodes can be used to perform intraoperative laryngeal electromyography of the thyroarytenoid muscles in children. In 5 of 10 cases reviewed, data from laryngeal electromyography recordings meaningfully influenced the care of children with vocal fold immobility and affected clinical decision-making, sometimes altering management strategies. In the remaining 5 children, data supported clinical impressions but did not alter treatment plans. Two children with idiopathic bilateral vocal fold paralysis initially presented with a lack of electrical activity on one or both sides but went on to develop motor unit action potentials that preceded recovery of motion in both vocal folds. Our findings suggest that standard nerve monitoring equipment can be used to perform intraoperative laryngeal electromyography and that electromyographic data can assist clinicians in the management of complex patients. Additionally, there may be a role for the use of serial intraoperative measurements in predicting recovery from vocal fold paralysis in the pediatric age group.

Destiny of autologous bone marrow-derived stromal cells implanted in the vocal fold.

PubMed

Kanemaru, Shin-ichi; Nakamura, Tatsuo; Yamashita, Masaru; Magrufov, Akhmar; Kita, Tomoko; Tamaki, Hisanobu; Tamura, Yoshihiro; Iguchi, Fuku-ichiro; Kim, Tae Soo; Kishimoto, Masanao; Omori, Koichi; Ito, Juichi

2005-12-01

The aim of this study was to investigate the destiny of implanted autologous bone marrow-derived stromal cells (BSCs) containing mesenchymal stem cells. We previously reported the successful regeneration of an injured vocal fold through implantation of BSCs in a canine model. However, the fate of the implanted BSCs was not examined. In this study, implanted BSCs were traced in order to determine the type of tissues resulting at the injected site of the vocal fold. After harvest of bone marrow from the femurs of green fluorescent transgenic mice, adherent cells were cultured and selectively amplified. By means of a fluorescence-activated cell sorter, it was confirmed that some cells were strongly positive for mesenchymal stem cell markers, including CD29, CD44, CD49e, and Sca-1. These cells were then injected into the injured vocal fold of a nude rat. Immunohistologic examination of the resected vocal folds was performed 8 weeks after treatment. The implanted cells were alive in the host tissues and showed positive expression for keratin and desmin, markers for epithelial tissue and muscle, respectively. The implanted BSCs differentiated into more than one tissue type in vivo. Cell-based tissue engineering using BSCs may improve the quality of the healing process in vocal fold injuries.

Performance of a reduced-order FSI model for flow-induced vocal fold vibration

NASA Astrophysics Data System (ADS)

Luo, Haoxiang; Chang, Siyuan; Chen, Ye; Rousseau, Bernard; PhonoSim Team

2017-11-01

Vocal fold vibration during speech production involves a three-dimensional unsteady glottal jet flow and three-dimensional nonlinear tissue mechanics. A full 3D fluid-structure interaction (FSI) model is computationally expensive even though it provides most accurate information about the system. On the other hand, an efficient reduced-order FSI model is useful for fast simulation and analysis of the vocal fold dynamics, which can be applied in procedures such as optimization and parameter estimation. In this work, we study performance of a reduced-order model as compared with the corresponding full 3D model in terms of its accuracy in predicting the vibration frequency and deformation mode. In the reduced-order model, we use a 1D flow model coupled with a 3D tissue model that is the same as in the full 3D model. Two different hyperelastic tissue behaviors are assumed. In addition, the vocal fold thickness and subglottal pressure are varied for systematic comparison. The result shows that the reduced-order model provides consistent predictions as the full 3D model across different tissue material assumptions and subglottal pressures. However, the vocal fold thickness has most effect on the model accuracy, especially when the vocal fold is thin.

In Vivo measurement of pediatric vocal fold motion using structured light laser projection.

PubMed

Patel, Rita R; Donohue, Kevin D; Lau, Daniel; Unnikrishnan, Harikrishnan

2013-07-01

The aim of the study was to present the development of a miniature structured light laser projection endoscope and to quantify vocal fold length and vibratory features related to impact stress of the pediatric glottis using high-speed imaging. The custom-developed laser projection system consists of a green laser with a 4-mm diameter optics module at the tip of the endoscope, projecting 20 vertical laser lines on the glottis. Measurements of absolute phonatory vocal fold length, membranous vocal fold length, peak amplitude, amplitude-to-length ratio, average closing velocity, and impact velocity were obtained in five children (6-9 years), two adult male and three adult female participants without voice disorders, and one child (10 years) with bilateral vocal fold nodules during modal phonation. Independent measurements made on the glottal length of a vocal fold phantom demonstrated a 0.13mm bias error with a standard deviation of 0.23mm, indicating adequate precision and accuracy for measuring vocal fold structures and displacement. First, in vivo measurements of amplitude-to-length ratio, peak closing velocity, and impact velocity during phonation in pediatric population and a child with vocal fold nodules are reported. The proposed laser projection system can be used to obtain in vivo measurements of absolute length and vibratory features in children and adults. Children have large amplitude-to-length ratio compared with typically developing adults, whereas nodules result in larger peak amplitude, amplitude-to-length ratio, average closing velocity, and impact velocity compared with typically developing children. Copyright © 2013 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

Effect of level difference between left and right vocal folds on phonation: Physical experiment and theoretical study.

PubMed

Tokuda, Isao T; Shimamura, Ryo

2017-08-01

As an alternative factor to produce asymmetry between left and right vocal folds, the present study focuses on level difference, which is defined as the distance between the upper surfaces of the bilateral vocal folds in the inferior-superior direction. Physical models of the vocal folds were utilized to study the effect of the level difference on the phonation threshold pressure. A vocal tract model was also attached to the vocal fold model. For two types of different models, experiments revealed that the phonation threshold pressure tended to increase as the level difference was extended. Based upon a small amplitude approximation of the vocal fold oscillations, a theoretical formula was derived for the phonation threshold pressure. This theory agrees with the experiments, especially when the phase difference between the left and right vocal folds is not extensive. Furthermore, an asymmetric two-mass model was simulated with a level difference to validate the experiments as well as the theory. The primary conclusion is that the level difference has a potential effect on voice production especially for patients with an extended level of vertical difference in the vocal folds, which might be taken into account for the diagnosis of voice disorders.

Vocal fold self-disruption after phonotrauma on a lead actor: a case presentation.

PubMed

Behlau, Mara; Oliveira, Gisele; Pontes, Paulo

2009-11-01

It is well known that phonotraumatic events may produce laryngeal inflammation, vocal fold hemorrhage and different types of mass lesions. This study describes a vocal fold self-disruption that occurred on stage to a lead actor in the role of Richard III. The study design is as case presentation. A 43-year-old actor presented with a sudden voice loss that first occurred on stage after a series of presentations. He also had a cold-like condition that had not been treated. His past medical history included an average of ten cigarettes per day for ten years and a 10-year history of gastritis and stomach ulcer. Perceptual, acoustic, and laryngeal analyses were performed following pharmacological and voice therapy. Perceptual and acoustic analyses showed mild deviations whereas laryngeal visual examination revealed a complete right vocal fold detachment from the anterior commissure to the vocal process, with generalized hyperemia. A mild diffuse Reinke's edema was observed on the left vocal fold. Mild discomfort was present only during the first day of the acute period. Modified vocal rest was recommended and a series of vocal exercises were administered. The patient performed again 4 days later, after following a series of behavioral modification techniques that included casting guidelines during the subsequent 15 days. Healing was exceptional and his voice returned to normal. This unique case with an exceptional recovery emphasizes the etiological aspects of scar formation after phonotrauma. Positive contributing factors may include a good vocal technique and adequate training as well as the protective upregulated genes present in Reinke's edema.

Evaluation of Dying Vocal Fold Epithelial Cells by Ultrastructural Features and TUNEL Method

PubMed Central

Novaleski, Carolyn K.; Mizuta, Masanobu; Rousseau, Bernard

2016-01-01

Cell death is a regulated mechanism of eliminating cells to maintain tissue homeostasis. This study described two methodological procedures for evaluating cell death in the epithelium of immobilized, approximated, and vibrated vocal folds from 12 New Zealand white breeder rabbits. The gold standard technique of transmission electron microscopy evaluated high-quality ultrastructural criteria of cell death and a common immunohistochemical marker, terminal deoxynucleotidyl transferase dUTP nick end labeling method, to confirm cell death signaling. Results revealed that ultrastructural characteristics of apoptotic cell death, specifically condensed chromatin and apoptotic bodies, were observed after vocal fold vibration and approximation. Although episodes of necrotic cell death were rare, few enlarged cell nuclei were present after vibration and approximation. The vocal fold expresses an immunohistochemical marker for apoptosis along the apical surface of the epithelium. This study provides a solid foundation for future investigations regarding the role of cell death in vocal fold health and disease. PMID:27537846

Evaluation of Dying Vocal Fold Epithelial Cells by Ultrastructural Features and TUNEL Method.

PubMed

Novaleski, Carolyn K; Mizuta, Masanobu; Rousseau, Bernard

2016-01-01

Cell death is a regulated mechanism of eliminating cells to maintain tissue homeostasis. This study described 2 methodological procedures for evaluating cell death in the epithelium of immobilized, approximated and vibrated vocal folds from 12 New Zealand white breeder rabbits. The gold standard technique of transmission electron microscopy evaluated high-quality ultrastructural criteria of cell death and a common immunohistochemical marker, the terminal deoxynucleotidyl transferase dUTP nick end labeling method, to confirm cell death signaling. Results revealed that ultrastructural characteristics of apoptotic cell death, specifically condensed chromatin and apoptotic bodies, were observed after vocal fold vibration and approximation. Although episodes of necrosis were rare, few enlarged cell nuclei were present after vibration and approximation. The vocal fold expresses an immunohistochemical marker for apoptosis along the apical surface of the epithelium. This study provides a solid foundation for future investigations regarding the role of cell death in vocal fold health and disease. © 2016 S. Karger AG, Basel.

Treatment of vocal fold scarring: rheological and histological measures of homologous collagen matrix.

PubMed

Kriesel, Kevin J; Thiebault, Susan L; Chan, Roger W; Suzuki, Tatsutoshi; VanGroll, Patrick J; Bless, Diane M; Ford, Charles N

2002-10-01

The current treatment options for dysphonia secondary to vocal fold scarring are limited. Few studies address changes in the lamina propria, which is critical to vocal fold biomechanical properties and voice production. Using rheological and histological measures of homologous collagen matrix (HCM)-injected vocal folds, we assessed HCM's potential for providing bulk and restoring biomechanical performance. Twenty rabbits underwent bilateral vocal fold scarring. After 10 weeks of scar maturation, the rabbits had unilateral injections of HCM or saline solution. Ten weeks after the injections, histological studies revealed well-defined collagen globules distributed throughout the lamina propria and underlying muscular tissue. Significantly more procollagen was observed in the HCM-treated group. No significant differences in elastic shear modulus or dynamic viscosity were found between the treatment groups. This study demonstrates that HCM is an inert, relatively stable injectate that may serve well for medialization but does not appear to improve the dynamic properties of the lamina propria.

Nonlinear vocal fold dynamics resulting from asymmetric fluid loading on a two-mass model of speech

NASA Astrophysics Data System (ADS)

Erath, Byron D.; Zañartu, Matías; Peterson, Sean D.; Plesniak, Michael W.

2011-09-01

Nonlinear vocal fold dynamics arising from asymmetric flow formations within the glottis are investigated using a two-mass model of speech with asymmetric vocal fold tensioning, representative of unilateral vocal fold paralysis. A refined theoretical boundary-layer flow solver is implemented to compute the intraglottal pressures, providing a more realistic description of the flow than the standard one-dimensional, inviscid Bernoulli flow solution. Vocal fold dynamics are investigated for subglottal pressures of 0.6 < ps < 1.5 kPa and tension asymmetries of 0.5 < Q < 0.8. As tension asymmetries become pronounced the asymmetric flow incites nonlinear behavior in the vocal fold dynamics at subglottal pressures that are associated with normal speech, behavior that is not captured with standard Bernoulli flow solvers. Regions of bifurcation, coexistence of solutions, and chaos are identified.

Hyaluronic acid hydrogels for vocal fold wound healing

PubMed Central

Gaston, Joel; Thibeault, Susan L.

2013-01-01

The unique vibrational properties inherent to the human vocal fold have a significant detrimental impact on wound healing and scar formation. Hydrogels have taken prominence as a tissue engineered strategy to restore normal vocal structure and function as cellularity is low. The frequent vibrational and shear forces applied to, and present in this connective tissue make mechanical properties of such hydrogels a priority in this active area of research. Hyaluronic acid has been chemically modified in a variety of ways to address cell function while maintaining desirable tissue mechanical properties. These various modifications have had mixed results when injected in vivo typically resulting in better biomechanical function but not necessarily with a concomitant decrease in tissue fibrosis. Recent work has focused on seeding mesenchymal progenitor cells within 3D architecture of crosslinked hydrogels. The data from these studies demonstrate that this approach has a positive effect on cells in both early and late wound healing, but little work has been done regarding the biomechanical effects of these treatments. This paper provides an overview of the various hyaluronic acid derivatives, their crosslinking agents, and their effect when implanted into the vocal folds of various animal models. PMID:23507923

Hyaluronic acid hydrogels for vocal fold wound healing.

PubMed

Gaston, Joel; Thibeault, Susan L

2013-01-01

The unique vibrational properties inherent to the human vocal fold have a significant detrimental impact on wound healing and scar formation. Hydrogels have taken prominence as a tissue engineered strategy to restore normal vocal structure and function as cellularity is low. The frequent vibrational and shear forces applied to, and present in this connective tissue make mechanical properties of such hydrogels a priority in this active area of research. Hyaluronic acid has been chemically modified in a variety of ways to address cell function while maintaining desirable tissue mechanical properties. These various modifications have had mixed results when injected in vivo typically resulting in better biomechanical function but not necessarily with a concomitant decrease in tissue fibrosis. Recent work has focused on seeding mesenchymal progenitor cells within 3D architecture of crosslinked hydrogels. The data from these studies demonstrate that this approach has a positive effect on cells in both early and late wound healing, but little work has been done regarding the biomechanical effects of these treatments. This paper provides an overview of the various hyaluronic acid derivatives, their crosslinking agents, and their effect when implanted into the vocal folds of various animal models.

Framework Surgery for Treatment of Unilateral Vocal Fold Paralysis

PubMed Central

Daniero, James J.; Garrett, C. Gaelyn; Francis, David O.

2014-01-01

Laryngeal framework surgery is the current gold standard treatment for unilateral vocal fold paralysis. It provides a permanent solution to glottic insufficiency caused by injury to the recurrent laryngeal nerve. Various modifications to the original Isshiki type I laryngoplasty procedure have been described to improve voice and swallowing outcomes. The success of this procedure is highly dependent on the experience of the surgeon as it epitomizes the intersection of art and science in the field. The following article reviews the evidence, controversies, and complications related to laryngoplasty for unilateral vocal fold paralysis. It also provides a detailed analysis of how and when arytenoid-positioning procedures should be considered, and summarizes the literature on postoperative outcomes. PMID:24883239

Apoptosis and Vocal Fold Disease: Clinically Relevant Implications of Epithelial Cell Death

ERIC Educational Resources Information Center

Novaleski, Carolyn K.; Carter, Bruce D.; Sivasankar, M. Preeti; Ridner, Sheila H.; Dietrich, Mary S.; Rousseau, Bernard

2017-01-01

Purpose: Vocal fold diseases affecting the epithelium have a detrimental impact on vocal function. This review article provides an overview of apoptosis, the most commonly studied type of programmed cell death. Because apoptosis can damage epithelial cells, this article examines the implications of apoptosis on diseases affecting the vocal fold…

Inpatient injection laryngoplasty for vocal fold immobility: When is it really necessary?

PubMed

Zuniga, Steven; Ebersole, Barbara; Jamal, Nausheen

To compare pulmonary and swallow outcomes of injection laryngoplasty when performed in the acute versus subacute setting in head & neck and thoracic cancer patients presenting with new onset unilateral vocal fold immobility. Case series with chart review at an academic cancer center over a 2year period. Based on swallow evaluation, patients diagnosed with vocal fold immobility were grouped into an unsafe swallow group, injected as inpatients, and a safe swallow group, for whom injection laryngoplasty was delayed to the outpatient setting or not performed. Rates of pneumonia, diet recommendations, and swallow outcomes were compared between groups. 24 patients with new-onset vocal fold immobility were evaluated. 7 underwent injection in the inpatient setting, 12 in the outpatient setting, and 5 did not undergo injection. There was no perceived difference in speech and swallow outcomes between the inpatient and outpatient injection groups. Injection laryngoplasty shows promise as an effective intervention for reducing aspiration risk and improving diet normalcy in patients with dysphagia as a result of unilateral vocal fold immobility. In patients determined to have a safe swallow, delay of injection laryngoplasty is not detrimental to swallow outcomes. Copyright © 2017 Elsevier Inc. All rights reserved.

Combining Multiobjective Optimization and Cluster Analysis to Study Vocal Fold Functional Morphology

PubMed Central

Palaparthi, Anil; Riede, Tobias

2017-01-01

Morphological design and the relationship between form and function have great influence on the functionality of a biological organ. However, the simultaneous investigation of morphological diversity and function is difficult in complex natural systems. We have developed a multiobjective optimization (MOO) approach in association with cluster analysis to study the form-function relation in vocal folds. An evolutionary algorithm (NSGA-II) was used to integrate MOO with an existing finite element model of the laryngeal sound source. Vocal fold morphology parameters served as decision variables and acoustic requirements (fundamental frequency, sound pressure level) as objective functions. A two-layer and a three-layer vocal fold configuration were explored to produce the targeted acoustic requirements. The mutation and crossover parameters of the NSGA-II algorithm were chosen to maximize a hypervolume indicator. The results were expressed using cluster analysis and were validated against a brute force method. Results from the MOO and the brute force approaches were comparable. The MOO approach demonstrated greater resolution in the exploration of the morphological space. In association with cluster analysis, MOO can efficiently explore vocal fold functional morphology. PMID:24771563

Biomechanical simulation of vocal fold dynamics in adults based on laryngeal high-speed videoendoscopy

PubMed Central

Gómez, Pablo; Patel, Rita R.; Alexiou, Christoph; Bohr, Christopher; Schützenberger, Anne

2017-01-01

Motivation Human voice is generated in the larynx by the two oscillating vocal folds. Owing to the limited space and accessibility of the larynx, endoscopic investigation of the actual phonatory process in detail is challenging. Hence the biomechanics of the human phonatory process are still not yet fully understood. Therefore, we adapt a mathematical model of the vocal folds towards vocal fold oscillations to quantify gender and age related differences expressed by computed biomechanical model parameters. Methods The vocal fold dynamics are visualized by laryngeal high-speed videoendoscopy (4000 fps). A total of 33 healthy young subjects (16 females, 17 males) and 11 elderly subjects (5 females, 6 males) were recorded. A numerical two-mass model is adapted to the recorded vocal fold oscillations by varying model masses, stiffness and subglottal pressure. For adapting the model towards the recorded vocal fold dynamics, three different optimization algorithms (Nelder–Mead, Particle Swarm Optimization and Simulated Bee Colony) in combination with three cost functions were considered for applicability. Gender differences and age-related kinematic differences reflected by the model parameters were analyzed. Results and conclusion The biomechanical model in combination with numerical optimization techniques allowed phonatory behavior to be simulated and laryngeal parameters involved to be quantified. All three optimization algorithms showed promising results. However, only one cost function seems to be suitable for this optimization task. The gained model parameters reflect the phonatory biomechanics for men and women well and show quantitative age- and gender-specific differences. The model parameters for younger females and males showed lower subglottal pressures, lower stiffness and higher masses than the corresponding elderly groups. Females exhibited higher subglottal pressures, smaller oscillation masses and larger stiffness than the corresponding similar aged

Impact of Cricothyroid Muscle Contraction on Vocal Fold Vibration: Experimental Study with High-Speed Videoendoscopy.

PubMed

Ishikawa, Camila Cristina; Pinheiro, Thais Gonçalves; Hachiya, Adriana; Montagnoli, Arlindo Neto; Tsuji, Domingos Hiroshi

2017-05-01

The aim of this study was to evaluate the effects of cricothyroid muscle contraction on vocal fold vibration, as evaluated with high-speed videoendoscopy, and to identify one or more aspects of vocal fold vibration that could be used as an irrefutable indicator of unilateral cricothyroid muscle paralysis. This was an experimental study employing excised human larynges. Twenty freshly excised human larynges were evaluated during artificially produced vibration. Each larynx was assessed in three situations: bilateral cricothyroid muscle contraction, unilateral cricothyroid muscle contraction, and no contraction of either cricothyroid muscle. The following parameters were evaluated by high-speed videoendoscopy: fundamental frequency, periodicity, amplitude of vocal fold vibration, and phase symmetry between the vocal folds. Although neither unilateral nor bilateral cricothyroid muscle contraction altered the periodicity of vibration or the occurrence of phase asymmetry, there was a significant decrease in fundamental frequency in parallel with decreasing longitudinal tension. We also found an increase in vibration amplitude of right and left vocal folds, which were similar in terms of their behavior for this parameter in the various situations studied. Our results suggest that differences in vibration amplitude and phase symmetry between vocal folds are not reliable indicators of unilateral cricothyroid muscle paralysis. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Augmentation surgery on the cartilaginous portion of the vocal fold in a patient with cricoarytenoid joint ankylosis.

PubMed

Fukahori, Mioko; Chitose, Shun-Ichi; Sato, Kiminori; Kamimura, Hiroyuki; Sato, Kiminobu; On, Ririko; Umeno, Hirohito

2018-08-01

Surgical management of cricoarytenoid joint (CAJ) ankylosis is challenging and has the risk of worsening voice quality. In the present case, augmentation surgery was performed on the cartilaginous portion of the vocal fold in a patient with CAJ ankylosis. A 24-year-old man sustained blunt trauma to the anterior neck three years prior to developing severe breathiness. Posterior glottal insufficiency resulting from lateral fixation of the right vocal fold was observed during phonation under laryngoscopy. In addition, electromyography and CT scan revealed severe ankylosis of the right CAJ. Type I thyroplasty performed on the right vocal fold did not improve postoperative vocal function. Therefore, augmentation surgery on the cartilaginous portion of the right vocal fold was performed via endolaryngeal microsurgery under general anesthesia with jet ventilation. A piece of temporalis fascia was autotransplanted into the submucosal space created at the posterior cartilaginous portion of the right vocal fold. This resulted in the narrowing of the posterior glottal gap during phonation, leading to improvement in hoarseness. Microsurgical management with autologous fascia augmentation of the cartilaginous portion of the vocal fold can be effective in patients with lateral vocal fold fixation due to CAJ ankylosis. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects of Dehydration on the Viscoelastic Properties of Vocal Folds in Large Deformations

PubMed Central

Miri, Amir K.; Barthelat, François; Mongeau, Luc

2012-01-01

Summary Dehydration may alter vocal fold viscoelastic properties, which may hamper phonation. The effects of water loss induced by an osmotic-pressure potential on vocal fold tissue viscoelastic properties were investigated. Porcine vocal folds were dehydrated by immersion in a hypertonic solution, and quasi-static and low-frequency dynamic traction tests were performed for elongations of up to 50%. Digital image correlation was used to determine local strains from surface deformations. The elastic modulus and the loss factor were then determined for normal and dehydrated tissues. An eight-chain hyperelastic model was used to describe the observed nonlinear stress-stretch behavior. Contrary to expectations, the mass history indicated that the tissue absorbed water during cyclic extension when submerged in a hypertonic solution. During loading history, the elastic modulus was increased for dehydrated tissues as a function of strain. The response of dehydrated tissues was much less affected when the load was releasing. This calls more attention to the modeling of vocal folds in micromechanics modeling. The internal hysteresis, which is often linked to phonation effort, increased significantly with water loss. The effects of dehydration on the viscoelastic properties of vocal fold tissue were quantified in a systematic way. The results will contribute to a better understanding of the basic biomechanics of voice production and ultimately will help establish objective dehydration and phonotrauma criteria. PMID:22483778

Dynamic viscosity of implantable autologous materials into the vocal fold.

PubMed

Wiikmann, Christian; da Silva, Marcelo Alves; Arêas, Elizabeth Pinheiro Gomes; Tsuji, Domingos Hiroshi; Sennes, Luiz Ubirajara

2012-07-01

To compare the dynamic viscosity (DV) of superficial layer of temporalis fascia (SLTF) with that of other biological tissues traditionally used for vocal fold implants to treat vocal fold rigidity. Experimental. Measurement of DV of samples of SLTF, deep layer of temporalis fascia (DLTF), and abdominal fat of 12 cadavers. DV values of the different samples were presented in the following increasing order: SLTF, DLTF, and abdominal fat. There was statistical difference between the samples. DV of SLTF is lower than of other tissues tested. Copyright © 2012 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

Contribution to the understanding of the etiology of vocal fold cysts: a functional and histologic study.

PubMed

Milutinović, Z; Vasiljević, J

1992-05-01

The etiological theories of vocal fold cysts can be divided into two basic groups: those of congenital and acquired cysts. In ongoing practice, the authors had noted that the greater number of cysts appeared at the functionally most active segment of the vocal folds which, on the other hand, has the least number of glands. Also, it had been noted that patients with vocal fold cysts tended to have hyperkinetic patterns of voice production. These observations indicated the possibility of a functional aspect in the etiology of vocal fold cysts, and consideration of such a possibility was the aim of this work. In 37 cases, the exact location of the cyst was established. In addition, the muscular activity of the phonatory apparatus was estimated, patient self-descriptions with respect to talkativeness were taken into account, and histological evaluations were made. The cysts were most frequently found in the area of the junction of the anterior and middle thirds of the free edge of the vocal fold. Muscular activity during speech and phonation was increased in study patients. Sixty-five percent of patients had epidermoid cysts and 35% had retention cysts of the vocal fold. According to study results, the functional aspect of cyst genesis has a marked role in the etiology of vocal fold cysts, which points to the great importance of functional care for cyst patients.

Impacts and limitations of medialization thyroplasty on swallowing function of patients with unilateral vocal fold paralysis.

PubMed

Tateya, Ichiro; Hirano, Shigeru; Kishimoto, Yo; Suehiro, Atsushi; Kojima, Tsuyohi; Ohno, Satoshi; Ito, Juichi

2010-11-01

Medialization thyroplasty was effective in improving swallowing function as well as vocal function in most cases with unilateral vocal fold paralysis. The impact of medialization thryoplasty was insufficient for the case with severe atrophy and that in which the vocal fold was fixed in the lateral position. To evaluate the impacts and limitations of medialization thyroplasty on swallowing function of the patients with unilateral vocal fold paralysis. Eight cases (mean age 68.5 years) with unilateral vocal fold paralysis chiefly complaining of swallowing disturbance were studied. All patients underwent thyroplasty type I. The causes of the paralysis were lung cancer in four cases, esophageal cancer in one case, aortic aneurysm in one case, subarachnoid hemorrhage in one case, and unknown in one case. Subjective swallowing function score, maximum phonation time (MPT), mean flow rate (MFR), amplitude perturbation quotient (APQ), and pitch perturbation quotient (PPQ) were examined pre- and postoperatively. The swallowing score improved in all except two cases. However, bilateral thryoplasty was necessary for the case with severe vocal fold atrophy and arytenoid adduction was needed for the case in which the vocal fold was fixed in the lateral position. The swallowing score, MPT, and MFR showed significant improvement after surgery.

Effects of Vocal Fold Nodules on Glottal Cycle Measurements Derived from High-Speed Videoendoscopy in Children

PubMed Central

2016-01-01

The goal of this study is to quantify the effects of vocal fold nodules on vibratory motion in children using high-speed videoendoscopy. Differences in vibratory motion were evaluated in 20 children with vocal fold nodules (5–11 years) and 20 age and gender matched typically developing children (5–11 years) during sustained phonation at typical pitch and loudness. Normalized kinematic features of vocal fold displacements from the mid-membranous vocal fold point were extracted from the steady-state high-speed video. A total of 12 kinematic features representing spatial and temporal characteristics of vibratory motion were calculated. Average values and standard deviations (cycle-to-cycle variability) of the following kinematic features were computed: normalized peak displacement, normalized average opening velocity, normalized average closing velocity, normalized peak closing velocity, speed quotient, and open quotient. Group differences between children with and without vocal fold nodules were statistically investigated. While a moderate effect size was observed for the spatial feature of speed quotient, and the temporal feature of normalized average closing velocity in children with nodules compared to vocally normal children, none of the features were statistically significant between the groups after Bonferroni correction. The kinematic analysis of the mid-membranous vocal fold displacement revealed that children with nodules primarily differ from typically developing children in closing phase kinematics of the glottal cycle, whereas the opening phase kinematics are similar. Higher speed quotients and similar opening phase velocities suggest greater relative forces are acting on vocal fold in the closing phase. These findings suggest that future large-scale studies should focus on spatial and temporal features related to the closing phase of the glottal cycle for differentiating the kinematics of children with and without vocal fold nodules. PMID:27124157

Objective Dysphonia Quantification in Vocal Fold Paralysis: Comparing Nonlinear with Classical Measures

PubMed Central

Little, Max A.; Costello, Declan A. E.; Harries, Meredydd L.

2010-01-01

Summary Clinical acoustic voice-recording analysis is usually performed using classical perturbation measures, including jitter, shimmer, and noise-to-harmonic ratios (NHRs). However, restrictive mathematical limitations of these measures prevent analysis for severely dysphonic voices. Previous studies of alternative nonlinear random measures addressed wide varieties of vocal pathologies. Here, we analyze a single vocal pathology cohort, testing the performance of these alternative measures alongside classical measures. We present voice analysis pre- and postoperatively in 17 patients with unilateral vocal fold paralysis (UVFP). The patients underwent standard medialization thyroplasty surgery, and the voices were analyzed using jitter, shimmer, NHR, nonlinear recurrence period density entropy (RPDE), detrended fluctuation analysis (DFA), and correlation dimension. In addition, we similarly analyzed 11 healthy controls. Systematizing the preanalysis editing of the recordings, we found that the novel measures were more stable and, hence, reliable than the classical measures on healthy controls. RPDE and jitter are sensitive to improvements pre- to postoperation. Shimmer, NHR, and DFA showed no significant change (P > 0.05). All measures detect statistically significant and clinically important differences between controls and patients, both treated and untreated (P < 0.001, area under curve [AUC] > 0.7). Pre- to postoperation grade, roughness, breathiness, asthenia, and strain (GRBAS) ratings show statistically significant and clinically important improvement in overall dysphonia grade (G) (AUC = 0.946, P < 0.001). Recalculating AUCs from other study data, we compare these results in terms of clinical importance. We conclude that, when preanalysis editing is systematized, nonlinear random measures may be useful for monitoring UVFP-treatment effectiveness, and there may be applications to other forms of dysphonia. PMID:19900790

Cause-effect relationship between vocal fold physiology and voice production in a three-dimensional phonation model

PubMed Central

Zhang, Zhaoyan

2016-01-01

The goal of this study is to better understand the cause-effect relation between vocal fold physiology and the resulting vibration pattern and voice acoustics. Using a three-dimensional continuum model of phonation, the effects of changes in vocal fold stiffness, medial surface thickness in the vertical direction, resting glottal opening, and subglottal pressure on vocal fold vibration and different acoustic measures are investigated. The results show that the medial surface thickness has dominant effects on the vertical phase difference between the upper and lower margins of the medial surface, closed quotient, H1-H2, and higher-order harmonics excitation. The main effects of vocal fold approximation or decreasing resting glottal opening are to lower the phonation threshold pressure, reduce noise production, and increase the fundamental frequency. Increasing subglottal pressure is primarily responsible for vocal intensity increase but also leads to significant increase in noise production and an increased fundamental frequency. Increasing AP stiffness significantly increases the fundamental frequency and slightly reduces noise production. The interaction among vocal fold thickness, stiffness, approximation, and subglottal pressure in the control of F0, vocal intensity, and voice quality is discussed. PMID:27106298

Day surgery for vocal fold lesions using a double-bent 60-mm Cathelin needle.

PubMed

Toyomura, Fumimasa; Tokashiki, Ryoji; Hiramatsu, Hiroyuki; Tsukahara, Kiyoaki; Motohashi, Ray; Sakurai, Eriko; Nomoto, Masaki; Suzuki, Mamoru

2014-11-01

Day surgery for vocal cord lesions overcomes the disadvantages of laryngomicrosurgery under general anesthesia. We present our experience with treatment of vocal fold lesions using a long double-bend Cathelin needle that can access all parts of the vocal cords. A 23G, 60-mm-long Cathelin needle was bent twice by 45(o) at a distance of 1 and 2 cm from the tip, and was attached to a syringe. Under topical anesthesia and nasal endoscopy of the laryngopharynx, the needle was inserted percutaneously perpendicular to the skin, the direction of insertion being altered when the bends in the needle reached the skin surface. This allows the tip of the needle to access all parts of the glottis, allowing the performance of procedures such as biopsies, excision of lesions, and injection into the vocal folds. Between January 2011 and December 2013, we used this technique to perform vocal fold procedures in 566 patients presenting for treatment of spasmodic dysphonia (412 cases, 73 %) and other vocal fold lesions. Only minor complications, such as hematoma (3 patients, 0.5 %) and slight bleeding from the puncture site in the epiglottic vallecula (all patients, 100 %), which ceased spontaneously within 10 min, were seen. Erroneous puncture occurred in three patients (0.5 %) and the puncture had to be repeated in 38 patients (6.7 %). The procedure was completed successfully in all cases (100 %). Surgery for vocal fold lesions under topical anesthesia using our double-bend Cathelin needle technique is simple, safe, and useful.

Epidemiology of Vocal Fold Paralyses After Total Thyroidectomy for Well-Differentiated Thyroid Cancer in Medicare Population

PubMed Central

Francis, David O.; Pearce, Elizabeth C.; Ni, Shenghua; Garrett, C. Gaelyn; Penson, David F.

2014-01-01

Objectives Population-level incidence of vocal fold paralysis after thyroidectomy for well-differentiated thyroid carcinoma (WDTC) is not known. This study aimed to measure longitudinal incidence of post-operative vocal fold paralyses and need for directed interventions in the Medicare population undergoing total thyroidectomy for WDTC. Study Design Retrospective Cohort Study Setting United States Population Subjects Medicare Beneficiaries Methods SEER-Medicare data (1991 – 2009) were used to identify beneficiaries who underwent total thyroidectomy for WDTC. Incident vocal fold paralyses and directed interventions were identified. Multivariate analyses were used to determine factors associated with odds of developing these surgical complications. Results Of 5,670 total thyroidectomies for WDTC, 9.5% were complicated by vocal fold paralysis [8.2% unilateral vocal fold paralysis (UVFP); 1.3% bilateral vocal fold paralysis (BVFP)]. Rate of paralyses decreased 5% annually from 1991 to 2009 (OR 0.95, 95% CI 0.93 – 0.97; p<0.001). Overall, 22% of patients with vocal fold paralysis required surgical intervention (UVFP 21%, BVFP 28%). Multivariate logistic regression revealed odds of post-thyroidectomy paralysis increased with each additional year of age, with non-Caucasian race, particular histologic types, advanced stage, and in particular registry regions. Conclusions Annual rates of post-thyroidectomy vocal fold paralyses are decreasing among Medicare beneficiaries with WDTC. High incidence in this aged population is likely due to a preponderance of temporary paralyses, which is supported by the need for directed intervention in less than a quarter of affected patients. Further population-based studies are needed to refine the population incidence and risk factors for paralyses in the aging population. PMID:24482349

Correlation of phonatory behavior with vocal fold structure, observed in a physical model

NASA Astrophysics Data System (ADS)

Krane, Michael; Walters, Gage; McPhail, Michael

2017-11-01

The effect of vocal fold shape and internal structure on phonation was studied experimentally using a physical model of the human airway. Model folds used a ``M5'' or a swept ellipse coronal cross-section shape. Models were molded in either 2 or three layers. Two-layer models included a more stiff ``body'' layer and a much softer ``cover'' layer, while the 3-layer models also incorporated an additional, thin, ``ligament/conus'' layer stiffer than the body layer. The elliptical section models were all molded in 3 such layers. Measurements of transglottal pressure, volume flow, mouth sound pressure, and high-speed imaging of vocal fold vibration were performed. These show that models with the ``ligament'' layer experienced much attenuated vertical deformation, that glottal closure was more likely, and that phonation was much easier to initiate. These findings suggest that the combination of the vocal ligament and the conus elasticus stabilize the vocal fold for efficient phonation by limiting vertical deformation, while allowing transverse deformations to occur. Acknowledge support from NIH DC R01005642-11.

Air pulse deformation measurement: a preliminary method for noninvasive vocal fold pliability analysis.

PubMed

Larsson, Hans; Lindestad, P Å; Hertegård, S

2011-01-01

A new method, air pulse pliability measurement, is presented, with which the pliability and elasticity of the vocal folds was measured in vitro and in vivo using air pulses. The size of the mucosal movements induced by air pulse stimulation was measured with a laser-based technique. The air pulses fed via a 2-mm tubing, introduced through the working channel of a flexible endoscope. Both in vitro and in vivo tests were performed. Nine normal, vocally healthy subjects were examined by air pulse stimulations of the vocal folds, of the skin (cheek and dorsum of the hand) and of the inside of the lips. The in vitro tests showed a coefficient of variation of 5% within a range of 1-5 mm from the probe to the surface. The elasticity data showed no differences between vocal folds, lips or cheek. The hand data showed a significantly higher stiffness as compared to the other 3 measuring points (p < 0.001). The coefficient of variation was about 35% for all measuring points, but in ideal conditions on skin it was 9%. The results show that the technique allows automatic, quantitative, noninvasive vocal fold pliability measurements on awake subjects. Copyright © 2010 S. Karger AG, Basel.

Symptom overlap between laryngopharyngeal reflux and glottic insufficiency in vocal fold atrophy patients.

PubMed

Patel, Anju K; Mildenhall, Nicholas R; Kim, William; Carroll, Thomas L

2014-04-01

To determine in true vocal fold (TVF) atrophy patients if symptoms of throat clearing and mucus sensation, attributed to laryngopharyngeal reflux (LPR), are due to glottic insufficiency. Is the TVF atrophy population being prescribed proton pump inhibitors unnecessarily? A retrospective review of patients with TVF atrophy but no other underlying laryngeal pathology seen at a tertiary voice center from July 2009 to May 2012 was conducted. Patient demographics, symptoms, LPR diagnosis, interventions, and pre-intervention and post-intervention Voice Handicap Index-10 (VHI) and Reflux Symptom Index (RSI) scores were recorded. Twenty-six patients met inclusion criteria, and 85% were treated for LPR. Throat clearing and mucus sensation (85%), dysphonia (54%), and globus sensation (46%) were recorded. Interventions included LPR medical management (65%), vocal fold augmentation (23%), and voice therapy (12%). Reflux Symptom Index scores improved in all groups. Voice Handicap Index-10 and RSI scores normalized in patients treated with augmentation. Globus was never present in patients who received augmentation. Throat clearing and mucus sensation may be due to underlying glottic insufficiency and changes of the aging larynx rather than LPR. High VHI and RSI scores normalized with TVF augmentation. Further work is needed to evaluate symptom presentation and risk versus benefit of treatment options, especially if it avoids unnecessary proton pump inhibitor trials.

Vocal fold hypomobility secondary to elective endotracheal intubation: a general surgeon's perspective.

PubMed

Sariego, Jack

2010-01-01

This study was performed retrospectively to evaluate the incidence of documented vocal fold injury as a result of elective endotracheal intubation during general surgical procedures. Medical record review was performed at a single institution and all surgical cases reviewed which required endotracheal intubation in the nonemergent setting between April 1, 2003 and August, 31, 2007. Cases with unexpected and documented vocal fold immobility postoperatively formed the study cohort, and data were gathered regarding diagnosis and procedures performed. Of 23,010 general surgery cases performed during the study period, only seven documented cases of vocal fold paralysis were discovered (0.03%). There were five women and two men in the group; all were adults. Only one patient had a primary diagnosis related to the head and neck. Comorbidities were recorded as well, but there were no statistically significant patterns discerned. Furthermore, during the study period, a total of 31 patients overall (both surgical and nonsurgical) were admitted who carried a primary diagnosis of vocal fold paralysis. Therefore, the study cohort therefore constituted 22.6% of this total. Finally, cohort patients spent a total of 150 days in hospital during the study period; this length of stay (an average of 16.7 hospital days per patient) was significantly longer than the average of 5.1 days, presumably at least in part related to the vocal paralysis. Copyright 2010 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

Spontaneous resolution of hemorrhagic polyps of the true vocal fold.

PubMed

Klein, Adam M; Lehmann, Marcus; Hapner, Edie R; Johns, Michael M

2009-01-01

Hemorrhagic polyps are the most common benign lesions surgically removed from the vocal folds. Although this modality does offer satisfactory results in most of the cases, there is a subset of polyps that seems to resolve with conservative therapy. This study was performed to examine this subset of polyps. Thirty-four consecutive subjects diagnosed with hemorrhagic polyps of the true vocal fold were retrospectively reviewed to determine the incidence of spontaneous resolution of the lesions with nonsurgical therapy. Sixteen subjects began conservative therapy, consisting of voice therapy and proper vocal hygiene, often while awaiting an optimal personal time for surgical intervention. Of these subjects, nine (56.3%) experienced a resolution of their lesion and symptoms without undergoing surgical therapy. Surgical removal of hemorrhagic polyps is often considered the standard of treatment for these benign lesions. However, these observations support a regimen of voice therapy and observation in select cases.

Vocal fold proteoglycans and their influence on biomechanics.

PubMed

Gray, S D; Titze, I R; Chan, R; Hammond, T H

1999-06-01

To examine the interstitial proteins of the vocal fold and their influence on the biomechanical properties of that tissue. Anatomic study of the lamina propria of human cadaveric vocal folds combined with some viscosity testing. Identification of proteoglycans is performed with histochemical staining. Quantitative analysis is performed using an image analysis system. A rheometer is used for viscosity testing. Three-dimensional rendering program is used for the computer images. Proteoglycans play an important role in tissue biomechanics. Hyaluronic acid is a key molecule that affects viscosity. The proteoglycans of the lamina propria have important biological and biomechanical effects. The role of hyaluronic acid in determining tissue viscosity is emphasized. Viscosity, its effect on phonatory threshold pressure and energy expended due to phonation is discussed. Proteoglycans, particularly hyaluronic acid, play important roles in determining biomechanical properties of tissue oscillation. Future research will likely make these proteins of important therapeutic interest.

[Aetiology and treatment of vocal fold paralysis: retrospective study of 108 patients].

PubMed

Bothe, Carolina; López, Montserrat; Quer, Miquel; León, Xavier; García, Jacinto; Lop, Joan

2014-01-01

To review the aetiology and treatment of laryngeal paralysis diagnosed at our hospital and to describe the available therapeutic options. Retrospective review of medical records of 108 patients diagnosed with unilateral and bilateral vocal fold paralysis between 2000 and 2012, identifying the cause of paralysis and its treatment. Of the 108 cases analysed, 70% had unilateral vocal fold immobility and 30% bilateral immobility. The most frequent aetiology in both cases was trauma (represented mainly by surgical injury), followed by tumours in unilateral paralysis and medical causes in bilateral paralysis. Half of the patients with unilateral paralysis (38) were treated surgically, with medialization thyroplasty. In bilateral vocal fold immobility, the treatment consisted of tracheostomy in patients with threatened airway (40%). We planned to widen the air passage in 9 patients (27%), performing cordectomy in most of them. The aetiology observed in our patients is similar to that described in the literature. In cases of unilateral vocal fold paralysis, we believe thyroplasty is the procedure of choice. In bilateral paralysis, it is possible to perform cordectomy in selected patients once the airway has been secured. Copyright © 2013 Elsevier España, S.L. y Sociedad Española de Otorrinolaringología y Patología Cérvico-Facial. All rights reserved.

Measurements of vocal fold tissue viscoelasticity: Approaching the male phonatory frequency range

NASA Astrophysics Data System (ADS)

Chan, Roger W.

2004-06-01

Viscoelastic shear properties of human vocal fold tissues have been reported previously. However, data have only been obtained at very low frequencies (<=15 Hz). This necessitates data extrapolation to the frequency range of phonation based on constitutive modeling and time-temperature superposition. This study attempted to obtain empirical measurements at higher frequencies with the use of a controlled strain torsional rheometer, with a design of directly controlling input strain that introduced significantly smaller system inertial errors compared to controlled stress rheometry. Linear viscoelastic shear properties of the vocal fold mucosa (cover) from 17 canine larynges were quantified at frequencies of up to 50 Hz. Consistent with previous data, results showed that the elastic shear modulus (G'), viscous shear modulus (G''), and damping ratio (ζ) of the vocal fold mucosa were relatively constant across 0.016-50 Hz, whereas the dynamic viscosity (ɛ') decreased monotonically with frequency. Constitutive characterization of the empirical data by a quasilinear viscoelastic model and a statistical network model demonstrated trends of viscoelastic behavior at higher frequencies generally following those observed at lower frequencies. These findings supported the use of controlled strain rheometry for future investigations of the viscoelasticity of vocal fold tissues and phonosurgical biomaterials at phonatory frequencies.

Mesenchymal stromal cell injection promotes vocal fold scar repair without long-term engraftment

PubMed Central

BARTLETT, R.S.; GUILLE, J.T.; CHEN, X.; CHRISTENSEN, M.B.; WANG, S.F.; THIBEAULT, S.L.

2016-01-01

Background Regenerative medicine holds promise for restoring voice in patients with vocal fold scarring. As experimental treatments approach clinical translation, several considerations remain. Our objective was to evaluate efficacy and biocompatibility of four bone marrow mesenchymal stromal cell (BM-MSC) and tunable hyaluronic acid based hydrogel (HyStem-VF) treatments for vocal fold scar using clinically acceptable materials, a preclinical sample size and a dosing comparison. Methods Vocal folds of 84 rabbits were injured and injected with four treatment variations (BM-MSC, HyStem-VF, and BM-MSC in HyStem-VF at two concentrations) 6 weeks later. Efficacy was assessed with rheometry, real-time polymerase chain reaction (PCR) and histology at 2, 4 and 10 weeks following treatment. Lung, liver, kidney, spleen and vocal folds were screened for biocompatibility by a pathologist. Results and discussion Persistent inflammation was identified in all hydrogel-injected groups. The BM-MSC alone treatment appeared to be the most efficacious and safe, providing an early resolution of viscoelasticity, gene expression consistent with desirable extracellular matrix remodeling (less fibronectin, collagen 1α2, collagen 3, procollagen, transforming growth factor [TGF]β1, alpha smooth muscle actin, interleukin-1β, interleukin-17β and tumor necrosis factor [TNF] than injured controls) and minimal inflammation. Human beta actin expression in BM-MSC–treated vocal folds was minimal after 2 weeks, suggesting that paracrine signaling from the BM-MSCs may have facilitated tissue repair. PMID:27637759

Mesenchymal stromal cell injection promotes vocal fold scar repair without long-term engraftment.

PubMed

Bartlett, R S; Guille, J T; Chen, X; Christensen, M B; Wang, S F; Thibeault, S L

2016-10-01

Regenerative medicine holds promise for restoring voice in patients with vocal fold scarring. As experimental treatments approach clinical translation, several considerations remain. Our objective was to evaluate efficacy and biocompatibility of four bone marrow mesenchymal stromal cell (BM-MSC) and tunable hyaluronic acid based hydrogel (HyStem-VF) treatments for vocal fold scar using clinically acceptable materials, a preclinical sample size and a dosing comparison. Vocal folds of 84 rabbits were injured and injected with four treatment variations (BM-MSC, HyStem-VF, and BM-MSC in HyStem-VF at two concentrations) 6 weeks later. Efficacy was assessed with rheometry, real-time polymerase chain reaction (RT-PCR) and histology at 2, 4 and 10 weeks following treatment. Lung, liver, kidney, spleen and vocal folds were screened for biocompatibility by a pathologist. Persistent inflammation was identified in all hydrogel-injected groups. The BM-MSC alone treatment appeared to be the most efficacious and safe, providing an early resolution of viscoelasticity, gene expression consistent with desirable extracellular matrix remodeling (less fibronectin, collagen 1α2, collagen 3, procollagen, transforming growth factor [TGF]β1, alpha smooth muscle actin, interleukin-1β, interleukin-17β and tumor necrosis factor [TNF] than injured controls) and minimal inflammation. Human beta actin expression in BM-MSC-treated vocal folds was minimal after 2 weeks, suggesting that paracrine signaling from the BM-MSCs may have facilitated tissue repair. Copyright © 2016 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

Evaluation of injection augmentation treatment of hyaluronic acid based materials on rabbit vocal folds viscoelasticity.

PubMed

Borzacchiello, A; Mayol, L; Gärskog, O; Dahlqvist, A; Ambrosio, L

2005-06-01

The viscoelastic properties of vocal folds after injection of hyaluronic acid (hyaluronan, HA) based materials have been studied in an animal model (rabbit) six months after injection. The results indicate that the viscoelastic properties of the vocal folds injected with the HA based materials are similar to the healthy vocal folds (non-injected samples) used as control. Histological analysis has been also performed to investigate on the fate of the injected materials after six months from the implant. The HA based materials remain up to six months and they recruited fibroblasts that induce the ingrowth of new connective tissue resulting in an endogenous soft tissue augmentation. The HA based compounds are good candidate for further studies aimed at restoring/preserving the vibratory capacity of the vocal folds with injection treatment in glottal insufficiency.

Bi-stable vocal fold adduction: a mechanism of modal-falsetto register shifts and mixed registration.

PubMed

Titze, Ingo R

2014-04-01

The origin of vocal registers has generally been attributed to differential activation of cricothyroid and thyroarytenoid muscles in the larynx. Register shifts, however, have also been shown to be affected by glottal pressures exerted on vocal fold surfaces, which can change with loudness, pitch, and vowel. Here it is shown computationally and with empirical data that intraglottal pressures can change abruptly when glottal adductory geometry is changed relatively smoothly from convergent to divergent. An intermediate shape between large convergence and large divergence, namely, a nearly rectangular glottal shape with almost parallel vocal fold surfaces, is associated with mixed registration. It can be less stable than either of the highly angular shapes unless transglottal pressure is reduced and upper stiffness of vocal fold tissues is balanced with lower stiffness. This intermediate state of adduction is desirable because it leads to a low phonation threshold pressure with moderate vocal fold collision. Achieving mixed registration consistently across wide ranges of F0, lung pressure, and vocal tract shapes appears to be a balancing act of coordinating laryngeal muscle activation with vocal tract pressures. Surprisingly, a large transglottal pressure is not facilitative in this process, exacerbating the bi-stable condition and the associated register contrast.

Bi-stable vocal fold adduction: A mechanism of modal-falsetto register shifts and mixed registration

PubMed Central

Titze, Ingo R.

2014-01-01

The origin of vocal registers has generally been attributed to differential activation of cricothyroid and thyroarytenoid muscles in the larynx. Register shifts, however, have also been shown to be affected by glottal pressures exerted on vocal fold surfaces, which can change with loudness, pitch, and vowel. Here it is shown computationally and with empirical data that intraglottal pressures can change abruptly when glottal adductory geometry is changed relatively smoothly from convergent to divergent. An intermediate shape between large convergence and large divergence, namely, a nearly rectangular glottal shape with almost parallel vocal fold surfaces, is associated with mixed registration. It can be less stable than either of the highly angular shapes unless transglottal pressure is reduced and upper stiffness of vocal fold tissues is balanced with lower stiffness. This intermediate state of adduction is desirable because it leads to a low phonation threshold pressure with moderate vocal fold collision. Achieving mixed registration consistently across wide ranges of F0, lung pressure, and vocal tract shapes appears to be a balancing act of coordinating laryngeal muscle activation with vocal tract pressures. Surprisingly, a large transglottal pressure is not facilitative in this process, exacerbating the bi-stable condition and the associated register contrast. PMID:25235006

Three-dimensional optical reconstruction of vocal fold kinematics using high-speed video with a laser projection system

PubMed Central

Luegmair, Georg; Mehta, Daryush D.; Kobler, James B.; Döllinger, Michael

2015-01-01

Vocal fold kinematics and its interaction with aerodynamic characteristics play a primary role in acoustic sound production of the human voice. Investigating the temporal details of these kinematics using high-speed videoendoscopic imaging techniques has proven challenging in part due to the limitations of quantifying complex vocal fold vibratory behavior using only two spatial dimensions. Thus, we propose an optical method of reconstructing the superior vocal fold surface in three spatial dimensions using a high-speed video camera and laser projection system. Using stereo-triangulation principles, we extend the camera-laser projector method and present an efficient image processing workflow to generate the three-dimensional vocal fold surfaces during phonation captured at 4000 frames per second. Initial results are provided for airflow-driven vibration of an ex vivo vocal fold model in which at least 75% of visible laser points contributed to the reconstructed surface. The method captures the vertical motion of the vocal folds at a high accuracy to allow for the computation of three-dimensional mucosal wave features such as vibratory amplitude, velocity, and asymmetry. PMID:26087485

Phasegram Analysis of Vocal Fold Vibration Documented With Laryngeal High-speed Video Endoscopy.

PubMed

Herbst, Christian T; Unger, Jakob; Herzel, Hanspeter; Švec, Jan G; Lohscheller, Jörg

2016-11-01

In a recent publication, the phasegram, a bifurcation diagram over time, has been introduced as an intuitive visualization tool for assessing the vibratory states of oscillating systems. Here, this nonlinear dynamics approach is augmented with quantitative analysis parameters, and it is applied to clinical laryngeal high-speed video (HSV) endoscopic recordings of healthy and pathological phonations. HSV data from a total of 73 females diagnosed as healthy (n = 42), or with functional dysphonia (n = 15) or with unilateral vocal fold paralysis (n = 16), were quantitatively analyzed. Glottal area waveforms (GAW) and left and right hemi-GAWs (hGAW) were extracted from the HSV recordings. Based on Poincaré sections through phase space-embedded signals, two novel quantitative parameters were computed: the phasegram entropy (PE) and the phasegram complexity estimate (PCE), inspired by signal entropy and correlation dimension computation, respectively. Both PE and PCE assumed higher average values (suggesting more irregular vibrations) for the pathological as compared with the healthy participants, thus significantly discriminating healthy group from the paralysis group (P = 0.02 for both PE and PCE). Comparisons of individual PE or PCE data for the left and the right hGAW within each subject resulted in asymmetry measures for the regularity of vocal fold vibration. The PCE-based asymmetry measure revealed significant differences between the healthy group and the paralysis group (P = 0.03). Quantitative phasegram analysis of GAW and hGAW data is a promising tool for the automated processing of HSV data in research and in clinical practice. Copyright © 2016 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

The influence of material anisotropy on vibration at onset in a three-dimensional vocal fold model

PubMed Central

Zhang, Zhaoyan

2014-01-01

Although vocal folds are known to be anisotropic, the influence of material anisotropy on vocal fold vibration remains largely unknown. Using a linear stability analysis, phonation onset characteristics were investigated in a three-dimensional anisotropic vocal fold model. The results showed that isotropic models had a tendency to vibrate in a swing-like motion, with vibration primarily along the superior-inferior direction. Anterior-posterior (AP) out-of-phase motion was also observed and large vocal fold vibration was confined to the middle third region along the AP length. In contrast, increasing anisotropy or increasing AP-transverse stiffness ratio suppressed this swing-like motion and allowed the vocal fold to vibrate in a more wave-like motion with strong medial-lateral motion over the entire medial surface. Increasing anisotropy also suppressed the AP out-of-phase motion, allowing the vocal fold to vibrate in phase along the entire AP length. Results also showed that such improvement in vibration pattern was the most effective with large anisotropy in the cover layer alone. These numerical predictions were consistent with previous experimental observations using self-oscillating physical models. It was further hypothesized that these differences may facilitate complete glottal closure in finite-amplitude vibration of anisotropic models as observed in recent experiments. PMID:24606284

High-Performance Agent-Based Modeling Applied to Vocal Fold Inflammation and Repair.

PubMed

Seekhao, Nuttiiya; Shung, Caroline; JaJa, Joseph; Mongeau, Luc; Li-Jessen, Nicole Y K

2018-01-01

Fast and accurate computational biology models offer the prospect of accelerating the development of personalized medicine. A tool capable of estimating treatment success can help prevent unnecessary and costly treatments and potential harmful side effects. A novel high-performance Agent-Based Model (ABM) was adopted to simulate and visualize multi-scale complex biological processes arising in vocal fold inflammation and repair. The computational scheme was designed to organize the 3D ABM sub-tasks to fully utilize the resources available on current heterogeneous platforms consisting of multi-core CPUs and many-core GPUs. Subtasks are further parallelized and convolution-based diffusion is used to enhance the performance of the ABM simulation. The scheme was implemented using a client-server protocol allowing the results of each iteration to be analyzed and visualized on the server (i.e., in-situ ) while the simulation is running on the same server. The resulting simulation and visualization software enables users to interact with and steer the course of the simulation in real-time as needed. This high-resolution 3D ABM framework was used for a case study of surgical vocal fold injury and repair. The new framework is capable of completing the simulation, visualization and remote result delivery in under 7 s per iteration, where each iteration of the simulation represents 30 min in the real world. The case study model was simulated at the physiological scale of a human vocal fold. This simulation tracks 17 million biological cells as well as a total of 1.7 billion signaling chemical and structural protein data points. The visualization component processes and renders all simulated biological cells and 154 million signaling chemical data points. The proposed high-performance 3D ABM was verified through comparisons with empirical vocal fold data. Representative trends of biomarker predictions in surgically injured vocal folds were observed.

High-Performance Agent-Based Modeling Applied to Vocal Fold Inflammation and Repair

PubMed Central

Seekhao, Nuttiiya; Shung, Caroline; JaJa, Joseph; Mongeau, Luc; Li-Jessen, Nicole Y. K.

2018-01-01

Fast and accurate computational biology models offer the prospect of accelerating the development of personalized medicine. A tool capable of estimating treatment success can help prevent unnecessary and costly treatments and potential harmful side effects. A novel high-performance Agent-Based Model (ABM) was adopted to simulate and visualize multi-scale complex biological processes arising in vocal fold inflammation and repair. The computational scheme was designed to organize the 3D ABM sub-tasks to fully utilize the resources available on current heterogeneous platforms consisting of multi-core CPUs and many-core GPUs. Subtasks are further parallelized and convolution-based diffusion is used to enhance the performance of the ABM simulation. The scheme was implemented using a client-server protocol allowing the results of each iteration to be analyzed and visualized on the server (i.e., in-situ) while the simulation is running on the same server. The resulting simulation and visualization software enables users to interact with and steer the course of the simulation in real-time as needed. This high-resolution 3D ABM framework was used for a case study of surgical vocal fold injury and repair. The new framework is capable of completing the simulation, visualization and remote result delivery in under 7 s per iteration, where each iteration of the simulation represents 30 min in the real world. The case study model was simulated at the physiological scale of a human vocal fold. This simulation tracks 17 million biological cells as well as a total of 1.7 billion signaling chemical and structural protein data points. The visualization component processes and renders all simulated biological cells and 154 million signaling chemical data points. The proposed high-performance 3D ABM was verified through comparisons with empirical vocal fold data. Representative trends of biomarker predictions in surgically injured vocal folds were observed. PMID:29706894

Fully-coupled aeroelastic simulation with fluid compressibility — For application to vocal fold vibration

PubMed Central

Yang, Jubiao; Wang, Xingshi; Krane, Michael; Zhang, Lucy T.

2017-01-01

In this study, a fully-coupled fluid–structure interaction model is developed for studying dynamic interactions between compressible fluid and aeroelastic structures. The technique is built based on the modified Immersed Finite Element Method (mIFEM), a robust numerical technique to simulate fluid–structure interactions that has capabilities to simulate high Reynolds number flows and handles large density disparities between the fluid and the solid. For accurate assessment of this intricate dynamic process between compressible fluid, such as air and aeroelastic structures, we included in the model the fluid compressibility in an isentropic process and a solid contact model. The accuracy of the compressible fluid solver is verified by examining acoustic wave propagations in a closed and an open duct, respectively. The fully-coupled fluid–structure interaction model is then used to simulate and analyze vocal folds vibrations using compressible air interacting with vocal folds that are represented as layered viscoelastic structures. Using physiological geometric and parametric setup, we are able to obtain a self-sustained vocal fold vibration with a constant inflow pressure. Parametric studies are also performed to study the effects of lung pressure and vocal fold tissue stiffness in vocal folds vibrations. All the case studies produce expected airflow behavior and a sustained vibration, which provide verification and confidence in our future studies of realistic acoustical studies of the phonation process. PMID:29527067

Characterization of Vocal Fold Vibration in Sulcus Vocalis Using High-Speed Digital Imaging

ERIC Educational Resources Information Center

Yamauchi, Akihito; Yokonishi, Hisayuki; Imagawa, Hiroshi; Sakakibara, Ken-Ichi; Nito, Takaharu; Tayama, Niro; Yamasoba, Tatsuya

2017-01-01

Purpose: The aim of the present study was to qualitatively and quantitatively characterize vocal fold vibrations in sulcus vocalis by high-speed digital imaging (HSDI) and to clarify the correlations between HSDI-derived parameters and traditional vocal parameters. Method: HSDI was performed in 20 vocally healthy subjects (8 men and 12 women) and…

The shear modulus of the human vocal fold, preliminary results from 20 larynxes.

PubMed

Goodyer, Eric; Hemmerich, Sandra; Müller, Frank; Kobler, James B; Hess, Markus

2007-01-01

Quantification of the elastic properties of the human vocal fold provides invaluable data for researchers deriving mathematical models of phonation, developing tissue engineering therapies, and as normative data for comparison between healthy and scarred tissue. This study measured the shear modulus of excised cadaver vocal folds from 20 subjects. Twenty freshly excised human larynxes were evaluated less than four days post-mortem. They were split along the saggital plane and mounted without tension. Shear modulus was obtained by two different methods. For method 1 cyclical shear stress was applied transversely to the mid-membranous portion of the vocal fold, and shear modulus derived by applying a simple shear model. For method 2 the apparatus was configured as an indentometer, and shear modulus obtained from the stress/strain data by applying an established analytical technique. Method 1 shear model for male larynxes yielded a range from 246 to 3,356 Pa, with a mean value of 1,008 and SD of 380. The range for female larynxes was 286-3,332 Pa, with a mean value of 1,237 and SD of 768. Method 2 indentometer model for male larynxes yielded a range from 552 to 2,741 Pa, with a mean value of 1,000 and SD of 460. The range for female larynxes was 509-1,989 Pa, with a mean value of 1,332 and SD of 428. We have successfully demonstrated two methodologies that are capable of directly measuring the shear modulus of the human vocal fold, without dissecting out the vocal fold cover tissue. The sample size of nine female and 11 male larynxes is too small to validate a general conclusion. The high degree of variability in this small cohort of subjects indicates that factors such as age, health status, and post-mortem delay may be significant; and that there is range of 'normality' for vocal fold tissue.

Comprehensive Outcome Researches of Intralesional Steroid Injection on Benign Vocal Fold Lesions.

PubMed

Wang, Chi-Te; Lai, Mei-Shu; Hsiao, Tzu-Yu

2015-09-01

This study investigated multidimensional treatment outcomes, including prognostic factors and side effects of vocal fold steroid injection (VFSI). We recruited 126 consecutive patients, including patients with 49 nodules, 47 polyps, and 30 mucus retention cysts. All the patients received VFSI under local anesthesia in the office settings. Treatment outcomes were evaluated 1 and 2 months after the procedure, including endoscopic evaluation, perceptual voice quality (GRB scores), acoustic analysis, and 10-item Voice Handicap Index (VHI-10). More than 80% of the patients reported subjective improvements after VFSI. Objective measurements revealed significant improvements from baseline in most of the outcome parameters (P<0.05). Higher occupational vocal demands and fibrotic vocal nodules were significantly associated with poorer clinical responses as measured by the VHI-10 and GRB scores, respectively. For vocal polyps, dysphonia for more than 12 months were significantly associated with higher postoperative VHI-10 scores, whereas patients with laryngopharyngeal reflux (LPR) showed significantly poor postoperative voice quality as measured by GRB scores. Side effects after VFSI included hematoma (27%), triamcinolone deposits (4%), and vocal atrophy (1%), which resolved spontaneously within 1-2 months. Presentation with vocal fold ectasias/varicosities and higher vocal demands were significantly correlated with postoperative vocal hematoma. This study demonstrated significant improvements after VFSI in vocal nodules, polyps, and cysts. Occupational vocal demand and subtypes of vocal nodules are closely related to the treatment outcomes after VFSI, whereas symptom duration and LPR were significant prognostic factors for VFSI treatment outcomes in vocal polyps. Side effects after receiving VFSI were mostly self-limited without sequel, whereas the incidence rates might be varied by the injection approach and the timing for postoperative follow-up. Copyright © 2015 The

Computational simulations of vocal fold vibration: Bernoulli versus Navier-Stokes.

PubMed

Decker, Gifford Z; Thomson, Scott L

2007-05-01

The use of the mechanical energy (ME) equation for fluid flow, an extension of the Bernoulli equation, to predict the aerodynamic loading on a two-dimensional finite element vocal fold model is examined. Three steady, one-dimensional ME flow models, incorporating different methods of flow separation point prediction, were compared. For two models, determination of the flow separation point was based on fixed ratios of the glottal area at separation to the minimum glottal area; for the third model, the separation point determination was based on fluid mechanics boundary layer theory. Results of flow rate, separation point, and intraglottal pressure distribution were compared with those of an unsteady, two-dimensional, finite element Navier-Stokes model. Cases were considered with a rigid glottal profile as well as with a vibrating vocal fold. For small glottal widths, the three ME flow models yielded good predictions of flow rate and intraglottal pressure distribution, but poor predictions of separation location. For larger orifice widths, the ME models were poor predictors of flow rate and intraglottal pressure, but they satisfactorily predicted separation location. For the vibrating vocal fold case, all models resulted in similar predictions of mean intraglottal pressure, maximum orifice area, and vibration frequency, but vastly different predictions of separation location and maximum flow rate.

The relation of vocal fold lesions and voice quality to voice handicap and psychosomatic well-being.

PubMed

Smits, R; Marres, H; de Jong, Felix

2012-07-01

Voice disorders have a multifactorial genesis and may be present in various ways. They can cause a significant communication handicap and impaired quality of life. To assess the effect of vocal fold lesions and voice quality on voice handicap and psychosomatic well-being. Female patients, aged 18-65 years, who were referred to the outpatient clinic with voice problems were subsequently assessed. Laryngostroboscopic examination and acoustic voice analysis were carried out, and the patients were asked to fill in the Voice Handicap Index (VHI) and Symptom Check List-90 questionnaires. Eighty-two patients were included. In 43 patients (52.4%), a vocal fold lesion was observed. The VHI and psychosomatic well-being did not differ significantly between patients with and without a vocal fold lesion. The patients with a vocal fold lesion showed lower scores on the Dysphonia Severity Index (DSI) compared with those without a vocal fold lesion. However, the DSI was not correlated with voice handicap and psychosomatic well-being, except for the VHI physical subscale. Objective measurement does not necessarily correlate with the subjective appraisal of the patient's voice handicap and psychosomatic well-being. Furthermore, the criterion of the presence of a vocal fold lesion as the base of indemnity that is applied by health insurance institutions should be questioned. Copyright © 2012 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

Detection of the Vibration Signal from Human Vocal Folds Using a 94-GHz Millimeter-Wave Radar

PubMed Central

Chen, Fuming; Li, Sheng; Zhang, Yang; Wang, Jianqi

2017-01-01

The detection of the vibration signal from human vocal folds provides essential information for studying human phonation and diagnosing voice disorders. Doppler radar technology has enabled the noncontact measurement of the human-vocal-fold vibration. However, existing systems must be placed in close proximity to the human throat and detailed information may be lost because of the low operating frequency. In this paper, a long-distance detection method, involving the use of a 94-GHz millimeter-wave radar sensor, is proposed for detecting the vibration signals from human vocal folds. An algorithm that combines empirical mode decomposition (EMD) and the auto-correlation function (ACF) method is proposed for detecting the signal. First, the EMD method is employed to suppress the noise of the radar-detected signal. Further, the ratio of the energy and entropy is used to detect voice activity in the radar-detected signal, following which, a short-time ACF is employed to extract the vibration signal of the human vocal folds from the processed signal. For validating the method and assessing the performance of the radar system, a vibration measurement sensor and microphone system are additionally employed for comparison. The experimental results obtained from the spectrograms, the vibration frequency of the vocal folds, and coherence analysis demonstrate that the proposed method can effectively detect the vibration of human vocal folds from a long detection distance. PMID:28282892

Modal response of a computational vocal fold model with a substrate layer of adipose tissue.

PubMed

Jones, Cameron L; Achuthan, Ajit; Erath, Byron D

2015-02-01

This study demonstrates the effect of a substrate layer of adipose tissue on the modal response of the vocal folds, and hence, on the mechanics of voice production. Modal analysis is performed on the vocal fold structure with a lateral layer of adipose tissue. A finite element model is employed, and the first six mode shapes and modal frequencies are studied. The results show significant changes in modal frequencies and substantial variation in mode shapes depending on the strain rate of the adipose tissue. These findings highlight the importance of considering adipose tissue in computational vocal fold modeling.

Predicted singers' vocal fold lengths and voice classification-a study of x-ray morphological measures.

PubMed

Roers, Friederike; Mürbe, Dirk; Sundberg, Johan

2009-07-01

Students admitted to the solo singing education at the University of Music Dresden, Germany have been submitted to a detailed physical examination of a variety of factors with relevance to voice function since 1959. In the years 1959-1991, this scheme of examinations included X-ray profiles of the singers' vocal tracts. This material of 132 X-rays of voice professionals was used to investigate different laryngeal morphological measures and their relation to vocal fold length. Further, the study aimed to investigate if there are consistent anatomical differences between singers of different voice classifications. The study design used was a retrospective analysis. Vocal fold length could be measured in 29 of these singer subjects directly. These data showed a strong correlation with the anterior-posterior diameter of the subglottis and the trachea as well as with the distance from the anterior contour of the thyroid cartilage to the anterior contour of the spine. These relations were used in an attempt to predict the 132 singers' vocal fold lengths. The results revealed a clear covariation between predicted vocal fold length and voice classification. Anterior-posterior subglottic-tracheal diameter yielded mean vocal fold lengths of 14.9, 16.0, 16.6, 18.4, 19.5, and 20.9mm for sopranos, mezzo-sopranos, altos, tenors, baritones, and basses, respectively. The data support the assumption that there are consistent anatomical laryngeal differences between singers of different voice classifications, which are of relevance to pitch range and timbre of the voice.

Three-dimensional biomechanical properties of human vocal folds: parameter optimization of a numerical model to match in vitro dynamics.

PubMed

Yang, Anxiong; Berry, David A; Kaltenbacher, Manfred; Döllinger, Michael

2012-02-01

The human voice signal originates from the vibrations of the two vocal folds within the larynx. The interactions of several intrinsic laryngeal muscles adduct and shape the vocal folds to facilitate vibration in response to airflow. Three-dimensional vocal fold dynamics are extracted from in vitro hemilarynx experiments and fitted by a numerical three-dimensional-multi-mass-model (3DM) using an optimization procedure. In this work, the 3DM dynamics are optimized over 24 experimental data sets to estimate biomechanical vocal fold properties during phonation. Accuracy of the optimization is verified by low normalized error (0.13 ± 0.02), high correlation (83% ± 2%), and reproducible subglottal pressure values. The optimized, 3DM parameters yielded biomechanical variations in tissue properties along the vocal fold surface, including variations in both the local mass and stiffness of vocal folds. That is, both mass and stiffness increased along the superior-to-inferior direction. These variations were statistically analyzed under different experimental conditions (e.g., an increase in tension as a function of vocal fold elongation and an increase in stiffness and a decrease in mass as a function of glottal airflow). The study showed that physiologically relevant vocal fold tissue properties, which cannot be directly measured during in vivo human phonation, can be captured using this 3D-modeling technique. © 2012 Acoustical Society of America

Three-dimensional biomechanical properties of human vocal folds: Parameter optimization of a numerical model to match in vitro dynamics

PubMed Central

Yang, Anxiong; Berry, David A.; Kaltenbacher, Manfred; Döllinger, Michael

2012-01-01

The human voice signal originates from the vibrations of the two vocal folds within the larynx. The interactions of several intrinsic laryngeal muscles adduct and shape the vocal folds to facilitate vibration in response to airflow. Three-dimensional vocal fold dynamics are extracted from in vitro hemilarynx experiments and fitted by a numerical three-dimensional-multi-mass-model (3DM) using an optimization procedure. In this work, the 3DM dynamics are optimized over 24 experimental data sets to estimate biomechanical vocal fold properties during phonation. Accuracy of the optimization is verified by low normalized error (0.13 ± 0.02), high correlation (83% ± 2%), and reproducible subglottal pressure values. The optimized, 3DM parameters yielded biomechanical variations in tissue properties along the vocal fold surface, including variations in both the local mass and stiffness of vocal folds. That is, both mass and stiffness increased along the superior-to-inferior direction. These variations were statistically analyzed under different experimental conditions (e.g., an increase in tension as a function of vocal fold elongation and an increase in stiffness and a decrease in mass as a function of glottal airflow). The study showed that physiologically relevant vocal fold tissue properties, which cannot be directly measured during in vivo human phonation, can be captured using this 3D-modeling technique. PMID:22352511

Practice variations in voice treatment selection following vocal fold mucosal resection.

PubMed

Moore, Jaime E; Rathouz, Paul J; Havlena, Jeffrey A; Zhao, Qianqian; Dailey, Seth H; Smith, Maureen A; Greenberg, Caprice C; Welham, Nathan V

2016-11-01

To characterize initial voice treatment selection following vocal fold mucosal resection in a Medicare population. Retrospective analysis of a large, nationally representative Medicare claims database. Patients with > 12 months of continuous Medicare coverage who underwent a leukoplakia- or cancer-related vocal fold mucosal resection (index) procedure during calendar years 2004 to 2009 were studied. The primary outcome of interest was receipt of initial voice treatment (thyroplasty, vocal fold injection, or speech therapy) following the index procedure. We evaluated the cumulative incidence of each postindex treatment type, treating the other treatment types as competing risks, and further evaluated postindex treatment utilization using the proportional hazards model for the subdistribution of a competing risk. Patient age, sex, and Medicaid eligibility were used as predictors. A total of 2,041 patients underwent 2,427 index procedures during the study period. In 14% of cases, an initial voice treatment event was identified. Women were significantly less likely to receive surgical or behavioral treatment compared to men. From age 65 to 75 years, the likelihood of undergoing surgical treatment increased significantly with each 5-year age increase; after age 75 years, the likelihood of undergoing either surgical or behavioral treatment decreased significantly every 5 years. Patients with low socioeconomic status were significantly less likely to undergo speech therapy. The majority of Medicare patients do not undergo voice treatment following vocal fold mucosal resection. Further, the treatments analyzed here appear disproportionally utilized based on patient sex, age, and socioeconomic status. Additional research is needed to determine whether these observations reflect clinically explainable differences or disparities in care. 2c. Laryngoscope, 126:2505-2512, 2016. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

Practice variations in voice treatment selection following vocal fold mucosal resection

PubMed Central

Moore, Jaime E.; Rathouz, Paul J.; Havlena, Jeffrey A.; Zhao, Qianqian; Dailey, Seth H.; Smith, Maureen A.; Greenberg, Caprice C.; Welham, Nathan V.

2016-01-01

Objective To characterize initial voice treatment selection following vocal fold mucosal resection in a Medicare population. Study Design Retrospective analysis of a large, nationally-representative Medicare claims database. Methods Patients with >12 months of continuous Medicare coverage who underwent a leukoplakia- or cancer-related vocal fold mucosal resection (index) procedure during calendar years 2004–2009 were studied. The primary outcome of interest was receipt of initial voice treatment (thyroplasty, vocal fold injection, or speech therapy) following the index procedure. We evaluated the cumulative incidence of each post-index treatment type treating the other treatment types as competing risks, and further evaluated post-index treatment utilization using the proportional hazards model for the subdistribution of a competing risk. Patient age, sex and Medicaid eligibility were used as predictors. Results 2041 patients underwent 2427 index procedures during the study period. An initial voice treatment event was identified in 14% of cases. Women were significantly less likely to receive surgical or behavioral treatment compared to men. From age 65–75 years, the likelihood of undergoing surgical treatment increased significantly with each 5-year age increase; after age 75 years, the likelihood of undergoing either surgical or behavioral treatment decreased significantly every 5 years. Patients with low socioeconomic status were significantly less likely to undergo speech therapy. Conclusions The majority of Medicare patients do not undergo voice treatment following vocal fold mucosal resection. Further, the treatments analyzed here appear disproportionally utilized based on patient sex, age and socioeconomic status. Additional research is needed to determine whether these observations reflect clinically explainable differences or disparities in care. Level of Evidence 2c PMID:26972900

War, politics, and voice: the vocal fold paralysis of George Orwell.

PubMed

Sulica, Lucian

2007-02-01

In 1936, like many individuals who felt the menace of fascism, George Orwell traveled to Spain to lend his support to the cause of the Republic, battling a right-wing coup. Spain, during its Civil War, was an eye-opening experience for him, yielding insights that allowed, and even compelled him to write Animal Farm and 1984. Spain was also a close brush with death. In May of 1937, in a trench on a windswept ridge near Huesca, Orwell was shot through the neck by a sniper, leaving him with a paralyzed vocal fold. A thorough review of firsthand accounts of Orwell's injury and subsequent care was made. These are presented in the context of current knowledge of ballistics, penetrating neck trauma, and vocal fold paralysis. Orwell survived largely because of the nature of his wounding with a high-velocity jacketed military round. His recovery followed a course in many ways typical for patients with vocal fold paralysis. His writings leave us a unique and extraordinary account of the experience of being shot, of the medical care of the day, of the handicap of paralytic dysphonia, and of survival and heroism under extraordinary circumstances.

In vivo comparison of biomimetic approaches for tissue regeneration of the scarred vocal fold.

PubMed

Thibeault, Susan L; Klemuk, Sarah A; Smith, Marshall E; Leugers, Cecilia; Prestwich, Glenn

2009-07-01

The objective of this study was to determine if three different biomimetic approaches could facilitate tissue regeneration and improve viscoelastic properties in the scarred vocal fold lamina propria extracellular matrix (ECM). Twenty rabbit vocal folds were biopsied bilaterally; 2 months postinjury rabbits were unilaterally treated with (i) autologous fibroblasts, (ii) a semisynthetic ECM (sECM), or (iii) autologous fibroblasts encapsulated in sECM. Saline was injected as a control into the contralateral fold. Animals were sacrificed 2 months after treatment. Outcomes measured were procollagen, collagen, and fibronectin levels in the lamina propria, and tissue viscosity and elasticity across three frequency decades. All treatment groups demonstrated accelerated proliferation of the ECM. Vocal fold lamina propria treated with autologous fibroblasts were found to have significantly improved viscosity (p = 0.0077) and elasticity (p = 0.0081) compared to saline. This treatment group had significantly elevated fibronectin levels. sECM and autologous fibroblasts/sECM groups had significantly elevated levels of procollagen, collagen, and fibronectin, indicating abundant matrix production as compared to saline with viscoelastic measures that did not differ statistically from controls. The use of autologous fibroblasts led to better restoration of the vocal fold lamina propria biomechanical properties. Optimization of cell-scaffold interactions and subsequent cell behavior is necessary for utilization of scaffold and scaffold-cell approaches.

Design of a mechanical larynx with agarose as a soft tissue substitute for vocal fold applications.

PubMed

Choo, J Q; Lau, D P C; Chui, C K; Yang, T; Chng, C B; Teoh, S H

2010-06-01

Mechanical and computational models consisting of flow channels with convergent and oscillating constrictions have been applied to study the dynamics of human vocal fold vibration. To the best of our knowledge, no mechanical model has been studied using a material substitute with similar physical properties to the human vocal fold for surgical experimentation. In this study, we design and develop a mechanical larynx with agarose as a vocal fold substitute, and assess its suitability for surgical experimentation. Agarose is selected as a substitute for the vocal fold as it exhibits similar nonlinear hyperelastic characteristics to biological soft tissue. Through uniaxial compression and extension tests, we determined that agarose of 0.375% concentration most closely resembles the vocal fold mucosa and ligament of a 20-year old male for small tensile strain with an R(2) value of 0.9634 and root mean square error of 344.05±39.84 Pa. Incisions of 10 mm lengthwise and 3 mm in depth were created parallel to the medial edge on the superior surface of agar phantom. These were subjected to vibrations of 80, 130, and 180 Hz, at constant amplitude of 0.9 mm over a period of 10 min each in the mechanical larynx model. Lateral expansion of the incision was observed to be most significant for the lower frequency of 80 Hz. This model serves as a basis for future assessments of wound closure techniques during microsurgery to the vocal fold.

Vocal Fold Epithelial Response to Luminal Osmotic Perturbation

ERIC Educational Resources Information Center

Sivasankar, Mahalakshmi; Fisher, Kimberly V.

2007-01-01

Purpose: Dry-air challenges increase the osmolarity of fluid lining the luminal surface of the proximal airway. The homeostasis of surface fluid is thought to be essential for voice production and laryngeal defense. Therefore, the authors hypothesized that viable vocal fold epithelium would generate a water flux to reduce an osmotic challenge (150…

Paradoxical vocal fold motion in children and adolescents.

PubMed

Sandage, Mary J; Zelazny, Sherri K

2004-10-01

Paradoxical vocal fold motion (PVFM) is a complex adductory disorder of the vocal folds that frequently is mistaken for asthma. PVFM typically requires behavioral intervention by a trained speech-language pathologist for complete resolution of the symptoms. Once thought to be limited to adults, PVFM has been increasingly documented and successfully treated in the child and adolescent population. Understanding PVFM requires thorough knowledge of the differential diagnoses, the clinical features of PVFM, the differentiation of PVFM from asthma, the medical professionals involved in the diagnosis and treatment, and the behavioral interventions that are commonly prescribed. Teachers, school nurses, and coaches may be the first professionals to see the symptoms in children and assume that they have asthma. Successful referral, diagnosis, and behavioral treatment requires a team of individuals in the child's community, including the school speech-language pathologist, who can work together to ensure identification and resolution of the symptoms. This article discusses etiologies, differential diagnosis, referral, medical management, evaluation, and behavioral treatment of the child or adolescent with PVFM.

Relation of structural and vibratory kinematics of the vocal folds to two acoustic measures of breathy voice based on computational modeling

PubMed Central

Samlan, Robin A.; Story, Brad H.

2011-01-01

Purpose To relate vocal fold structure and kinematics to two acoustic measures: cepstral peak prominence (CPP) and the amplitude of the first harmonic relative to the second (H1-H2). Method A computational, kinematic model of the medial surfaces of the vocal folds was used to specify features of vocal fold structure and vibration in a manner consistent with breathy voice. Four model parameters were altered: degree of vocal fold adduction, surface bulging, vibratory nodal point, and supraglottal constriction. CPP and H1-H2 were measured from simulated glottal area, glottal flow and acoustic waveforms and related to the underlying vocal fold kinematics. Results CPP decreased with increased separation of the vocal processes, whereas the nodal point location had little effect. H1-H2 increased as a function of separation of the vocal processes in the range of 1–1.5 mm and decreased with separation > 1.5 mm. Conclusions CPP is generally a function of vocal process separation. H1*-H2* will increase or decrease with vocal process separation based on vocal fold shape, pivot point for the rotational mode, and supraglottal vocal tract shape, limiting its utility as an indicator of breathy voice. Future work will relate the perception of breathiness to vocal fold kinematics and acoustic measures. PMID:21498582

Relation of structural and vibratory kinematics of the vocal folds to two acoustic measures of breathy voice based on computational modeling.

PubMed

Samlan, Robin A; Story, Brad H

2011-10-01

To relate vocal fold structure and kinematics to 2 acoustic measures: cepstral peak prominence (CPP) and the amplitude of the first harmonic relative to the second (H1-H2). The authors used a computational, kinematic model of the medial surfaces of the vocal folds to specify features of vocal fold structure and vibration in a manner consistent with breathy voice. Four model parameters were altered: degree of vocal fold adduction, surface bulging, vibratory nodal point, and supraglottal constriction. CPP and H1-H2 were measured from simulated glottal area, glottal flow, and acoustic waveforms and were related to the underlying vocal fold kinematics. CPP decreased with increased separation of the vocal processes, whereas the nodal point location had little effect. H1-H2 increased as a function of separation of the vocal processes in the range of 1.0 mm to 1.5 mm and decreased with separation > 1.5 mm. CPP is generally a function of vocal process separation. H1*-H2* (see paragraph 6 of article text for an explanation of the asterisks) will increase or decrease with vocal process separation on the basis of vocal fold shape, pivot point for the rotational mode, and supraglottal vocal tract shape, limiting its utility as an indicator of breathy voice. Future work will relate the perception of breathiness to vocal fold kinematics and acoustic measures.

Computation of physiological human vocal fold parameters by mathematical optimization of a biomechanical model

PubMed Central

Yang, Anxiong; Stingl, Michael; Berry, David A.; Lohscheller, Jörg; Voigt, Daniel; Eysholdt, Ulrich; Döllinger, Michael

2011-01-01

With the use of an endoscopic, high-speed camera, vocal fold dynamics may be observed clinically during phonation. However, observation and subjective judgment alone may be insufficient for clinical diagnosis and documentation of improved vocal function, especially when the laryngeal disease lacks any clear morphological presentation. In this study, biomechanical parameters of the vocal folds are computed by adjusting the corresponding parameters of a three-dimensional model until the dynamics of both systems are similar. First, a mathematical optimization method is presented. Next, model parameters (such as pressure, tension and masses) are adjusted to reproduce vocal fold dynamics, and the deduced parameters are physiologically interpreted. Various combinations of global and local optimization techniques are attempted. Evaluation of the optimization procedure is performed using 50 synthetically generated data sets. The results show sufficient reliability, including 0.07 normalized error, 96% correlation, and 91% accuracy. The technique is also demonstrated on data from human hemilarynx experiments, in which a low normalized error (0.16) and high correlation (84%) values were achieved. In the future, this technique may be applied to clinical high-speed images, yielding objective measures with which to document improved vocal function of patients with voice disorders. PMID:21877808

A bioreactor for the dynamic mechanical stimulation of vocal-fold fibroblasts based on vibro-acoustography

NASA Astrophysics Data System (ADS)

Chan, Roger W.; Rodriguez, Maritza

2005-09-01

During voice production, the vocal folds undergo airflow-induced self-sustained oscillation at a fundamental frequency of around 100-1000 Hz, with an amplitude of around 1-3 mm. The vocal-fold extracellular matrix (ECM), with appropriate tissue viscoelastic properties, is optimally tuned for such vibration. Vocal-fold fibroblasts regulate the gene expressions for key ECM proteins (e.g., collagen, fibronectin, fibromodulin, and hyaluronic acid), and these expressions are affected by the stress fields experi- enced by the fibroblasts. This study attempts to develop a bioreactor for cultivating cells under a micromechanical environment similar to that in vivo, based on the principle of vibro-acoustography. Vocal-fold fibroblasts from primary culture were grown in 3D, biodegradable scaffolds, and were excited dynamically by the radiation force generated by amplitude modulation of two confocal ultrasound beams of slightly different frequencies. Low-frequency acoustic radiation force was applied to the scaffold surface, and its vibratory response was imaged by videostroboscopy. A phantom tissue (standard viscoelastic material) with known elastic modulus was also excited and its vibratory frequency and amplitude were measured by videostroboscopy. Results showed that the bioreactor was capable of delivering mechanical stimuli to the tissue constructs in a physiological frequency range (100-1000 Hz), supporting its potential for vocal-fold tissue engineering applications. [Work supported by NIH Grant R01 DC006101.

Voice-related quality of life (V-RQOL) following type I thyroplasty for unilateral vocal fold paralysis.

PubMed

Hogikyan, N D; Wodchis, W P; Terrell, J E; Bradford, C R; Esclamado, R M

2000-09-01

Unilateral vocal fold paralysis is a common clinical problem which frequently causes severe dysphonia. Various treatment options exist for this condition, with the type I thyroplasty being one of the more commonly performed surgical procedures for vocal rehabilitation. The Voice-Related Quality of Life (V-RQOL) Measure is a validated outcomes instrument for voice disorders. This study measured the V-RQOL of patients with unilateral vocal fold paralysis who had undergone a type I thyroplasty and compared these scores to those of patients with untreated and uncompensated unilateral vocal fold paralysis and to normals. Treated patients had significantly higher domain and overall V-RQOL scores than untreated patients, but also scored lower than normals. These differences were true across gender and age. Patients who were more distant from surgery had lower V-RQOL scores than those who had more recently been treated. It is concluded that type I thyroplasty leads to a significantly higher V-RQOL for patients with unilateral vocal fold paralysis. This study also demonstrates further the utility of patient-oriented measures of treatment outcome.

Numerical solution of fluid-structure interaction represented by human vocal folds in airflow

NASA Astrophysics Data System (ADS)

Valášek, J.; Sváček, P.; Horáček, J.

2016-03-01

The paper deals with the human vocal folds vibration excited by the fluid flow. The vocal fold is modelled as an elastic body assuming small displacements and therefore linear elasticity theory is used. The viscous incompressible fluid flow is considered. For purpose of numerical solution the arbitrary Lagrangian-Euler method (ALE) is used. The whole problem is solved by the finite element method (FEM) based solver. Results of numerical experiments with different boundary conditions are presented.

Acute exposure to vibration is an apoptosis-inducing stimulus in the vocal fold epithelium.

PubMed

Novaleski, Carolyn K; Kimball, Emily E; Mizuta, Masanobu; Rousseau, Bernard

2016-10-01

Clinical voice disorders pose significant communication-related challenges to patients. The purpose of this study was to quantify the rate of apoptosis and tumor necrosis factor-alpha (TNF-α) signaling in vocal fold epithelial cells in response to increasing time-doses and cycle-doses of vibration. 20 New Zealand white breeder rabbits were randomized to three groups of time-doses of vibration exposure (30, 60, 120min) or a control group (120min of vocal fold adduction and abduction). Estimated cycle-doses of vocal fold vibration were extrapolated based on mean fundamental frequency. Laryngeal tissue specimens were evaluated for apoptosis and gene transcript and protein levels of TNF-α. Results revealed that terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining was significantly higher after 120min of vibration compared to the control. Transmission electron microscopy (TEM) revealed no significant effect of time-dose on the mean area of epithelial cell nuclei. Extrapolated cycle-doses of vibration exposure were closely related to experimental time-dose conditions, although no significant correlations were observed with TUNEL staining or mean area of epithelial cell nuclei. TUNEL staining was positively correlated with TNF-α protein expression. Our findings suggest that apoptosis can be induced in the vocal fold epithelium after 120min of modal intensity phonation. In contrast, shorter durations of vibration exposure do not result in apoptosis signaling. However, morphological features of apoptosis are not observed using TEM. Future studies are necessary to examine the contribution of abnormal apoptosis to vocal fold diseases. Copyright © 2016 Elsevier Ltd. All rights reserved.

Acute Exposure to Vibration is an Apoptosis-Inducing Stimulus in the Vocal Fold Epithelium

PubMed Central

Novaleski, Carolyn K.; Kimball, Emily E.; Mizuta, Masanobu; Rousseau, Bernard

2016-01-01

Clinical voice disorders pose significant communication-related challenges to patients. The purpose of this study was to quantify the rate of apoptosis and tumor necrosis factor-alpha (TNF-α) signaling in vocal fold epithelial cells in response to increasing time-doses and cycle-doses of vibration. 20 New Zealand white breeder rabbits were randomized to three groups of time-doses of vibration exposure (30, 60, 120 minutes) or a control group (120 minutes of vocal fold adduction and abduction). Estimated cycle-doses of vocal fold vibration were extrapolated based on mean fundamental frequency. Laryngeal tissue specimens were evaluated for apoptosis and gene transcript and protein levels of TNF-α. Results revealed that terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining was significantly higher after 120 minutes of vibration compared to the control. Transmission electron microscopy (TEM) revealed no significant effect of time-dose on the mean area of epithelial cell nuclei. Extrapolated cycle-doses of vibration exposure were closely related to experimental time-dose conditions, although no significant correlations were observed with TUNEL staining or mean area of epithelial cell nuclei. TUNEL staining was positively correlated with TNF-α protein expression. Our findings suggest that apoptosis can be induced in the vocal fold epithelium after 120 minutes of modal intensity phonation. In contrast, shorter durations of vibration exposure do not result in apoptosis signaling. However, morphological features of apoptosis are not observed using TEM. Future studies are necessary to examine the contribution of abnormal apoptosis to vocal fold diseases. PMID:27577014

Ansa-RLN reinnervation for unilateral vocal fold paralysis in adolescents and young adults.

PubMed

Smith, Marshall E; Roy, Nelson; Stoddard, Kelly

2008-09-01

To assess the outcomes of management of unilateral vocal fold paralysis by ansa-RLN reinnervation in a series of patients ages 12-21. Clinical outcomes study. Six consecutive adolescents and young adults (ages 12-21 years) seeking treatment for unilateral vocal fold paralysis and glottal incompetence underwent ansa-RLN neurorraphy. Pre- and post-operative voice recordings acquired at least 1 year following surgery were submitted to acoustic and perceptual analysis. Patient-based measures were also taken. Mean perceptual visual analogue scale rating of dysphonia severity (0mm=profoundly abnormal voice, 100mm=completely normal voice) improved from 50mm pre-operatively to 82mm post-operatively. Mean maximum phonation time improved from 6.5s to 13.2s. Pitch and dynamic range were also observed to improve. Global self-ratings of voice function (0-100%) increased from 31.2% to 81.6% of normal. Ansa-RLN reinnervation is an effective treatment option for adolescents and young adults with unilateral vocal fold paralysis. The procedure has the potential to improve vocal function substantially, especially in those with isolated paralysis of the recurrent laryngeal nerve. The procedure alleviates the disadvantages associated with other surgical options for this age group.

Medial surface dynamics of the vocal folds in an in vivo canine model

NASA Astrophysics Data System (ADS)

Doellinger, Michael; Berke, Gerald S.; Chhetri, Dinesh K.; Berry, David A.

2004-05-01

Quantitative measurement of the medial surface dynamics of the vocal folds is important for understanding how sound is generated in the larynx. However, such data are hard to gather because of the inaccessibility of the vocal folds. Recent studies have applied hemi-larynx methodology to excised human larynges, to visualize these dynamics. The present study extends this methodology to obtain similar quantitative measurements using an in vivo canine hemi-larynx setup, with varying levels of stimulation to the recurrent laryngeal nerve. Use of an in vivo model allows us to examine effects of intrinsic muscle contraction on the medial surface of the vocal folds, to provide greater insight into mechanisms of vocal control. Data were collected using digital high-speed imaging with a sampling frequency of up to 4000 Hz, and a spatial resolution of up to 1024×1024 pixels. Three-dimensional motion will be extracted, computed, visualized, and contrasted as a function of the level of stimulation to the recurrent laryngeal nerve. Results will also be compared to patterns of vibration in excised larynges. Finally, commonly applied quantitative analyses will be performed to investigate the underlying modes of vibration. [Work supported by NIH/NIDCD.

Do Talkativeness and Vocal Loudness Correlate With Laryngeal Pathology? A Study of the Vocal Overdoer/Underdoer Continuum.

PubMed

Bastian, Robert W; Thomas, James P

2016-09-01

Assess the correlation between self-rating scales of talkativeness and loudness with various types of voice disorders. This is a retrospective study. A total of 974 patients were analyzed. The cohort study included 430 consecutive patients presenting to the senior author with voice complaints from December 1995 to December 1998. The case-control study added 544 consecutive patients referred to the same examiner from January 1988 to December 1998 for vocal fold examination before thyroid, parathyroid, and carotid surgery. Patient responses on seven-point Likert self-rating scales of talkativeness and loudness were compared with laryngeal disease. Mucosal lesions clearly associated with vibratory trauma are strongly associated with a high self-rating of talkativeness. Laryngeal deconditioning disorders were associated with a low self-rating of talkativeness. Use of a simple self-rating scale of vocal loudness and talkativeness during history taking can reliably orient the examiner to the types of voice disorders likely to be diagnosed subsequently during vocal capability testing and visual laryngeal examination. The high degree of talkativeness and loudness seen in vocal overdoers correlates well with mucosal disorders such as nodules, polyps, capillary ectasia, epidermoid inclusion cysts, and hemorrhage. A lower degree of talkativeness correlates with muscle deconditioning disorders such as vocal fold bowing, atrophy, presbyphonia, and vocal fatigue syndrome. Copyright © 2016 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Identification of Distinct Layers Within the Stratified Squamous Epithelium of the Adult Human True Vocal Fold

PubMed Central

Dowdall, Jayme R.; Sadow, Peter M.; Hartnick, Christopher; Vinarsky, Vladimir; Mou, Hongmei; Zhao, Rui; Song, Phillip C.; Franco, Ramon A.; Rajagopal, Jayaraj

2016-01-01

Objectives/Hypothesis A precise molecular schema for classifying the different cell types of the normal human vocal fold epithelium is lacking. We hypothesize that the true vocal fold epithelium has a cellular architecture and organization similar to that of other stratified squamous epithelia including the skin, cornea, oral mucosa, and esophagus. In analogy to disorders of the skin and gastrointestinal tract, a molecular definition of the normal cell types within the human vocal fold epithelium and a description of their geometric relationships should serve as a foundation for characterizing cellular changes associated with metaplasia, dysplasia, and cancer. Study Design Qualitative study with adult human larynges. Methods Histologic sections of normal human laryngeal tissue were analyzed for morphology (hematoxylin and eosin) and immunohistochemical protein expression profile, including cytokeratins (CK13 and CK14), cornified envelope proteins (involucrin), basal cells (NGFR/p75), and proliferation markers (Ki67). Results We demonstrated that three distinct cell strata with unique marker profiles are present within the stratified squamous epithelium of the true vocal fold. We used these definitions to establish that cell proliferation is restricted to certain cell types and layers within the epithelium. These distinct cell types are reproducible across five normal adult larynges. Conclusion We have established that three layers of cells are present within the normal adult stratified squamous epithelium of the true vocal fold. Furthermore, replicating cell populations are largely restricted to the parabasal strata within the epithelium. This delineation of distinct cell populations will facilitate future studies of vocal fold regeneration and cancer. Level of Evidence N/A. PMID:25988619

Identification of distinct layers within the stratified squamous epithelium of the adult human true vocal fold.

PubMed

Dowdall, Jayme R; Sadow, Peter M; Hartnick, Christopher; Vinarsky, Vladimir; Mou, Hongmei; Zhao, Rui; Song, Phillip C; Franco, Ramon A; Rajagopal, Jayaraj

2015-09-01

A precise molecular schema for classifying the different cell types of the normal human vocal fold epithelium is lacking. We hypothesize that the true vocal fold epithelium has a cellular architecture and organization similar to that of other stratified squamous epithelia including the skin, cornea, oral mucosa, and esophagus. In analogy to disorders of the skin and gastrointestinal tract, a molecular definition of the normal cell types within the human vocal fold epithelium and a description of their geometric relationships should serve as a foundation for characterizing cellular changes associated with metaplasia, dysplasia, and cancer. Qualitative study with adult human larynges. Histologic sections of normal human laryngeal tissue were analyzed for morphology (hematoxylin and eosin) and immunohistochemical protein expression profile, including cytokeratins (CK13 and CK14), cornified envelope proteins (involucrin), basal cells (NGFR/p75), and proliferation markers (Ki67). We demonstrated that three distinct cell strata with unique marker profiles are present within the stratified squamous epithelium of the true vocal fold. We used these definitions to establish that cell proliferation is restricted to certain cell types and layers within the epithelium. These distinct cell types are reproducible across five normal adult larynges. We have established that three layers of cells are present within the normal adult stratified squamous epithelium of the true vocal fold. Furthermore, replicating cell populations are largely restricted to the parabasal strata within the epithelium. This delineation of distinct cell populations will facilitate future studies of vocal fold regeneration and cancer. N/A. © 2015 The American Laryngological, Rhinological and Otological Society, Inc.

A mixed-effects model approach for the statistical analysis of vocal fold viscoelastic shear properties.

PubMed

Xu, Chet C; Chan, Roger W; Sun, Han; Zhan, Xiaowei

2017-11-01

A mixed-effects model approach was introduced in this study for the statistical analysis of rheological data of vocal fold tissues, in order to account for the data correlation caused by multiple measurements of each tissue sample across the test frequency range. Such data correlation had often been overlooked in previous studies in the past decades. The viscoelastic shear properties of the vocal fold lamina propria of two commonly used laryngeal research animal species (i.e. rabbit, porcine) were measured by a linear, controlled-strain simple-shear rheometer. Along with published canine and human rheological data, the vocal fold viscoelastic shear moduli of these animal species were compared to those of human over a frequency range of 1-250Hz using the mixed-effects models. Our results indicated that tissues of the rabbit, canine and porcine vocal fold lamina propria were significantly stiffer and more viscous than those of human. Mixed-effects models were shown to be able to more accurately analyze rheological data generated from repeated measurements. Copyright © 2017 Elsevier Ltd. All rights reserved.

Aerodynamically and acoustically driven modes of vibration in a physical model of the vocal folds.

PubMed

Zhang, Zhaoyan; Neubauer, Juergen; Berry, David A

2006-11-01

In a single-layered, isotropic, physical model of the vocal folds, distinct phonation types were identified based on the medial surface dynamics of the vocal fold. For acoustically driven phonation, a single, in-phase, x-10 like eigenmode captured the essential dynamics, and coupled with one of the acoustic resonances of the subglottal tract. Thus, the fundamental frequency appeared to be determined primarily by a subglottal acoustic resonance. In contrast, aerodynamically driven phonation did not naturally appear in the single-layered model, but was facilitated by the introduction of a vertical constraint. For this phonation type, fundamental frequency was relatively independent of the acoustic resonances, and two eigenmodes were required to capture the essential dynamics of the vocal fold, including an out-of-phase x-11 like eigenmode and an in-phase x-10 like eigenmode, as described in earlier theoretical work. The two eigenmodes entrained to the same frequency, and were decoupled from subglottal acoustic resonances. With this independence from the acoustic resonances, vocal fold dynamics appeared to be determined primarily by near-field, fluid-structure interactions.

A two-layer composite model of the vocal fold lamina propria for fundamental frequency regulation.

PubMed

Zhang, Kai; Siegmund, Thomas; Chan, Roger W

2007-08-01

The mechanical properties of the vocal fold lamina propria, including the vocal fold cover and the vocal ligament, play an important role in regulating the fundamental frequency of human phonation. This study examines the equilibrium hyperelastic tensile deformation behavior of cover and ligament specimens isolated from excised human larynges. Ogden's hyperelastic model is used to characterize the tensile stress-stretch behaviors at equilibrium. Several statistically significant differences in the mechanical response differentiating cover and ligament, as well as gender are found. Fundamental frequencies are predicted from a string model and a beam model, both accounting for the cover and the ligament. The beam model predicts nonzero F(0) for the unstretched state of the vocal fold. It is demonstrated that bending stiffness significantly contributes to the predicted F(0), with the ligament contributing to a higher F(0), especially in females. Despite the availability of only a small data set, the model predicts an age dependence of F(0) in males in agreement with experimental findings. Accounting for two mechanisms of fundamental frequency regulation--vocal fold posturing (stretching) and extended clamping--brings predicted F(0) close to the lower bound of the human phonatory range. Advantages and limitations of the current model are discussed.

Expression and distribution of hyaluronic acid and CD44 in unphonated human vocal fold mucosa.

PubMed

Sato, Kiminori; Umeno, Hirohito; Nakashima, Tadashi; Nonaka, Satoshi; Harabuchi, Yasuaki

2009-11-01

The tension caused by phonation (vocal fold vibration) is hypothesized to stimulate vocal fold stellate cells (VFSCs) in the maculae flavae (MFe) to accelerate production of extracellular matrices. The distribution of hyaluronic acid (HA) and expression of CD44 (a cell surface receptor for HA) were examined in human vocal fold mucosae (VFMe) that had remained unphonated since birth. Five specimens of VFMe (3 adults, 2 children) that had remained unphonated since birth were investigated with Alcian blue staining, hyaluronidase digestion, and immunohistochemistry for CD44. The VFMe containing MFe were hypoplastic and rudimentary. The VFMe did not have a vocal ligament, Reinke's space, or a layered structure, and the lamina propria appeared as a uniform structure. In the children, HA was distributed in the VFMe containing MFe. In the adults, HA had decreased in the VFMe containing MFe. In both groups, the VFSCs in the MFe and the fibroblasts in the lamina propria expressed little CD44. This study supports the hypothesis that the tensions caused by vocal fold vibration stimulate the VFSCs in the MFe to accelerate production of extracellular matrices and form the layered structure. Phonation after birth is one of the important factors in the growth and development of the human VFMe.

The Cystic Fibrosis Transmembrane Conductance Regulator and Chloride-Dependent Ion Fluxes of Ovine Vocal Fold Epithelium

ERIC Educational Resources Information Center

Leydon, Ciara; Fisher, Kimberly V.; Lodewyck-Falciglia, Danielle

2009-01-01

Purpose: Ion-driven transepithelial water fluxes participate in maintaining superficial vocal fold hydration, which is necessary for normal voice production. The authors hypothesized that Cl[superscript -] channels are present in vocal fold epithelial cells and that transepithelial Cl[superscript -] fluxes can be manipulated pharmacologically.…

Application of motion analysis in the study of the effect of botulinum toxin to rat vocal folds

NASA Astrophysics Data System (ADS)

Saadah, Abdul K.; Galatsanos, Nikolas P.; Inagi, K.; Bless, D.

1997-05-01

In the past we have proposed a system that measures the deformations of the vocal folds from videostroboscopic images of the larynx, in that system: (1) we extract the boundaries of the vocal folds, (2) we register elastically the vocal fold boundaries in successive frames. This yields the displacement vector field (DVF) between adjacent frames, and (3) we fit using a least-squares approach an affine transformation model to succinctly describe the deformations between adjacent frames. In this paper, we present as an example of the capabilities of this system, an initial study of the deformation changes in rat vocal folds pre and post injection with Botulinum toxin. For this application the generated DVF was segmented into right DVF and left DVF and the deformation of each segment is studied separately.

Self-oscillating Vocal Fold Model Mechanics: Healthy, Diseased, and Aging

NASA Astrophysics Data System (ADS)

Hiubler, Elizabeth P.; Pollok, Lucas F. E.; Apostoli, Adam G.; Hancock, Adrienne B.; Plesniak, Michael W.

2014-11-01

Voice disorders have been estimated to have a substantial economic impact of 2.5 billion annually. Approximately 30% of people will suffer from a voice disorder at some point in their lives. Life-sized, self-oscillating, synthetic vocal fold (VF) models are fabricated to exhibit material properties representative of human VFs. These models are created both with and without a polyp-like structure, a pathology that has been shown to produce rich viscous flow structures not normally observed for healthy VFs during normal phonation. Pressure measurements are acquired upstream of the VFs and high-speed images are captured at varying flow rates during VF oscillation to facilitate an understanding of the characteristics of healthy and diseased VFs. The images are analyzed using a videokymography line-scan technique. Clinically-relevant parameters calculated from the volume-velocity output of a circumferentially-vented mask (Rothenberg mask) are compared to human data collected from two groups of males aged 18-30 and 60-80. This study extends the use of synthetic VF models by assessing their ability to replicate behaviors observed in human subject data to advance a means of investigating changes associated with normal, pathological, and the aging voice. Supported by the GWU Institute for Biomedical Engineering (GWIBE) and GWU Center for Biomimetics and Bioinspired Engineering (COBRE).

Optimal Duration for Voice Rest After Vocal Fold Surgery: Randomized Controlled Clinical Study.

PubMed

Kaneko, Mami; Shiromoto, Osamu; Fujiu-Kurachi, Masako; Kishimoto, Yo; Tateya, Ichiro; Hirano, Shigeru

2017-01-01

Voice rest is commonly recommended after phonomicrosurgery to prevent worsening of vocal fold injuries. However, the most effective duration of voice rest is unknown. Recently, early vocal stimulation was recommended as a means to improve wound healing. The purpose of this study is to examine the optimal duration of voice rest after phonomicrosurgery. Randomized controlled clinical study. Patients undergoing phonomicrosurgery for leukoplakia, carcinoma in situ, vocal fold polyp, Reinke's edema, and cyst were chosen. Participants were randomly assigned to voice rest for 3 or 7 postoperative days. Voice therapy was administered to both groups after voice rest. Grade, roughness, breathiness, asthenia, and strain (GRBAS) scale, stroboscopic examination, aerodynamic assessment, acoustic analysis, and Voice Handicap Index-10 (VHI-10) were performed pre- and postoperatively at 1, 3, and 6 months. Stroboscopic examination evaluated normalized mucosal wave amplitude (NMWA). Parameters were compared between both groups. Thirty-one patients were analyzed (3-day group, n = 16; 7-day group, n = 15). Jitter, shimmer, and VHI-10 were significantly better in the 3-day group at 1 month post operation. GRBAS was significantly better in the 3-day group at 1 and 3 months post operation, and NMWA was significantly better in the 3-day group at 1, 3, and 6 months post operation compared to the 7-day group. The data suggest that 3 days of voice rest followed by voice therapy may lead to better wound healing of the vocal fold compared to 7 days of voice rest. Appropriate mechanical stimulation during early stages of vocal fold wound healing may lead to favorable functional recovery. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Long-term consequences of vocal fold hemorrhage.

PubMed

Kerwin, Lewis J; Estes, Christine; Oromendia, Clara; Christos, Paul; Sulica, Lucian

2017-04-01

To assess the long-term impact of vocal fold hemorrhage (VFH) on vocal function and health, and compare these parameters to those in similar patients who have not had VFH. Retrospective cohort study. Patients with a history of VFH (N = 41) were characterized through a review of records and assessed by means of a survey for vocal health and professional functioning as well as the Voice Handicap Index-10 (VHI-10) and, if appropriate (n = 30, 73.2%), the Singing Voice Handicap Index (SVHI-10). They were compared to a group of demographically and occupationally similar patients without VFH (N = 25, 60.9%). Patients with multiple episodes of VFH (n = 9, 22.0%) were compared to patients with a single event. After a median of 41 months follow-up, patients with VFH had favorable vocal function assessment and low median VHI-10 and SVHI-10 scores (4 and 6, respectively), substantially similar to patients without VFH (VHI-10, P = .905 and SVHI 10, P =.991). The two groups showed similarly low rates of change in occupation (7.3%vs. 8.0%, P =.999). Patients with VFH were more likely to have missed days of work due to a voice problem. Analysis of patients with one versus multiple VFH episodes showed no differences, except patients with multiple episodes had significantly greater confidence in their ability to address future VFH. Contrary to commonly held belief, VFH appears to have no significant long-term impact on vocational stability, subjective voice quality, or perceptions of vocal function. Moreover, among those with VFH, recurrence seems only to diminish anxiety over this transient injury. 4 Laryngoscope, 127:900-906, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

Injection laryngoplasty as miniinvasive office-based surgery in patients with unilateral vocal fold paralysis - voice quality outcomes.

PubMed

Sielska-Badurek, Ewelina M; Sobol, Maria; Jędra, Katarzyna; Rzepakowska, Anna; Osuch-Wójcikiewicz, Ewa; Niemczyk, Kazimierz

2017-09-01

Injection laryngoplasty (glottis augmentation) is the preferred method in surgical management of unilateral vocal fold paralysis (UVFP). Traditionally, these procedures are performed in the operating room. Nowadays, however, these procedures have moved into the office. To evaluate the voice quality after transoral injection laryngoplasty under local anaesthesia in patients with unilateral vocal fold paralysis. Fourteen subjects (5 women and 9 men) with unilateral vocal fold paresis (9 with right vocal fold paresis and 5 with left vocal fold paresis) were included in the study. The mean age of the group was 57.8 ±19.0 years (32-83 years). All of the injection laryngoplasties were performed transorally, under local anaesthesia. The injection material was calcium hydroxylapatite. Before and 1, 3 and 6 months after the procedure the following variables were evaluated: voice perception, videostroboscopy, acoustic analysis, aerodynamic evaluation, and the subjective rating of the voice quality by the patient. After injection laryngoplasty, complete glottal closure was achieved or there was a significant improvement in the glottal closure of each subject. We noted great improvement in the post-injection objective and subjective voice outcomes and patients reported improvement in the voice-related quality of life. The transoral approach for injection laryngoplasty under local anaesthesia is an effective and safe way to treat incomplete glottal closure in patients with UVFP. The transoral approach is an efficient alternative to other surgical techniques used for vocal fold injection.

Factors associated with the improvement of vocal fold movement: an analysis of LEMG and laryngeal CT parameters.

PubMed

Mengsteab, Paulos Y; Kwon, Jeong-Yi; Han, Tai Ryoon; Kwon, Tack Kyun; Kim, Deok-Ho; Kim, Sang Jun

2015-02-01

The aim of this study is to elucidate the relationship of laryngeal electromyography (LEMG) and computed tomographic (CT) parameters to improve the prognosis of recurrent laryngeal nerve injury. 22 patients clinically suspected of having recurrent laryngeal nerve injury were examined with LEMG and CT studies. Bilateral thyroarytenoid (TA) muscles were examined and findings were interpreted by a single blind technique. Laryngeal CT image analysis of the ventricle dilation symmetry determined TA muscle atrophy. Finally, a follow-up laryngoscopic examination determined improvement of vocal fold movement. Ventricle dilation symmetry and the dichotomized TA muscle atrophy parameter significantly relate to the improvement of vocal fold movement (χ(2)=4.029, P=0.039, and χ(2)=3.912, P=0.048, respectively). When the severity of vocal fold impairment was classified as severe TA muscle atrophy or none/discrete MUAP recruitment, it was found to significantly relate with the improvement of vocal fold movement (χ(2)=6.712, P=.010). From this study, image analysis of the ventricle dilation symmetry to determine the severity of TA muscle atrophy shows promise for the improved prognosis of vocal fold immobility. Copyright © 2014 Elsevier Ltd. All rights reserved.

Simultaneous temporally resolved DPIV and pressure measurements of symmetric oscillations in a scaled-up vocal fold model

NASA Astrophysics Data System (ADS)

Ringenberg, Hunter; Rogers, Dylan; Wei, Nathaniel; Krane, Michael; Wei, Timothy

2017-11-01

The objective of this study is to apply experimental data to theoretical framework of Krane (2013) in which the principal aeroacoustic source is expressed in terms of vocal fold drag, glottal jet dynamic head, and glottal exit volume flow, reconciling formal theoretical aeroacoustic descriptions of phonation with more traditional lumped-element descriptions. These quantities appear in the integral equations of motion for phonatory flow. In this way time resolved velocity field measurements can be used to compute time-resolved estimates of the relevant terms in the integral equations of motion, including phonation aeroacoustic source strength. A simplified 10x scale vocal fold model from Krane, et al. (2007) was used to examine symmetric, i.e. `healthy', oscillatory motion of the vocal folds. By using water as the working fluid, very high spatial and temporal resolution was achieved. Temporal variation of transglottal pressure was simultaneously measured with flow on the vocal fold model mid-height. Experiments were dynamically scaled to examine a range of frequencies corresponding to male and female voice. The simultaneity of the pressure and flow provides new insights into the aeroacoustics associated with vocal fold oscillations. Supported by NIH Grant No. 2R01 DC005642-11.

Long-term Surveillance Following Intralesional Steroid Injection for Benign Vocal Fold Lesions.

PubMed

Wang, Chi-Te; Lai, Mei-Shu; Cheng, Po-Wen

2017-06-01

The short-term outcomes of vocal fold steroid injection (VFSI) are well documented. However, few studies have reported the long-term outcomes following VFSI. To investigate the incidence rates of symptom recurrence and secondary interventions following VFSI for benign vocal fold lesions. This prospective cohort study was conducted at a tertiary referral medical center in Taipei, Taiwan. The cohort included 189 patients with vocal fold lesions who had received VFSI as the primary treatment between August 2011 and September 2013. All participants underwent VFSI. Long-term surveillance was conducted through structured telephonic interviews and by reviewing medical charts every 6 months over a 2-year period. We assessed the 10-item voice handicap index, dysphonic symptoms, and whether the patients had received any additional interventions after the initial VFSI. The 189 participants (32 men and 157 women; mean [SD] age, 39 [10] years [range, 20-74 years] included patients who had undergone VFSI for vocal fold nodules (n = 72), polyps (n = 72), or mucus-retention cysts (n = 45). Following VFSI, 141 patients (74.6%; 23 men and 118 women; mean age, 39 years [range, 20-70 years]) showed positive response (ie, clinically significant symptom resolution without the need for additional procedures) and received long-term surveillance. The median follow-up period was 19.4 months, and 2 patients were lost to follow-up postoperatively within 1 year. The cumulative failure rates (subjective symptom recurrence plus secondary treatments) at 6, 12, 18, and 24 months after VFSI were 12%, 17%, 24%, and 32%, respectively. When the initial response rate to VFSI (141 of 189, 74.6%) was considered altogether, VFSI remained effective after 2 years in 50% of the initially recruited 189 patients. The highest rate of long-term effectiveness of VFSI occurred in vocal polyps (54%), followed by nodules (49%) and cysts (43%). This study demonstrates that VFSI can be beneficial in

Evidence-based practice: evaluation and management of unilateral vocal fold paralysis.

PubMed

Misono, Stephanie; Merati, Albert L

2012-10-01

This article discusses the causes and symptoms, evaluation, and management of unilateral vocal fold paralysis (UVFP). Cross-sectional imaging is appropriate in the work-up of idiopathic UVFP, but the routine use of serology is not well supported. The usefulness of laryngeal electromyography has remained controversial. Predictors of poor prognosis for functionally meaningful recovery include fibrillation potentials, positive sharp waves, and absent/reduced voluntary motor unit potentials. Voice therapy may be helpful. Injection and laryngeal framework surgery (medialization thyroplasty) improve vocal quality. The vocal impact of laryngeal reinnervation is comparable with that of medialization. Some patients may benefit from multiple procedures. Copyright © 2012 Elsevier Inc. All rights reserved.

Periodic botulinum toxin injections for paradoxical vocal fold motion in a child with cerebral palsy: a case study.

PubMed

Cheng, Yew Song; Bhutta, Mahmood F; Ramsden, James D; Lennox, Penny

2014-03-01

We describe an unusual case of paradoxical vocal fold motion in a child with cerebral palsy. Clinically, the child presented with mild stridor, which worsened over months, eventually requiring emergency intubation. After an unsuccessful trial of medical management, microlaryngoscopy revealed abnormal adduction of the vocal folds during inspiration. This was successfully treated with periodic type A botulinum toxin injections to the vocal folds, sparing the child from tracheostomy. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Paradoxical vocal fold motion (PVFM) in pediatric otolaryngology.

PubMed

Smith, Blake; Milstein, Claudio; Rolfes, Bryan; Anne, Samantha

Paradoxical vocal fold motion (PVFM) is a condition in which the vocal cords exhibit inappropriate inspiratory adduction, and it has been poorly studied in the pediatric population. Pediatric patients diagnosed with PVCM by a pediatric otolaryngologist and doctor of speech pathology from 2008 to 2012 were reviewed. Patients in whom another cause for their respiratory disturbance was eventually identified were excluded. Patient demographics, characteristics, treatment, and outcomes were reviewed. The study was approved by the Institutional Review Board at our institution. Thirty patients met criteria for inclusion; one with chiari malformation was excluded. 17/29 (59%) were female. Body mass index (BMI) numbers ranged from 16 to 25 with a mean of 21. 9/29 (31%) competed at the highest level of a sport; only 3/29 (10%) did not participate in athletics. Average age of onset was 12.0years; average diagnosis delay was 1.3years. Mean follow up was 2.3years. 24/29 (83%) were previously treated for asthma. 23/29(79%) were previously treated for reflux. 25/29(86%) completed at least one session of respiratory and laryngeal control therapy with overall average of 2.2 sessions completed. All patients who attended a second therapy session were recorded as having improvement in symptoms. Pediatric patients with PVFM often participate in high levels of organized sports and the frequency of concurrent asthma and reflux symptoms in this population supports the theory that laryngeal hypersensitivity contributes to the pathophysiology of PVFM. These patients were not found to have any associated psychiatric diagnoses. Pediatric patients with PVFM have an excellent prognosis when treated with speech therapy and for comorbid conditions as indicated. Copyright © 2017 Elsevier Inc. All rights reserved.

The anisotropic nature of the human vocal fold: an ex vivo study.

PubMed

Rohlfs, Anna-Katharina; Goodyer, Eric; Clauditz, Till; Hess, Markus; Kob, Malte; Koops, Susan; Püschel, Klaus; Roemer, Frank W; Müller, Frank

2013-05-01

The purpose of this study was to measure the relationship between the shear elastic properties of vocal fold with respect to the direction of applied stress. There is extensive published material that quantifies the shear viscoelastic properties of the vocal fold, but as much of these data were obtained using rotating parallel plate rheometers, which are unable to resolve out difference of the shear elastic behaviour with respect to direction, there is very little data that indicates anisotropic behaviour. To overcome this gap in knowledge, the team devised an apparatus that is capable of applying a shear stress in a known direction. A series of measurements were taken at the mid-membranous position, in the transverse and longitudinal directions. Point-specific measurements were performed using fourteen human cadaver excised larynges, which were hemi-sectioned to expose the vocal fold. An extremely low sinusoidal shear force of 1 g was applied tangentially to the membrane surface in both the longitudinal and transverse direction, and the resultant shear strain was measured. With the probe applied to the intact vocal fold, the average ratio of the elasticity in the transverse with respect to the longitudinal direction was 0.55. Further investigation using histological staining of collagens in the lamina propria indicates that there is a visible difference in the general alignment of collagen fibres when comparing the coronal and the sagittal sections. Our conclusion is that there is a quantifiable difference between the shear elastic response of the lamina propria in the longitudinal and transverse directions, and that this could be explained by the difference in alignment of collagen fibres within the lamina propria.

Effect of topical mitomycin-C on total collagen deposits on the submucosa of intact vocal folds in swine.

PubMed

Pereira, Marcelo Charles; Repka, Carlos Domingues; Camargo, Paulo Antonio Monteiro; Rispoli, Daniel Zeni; Campos, Antônio Carlos Ligocki; Matias, Jorge Eduardo Fouto

2009-07-01

To compare the effects of topical mitomycin-C at different concentrations on submucosal collagen deposition on the vocal folds of swine. The animals were divided into three groups according to the composition of the topical solution to be applied to the vocal folds: 0.9% saline solution (control group); 4 mg/ml mitomycin-C (group 1) and 8 mg/ml mitomycin-C (group 2). Thirty days after the application, all animals were sacrificed, their vocal folds were collected and stained by the picrosirius red technique, and submucosal collagen deposition areas were estimated by the Image Pro Plus 4.5 software. Mann-Whitney test was used to compare differences between parameters of each group. The means of the areas of submucosal collagen deposits on vocal folds were 3110.44 square micrometers (microm(2)), 3115.98 microm(2) and 3105.78 microm(2) for groups control, 1 and 2, respectively. There were no statistical differences across the three groups (p>0.05). Mitomycin-C topically applied to intact vocal folds of swine did not alter submucosal collagen deposition.

Kinematic Measurements of the Vocal-Fold Displacement Waveform in Typical Children and Adult Populations: Quantification of High-Speed Endoscopic Videos

ERIC Educational Resources Information Center

Patel, Rita; Donohue, Kevin D.; Unnikrishnan, Harikrishnan; Kryscio, Richard J.

2015-01-01

Purpose: This article presents a quantitative method for assessing instantaneous and average lateral vocal-fold motion from high-speed digital imaging, with a focus on developmental changes in vocal-fold kinematics during childhood. Method: Vocal-fold vibrations were analyzed for 28 children (aged 5-11 years) and 28 adults (aged 21-45 years)…

The role of allergy in the etiology of Reinke's edema on vocal folds.

PubMed

Kravos, Alenka; Zupevc, Avgust; Cizmarevic, Bogdan; Hocevar-Boltezar, Irena

2010-05-01

To identify the role of allergy in the occurrence of Reinke's edema on vocal folds. This was a prospective study in patients with Reinke's edema on vocal folds (n = 80) and a control group of patients without Reinke's edema (n = 80). All the patients were examined by the same ENT specialist at an ENT outpatient center in the period 2001-2003. The control group comprised 80 successive patients from the same clinic who were willing to cooperate in the study and were not already being treated for allergic disease by any specialist other than an ENT specialist. Patients from both groups were examined by rigid laryngoscope, skin prick allergic testing (type I allergy) and laboratory determination of serum thyroid-stimulating hormone level. The prevalence of allergy was not significantly different between the two groups: 20.0% in the patients with Reinke's edema and 23.8% in the control group (P = 0.576). No significant difference was detected in the prevalence of allergy when comparing patients with recurrent Reinke's edema after previous surgical treatment (n = 10) with patients with a first occurrence (n = 70) (P = 1.000). However, we found significantly more type I allergy in the patients with Reinke's edema and chronic hyperplastic rhinitis than in the patients with Reinke's edema without chronic hyperplastic rhinitis. All other risk factors (reflux of gastric content to the larynx, vocal abuse or misuse, unfavorable microclimate conditions at work, thyroid diseases) appeared significantly more often in the group with Reinke's edema on vocal folds than in the control group. Type I allergy is not a crucial factor in the pathogenesis of Reinke's edema on vocal folds or in recurrence of the disease after surgical treatment.

Functional histology of the macula flava in the human vocal fold--Part 1: its role in the adult vocal fold.

PubMed

Sato, Kiminori; Umeno, Hirohito; Nakashima, Tadashi

2010-01-01

This study aims to clarify the role of the maculae flavae (MFe) in the human adult vocal fold mucosa (VFM). Our current results concerning MFe in the human adult VFM are summarized. MFe were found to be composed of dense masses of vocal fold stellate cells (VFSCs) and extracellular matrices (EM), such as fibrous proteins and glycosaminoglycans, which are essential for the EM in the human VFM. VFSCs in the MFe demonstrated marked morphologic differences from conventional fibroblasts. They were irregular and stellate in shape and possessed slender cytoplasmic processes. They had well-developed intracellular organelles. A number of vesicles were present at the periphery of the cytoplasm. They constantly synthesized EM. The VFSCs possessed lipid droplets and stored vitamin A. VFSCs formed an independent cell category of cells in the human VFM. The VFSCs in aged adult MFe decreased their activity, and had abnormal metabolism. Human MFe including VFSCs seem to be involved in the metabolism of EM which are essential for the viscoelasticity of the lamina propria of the VFM, and to be responsible for maintaining the characteristic layered structure of the human VFM. Age-related changes in VFSCs were found to influence the metabolism of EM in the VFM. (c) 2010 S. Karger AG, Basel.

Intraoperative laryngeal electromyography in children with vocal fold immobility: results of a multicenter longitudinal study.

PubMed

Maturo, Stephen C; Braun, Nicole; Brown, David J; Chong, Peter Siao Tick; Kerschner, Joseph E; Hartnick, Christopher J

2011-12-01

To determine whether laryngeal electromyography (LEMG) can predict recurrent laryngeal nerve function return in children and whether LEMG can aid in the management of vocal fold immobility (VFI). Prospective case series. Tertiary pediatric aerodigestive centers. Twenty-five children aged 14 days to 7 years at the time of first LEMG (mean age, 21.4 months) with VFI who underwent flexible fiberoptic laryngeal examination, intraoperative LEMG of the thyroarytenoid muscles, and 12-month follow-up. To compare results of LEMG with flexible fiberoptic laryngeal examination in children with vocal fold paresis and to determine if LEMG can predict vocal fold return. In children who had a patent ductus arteriosus ligation, the LEMG data suggest that if there is no activity 6 months after injury, then the nerve is unlikely to regain function. In 3 of 3 children with central causes of VFI, normal LEMG findings predicted return of nerve function 2 to 7 months before vocal fold movement on fiberoptic examination. Finally, in 3 of 3 children with idiopathic VFI, LEMG predicted return within 2 to 14 months of vocal folds with normal findings. Intraoperative LEMG is a safe, easy-to-use method for determining the likelihood of recurrent laryngeal nerve function return in children who have undergone patent ductus arteriosus ligation, in children with centrally correctable lesions, and in children with idiopathic VFI. More work is needed in the area of pediatric LEMG, but it is possible that LEMG data can be used to aid in management strategies and provide families with more information to make better informed decisions regarding their child's care.

Electroglottographic parameterization of the effects of gender, vowel and phonatory registers on vocal fold vibratory patterns: an Indian perspective.

PubMed

Paul, Nilanjan; Kumar, Suman; Chatterjee, Indranil; Mukherjee, Biswarup

2011-01-01

In-depth study on laryngeal biomechanics and vocal fold vibratory patterns reveal that a single vibratory cycle can be divided into two major phases, the closed and open phase, which is subdivided into opening and closing phases. Studies reveal that the relative time course of abduction and adduction, which in turn is dependent on the relative relaxing and tensing of the vocal fold cover and body, to be the determining factor in production of a particular vocal register like the modal (or chest), falsetto, glottal fry registers. Studies further point out Electroglottography to be particularly suitable for the study of vocal vibratory patterns during register changes. However, to date, there has been limited study on quantitative parameterization of EGG wave form in vocal fry register. Moreover, contradictory findings abound in literature regarding effects of gender and vowel types on vocal vibratory patterns, especially during phonation at different registers. The present study endeavors to find out the effects of vowel and gender differences on the vocal fold vibratory patterns in different registers and how these would be reflected in standard EGG parameters of Contact Quotient (CQ) and Contact Index (CI), taking into consideration the Indian sociolinguistic context. Electroglottographic recordings of 10 young adults (5 males and 5 females) were taken while the subjects phonated the three vowels /a/,/i/,/u/ each in two vocal registers, modal and vocal fry. Obtained raw EGG were further normalized using the Derived EGG algorithm and theCQ and CI values were derived. Obtained data were subject to statistical analysis using the 3-way ANOVA with gender, vowel and vocal register as the three variables. Post-hoc Dunnett C multiple comparison analysis were also performed. Results reveal that CQ values are significantly higher in vocal fry than modal phonation for both males and females, indicating a relatively hyperconstricted vocal system during vocal fry. The males

Frequency response of synthetic vocal fold models with linear and nonlinear material properties.

PubMed

Shaw, Stephanie M; Thomson, Scott L; Dromey, Christopher; Smith, Simeon

2012-10-01

The purpose of this study was to create synthetic vocal fold models with nonlinear stress-strain properties and to investigate the effect of linear versus nonlinear material properties on fundamental frequency (F0) during anterior-posterior stretching. Three materially linear and 3 materially nonlinear models were created and stretched up to 10 mm in 1-mm increments. Phonation onset pressure (Pon) and F0 at Pon were recorded for each length. Measurements were repeated as the models were relaxed in 1-mm increments back to their resting lengths, and tensile tests were conducted to determine the stress-strain responses of linear versus nonlinear models. Nonlinear models demonstrated a more substantial frequency response than did linear models and a more predictable pattern of F0 increase with respect to increasing length (although range was inconsistent across models). Pon generally increased with increasing vocal fold length for nonlinear models, whereas for linear models, Pon decreased with increasing length. Nonlinear synthetic models appear to more accurately represent the human vocal folds than do linear models, especially with respect to F0 response.

Laser arytenoidectomy in children with bilateral vocal fold immobility.

PubMed

Worley, G; Bajaj, Y; Cavalli, L; Hartley, B

2007-01-01

Bilateral vocal fold immobility in children is a challenging problem because a balance between good airway and voice quality has to be achieved. Surgery to improve the airway is often postponed or avoided because of fear of losing the voice. In this study our results of laser arytenoidectomy in children are described. This was a retrospective case notes review at a tertiary level paediatric ENT department. The six patients in this case series ranged from nine to 16 years old at the time of laser arytenoidectomy. Post-operative airway and voice quality were assessed. All children in the series had an adequate post-operative airway. Four of these patients had tracheostomies pre-operatively and achieved decannulation. All six patients rated their post-operative voice as better than pre-operatively. This is principally due to increased loudness associated with increased airflow through the larynx, particularly after tracheostomy decannulation. It is recommended that special care should be taken not to disturb the anterior two thirds of the vocal fold during the surgery in order to achieve a good post-operative voice outcome.

Bipedicled strap muscle transposition for vocal fold deficit after laser cordectomy in early glottic cancer patients.

PubMed

Su, Chih-Ying; Chuang, Hui-Ching; Tsai, Shang-Shyue; Chiu, Jeng-Fen

2005-03-01

In treating early glottic carcinomas, the outcomes of endoscopic laser cordectomy have been proven to be valuable in local control, survival, and vocal function preservation. In some extended cases, however, laser cordectomy may leave patients with poor vocal function because of vocal fold deficit. This work assesses the vocal outcome of medialization laryngoplasty with bipedicled strap muscle transposition for vocal fold deficit resulting from laser cordectomy in early glottic cancer patients. A prospective clinical series. Thirteen early glottic cancer patients who had vocal fold deficit caused by previous laser cordectomy underwent medialization laryngoplasty with bipedicled strap muscle transposition. The thyroid lamina on the cordectomy side was paramedially separated. The inner perichondrium was circumspectly raised from the overlying thyroid cartilage. After separating the thyrohyoid and cricothyroid membranes, the lamina was retracted laterally. A bipedicled strap muscle flap was then transposed into the area between the lamina and the paraglottic soft tissue. The thyroid cartilages were carefully sutured back in position. All patients received pre- and postoperative voice assessments comprising laryngostroboscopy and vocal function studies. Vocal enhancement was present in 92% (12/13) of patients after medialization laryngoplasty with strap muscle transposition. The glottal closure and maximal phonation time were noticeably improved by surgery. No dyspnea or other significant complications were observed in any patients. The outcomes show that bipedicled strap muscle transposition is a prosthesis-free, safe, and valuable laryngoplastic technique for correcting glottal incompetence caused by endoscopic laser cordectomy in early glottic cancer patients.

Lamina propria of the human vocal fold: histomorphometric study of collagen fibers.

PubMed

Prades, Jean-Michel; Dumollard, Jean Marc; Duband, Sébastien; Timoshenko, Andrei; Richard, Céline; Dubois, Marie Dominique; Martin, Christian; Peoc'h, Michel

2010-04-01

Since the seminal work of M. Hirano, which defined the three-layered lamina propria of the human vocal fold, there has been confusion in the labeling of each layer. Recent studies described the composition of fibers and interstitial molecules within the lamina propria leading to various biomechanical properties. However, collagen fibers appear as the most important structure component. We used an optical analysis and the picrosirius-polarization method to describe collagen fibers from six adult and two fetal human larynges fixed in formalin and frontally sectioned in the middle part of the vocal fold. The deep layer of the lamina propria is the most densely organized band of collagen fibers penetrating the superficial muscle bundles of the vocal muscle. The mean thickness of this layer is about 36% of the lamina propria and shows a network of strongly birefringent fibers (collagen type I and III). The superficial layer of the lamina propria is a narrow band of collagen fibers immediately below the basement membrane of the epithelium. The mean thickness of this layer is about 13% of the lamina propria and shows strong birefringent fibers. The intermediate layer is the less densely organized band between the deep and superficial layers. The mean thickness of this layer is about 51% of the lamina propria and shows clear, green weakly birefringent fibers characterized as collagen type III. The fetal lamina propria contains only a monolayer distribution of loose collagen fibers between the epithelium and the vocal muscle. These results help describe the distribution of collagen fibers within the lamina propria of the human vocal fold and have implications to understand the cover-body theory of voice production both in the adult and newborn.

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

ERIC Educational Resources Information Center

Galindo, Gabriel E.; Peterson, Sean D.; Erath, Byron D.; Castro, Christian; Hillman, Robert E.; Zañartu, Matías

2017-01-01

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…

Assessment of canine vocal fold function after injection of a new biomaterial designed to treat phonatory mucosal scarring.

PubMed

Karajanagi, Sandeep S; Lopez-Guerra, Gerardo; Park, Hyoungshin; Kobler, James B; Galindo, Marilyn; Aanestad, Jon; Mehta, Daryush D; Kumai, Yoshihiko; Giordano, Nicholas; d'Almeida, Anthony; Heaton, James T; Langer, Robert; Herrera, Victoria L M; Faquin, William; Hillman, Robert E; Zeitels, Steven M

2011-03-01

Most cases of irresolvable hoarseness are due to deficiencies in the pliability and volume of the superficial lamina propria of the phonatory mucosa. By using a US Food and Drug Administration-approved polymer, polyethylene glycol (PEG), we created a novel hydrogel (PEG30) and investigated its effects on multiple vocal fold structural and functional parameters. We injected PEG30 unilaterally into 16 normal canine vocal folds with survival times of 1 to 4 months. High-speed videos of vocal fold vibration, induced by intratracheal airflow, and phonation threshold pressures were recorded at 4 time points per subject. Three-dimensional reconstruction analysis of 11.7 T magnetic resonance images and histologic analysis identified 3 cases wherein PEG30 injections were the most superficial, so as to maximally impact vibratory function. These cases were subjected to in-depth analyses. High-speed video analysis of the 3 selected cases showed minimal to no reduction in the maximum vibratory amplitudes of vocal folds injected with PEG30 compared to the non-injected, contralateral vocal fold. All PEG30-injected vocal folds displayed mucosal wave activity with low average phonation threshold pressures. No significant inflammation was observed on microlaryngoscopic examination. Magnetic resonance imaging and histologic analyses revealed time-dependent resorption of the PEG30 hydrogel by phagocytosis with minimal tissue reaction or fibrosis. The PEG30 hydrogel is a promising biocompatible candidate biomaterial to restore form and function to deficient phonatory mucosa, while not mechanically impeding residual endogenous superficial lamina propria.

Injection laryngoplasty as miniinvasive office-based surgery in patients with unilateral vocal fold paralysis – voice quality outcomes

PubMed Central

Sielska-Badurek, Ewelina M.; Jędra, Katarzyna; Rzepakowska, Anna; Osuch-Wójcikiewicz, Ewa; Niemczyk, Kazimierz

2017-01-01

Introduction Injection laryngoplasty (glottis augmentation) is the preferred method in surgical management of unilateral vocal fold paralysis (UVFP). Traditionally, these procedures are performed in the operating room. Nowadays, however, these procedures have moved into the office. Aim To evaluate the voice quality after transoral injection laryngoplasty under local anaesthesia in patients with unilateral vocal fold paralysis. Material and methods Fourteen subjects (5 women and 9 men) with unilateral vocal fold paresis (9 with right vocal fold paresis and 5 with left vocal fold paresis) were included in the study. The mean age of the group was 57.8 ±19.0 years (32–83 years). All of the injection laryngoplasties were performed transorally, under local anaesthesia. The injection material was calcium hydroxylapatite. Before and 1, 3 and 6 months after the procedure the following variables were evaluated: voice perception, videostroboscopy, acoustic analysis, aerodynamic evaluation, and the subjective rating of the voice quality by the patient. Results After injection laryngoplasty, complete glottal closure was achieved or there was a significant improvement in the glottal closure of each subject. We noted great improvement in the post-injection objective and subjective voice outcomes and patients reported improvement in the voice-related quality of life. Conclusions The transoral approach for injection laryngoplasty under local anaesthesia is an effective and safe way to treat incomplete glottal closure in patients with UVFP. The transoral approach is an efficient alternative to other surgical techniques used for vocal fold injection. PMID:29062449

Preliminary experiments to quantify liquid movement under mimetic vocal fold vibrational forces.

PubMed

Titze, Ingo R; Klemuk, Sarah; Lu, Xiaoying

2014-07-01

Hydration of vocal fold tissues is essential for self-sustained oscillation. Normal regulatory processes of liquid transport to and from the vocal folds would be expected through the autonomic systems, but the possibility exists that liquid movement may occur locally due to vibrational pressures. Such movement may cause regions of lower or higher concentrations of liquid viscosity and therewith changes in phonation threshold pressure. Hyaluronic acid, a glycosaminoglycan that attracts large quantities of free water, may be a key molecule for transporting or localizing liquids. Some preliminary experiments are reported in which attempts were made to move low-concentration HA liquids with vibration. None of the experiments was conclusive, but collectively they lay some groundwork for future explorations.

Effects of the epilarynx area on vocal fold dynamics and the primary voice signal.

PubMed

Döllinger, Michael; Berry, David A; Luegmair, Georg; Hüttner, Björn; Bohr, Christopher

2012-05-01

For the analysis of vocal fold dynamics, sub- and supraglottal influences must be taken into account, as recent studies have shown. In this work, we analyze the influence of changes in the epilaryngeal area on vocal fold dynamics. We investigate two excised female larynges in a hemilarynx setup combined with a synthetic vocal tract consisting of hard plastic and simulating the vowel /a/. Eigenmodes, amplitudes, and velocities of the oscillations, the subglottal pressures (P(sub)), and sound pressure levels (SPLs) of the generated signal are investigated as a function of three distinctive epilaryngeal areas (28.4 mm(2), 71.0 mm(2), and 205.9 mm(2)). The results showed that the SPL is independent of the epilarynx cross section and exhibits a nonlinear relation to the insufflated airflow. The P(sub) decreased with an increase in the epilaryngeal area and displayed linear relations to the airflow. The principal eigenfunctions (EEFs) from the vocal fold dynamics exhibited lateral movement for the first EEF and rotational motion for the second EEF. In total, the first two EEFs covered a minimum of 60% of the energy, with an average of more than 50% for the first EEF. Correlations to the epilarynx areas were not found. Maximal values for amplitudes (up to 2.5 mm) and velocities (up to 1.57 mm/ms) changed with varying epilaryngeal area but did not show consistent behavior for both larynges. We conclude that the size of the epilaryngeal area has significant influence on vocal fold dynamics but does not significantly affect the resultant SPL. Copyright © 2012 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

Long-term follow-up of vocal fold movement impairment and feeding after neonatal cardiac surgery.

PubMed

Richter, Amy Li; Ongkasuwan, Julina; Ocampo, Elena C

2016-04-01

To determine the long-term prognosis of children with vocal fold mobility impairment (VFMI) after cardiac surgery, with respect to time to normal feeding and incidence of admissions for pneumonia and feeding difficulties. A retrospective chart review was conducted of all neonates who had otolaryngology exam after cardiac surgery at a tertiary children's hospital from May 2007 to May 2008. Charts were reviewed for demographics, type of cardiac surgery, vocal fold mobility, diet at time of discharge and at last follow-up, time to full oral feeding, and hospital admissions. There were a total of 94 patients included in the study, 17 of whom had VFMI. While significantly more patients with VFMI required modified diet at discharge, 48% compared to 19% of patients with normal vocal fold mobility; there was no statistically significant difference in time to regular diet on long-term follow-up, 0.8 years (VFMI) compared to 0.4 years (normal vocal fold mobility). Of the 25 patients with modified diet or gastrostomy tube at discharge, 52% returned to full feeds within a year. There was no difference in hospitalizations for pneumonia in patients with or without VFMI. However in patients with VFMI, 35% required readmission for feeding difficulty or poor weight gain compared to only 5% in the infants with normal vocal fold mobility. After neonatal cardiac surgery, there do not appear to be long-term effects of VFMI with regards to readmission for pneumonia. However, there is an increased risk for hospitalization with respect to feeding difficulties in those neonates with VFMI. The overall prognosis for time to oral feeding is good. Copyright © 2016. Published by Elsevier Ireland Ltd.

The effect of vocal fold vertical stiffness gradient on sound production

NASA Astrophysics Data System (ADS)

Geng, Biao; Xue, Qian; Zheng, Xudong

2015-11-01

It is observed in some experimental studies on canine vocal folds (VFs) that the inferior aspect of the vocal fold (VF) is much stiffer than the superior aspect under relatively large strain. Such vertical difference is supposed to promote the convergent-divergent shape during VF vibration and consequently facilitate the production of sound. In this study, we investigate the effect of vertical variation of VF stiffness on sound production using a numerical model. The vertical variation of stiffness is produced by linearly increasing the Young's modulus and shear modulus from the superior to inferior aspects in the cover layer, and its effect on phonation is examined in terms of aerodynamic and acoustic quantities such as flow rate, open quotient, skewness of flow wave form, sound intensity and vocal efficiency. The flow-induced vibration of the VF is solved with a finite element solver coupled with 1D Bernoulli equation, which is further coupled with a digital waveguide model. This study is designed to find out whether it's beneficial to artificially induce the vertical stiffness gradient by certain implanting material in VF restoring surgery, and if it is beneficial, what gradient is the most favorable.

Relation of Structural and Vibratory Kinematics of the Vocal Folds to Two Acoustic Measures of Breathy Voice Based on Computational Modeling

ERIC Educational Resources Information Center

Samlan, Robin A.; Story, Brad H.

2011-01-01

Purpose: To relate vocal fold structure and kinematics to 2 acoustic measures: cepstral peak prominence (CPP) and the amplitude of the first harmonic relative to the second (H1-H2). Method: The authors used a computational, kinematic model of the medial surfaces of the vocal folds to specify features of vocal fold structure and vibration in a…

Recurrent laryngeal nerve regeneration through a silicone tube produces reinnervation without vocal fold mobility in rats.

PubMed

Kumai, Yoshihiko; Aoyama, Takashi; Nishimoto, Kohei; Sanuki, Tetsuji; Minoda, Ryosei; Yumoto, Eiji

2013-01-01

We established an animal model of recurrent laryngeal nerve reinnervation with persistent vocal fold immobility following recurrent laryngeal nerve injury. In 36 rats, the left recurrent laryngeal nerve was transected and the stumps were abutted in a silicone tube with a 1-mm interspace, facilitating regeneration. The mobility of the vocal folds was examined endoscopically 5, 10, and 15 weeks later. Electromyography of the thyroarytenoid muscle was performed. Reinnervation was assessed by means of a quantitative immunohistologic evaluation with anti-neurofilament antibody in the nerve both proximal and distal to the silicone tube. The atrophy of the thyroarytenoid muscle was assessed histologically. We observed that all animals had a fixed left vocal fold throughout the study. The average neurofilament expression in the nerve both distal and proximal to the silicone tube, the muscle area, and the amplitude of the compound muscle action potential recorded from the thyroarytenoid muscle on the treated side increased significantly (p < 0.05) over time, demonstrating regeneration through the silicone tube. Recurrent laryngeal nerve regeneration through a silicone tube produced reinnervation without vocal fold mobility in rats. The efficacy of new laryngeal reinnervation treatments can be assessed with this model.

Treatment of Acute Vocal Fold Injury With Platelet-Rich Plasma.

PubMed

Cobden, Serap Bulut; Oztürk, Kayhan; Duman, Selcuk; Esen, Hasan; Aktan, Tahsin Murad; Avunduk, Mustafa Cihat; Elsurer, Cagdas

2016-11-01

Platelet-rich plasma (PRP) is a reliable and has low side-effect profile and has beneficial effects on wound healing. Its investigatory effects on wound-healing process were shown on various tissues. The aim of the present study was to evaluate effectiveness of PRP application on scar tissue of acute vocal fold injury. Twenty-four Wistar rats were used in the study. The entire layer of the lamina propria down to the thyroarytenoid muscle of 10 subjects was unilaterally injured by with a microscissor. Gelfoam-absorbed PRP was applied on the injured area for 10 minutes. Control group consisted of rats unilaterally injured using a microscissor, and gelfoam with normal saline was applied on the injured area. Following sacrifice, the larynxes were carefully dissected and removed for histopathologic examination. After excised larynx experiments, serial sections were prepared from vocal fold. Hematoxylin eosin and immunohistochemical staining were done for epithelial growth factor receptor (EGFR), fibroblast growth factor receptor (FGFR1), and vascular endothelial growth factor (VEGF) staining for histopathologic examinations. There was not a significant difference between the two groups for lymphocyte. Although collagen and VEGF were higher in the study group, there was not a significant difference between the groups (P > 0.05). There was a significant difference between control and study groups for EGFR and FGFR1(P < 0.05). PRP has beneficial effects on wound healing. PRP accelerates epithelization of injured rat vocal folds by inducing EGFR secretion. PRP is an autogenous, reliable, low side-effect profile, easily harvested material. PRP may be useful to prevent scar formation. Copyright © 2016 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Biochemical basis of vocal fold mobilization after microflap surgery in a rabbit model.

PubMed

Mitchell, Joshua R; Kojima, Tsuyoshi; Wu, Hongmei; Garrett, C Gaelyn; Rousseau, Bernard

2014-02-01

To investigate phonation-related extracellular matrix (ECM) changes in the vocal fold lamina propria after microflap surgery using an in vivo rabbit phonation model. Prospective animal study. Twenty-four New Zealand White rabbits were used in this study. Quantitative polymerase chain reaction and immunohistochemistry were used to investigate alterations in vocal fold ECM proinflammatory and profibrotic gene, and protein expression from a control group of animals receiving a microflap without phonation and a separate group of animals receiving experimentally induced phonation on postmicroflap days 0, 3, and 7. IHC demonstrated the highest concentration of CD45 in vocal folds on postoperative day 0. Staining for CD45 was absent by postoperative day 7, with no differences in CD45 staining between groups. Fibronectin gene expression increased significantly on postoperative day 3 in the control and experimentally induced phonation groups, with maximal staining of fibronectin around the microflap incision on postoperative day 7. No alterations in cyclooxygenase-2, interleukin-1β, and transforming growth factor-β1 gene expression were observed between groups. Results of the present study revealed an acute inflammatory response in the vocal fold at the time of microflap (day 0) and up to 3 days post-microflap. By post-operative day 3, staining of CD45 positive cells decreased, with essentially no evidence of inflammation by post-operative day 7. With the end of the acute inflammatory response occurring around day 3, these data may provide support for mobilizing tissue after inflammation has subsided and the process of active tissue remodeling has ensued (days 3-7). N/A. © 2013 The American Laryngological, Rhinological and Otological Society, Inc.

Spatiotemporal Quantification of Vocal Fold Vibration After Exposure to Superficial Laryngeal Dehydration: A Preliminary Study.

PubMed

Patel, Rita R; Walker, Reuben; Sivasankar, Preeti M

2016-07-01

The aim of the study was to evaluate the effects of a superficial laryngeal dehydration challenge on vocal fold vibration in young healthy adults using high-speed video imaging. In this prospective study, the effects of a 60-minute superficial laryngeal dehydration challenge on spatial (speed quotient, amplitude quotient) and temporal measures (jitter percentage, vibratory onset time) of vocal fold vibration and phonation threshold pressure (PTP) were evaluated in 10 (male = 4, female = 6) vocally normal adults (21-29 years). All measures except the vibratory onset time were measured at the 10 (low) and 80 (high) percent level of their pitch range. The vibratory onset time was obtained at habitual pitch and loudness level. Superficial laryngeal dehydration was induced by oral breathing in low ambient humidity. Prechallenge and postchallenge differences were statistically investigated using t tests with Bonferroni correction. The speed quotient at low-pitch phonation significantly decreased after oral breathing of low ambient humidity. Other spatiotemporal measures and PTP at low and high pitch were not significant after challenge. Results from this initial study have implications for the use of high-speed video imaging to detect and quantify the subtle changes in vocal fold vibrations after superficial dehydration in healthy individuals. Preliminary findings indicate that superficial dehydration in healthy individuals results in spatial deviations at low pitch. However, further studies are warranted to identify additional spatiotemporal changes in vocal fold vibration after superficial dehydration in normal and disordered populations. Published by Elsevier Inc.

Frequency Response of Synthetic Vocal Fold Models with Linear and Nonlinear Material Properties

PubMed Central

Shaw, Stephanie M.; Thomson, Scott L.; Dromey, Christopher; Smith, Simeon

2014-01-01

Purpose The purpose of this study was to create synthetic vocal fold models with nonlinear stress-strain properties and to investigate the effect of linear versus nonlinear material properties on fundamental frequency during anterior-posterior stretching. Method Three materially linear and three materially nonlinear models were created and stretched up to 10 mm in 1 mm increments. Phonation onset pressure (Pon) and fundamental frequency (F0) at Pon were recorded for each length. Measurements were repeated as the models were relaxed in 1 mm increments back to their resting lengths, and tensile tests were conducted to determine the stress-strain responses of linear versus nonlinear models. Results Nonlinear models demonstrated a more substantial frequency response than did linear models and a more predictable pattern of F0 increase with respect to increasing length (although range was inconsistent across models). Pon generally increased with increasing vocal fold length for nonlinear models, whereas for linear models, Pon decreased with increasing length. Conclusions Nonlinear synthetic models appear to more accurately represent the human vocal folds than linear models, especially with respect to F0 response. PMID:22271874

Silastic injection for vocal fold medialization resulting in a false-positive finding on F18 FDG-PET/CT.

PubMed

Mahfouz, Ayman; Naji, Meeran; Mok, Wing Yan; Taghi, Ali S; Win, Zarni

2015-09-01

A false-positive uptake of F18-fluorodeoxyglucose (FDG) on positron-emission tomography/computed tomography (PET/CT) can result in confusion and misinterpretation of scans. Such uptakes have been previously described after injection of polytetrafluoroethylene (Teflon) into the vocal folds. Similarly, vocal fold injection of silicone elastomer (Silastic) can result not only in a false-positive FDG uptake on PET/CT, but also in chronic inflammation. We report a case of increased FDG uptake in a vocal fold after Silastic injection that was misinterpreted as a malignancy in a 70-year-old woman who had metastatic carcinoma of the stomach.

Visualizing the movement of the contact between vocal folds during vibration by using array-based transmission ultrasonic glottography

PubMed Central

Jing, Bowen; Chigan, Pengju; Ge, Zhengtong; Wu, Liang; Wang, Supin; Wan, Mingxi

2017-01-01

For the purpose of noninvasively visualizing the dynamics of the contact between vibrating vocal fold medial surfaces, an ultrasonic imaging method which is referred to as array-based transmission ultrasonic glottography is proposed. An array of ultrasound transducers is used to detect the ultrasound wave transmitted from one side of the vocal folds to the other side through the small-sized contact between the vocal folds. A passive acoustic mapping method is employed to visualize and locate the contact. The results of the investigation using tissue-mimicking phantoms indicate that it is feasible to use the proposed method to visualize and locate the contact between soft tissues. Furthermore, the proposed method was used for investigating the movement of the contact between the vibrating vocal folds of excised canine larynges. The results indicate that the vertical movement of the contact can be visualized as a vertical movement of a high-intensity stripe in a series of images obtained by using the proposed method. Moreover, a visualization and analysis method, which is referred to as array-based ultrasonic kymography, is presented. The velocity of the vertical movement of the contact, which is estimated from the array-based ultrasonic kymogram, could reach 0.8 m/s during the vocal fold vibration. PMID:28599522

Functional reinnervation of vocal folds after selective laryngeal adductor denervation-reinnervation surgery for spasmodic dysphonia.

PubMed

DeConde, Adam S; Long, Jennifer L; Armin, Bob B; Berke, Gerald S

2012-09-01

Selective laryngeal adductor denervation-reinnervation surgery (SLAD-R) offers a viable surgical alternative for patients with adductor spasmodic dysphonia refractory to botulinum toxin injections. SLAD-R selectively denervates the symptomatic thyroarytenoid muscle by dividing the distal adductor branch of the recurrent laryngeal nerve (RLN), and preventing reinnervation, by the proximal RLN and maintaining vocal fold bulk and tone by reinnervating the distal RLN with the ansa cervicalis. We present a patient who had previously undergone successful SLAD-R but presented 10 years postoperatively with a new regional dystonia involving his strap muscles translocated to his reinnervated larynx by his previous ansa-RLN neurorraphy. The patient's symptomatic vocal fold adduction resolved completely on division of the ansa-RLN neurorraphy confirming successful selective functional reinnervation of vocal fold adductors by the ansa cervicalis. Copyright © 2012 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

Impact of Perioperative Voice Therapy on Outcomes in the Surgical Management of Vocal Fold Cysts.

PubMed

Tibbetts, Kathleen M; Dominguez, Laura M; Simpson, C Blake

2018-05-01

Vocal fold cysts are benign mid-membranous lesions of the true vocal fold, classified as mucus retention or epidermal inclusion cysts. Treatment is surgical excision with or without postoperative voice therapy. A retrospective review was performed of the demographics, treatment approach, and outcomes of patients treated for vocal fold cysts between 2009 and 2014. Voice Handicap Index (VHI)-10 scores before and after treatment were compared using the Wilcoxon Rank-Sum test and the two-tailed Student's t test. Videostroboscopy examinations were reviewed for posttreatment changes in vibratory characteristics of the vocal folds. Twenty-five patients were identified, and one was excluded for incomplete records. Mean age was 41.9 years (66.7% female), and mean follow-up time was 5.58 months. Microflap excision was pursued by 21/24 (87.5%) patients, with 14 patients (58.3%) undergoing perioperative voice therapy. One cyst recurred. Two patients elected for observation, and their cysts persisted. VHI-10 decreased from 23.8 to 6.6 (P < 0.001) overall. There was a statistically significant reduction in VHI-10 in patients undergoing surgery with and without postoperative voice therapy (P < 0.004 and 0.001), but there was no significant difference between these two groups. Mucosal wave was classified as normal or improved in the majority. Cysts were characterized as mucus retention cysts in 19/21 (90%) and as epidermal inclusion cysts in 2/21 (10%). Vocal fold cysts impact mucosal wave and glottic closure. Surgical excision resulted in low rates of recurrence, and in improvement in the mucosal wave and VHI-10. Perioperative voice therapy did not offer a significant benefit. Mucus retention cysts were the majority, in contrast to other published studies. Copyright © 2018 The Voice Foundation. Published by Elsevier Inc. All rights reserved.