Vocal Fold Disorders Research Articles

Laryngeal Reflexes: Physiology, Technique, and Clinical Use.

This review examines the current level of knowledge and techniques available for the study of laryngeal reflexes. Overall, the larynx is under constant control of several systems (including respiration, swallowing and cough) as well as sensory motor reflex responses involving glossopharyngeal, pharyngeal, laryngeal, and tracheobronchial sensory receptors. Techniques for the clinical assessment of these reflexes are emerging and need to be examined for sensitivity and specificity in identifying laryngeal sensory disorders. Quantitative assessment methods for the diagnosis of sensory reductions and sensory hypersensitivity may account for laryngeal disorders, such as chronic cough, paradoxical vocal fold disorder, and muscular tension dysphonia. The development of accurate assessment techniques could improve our understanding of the mechanisms involved in these disorders.

Classification of laryngeal disorders based on shape and vascular defects of vocal folds

Vocal fold disorders such as laryngitis, vocal nodules, and vocal polyps may cause hoarseness, breathing and swallowing difficulties due to vocal fold malfunction. Despite the fact that state of the art medical imaging techniques help physicians to obtain more detailed information, difficulty in differentiating minor anomalies of vocal folds encourages physicians to research new strategies and technologies to aid the diagnostic process. Recent studies on vocal fold disorders note the potential role of the vascular structure of vocal folds in differential diagnosis of anomalies. However, standards of clinical usage of the blood vessels have not been well established yet due to the lack of objective and comprehensive evaluation of the vascular structure.In this paper, we present a novel approach that categorizes vocal folds into healthy, nodule, polyp, sulcus vocalis, and laryngitis classes exploiting visible blood vessels on the superior surface of vocal folds and shapes of vocal fold edges by using image processing techniques and machine learning methods. We first detected the vocal folds on videolaryngostroboscopy images by using Histogram of Oriented Gradients (HOG) descriptors. Then we examined the shape of vocal fold edges in order to provide features such as size and splay portion of mass lesions. We developed a new vessel centerline extraction procedure that is specialized to the vascular structure of vocal folds. Extracted vessel centerlines were evaluated in order to get vascular features of vocal folds, such as the amount of vessels in the longitudinal and transverse form. During the last step, categorization of vocal folds was performed by a novel binary decision tree architecture, which evaluates features of the vocal fold edge shape and vascular structure.The performance of the proposed system was evaluated by using laryngeal images of 70 patients. Sensitivity of 86%, 94%, 80%, 73%, and 76% were obtained for healthy, polyp, nodule, laryngitis, and sulcus vocalis classes, respectively. These results indicate that visible vessels of vocal folds can act as a prognostic marker for vocal fold pathologies, as well as the vocal fold shape features, and may play a critical role in more effective diagnosis.

Treatment of aging vocal folds: surgical approaches.

Aging may affect the voice through either physiological or pathological changes. Globally society is aging and the working lifetime is extending. Increasing numbers of elderly will present with voice issues. This review examines current thinking regarding surgical treatment of the aging voice. The mainstay of surgical treatment remains injection laryngoplasty and medialization thyroplasty. In-office injection laryngoplasty is increasingly common. Data suggest that patients with vocal fold atrophy do not achieve as much benefit from augmentation treatments as other causes of glottal incompetence. In addition the timing of injection laryngoplasty may influence the rate of subsequent medialization thyroplasty. Disease-specific treatments can provide some benefit to voice, such as deep brain stimulation in Parkinson's disease. Novel treatments including growth factor therapy are entering clinical practice and will provide new options for the clinician in future. Voice disorders affect approximately 20% of the elderly population. Causes include neurologic, malignant, iatrogenic and benign vocal fold disorders. These should be ruled out before accepting dysphonia is age-related in nature. Treatment should be specific to recognized vocal disorders but may also address physiologic changes in the glottis. Injection laryngoplasty and thyroplasty remain effective options for treating glottal incompetence but novel therapies are showing promising results.

Lipopolysaccharide responsiveness in vocal fold fibroblasts

BackgroundVocal fold fibroblast’s (VFF) strategic location in the lamina propria and their ability to respond to external stimuli by producing inflammatory molecules suggest their possible direct involvement in innate immunity. Toll-like receptors (TLRs) are an essential signaling component to this response, as they allow for recognition of various microorganisms, leading to subsequent induction of pro-inflammatory genes. The objective of this study was to elucidate the role of VFF in the host immune response and subsequent influence on inflammatory cytokine secretion.MethodsVFF derived from polyp, scar, and normal tissue were treated with 5 μg/ml lipopolysaccharide (LPS). TLR1 through 9, CD14, and MD-2 were measured during stable conditions by polymerase chain reaction (PCR). Expression of TLR4 and IL-1R type-1 genes were quantified after 24 hrs LPS stimulation by reverse transcription-PCR. LPS responsiveness was determined by NF-κB nuclear translocation as measured by subunit p65 expression in nucleus with immunocytochemistry. Downstream effects were confirmed with immunoassay measuring IL-8 concentrations in supernatant after 8 hrs.ResultsAll VFFs constitutively expressed TLR1 to 6, TLR9, CD14, and MD-2 mRNA. Polyp VFF exhibited significantly higher TLR4 transcript levels (p < 0.001) in comparison to scar and normal VFF. LPS stimulated scar and polyp VFF exhibited increased levels of p65 in the nucleus (p < 0.01) and secreted greater IL-8 protein (p < 0.0001) compared to normal VFF.ConclusionVFF constitutively express genes for the receptors essential to the host immune response. Scar and polyp VFF produced greater LPS responsiveness resulting in over-activated inflammatory patterns. These findings support VFF role in the pathogenesis of inflammatory vocal fold disorders and suggests their presence in the wound bed could lead to chronic inflammation.

Automatic recognizing of vocal fold disorders from glottis images.

The laryngeal video stroboscope is an important instrument to test glottal diseases and read vocal fold images and voice quality for physician clinical diagnosis. This study is aimed to develop a medical system with functionality of automatic intelligent recognition of dynamic images. The static images of glottis opening to the largest extent and closing to the smallest extent were screened automatically using color space transformation and image preprocessing. The glottal area was also quantized. As the tongue base movements affected the position of laryngoscope and saliva would result in unclear images, this study used the gray scale adaptive entropy value to set the threshold in order to establish an elimination system. The proposed system can improve the effect of automatically captured images of glottis and achieve an accuracy rate of 96%. In addition, the glottal area and area segmentation threshold were calculated effectively. The glottis area segmentation was corrected, and the glottal area waveform pattern was drawn automatically to assist in vocal fold diagnosis. When developing the intelligent recognition system for vocal fold disorders, this study analyzed the characteristic values of four vocal fold patterns, namely, normal vocal fold, vocal fold paralysis, vocal fold polyp, and vocal fold cyst. It also used the support vector machine classifier to identify vocal fold disorders and achieved an identification accuracy rate of 98.75%. The results can serve as a very valuable reference for diagnosis.

Laryngoscopic, Acoustic, Perceptual, and Functional Assessment of Voice in Rock Singers

Objective: The present study aimed to vocally assess a group of rock singers who use growl voice and reinforced falsetto. Method: A group of 21 rock singers and a control group of 18 pop singers were included. Singing and speaking voice was assessed through acoustic, perceptual, functional and laryngoscopic analysis. Results: No significant differences were observed between groups in most of the analyses. Acoustic and perceptual analysis of the experimental group demonstrated normality of speaking voice. Endoscopic evaluation showed that most rock singers presented during singing voice a high vertical laryngeal position, pharyngeal compression and laryngeal supraglottic compression. Supraglottic activity during speaking voice tasks was also observed. However, overall vocal fold integrity was demonstrated in most of the participants. Slightly abnormal observations were demonstrated in few of them. Singing voice handicap index revealed that the most affected variable was the physical sphere, followed by the social and emotional spheres. Conclusions: Although growl voice and reinforced falsetto represent laryngeal and pharyngeal hyperfunctional activity, they did not seem to contribute to the presence of any major vocal fold disorder in our subjects. Nevertheless, we cannot rule out the possibility that more evident vocal fold disorders could be found in singers who use these techniques more often and during a longer period of time.

Voice Pathology Assessment Systems for Dysphonic Patients: Detection, Classification, and Speech Recognition

ABSTRACTIn the past decade, much research has been done on automatic detection and classification of vocal fold disorders, and these tasks continue to require further investigation. The aim of this study is to develop systems that may help in diagnosing patients from their speech. The systems will perform voice disorder detection, classification of voice disorders, and digit recognition. To find the best system, we will compare the system performance when using different voice features. We are the first to explore the use relative spectral transform perceptual linear predictive (RASTA-PLP) feature for speech pathology. The speech samples used in most of the literature are sustained vowels, while the speech samples we worked on are words, which are more natural. To evaluate the performance of the developed system, we used a database containing five types of vocal fold disorders. The database includes a total of 142 speakers half of them were normal speakers. The best accuracy achieved for the voice disorder detection system was 92.40%. In the voice disorder classification system, the maximum obtained recognition rate by using words was 73%. For the digit recognition system, a recognition rate of 98.57% was obtained. PLP and RASTA_PLP showed better performance in the developed pathology assessment systems.

Dynamic Vibration Cooperates with Connective Tissue Growth Factor to Modulate Stem Cell Behaviors

Vocal fold disorders affect 3-9% of the U.S. population. Tissue engineering offers an alternative strategy for vocal fold repair. Successful engineering of vocal fold tissues requires a strategic combination of therapeutic cells, biomimetic scaffolds, and physiologically relevant mechanical and biochemical factors. Specifically, we aim to create a vocal fold-like microenvironment to coax stem cells to adopt the phenotype of vocal fold fibroblasts (VFFs). Herein, high frequency vibratory stimulations and soluble connective tissue growth factor (CTGF) were sequentially introduced to mesenchymal stem cells (MSCs) cultured on a poly(ɛ-caprolactone) (PCL)-derived microfibrous scaffold for a total of 6 days. The initial 3-day vibratory culture resulted in an increased production of hyaluronic acids (HA), tenascin-C (TNC), decorin (DCN), and matrix metalloproteinase-1 (MMP1). The subsequent 3-day CTGF treatment further enhanced the cellular production of TNC and DCN, whereas CTGF treatment alone without the vibratory preconditioning significantly promoted the synthesis of collagen I (Col 1) and sulfated glycosaminoglycans (sGAGs). The highest level of MMP1, TNC, Col III, and DCN production was found for cells being exposed to the combined vibration and CTGF treatment. Noteworthy, the vibration and CTGF elicited a differential stimulatory effect on elastin (ELN), HA synthase 1 (HAS1), and fibroblast-specific protein-1 (FSP-1). The mitogenic activity of CTGF was only elicited in naïve cells without the vibratory preconditioning. The combined treatment had profound, but opposite effects on mitogen-activated protein kinase (MAPK) pathways, Erk1/2 and p38, and the Erk1/2 pathway was critical for the observed mechano-biochemical responses. Collectively, vibratory stresses and CTGF signals cooperatively coaxed MSCs toward a VFF-like phenotype and accelerated the synthesis and remodeling of vocal fold matrices.

Knowledge, Experience, and Anxieties of Young Classical Singers in Training

Young classical singers in training have a wide variety of knowledge about the anatomy and physiology of the voice and vocal pathology and harbor anxiety about treatment of vocal fold disorders. This study aimed to examine differences in knowledge, experience, and anxiety across levels of training at elite conservatories and young artist programs in the United States. Prospective cohort questionnaire. Undergraduate (50), master's (35), and doctoral/young artist (25) singers (n=110) were given an 80-point questionnaire assessing experience with vocal pathology, otolaryngologists, speech pathologists, and participation in choir or teaching. Participants were asked questions to test their medical knowledge in vocal anatomy, physiology, and care. They were also asked questions about their anxiety about medical visits and vocal pathology and about their habits in the care of their own voices. There was no statistically significant difference in test scores for vocal knowledge across the three levels of training (P=0.47). Mean scores were just above 50% with standard deviations around 12-13 points. The lowest score was 26% and the highest score was 84%. Doctoral/young artist-level participants were more anxious regarding general office visits to an otolaryngologist compared with undergraduate and master's level participants. There were no other significant differences by level of training regarding anxiety about vocal pathology, scope examinations, or visits to a speech pathologist. There were no significant differences in self-reported levels of knowledge. All groups of young singers expressed marked interest in expanding their knowledge of anatomy and physiology, speech pathology, care of the vocal mechanism, and vocal disorders. More advanced singers do not have significantly greater knowledge of vocal form and function and are more anxious about visits to otolaryngologists and vocal pathology; a clear majority of singers indicate interest in knowing more. There is thus ample opportunity for innovation in the development of medical curricula in the instruction of young singers and clear interest in more knowledge on their part.

Transnasal endoscopic steroid injection: A practical and effective alternative treatment for benign vocal fold disorders

Emerging literature has documented the effectiveness of intralesional steroid injection as an alternative treatment for benign vocal fold disorders. However, clinical application is frequently limited by the associated technical demands for adequate anesthesia and precise needle placement. This study investigated the applicability and effectiveness of the more practical and less technically demanding method of transnasal endoscopic steroid injection (TESI). Prospective case series. This study recruited 30 patients with vocal nodules and polyps. Dexamethasone was injected into the Reinke's space under local anesthesia via the operating channel of a transnasal flexible laryngoscope in an office setting. Treatment outcome were measured before, 1 month after, and 3 months after the injection, using videolaryngostroboscopy (VLS), maximal phonation time (MPT), 10-item voice handicap index (VHI-10), acoustic analysis, and perceptual evaluation. VLS examinations at 3 months post-treatment demonstrated that vocal lesions of 10 and 19 patients were resolved or reduced, respectively. Objective measurements showed increased MPT and decreased VHI-10 (P < .05 and P < .01, respectively). Acoustic analysis revealed significant decrease in jitter and shimmer (P < .05). Perceptual evaluation using the GRB (grade, roughness, breathiness) scale also showed improved voice quality (P < .01). Treatment outcomes were similar between vocal nodules and polyps (P > .05). Mild vocal hematoma occurred in three patients following TESI, but resolved spontaneously within 1 month. TESI is a simple and practical office-based treatment modality for benign vocal fold lesions, suitable for most otolaryngologists. Treatment outcomes showed significant subjective and objective improvements that were comparable to the results of other injection procedures reported in the literature. 4.

Optimal Selection of Long Time Acoustic Features Using GA for the Assessment of Vocal Fold Disorders

In recent times, vocal fold problems have been increasing dramatically due to unhealthy social habits and voice abuse. Non-invasive methods like acoustic analysis of voice signals can be used to investigate such problems. Various feature extraction techniques are used to classify the voice signals into normal and pathological. Among them, long-time acoustical parameters are used by many researchers. The selection of best long-time acoustical parameters is very important to reduce the computational complexity, as well as to achieve better accuracy with minimum number of features. In order to select best long-time acoustical parameters, different feature reduction methods or feature selection methods are proposed by researchers. In this work, genetic algorithm (GA) based optimal selection of long-time acoustical parameters is proposed to achieve higher accuracy with minimum number of features. The classification is carried out using k-nearest neighbourhood (k-NN) classifier. In comparison with other works in the literature, the simulation results show that a minimum of 5 features are required to classify the voice signals by GA and a better accuracy of 94.29% is achieved.

Intralesional steroid injection for benign vocal fold disorders: A systematic review and meta‐analysis

Emerging literature had documented the potential usefulness of vocal fold steroid injection (VFSI) as an alternative treatment option for benign vocal lesions. This study aims to conduct a qualitative synthesis and quantitative meta-analysis of vocal fold steroid injection Systematic review and meta-analysis. Electronic databases were searched using relevant keywords. Extracted data include author, year of publication, diagnosis, steroid regimen, recurrence and side effects. Reported treatment outcomes were clustered into five categories, i.e. subjective, perceptual, acoustic, aerodynamic, and stroboscopic. Meta-analyses were performed on studies with numerical results using random effects model. Six articles were identified with a total of 321 patients. All the studies reported significant improvements after VFSI in each category of outcome measurements. Proposed indications for VFSI include vocal nodules, polyp/cyst, Reinke's edema, and scar. Meta-analysis demonstrated a significant increase in maximal phonation time after VFSI by 1.82 seconds (p<0.001, 95% confidence interval (CI): 0.29 ≈ 3.35) and a 27.61 points decrease in voice handicap index (p<0.001, 95% CI: 16.49 ≈ 38.73). Adverse effects include local hematoma, whitish deposition of triamcinolone, and mild vocal fold atrophy, which resolve spontaneously within 1 to 2 months. The recurrence rate after VFSI was between 4% and 31%. VFSI is well-tolerated under local anesthesia in the office setting. The invasiveness and morbidity of VFSI are low and the side effects are self-limited. Meta-analyses demonstrated significant improvements from both objective and subjective measurements. Further controlled studies with longer follow-up periods may evaluate the effectiveness of VFSI more reliably.

Health Care, Business Topics Draw 600 to Seattle Conference

Health Care, Business Topics Draw 600 to Seattle Conference

Application of the Mandarin Chinese Version of the Voice Handicap Index

To investigate the characteristics and clinical application of Mandarin Chinese version of the Voice Handicap Index (VHI). A cross-culture adaptation was used to develop the Mandarin Chinese version of the VHI. The translated version was then administered to 1766 dysphonic patients and 120 control subjects; 210 of the patients were treated with phonosurgery or BOTOX injection. Disorders were chronic laryngitis, benign vocal fold disorders, pathologic sulcus vocalis, benign or malignant tumors of vocal fold, spasmodic dysphonia (SD) and unilateral vocal fold paralysis (UVFP), and functional dysphonia. The Cronbach's α score for the overall VHI was 0.956; the functional, physical, and emotional subscales had values of 0.922, 0.872, and 0.933, respectively. The test-retest reliability coefficient was 0.991 (P<0.01). Correlations between the subscales and the overall VHI as well as among the subscales were all significant (P<0.01) Principal-component analysis revealed six-factor eigenvalues exceeding 1, explaining 75.39% of the total variance. The total VHI scores and subscale scores were statistically higher for dysphonic groups (P<0.001). The order of disease classification from highest score to lowest score was: SD, functional dysphonia, UVFP, sulcus vocalis, benign and malignant tumor, benign vocal fold disorders, and chronic laryngitis. The emotional scores were the highest in SD, and followed by functional dysphonia; the physical scores were the highest in the other groups. Treatment leads to statistically improvement in VHIscores (P<0.05). The Mandarin Chinese version of VHI appears to be a reliable and valid tool in assessing dysphonia in Mandarin Chinese speakers.

Pathological assessment of patients’ speech signals using nonlinear dynamical analysis

Acoustic analysis of voice features can complete the invasive observation-based methods for the diagnosis of vocal fold pathologies. Selection of an appropriate feature extraction method from the voice can significantly improve the diagnostic results for patients with vocal disorders. In this paper, the performance of nonlinear dynamics and acoustical perturbation features is evaluated in order to distinguish patients with vocal fold disorder and other normal cases. As a matter of fact, vocal fold pathology is one of the major causes of voice quality reduction or feature variation in patients with dysphonic voices. Due to the devastating impact of vocal folds dysfunction on the complex dynamical structure of the speech signals, spectral analysis methods are not suitable for characterizing such changes in disordered voices. Therefore, the using measures that can reflect the nonlinear nature of such changes in the acoustical signals is an efficient alternative for the conventional methods. In order to compare and contrast the effectiveness of such approaches, we exploit features such as correlation dimension, the largest Lyapunov exponent, approximate entropy, fractal dimension and Ziv–Lempel complexity, and we also evaluate their performance with respect to some conventional features like jitter and shimmer, in the voice diagnosis task. Using the support vector machine classifier, our simulation results show that correlation dimension and the largest Lyapunov exponent features with the highest recognition rates of 94.44% and 88.89% can be used as a highly reliable method for the clinical diagnosis of vocal folds pathologies and other relevant applications.

Optimal feature selection for the assessment of vocal fold disorders

Unilateral vocal fold paralysis, vocal fold polyp, and vocal fold nodules are the most common types of neurogenic and organic vocal disorders. This article aims to distinguish these types of vocal diseases into four different classes for the purpose of automatic screening. Firstly, the reconstructed signal at each wavelet packet decomposition sub-band in five levels of decomposition with mother wavelet of (db10) is used to extract the nonlinear features of self-similarity and approximate entropy. Also, wavelet packet coefficients are used to measure energy and Shannon entropy features at different spectral sub-bands. Consequently, to find a discriminant feature vector, three different methods have been applied: Davies–Bouldin (DB) criteria, genetic algorithm (GA) with the fitness functions of support vector machine's (SVM) and k-nearest neighbor's (KNN) recognition rates. Finally, obtained feature vectors have been passed on to SVM and KNN classifiers. The results show that a feature vector of length 12 obtained by the optimization method of GA with the fitness function of SVM's recognition rate fed to SVM classifier achieves the highest classification accuracy of 91%. Furthermore, nonlinear features play an important role in pathological voice classification by participating rate of approximately 67% in the optimal feature vector.

An Impedance Detector for Glottography

Impedance glottography, or electroglottography, is a noninvasive technique for monitoring the variation of the degree of contact between the vibrating vocal cords during voice production. Electrical impedance is sensed using a pair of electrodes placed on either side of the larynx, by injecting a low-level high-frequency current. A wide-band impedance detector circuit has been developed using a precision rectifier based on voltage feedback clamping amplifier and approximately linear-phase lowpass filter. The circuit can be used for obtaining electroglottogram signal for diagnosis of vocal fold disorders.

Vocal Fold Bridge: A Complication of a Sulcus Cyst Surgery

Vocal fold bridges are rare pathologies and mostly coincidentally discovered in direct laryngoscopy. Although the pathophysiology of formation is not well established, it is attributed as a primary pathology that accompanies sulcus and related vocal fold disorders. This paper presents a vocal fold bridge formation in a professional singer after surgical removal of a sulcus cyst formed as a sequela with typical histologic findings resembling the primary bridges. This case report addresses a very rare unpublished complication of a phonomicrosurgical procedure and implicates the evidence of trauma in the etiology.

Imaging the Mucosa of the Human Vocal Fold with Optical Coherence Tomography

Discerning the layered microstructure of the vocal folds is critical for effective phonomicrosurgery. Optical coherence tomography (OCT), a noncontact, noninvasive technology that provides cross-sectional images by means of backscattered light, offers the potential for delineating these layers in vivo. The glottal mucosa of 3 human cadaver larynges was imaged with conventional OCT and polarization-sensitive OCT (PS-OCT). Images were obtained through the epithelium and lamina propria. Although the superficial layer of the lamina propria appeared quite homogeneous, the outer surface of the superficial lamina propria was correlated with an increase in backscatter with OCT. The superficial lamina propria and vocal ligament were correlated with a marked increase in tissue birefringence with PS-OCT. This preliminary study demonstrates the capacity of OCT and PS-OCT for visualizing the layered microstructure of the vocal fold mucosa. We believe that these imaging techniques will have applications in the exploration of solutions to vocal fold scarring and in imaging vocal fold disorders in the clinic and operating room.

Observed Similarities in Four Adolescents with Paradoxical Vocal Fold Disorder

Observed Similarities in Four Adolescents with Paradoxical Vocal Fold Disorder