Sensitivity of Phonation Onset Pressure to Vocal Fold Stiffness Distribution

Phonation onset is characterized by the unstable growth of vocal fold (VF) vibrations that ultimately results in self-sustained oscillation and the production of modal voice. Motivated by histological studies, much research has focused on the role of the layered structure of the vocal folds in influencing phonation onset, wherein the outer "cover" layer is relatively soft and the inner "body" layer is relatively stiff. Recent research, however, suggests that the body-cover (BC) structure over-simplifies actual stiffness distributions by neglecting important spatial variations, such as inferior-superior (IS) and anterior-posterior gradients and smooth transitions in stiffness from one histological layer to another. Herein, we explore sensitivity of phonation onset to stiffness gradients and smoothness. By assuming no a priori stiffness distribution and considering a second-order Taylor series sensitivity analysis of phonation onset pressure with respect to stiffness, we find two general smooth stiffness distributions most strongly influence onset pressure: a smooth stiffness containing aspects of BC differences and IS gradients in the cover, which plays a role in minimizing onset pressure, and uniform increases in stiffness, which raise onset pressure and frequency. While the smooth stiffness change contains aspects qualitatively similar to layered BC distributions used in computational studies, smooth transitions in stiffness result in higher sensitivity of onset pressure than discrete layering. These two general stiffness distributions also provide a simple, low-dimensional, interpretation of how complex variations in VF stiffness affect onset pressure, enabling refined exploration of the effects of stiffness distributions on phonation onset.

Vocal fold electromyography in patients with endoscopic features of unilateral laryngeal paralysis

<b><br>Introduction:</b> Electromyography (EMG) of the larynx provides information on the electrophysiological condition of laryngeal muscles and innervation. Integration of information obtained from the EMG exams with the clinical parameters as obtained by other methods for laryngeal assessment (endoscopy, perceptual and acoustic analysis, voice self-assessment) provides a multidimensional picture of dysphonia, which is of particular importance in patients with vocal fold (VF) mobility disorders accompanied by glottic insufficiency.</br> <b><br>Aim:</b> The aim of this study was to evaluate laryngeal EMG records acquired in subjects with unilateral vocal fold immobilization with signs of atrophy and glottic insufficiency.</br> <b><br>Material and methods:</b> From the available material of 74 EMG records of patients referred for the exam due to unilateral laryngeal paralysis, records of 17 patients with endoscopic features suggestive of complete laryngeal muscle denervation were selected. The EMG study of thyroarytenoid muscles of mobile and immobile VFs was evaluated qualitatively and quantitatively at rest and during volitional activity involving free phonation of vowel /e/ [ε].</br> <b><br>Results:</b> In all patients, the EMG records from mobile VFs were significantly different from those from immobile VFs. Despite endoscopic features of paralysis, no VF activity whatsoever was observed in as few as 2 patients so as to meet the neurophysiological definition of paralysis. In 88% of cases, electromyographic activity of the thyroarytenoid muscle was observed despite immobilization and atrophy of the vocal fold. In these patients, neurogenic type of record was observed with numerous high- -amplitude mobility units. On the basis of the results, quantitative features of EMG records indicative of paralysis and residual activity of the thyroarytenoid muscle were determined.</br> <b><br>Conclusions:</b> Qualitative and quantitative analysis of laryngeal EMG records provides detailed information on the condition of vocal fold muscles and innervation. EMG records of mobile vs immobile VFs differ significantly from each other. Endoscopic evaluation does not provide sufficient basis for the diagnosis of complete laryngeal muscle denervation.</br>.

Efficacy of Botulinum A Injection to the Laryngeal Adductor Compartment for Treatment of Cough

OBJECTIVES

Studies examining electromyography (EMG)-guided laryngeal onobotulinumtoxinA (BTxA) injection for chronic cough reveal promising efficacy, however, are limited by small cohorts and absent quantifiable outcomes. It further remains unclear if pulmonary disease limits efficacy, or if vagal motor neuropathy prognosticates response. We hypothesize BTxA injection results in qualitative improvement in cough, decrease in Cough Severity Index (CSI), no change in Voice Handicap Index-10 (VHI-10), and complication rates comparable to historical data. We also examine the correlation of pulmonary comorbidities and vocal fold hypomobility with treatment efficacy.

STUDY DESIGN

Retrospective review.

METHODS

Charts for patients receiving percutaneous adductor compartment BTxA injection for cough were reviewed for the binary outcome of patient-reported presence or absence of improvement. Generalized estimating equations regression models were used to analyze the change in CSI (ΔCSI) and the correlation of ΔCSI with qualitative outcomes. Multivariable analyses were used to examine correlation of vocal fold hypomobility and pulmonary disease with qualitative outcomes and ΔCSI.

RESULTS

Forty-seven patients underwent 197 BTxA injections from June 2012 to June 2022. A statistical proportion of 0.698 (0.599-0.813, p < 0.0001) or 69.8% of injections resulted in subjective improvement. Mean ΔCSI was -2.12 (0.22-4.02, p < 0.05), indicating overall improvement. With and without subjective improvement, estimated ΔCSI was -4.43 and +2.68, respectively (p < 0.0001). VHI-10 did not change (0.69, p = 0.483). Neither pulmonary disease nor vocal fold hypomobility correlated with subjective improvement or ΔCSI. Dysphagia occurred following 15 (7.6%) injections with no aspiration pneumonia or hospitalization.

CONCLUSIONS

BTxA injection to the laryngeal adductors may effectively treat cough with limited risk for serious complications.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:1749-1756, 2024.

An Integrated Experimental-Computational Study of Vocal Fold Vibration in Type I Thyroplasty

Subject-specific computational modeling of vocal fold (VF) vibration was integrated with an ex vivo animal experiment of type 1 thyroplasty to study the effect of the implant on the vocal fold vibration. In the experiment, a rabbit larynx was used to simulate type 1 thyroplasty, where one side of the vocal fold was medialized with a trans-muscular suture while the other side was medialized with a silastic implant. Vocal fold vibration was then achieved by flowing air through the larynx and was filmed with a high-speed camera. The three-dimensional computational model was built upon the pre-operative scan of the laryngeal anatomy. This subject-specific model was used to simulate the vocal fold medialization and then the fluid-structure interaction (FSI) of the vocal fold. Model validation was done by comparing the vocal fold displacement with postoperative scan (for medialization), and by comparing the vibratory characteristics with the high-speed images (for vibration). These comparisons showed the computational model successfully captured the effect of the implant and thus has the potential for presurgical planning.

Exploring Mental Health in a Pediatric Paradoxical Vocal Fold Motion Sample Using Patient-Reported Outcomes

OBJECTIVE

Paradoxical vocal fold motion (PVFM) is characterized by inappropriate adduction of vocal folds during inspiration causing dyspnea. While anxiety is suspected to be a predisposing factor, incidence has been understudied.

STUDY DESIGNS

Retrospective review.

SETTING

Multidisciplinary PVFM hospital clinic.

METHODS

We used patient-reported outcome measures to examine anxiety and depression in consecutive patients aged 10 to 17 years using Pediatric SFv1.1 Anxiety 8b and Level 2-Depression inventories (parents completed proxy forms). T-scores were classified as normal (none to slight <55) or elevated (mild 55-59.9, moderate 60-69.9, severe >70).

RESULTS

Twenty-three pediatric patients and 20 parents completed surveys. Mean age was 13.74 years. For anxiety, 69.6% of patients and 40% of parents identified elevated levels. For depression, 30.4% of patients and 15% of parents identified elevated levels. Therapy need for the sample was 65.2% (34.8% active in services and 30.4% referred). Child anxiety scores were significantly higher in the therapy need group, U = 17, P = .004.

CONCLUSION

This study of adolescents with PVFM confirmed elevated anxiety and depression scores in 2/3 of the participants. Anxiety likely precedes diagnosis and is a predisposing factor. Referral for individualized intervention targeting anxiety and depression is indicated.

Predominantly unilateral laryngomalacia in infants with unilateral vocal fold paralysis

BACKGROUND

Neonatal unilateral vocal fold paralysis may arise iatrogenically, idiopathically, or in the context of an underlying neurologic disorder. Management is often supportive, focusing on diet modification to allow for safe oral feeding. We describe the clinical course of six infants with unilateral vocal fold paralysis who developed predominantly unilateral laryngomalacia ipsilateral to the affected vocal fold with associated severe respiratory symptoms and feeding difficulty.

METHODS

Retrospective review of six infants with unilateral vocal fold paralysis and predominantly unilateral laryngomalacia. Charts were reviewed for etiology of vocal fold paralysis, presenting symptoms, operative details, postoperative course, and outcomes for breathing and swallowing.

RESULTS

Etiology of vocal fold paralysis included cardiac surgery in four patients, intubation-related in one, and idiopathic in one. Presenting symptoms included increased work of breathing, stridor, feeding difficulty, respiratory failure requiring noninvasive respiratory support, and weak cry. All infants were on nasogastric tube feedings. Direct microlaryngoscopy with unilateral or predominantly unilateral (conservative contralateral aryepiglottic fold division) supraglottoplasty was performed. Stridor and work of breathing improved in all six patients within 1 week postoperatively. Oral feeding improved in three patients within 2 weeks. Three patients had persistent feeding impairment with improvement within one year.

CONCLUSIONS

Predominantly unilateral laryngomalacia may arise in the context of unilateral vocal fold paralysis. Addressing the ipsilateral cuneiform collapse can improve breathing and feeding. This may be an under-described phenomenon and represents an additional reason to include the otolaryngologist early in the care of infants with suspected possible new unilateral vocal fold paralysis. Breathing and swallow can improve post-operatively, but feeding may remain limited by the vocal fold paralysis and any medical comorbidities. Ongoing follow-up and collaboration with speech-language pathology to optimize feeding are important.

Characteristics of lower airway parameters in an adult Asian population related to endotracheal tube design: a cadaveric study

The risk of endotracheal tube (ETT) placement includes endobronchial intubation and subglottic injury. This study aimed to describe the lengths of lower airway parameters related to cuff location and vocal cord markings in different adult-sized ETTs. Eighty cadavers were examined for the lengths of the lower airway, including their correlations and linear regressions with height. Thirty adult-sized ETTs from seven different brands were examined for Mark-Cuff and Mark-Tip distances. The depth of ETT placement was simulated for each brand using vocal cord marking. The mean (standard deviation) lengths from the subglottis, trachea, vocal cord to mid- trachea, and vocal cord to carina were 24.2 (3.5), 97.9 (8.6), 73.2 (5.3), and 122.1 (9.0) mm, respectively. Airway lengths were estimated as: (1) subglottis (mm) = 0.173 * (height in cm) - 3.547; (2) vocal cord to mid-trachea (mm) = 0.28 * (height in cm) + 28.391. There were variations in the Mark-Cuff and Mark-Tip distances among different ETTs. In the simulation, endobronchial intubation ranged between 2.5 and 5% and the cuff in the subglottis ranged between 2.5 and 97.5%. In summary, the lower airway parameters were height-related. ETT placement using vocal cord marking puts the patient at a high risk of cuff placement in the subglottis.

Simulation of Multiple Source Vocalization in the Larynx: How True Folds, False Folds, and Aryepiglottic Folds May Interact

PURPOSE

This study was a modest beginning to determine dominance and entrainment between three soft tissues in the larynx that can be set into flow-induced oscillation and act as sound sources. The hypothesis was that they interact as coupled oscillators with observable bifurcations as energy is exchanged between them.

METHODOLOGY

The true vocal folds, the ventricular (false) folds, and the aryepiglottic folds were part of a soft-walled airway that produced airflow for sound production. The methodology was computational, based on a simplified Navier-Stokes solution of convective and compressible airflow in a variable-geometry airway.

RESULTS

Three serially connected sources could all produce flow-induced self-oscillation with soft wall tissue and small cross-sectional area. When the glottal cross-sectional areas were similar, bifurcations such as subharmonics, delayed voice onset, and aphonia occurred in the coupled oscillations.

CONCLUSIONS

Closely spaced sound sources in the larynx are highly interactive. They appear to entrain to the source that has the combined advantage of small cross-sectional glottal area and proximity to a downstream vocal tract that supports oscillation with acoustic inertance.

Laryngeal office-based procedures: A safe approach

PURPOSE

Laryngeal surgeries using a flexible nasopharyngoscope equipped with an operative channel has gained popularity, with gradual increase in the variety of interventional office-based procedures, under local anesthesia. The purpose of this study is to analyze the tolerance of such procedures.

MATERIALS AND METHODS

Retrospective cohort study. 337 cases were performed during 2 years. We collected the following data: type of pathology, type of procedure and modalities of anesthesia, adverse events.

RESULTS

19 % of the visits were for the purpose of Biopsy, 65 % for an injection, and Trublue Laser was utilized in 12 % of the procedures. Regarding the pathologies, 27 % were vocal fold paralysis, 18 % leukoplakia or another suspicious lesion, 15 % recurrent respiratory papillomatosis, 13 % neuromuscular disorder, 9 % vocal fold scarring, 7 % vocal cord atrophy and 6 % had an inflammatory presentation. Side effects were documented in 26 visits (7.7 %) and were minor in almost all the encounters: they included strong reflexive cough, deep throat pain, discomfort, gag reflex, anxiety, vagal discomfort, malaise, hypersalivation, nose pain, labile hypertension. More severe side effects were very rare and included septal wound and epistaxis, erythematous rash, dyspnea, and transient dysarthria. 13 procedures were either aborted, or canceled at initial steps, due to inability of the patient to tolerate the procedure and were rescheduled for general anesthesia. 97 % of the cases were released home after 1 h of surveillance.

CONCLUSION

Office-based flexible interventional laryngoscopy under local anesthesia is a safe and well-tolerated procedure, with abundance of various interventions feasible on ambulatory, office-based setup.

Demographic Differences in Clinical Presentation of Pediatric Paradoxical Vocal Fold Motion (PVFM)

OBJECTIVES

Paradoxical vocal fold motion (PVFM) is involuntary closure of the vocal folds during inspiration, often presenting in children and young adults. Although common symptoms and triggers are known, differences in clinical presentation based on patient demographics are unknown. This study characterizes differences in clinical presentation of pediatric PVFM based on age, sex, and race/ethnicity.

METHODS

We reviewed electronic medical records of patients 0-21 years old with PVFM based on ICD codes from 2009 to 2019 within a tertiary academic health system. Demographics, symptoms, triggers, concurrent diagnoses, and laryngoscopy findings were abstracted. Odds ratios (ORs) and 95% confidence intervals (CI) were estimated using logistic regression.

RESULTS

Among 96 individuals the mean age was 10.6 years (standard deviation ±6.5) and 66 (69%) were female. In comparison to 13-21 year olds, those 0-2 years more often had PVFM observed on laryngoscopy (OR = 17.84, 95% CI: 3.14-101.51) and had less shortness of breath (OR = 0.01, 95% CI: 0.00-0.09). Those 3-12 years had more asthma (OR = 3.07, 95% CI: 1.07-8.81) and cough (OR = 6.12, 95% CI: 1.77-21.13). Both 0-2 (OR = 0.07, 95% CI: 0.02-0.24) and 3-12 year olds (OR = 0.13, 95% CI: 0.04-0.40) presented less with activity as a trigger. Racial/ethnic minorities were more likely to present with pharyngeal findings (eg mucosal inflammation, adenotonsillar hypertrophy) on laryngoscopy (OR = 4.58, 95% CI: 1.45-15.37) compared to non-Hispanic Whites. Differences in clinical presentation by sex were not observed.

CONCLUSION

We identified several differences in symptoms, triggers, and laryngoscopy findings in pediatric PVFM based on age and race/ethnicity. Associations between sex and clinical presentation were not observed.

Immediate and Short-term Effects of Straw Phonation in Air or Water on Vocal Fold Vibration and Supraglottic Activity of Adult Patients with Voice Disorders Visualized with Strobovideolaryngoscopy: A Pilot Study

Purpose The first purpose of this study was to investigate and compare the short-term effects after a semi-occluded vocal tract (SOVT) therapy session consisting of straw phonation (SP) in air or water on vocal fold vibration and supraglottic activity of adult patients with voice disorders, visualized with strobovideolaryngoscopy (SVL). The second purpose of this study was to investigate and compare immediate changes in the patients' vocal fold vibration and supraglottic activity during SP in air or water, visualized with SVL. Methods Twelve adult patients with voice disorders (eight women and four men, mean age 52 years) were assigned randomly to one of two study groups: SP in air or SP in water. Immediately before and after a therapy session of 15 min, participants underwent a rigid SVL to determine the short-term effects of the SP session. At the posttherapy examination, flexible SVL while performing SP was added to determine the effects occurring during SP. The visual-perceptual ratings were performed blindly and in random order by three laryngologists, using the Voice-Vibratory Assessment with Laryngeal Imaging rating form for stroboscopy. ResultsShort-term effects after SP: After the SP-in-air session, the supraglottic mediolateral compression decreased significantly. The SP-in-water session led to significantly increased left vibrational amplitude. Immediate effects during SP: During SP in air, a significantly increased left amplitude and mucosal wave, and significantly decreased mediolateral supraglottic activity, were found. SP in water tended to decrease the vibrational amplitude during performance of the task. A trend toward higher anteroposterior supraglottic compression was observed during both SP in air and water, being more prominent in the latter. Conclusion SP in air led to less false vocal fold adduction and consequently less hyperfunction. The small increment in anteroposterior supraglottic activity during SP in air and water might be related to epilarynx narrowing, an economic phenomenon associated with SOVT exercises. The effects on vibrational amplitude were rather ambiguous. The small reduction in amplitude during SP in water is expected to diminish vocal fold impact stress and therefore creates an ideal basis for voice therapy. The increment in amplitude and mucosal wave during SP in air might indicate insufficient supraglottic pressure to obtain the favorable effects of semi-occlusion. Whether or not the rise in amplitude after the SP-in-water session is due to voice efficiency or voice fatigue remains unknown. Future larger-scale investigation in subgroups of voice patients is needed to explore these hypotheses.

Accelerometry May be Superior to EMG for Early Evaluation of Vocal Cord Function After Nerve Injury in a Pig Model

OBJECTIVE

Vocal cord (VC) movement has been demonstrated by the use of accelerometry (ACC) to decrease in parallel with the electromyographic amplitude (EMG) during ongoing traction injury to the recurrent laryngeal nerve (RLN). When RLN function recovers, discrepancies between EMG and VC movement have been reported in clinical and experimental studies. The present study was conducted to clarify the actual relationship between EMG and VC movement measured by ACC during nerve recovery.

METHODS

EMG obtained by continuous nerve monitoring (C-IONM) was compared with ACC during traction injury to the RLN, and throughout 40-min nerve recovery. A three-axis linear accelerometer probe was attached to the VC, and ACC data were registered as described. Traction damage was applied to the RLN until there was a 70% amplitude decrease from baseline EMG, or until loss of signal (LOS), that is, EMG values ≤100 μV.

RESULTS

Thirty-two RLN from 16 immature pigs were studied. Correlation between EMG and ACC were calculated during nerve injury and nerve recovery. The mean correlations were for the 70% and LOS group from start to end of traction: 0.82 (±0.17) and 0.87 (±0.17), respectively. Corresponding correlation coefficients during 40-min recovery was 0.50 (±0.48) in the 70% group and 0.53 (±0.33) in the LOS group.

CONCLUSION

There is a high correlation between EMG and VC movement during nerve injury, and a moderate correlation during early nerve recovery. EMG recovery after RLN injury ensures sufficient VC function as assessed by ACC.

LEVEL OF EVIDENCE

N/A Laryngoscope, 134:1485-1491, 2024.

Cough and Swallowing Therapy and Their Effects on Vocal Fold Bowing and Laryngeal Lesions

OBJECTIVE

Expiratory muscle strength training (EMST) and sensorimotor training of airway protection (smTAP) are two exercises intended to improve cough and swallowing in people with Parkinson's Disease (PwPD). The aims of this study were to (1) examine whether EMST or smTAP elicit changes to vocal fold bowing; and (2) describe the safety of EMST and smTAP as it relates to the development of vocal fold lesions.

METHOD(S)

This was a secondary analysis of data from PwPD who completed EMST or smTAP as part of a prospective randomized controlled trial. Vocal fold bowing (BI) and the presence of laryngeal lesions were blindly analyzed from flexible endoscopic evaluation of swallowing (FEES) using ImageJ software and operational definitions. Linear regression was used to examine the influence time (pre- vs. post-therapy) and therapy (EMST vs. smTAP) on vocal fold bowing. Descriptive statistics were used to describe the presence of laryngeal lesions.

RESULT(S)

Overall, 56 participants were included, 28 per group. The median BI scores pre- and post-therapy were 8.2% and 8.3% for the EMST group and 11.3% and 8.4% for the smTAP group, respectively. Statistical analyses revealed insufficient evidence to suggest an effect of time and treatment type on BI (p > 0.05) or on the presence of vocal fold lesions (p > 0.05).

CONCLUSION

Based on these and previous findings, it appears that changes in vocal fold bowing do not drive treatment effects following EMST and smTAP. Also, this study further supports the safety of smTAP and EMST despite the required forceful exhalation and repetitive coughing.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:1127-1132, 2024.

Evaluation of Size, Laterality, and Location of Unilateral Vocal Fold Lesions on Voice Quality

INTRODUCTION

The presence of a vocal fold mass implies high mechanical stress at the vocal fold base during vibration and an impaired glottic closure. However, evidence about its potential effects on diagnostic tools used in voice evaluation is lacking. We aimed to evaluate the impact of the location, laterality, and size of a unilateral unique vocal fold lesion on patient self-assessment questionnaires, acoustic-aerodynamic voice measures, and perceptual voice evaluation (GRBAS scale).

METHODS

A retrospective chart review involving patients with a diagnosis of a unique unilateral vocal fold lesion and a complete voice evaluation was performed. A total of 58 patients were enrolled and demographics, characteristics of the vocal fold lesion (size, laterality, and location), self-assessment questionnaires, acoustic-aerodynamic measures, and perceptual evaluation (GRBAS scale) were analyzed. Pearson correlation and ANOVA analysis were completed to evaluate the correlation between the clinical characteristics of the vocal fold mass and self-assessment questionnaires, and to compare the level of significance for the differences between the continuous variables between groups of patients once stratified according to the location or laterality of the vocal fold mass.

RESULTS

Glottal Function Index was found to correlate with the location of the vocal fold mass (P < 0.05), however, no correlation was found when evaluating the Reflux Symptom Index or the Voice Handicap Index (P > 0.05). Patients with a lesion located in the anterior-middle 2/3 of the vocal fold were found to have a higher mean Glottal Function Index and (G) component of the GRBAS scale (P < 0.05). No differences were observed when analyzing the remaining self-assessment questionnaires or the acoustic-aerodynamic voice measures according to size, location, or laterality of the vocal fold lesion (P > 0.05).

CONCLUSION

The size and location of unilateral vocal fold lesions were found to have no effect on the majority of measures analyzed in this study. This is the first study we know of to assess the effect that laterality of the vocal fold lesion may have on the self-assessment questionnaires, audio-perceptual, and acoustic-aerodynamic measures included in this study. Our study found no significant differences in regard to laterality. This may indicate that other factors (eg, stiffness of lesion, amount of extraneous muscle tension, etc) could have more of an impact on audio-perceptual, self-assessment questionnaires, and acoustic-aerodynamic measures. Further research with larger cohort sizes and possibly prospective analysis is needed.

Impact of Acid, Weakly Acid and Alkaline Laryngopharyngeal Reflux on Voice Quality

OBJECTIVES

To analyze pre to posttreatment voice changes regarding the type of reflux in patients with acid, weakly acid or alkaline laryngopharyngeal reflux (LPR).

METHODS

Patients with LPR, diagnosed using hypopharyngeal-esophageal multichannel intraluminal impedance pH-monitoring (HEMII-pH), were prospectively recruited from three University Hospitals. Patients were treated with a combination of diet, proton pump inhibitors, magaldrate and alginate for 3 months. The following clinical and voice quality outcomes were studied pre to posttreatment according to the type of reflux (acid, weakly acid, nonacid): HEMII-pH, gastrointestinal endoscopy features, reflux symptom score (RSS), reflux sign assessment (RSA), voice handicap index (VHI), perceptual voice assessment (grade of dysphonia and roughness), aerodynamic and acoustic measurements.

RESULTS

From December 2018 to March 2021, 160 patients completed the evaluations, accounting for 60 acid, 52 weakly acid, and 48 alkaline cases of LPR. There were no baseline differences in clinical and voice quality outcomes between groups. RSS and RSA significantly improved from pre to posttreatment in the entire cohort and in all patient groups. VHI, dysphonia and roughness, maximum phonation time, Jitter, Shimmer and noise to harmonic ratio significantly improved from pre to posttreatment. Individuals with alkaline reflux reported better voice quality improvements as compared to acid and weakly acid reflux patients.

CONCLUSION

Patients with acid and alkaline reflux reported better posttreatment voice quality outcomes as compared to weakly acid reflux patients. Future basic science and clinical studies are needed to better understand the histological changes of the vocal folds due to reflux of varying pH types and gastroduodenal enzyme content.

Validation of the 10-Item Unilateral Vocal Fold Paralysis-Handicap Index quality of life questionnaire

OBJECTIVES

To validate and test the reliability of the 10-Item Unilateral Vocal Fold Paralysis-Voice Handicap Index (UVFP-HI-10) quality of life (QoL) questionnaire for patients with UVFP.

DESIGN

Prospective describe study based on perceptive surveys.

PARTICIPANTS

We recruited 61 patients with UVFP and 53 healthy individuals comprised the control group.

MAIN OUTCOME MEASURES

Both the patients and controls completed the UVFP-HI-10 questionnaire. A statistical analysis was performed to assess the internal consistency and validity of the survey. In addition, maximum phonation time (MPT) was used to objectively measure patient QoL.

RESULTS

Internal consistency was high (α = .914) and the correlation with MPT was significant (rs = -0.722). The estimated marginal mean in the discriminant validity study was around seven times higher in the UVFP group compared to the controls. The UVFP-HI-10 cut-off value was more than 0.9 and the sensitivity and specificity were more than 0.8.

CONCLUSIONS

The UVFP-HI-10 is a self-administered patient-reported outcome questionnaire with a high reliability and excellent criterion-based validity. This questionnaire can be used to evaluate specific clinical complaints (e.g., vocalisation, swallowing, and breathing) in terms of their impact on QoL in patients with UVFP. Thus, its use is appropriate as a basic assessment tool as part of a specific UVFP treatment protocol.

Needle Fracture During Injection Medialization Laryngoplasty

OBJECTIVES

Awake injection medialization laryngoplasty is one of the most common therapeutic procedures done by laryngologists in the office or at the bedside. Complications of injection needle fracture are rarely reported.

METHODS

This is a case report of a 59-year-old male inpatient who developed left vocal fold immobility with significant glottic insufficiency after pneumonectomy for a large left-sided lung cancer. During bedside injection medialization using thyrohyoid approach, the 25 G needle fractured at the hub and was embedded partly in pre-epiglottic space and partly extending over rima glottidis.

RESULTS

Fractured needle was successfully retrieved at the bedside with an endoscopic biopsy forcep using flexible bronchoscope.

CONCLUSION

It is imperative to be aware of rare complications of routine procedures like injection laryngoplasty so they can be managed timely and effectively.

Acoustic, Aerodynamic, Morphometric, and Perceptual Changes During and After Semi-Occluded Vocal Tract Exercise: An Integrative Review

OBJECTIVE

The body of literature discussing the acoustic, aerodynamic, perceptual, and morphometric changes that occur during and after semi-occluded vocal tract exercise (SOVTE) has dramatically expanded within the past 20 years. The current study integrates the literature on SOVTE from the 1990s onward, reviewing the technique's clinically relevant effects in vocally untrained adults both with and without dysphonia. The study aims to give clinicians actionable information on how SOVTEs alter vocal function in both normal and pathological states.

METHODS

The author queried the MEDLINE database for combinations of search terms related to semi-occluded vocal tract exercise. To improve article identification, the author also performed iterative citation webbing in which the reference lists of each article selected for full-text screening were cross-referenced against the articles returned in the initial MEDLINE search. Articles identified by iterative citation webbing that did not appear in the initial MEDLINE search were then screened individually. The second author independently verified adherence to the review's inclusion and exclusion criteria in both the initial search and data extraction phases.

RESULTS

The initial MEDLINE search returned 869 articles, 111 of which passed the title and abstract screening phase. Iterative citation webbing returned an additional 20 studies, resulting in a total of 131 articles that qualified for full-text screening. 53 articles passed full-text screening and were included in the current review.

DISCUSSION

Semi-occluded vocal tract exercise increases the inertive reactance of the glottis, vocal tract, and air column, as well as introducing flow resistance at the level of the lips or velopharyngeal port. Each of these mechanisms yields downstream acoustic, aerodynamic, morphometric, and perceptual changes, including reductions in phonation threshold pressure and perceived phonatory effort, improved spectral characteristics of the acoustic signal, attenuation of vocal fold impact stress as indexed by various metrics such as maximum area declination rate, and alterations to the physical dimensions of the vocal tract. Although few studies examined the duration of these changes post exercise, several RCTs support the assertion that SOVTE's effects can be sustained with regular practice over weeks or months, regardless of current vocal health status.

Physiological Effects of Voice Therapy for Aged Vocal Fold Atrophy Revealed by EMG Study

OBJECTIVES

Age-related voice changes are characterized as breathy, weak and strained, and a deterioration in vocal function in the elderly has been putatively linked to a reduced intensity of speech. They contribute to undesirable voice changes known as presbyphonia. These changes are caused by histological alterations in the lamina propria of the vocal fold mucosa and atrophy of the thyroarytenoid muscle, as well as by decreased respiratory support. There are several clinical studies on presbylarynx dysphonia showing the effectiveness of voice therapy. However, physiological changes of the presbylarynx following voice therapy have not been verified. The purpose of this prospective study was to demonstrate the clinical effectiveness of voice therapy for rehabilitating presbylarynx dysphonia, using vocal function assessments and thyroarytenoid muscular activity detection on laryngeal electromyography (LEMG).

METHODS

10 patients who were diagnosed with aged vocal fold atrophy from ages 60 to 87 years (mean age: 72 years) underwent approximately 12 weeks of voice therapy, mainly using forward-focused voice and vocal resistance training. Stroboscopic examination, aerodynamic assessment, acoustic analysis, Voice Handicap Index (VHI)-10, and LEMG were performed pre- and post-voice therapy. Vocal fold vibratory amplitude (VFVA) was measured by image analysis from the stroboscopic examinations. Turns analysis during steady phonation on LEMG was also assessed.

RESULTS

Maximum phonation time, subglottic pressure, jitter, shimmer, VFVA, and VHI-10 significantly improved after voice therapy. The number of turns per second on LEMG also significantly increased.

CONCLUSION

Our data suggest that voice therapy may improve vocal function and thyroarytenoid muscle activity in patients with aged vocal fold atrophy.

Articulatory and Vocal Fold Movement Patterns During Loud Speech in Children With Cerebral Palsy

PURPOSE

Speech motor control changes underlying louder speech are poorly understood in children with cerebral palsy (CP). The current study evaluates changes in the oral articulatory and laryngeal subsystems in children with CP and their typically developing (TD) peers during louder speech.

METHOD

Nine children with CP and nine age- and sex-matched TD peers produced sentence repetitions in two conditions: (a) with their habitual rate and loudness and (b) with louder speech. Lip and jaw movements were recorded with optical motion capture. Acoustic recordings were obtained to evaluate vocal fold articulation.

RESULTS

Children with CP had smaller jaw movements, larger lower lip movements, slower jaw speeds, faster lip speeds, reduced interarticulator coordination, reduced low-frequency spectral tilt, and lower cepstral peak prominences (CPP) in comparison to their TD peers. Both groups produced louder speech with larger lip and jaw movements, faster lip and jaw speeds, increased temporal coordination, reduced movement variability, reduced spectral tilt, and increased CPP.

CONCLUSIONS

Children with CP differ from their TD peers in the speech motor control of both the oral articulatory and laryngeal subsystems. Both groups alter oral articulatory and vocal fold movements when cued to speak loudly, which may contribute to the increased intelligibility associated with louder speech.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.24970302.

Laryngopharyngeal Reflux and Benign Vocal Fold Lesions: A Systematic Review and Meta-analysis

OBJECTIVE

There is a link between laryngopharyngeal reflux (LPR) and the formation of benign vocal fold lesions (BVFLs). However, previous studies have mainly focused on LPR suggested by symptoms and signs, rather than objectively diagnosed LPR via pharyngeal pH monitoring. We, therefore, conducted a Meta-analysis to evaluate the association between pharyngeal pH monitoring diagnosed LPR and the odds of BVFLs.

DATA SOURCES

Relevant observational studies were identified by searching PubMed, Embase, Cochrane Library, and Web of Science.

REVIEW METHODS

We evaluated between-study heterogeneity using the Cochrane Q test and estimated the I2 statistic. Random-effects models were used when significant heterogeneity was observed; otherwise, fixed-effects models were used.

RESULTS

Thirteen datasets from 9 studies were included. Among them, 493 were diagnosed with LPR and 344 had BVFLs. LPR was related to a higher odds of BVFLs (odds ratio: 3.26, 95% confidence interval: 1.84-5.76, P < .001) with moderate heterogeneity (P for Cochrane Q test = .006, I2  = 57%). Subgroup analyses showed that the association was similar in studies with only pharyngeal pH monitoring (Restech), with double-probe or 3-site pH monitoring, and with 24-hour multichannel intraluminal impedance-pH monitoring (P for subgroup difference = .15). In addition, subgroup analysis showed consistent results in studies from Asia and Europe (P for subgroup analysis = .12), and the association seemed to be consistent for vocal Reinke's edema, nodules, and polyps (P for subgroup difference = .09).

CONCLUSION

Pharyngeal pH monitoring diagnosed LPR is associated with the formation of BVFLs.

Management of Idiopathic Vocal Process Granuloma: A Survey of Academic Laryngologists

OBJECTIVES

Vocal process granulomas (VPGs) are benign laryngeal lesions that may manifest as ulcerated regions of the vocal fold or nodular polypoid lesions. Gold standard treatments for idiopathic VPG are yet to be established at this time. This study evaluated clinical decision-making and outcomes in the treatment of VPG patients based on experiences of academic laryngologists across the United States.

METHODS

A 21-question survey was developed to evaluate each respondent's specific VPG patient population, clinical decision-making in treating VPG, and corresponding treatment outcomes. The survey was distributed to 168 laryngologists at academic institutions across the United States. Data were analyzed through the Qualtrics platform.

RESULTS

A total of 106 responses were analyzed, with a completion rate of 63.1%. Etiology of VPG was most commonly attributed to phonotrauma (96.2%) and reflux (71.8%). Primary first-line treatment was most commonly antireflux medications (92%). Other common first line treatments included voice therapy (58.8%) and inhaled steroids (42.5%). With these treatments, the majority of laryngologists report that recurrence is uncommon (68.4%). Dysphonia was cited as the most frequent long-term sequelae at 27.8%.

CONCLUSIONS

VPG treatment strategies continue to be controversial across the United States with many treatments described in the literature with variable application in the practice of academic laryngologists today. Based on survey results, antireflux medications and voice therapy may be the most widely used and most effective treatment options. Establishment of gold standard therapy for VPG as well as further research into recurrent or persistent VPG despite antireflux and voice therapy should be explored.

LEVEL OF EVIDENCE

5 Laryngoscope, 134:795-802, 2024.

The Effect of an Increasing Subglottal Stenosis Constriction That Extends From the Vocal Folds to the Inferior Border of the Cricoid Cartilage

Acquired subglottal stenosis is an unpredicted complication that can occur in some patients who have undergone prolonged endotracheal intubation. It is a narrowing of the airway at the level of the cricoid cartilage that can restrict airflow and cause breathing difficulty. Stenosis is typically treated with endoscopic airway dilation, with some patients experiencing multiple recurrences. The study highlights the potential of computational fluid dynamics as a noninvasive method for monitoring subglottic stenosis, which can aid in early diagnosis and surgical planning. An anatomically accurate human laryngeal airway model was constructed from computerized tomography (CT) scans. The subglottis cross-sectional area was narrowed systematically using ≈10% decrements. A quadratic profile was used to interpolate the transformation of the airway geometry from its modified shape to the baseline geometry. The numerical results were validated by static pressure measurements conducted in a physical model. The results show that airway resistance follows a squared ratio that is inversely proportional to the size of the subglottal opening (R∝A-2). The study found that critical constriction occurs in the subglottal region at 70% stenosis (upper end of grade 2). Moreover, removing airway tissue below 40% stenosis during surgical intervention does not significantly decrease airway resistance.

Nonlinear dynamics and chaos in a vocal-ventricular fold system

In humans, ventricular folds are located superiorly to the vocal folds. Under special circumstances such as voice pathology or singing, they vibrate together with the vocal folds to contribute to the production of voice. In the present study, experimental data measured from physical models of the vocal and ventricular folds were analyzed in the light of nonlinear dynamics. The physical models provide a useful experimental framework to study the biomechanics of human vocalizations. Of particular interest in this experiment are co-oscillations of the vocal and ventricular folds, occasionally accompanied by irregular dynamics. We show that such a system can be regarded as two coupled oscillators, which give rise to various cooperative behaviors such as synchronized oscillations with a 1:1 or 1:2 frequency ratio and desynchronized oscillations with torus or chaos. The insight gained from the view of nonlinear dynamics should be of significant use for the diagnosis of voice pathologies, such as ventricular fold dysphonia.

Vocal cord dysfunction causing hypoxaemia in the postanaesthesia care unit

Hypoxaemia in the postanaesthesia care unit is common and the majority is caused by hypoventilation or upper airway obstruction due to the (residual) effects of anaesthetic and analgesic agents. We present a case of upper airway obstruction caused by vocal cord dysfunction, a less frequently occurring aetiology. The patient's case suggests a notable relationship between procedural laryngeal stimulus and the onset of symptoms. Approach to the diagnosis and flexible laryngoscopy to either rule-in or rule-out several relevant differentials are discussed.

Vision-Based Assistance for Vocal Fold Identification in Laryngoscopy with Knowledge Distillation

Laryngoscopy images play a vital role in merging computer vision and otorhinolaryngology research. However, limited studies offer laryngeal datasets for comparative evaluation. Hence, this study introduces a novel dataset focusing on vocal fold images. Additionally, we propose a lightweight network utilizing knowledge distillation, with our student model achieving around 98.4% accuracy-comparable to the original EfficientNetB1 while reducing model weights by up to 88%. We also present an AI-assisted smartphone solution, enabling a portable and intelligent laryngoscopy system that aids laryngoscopists in efficiently targeting vocal fold areas for observation and diagnosis. To sum up, our contribution includes a laryngeal image dataset and a compressed version of the efficient model, suitable for handheld laryngoscopy devices.

An Atypical Cause of Hoarseness in a Patient With Thyroid Nodules

Hoarseness due to vocal fold paresis (VFP) has a multitude of etiologies including systemic lupus erythematosus (SLE). During a clinical evaluation of a 58-year-old woman with long-standing hoarseness, an incidental finding of thyroid nodules was found to have VFP. Direct laryngoscopy and vocal fold biopsy confirmed the source was an inflammatory process involving the cricoarytenoid joint of the right hemilarynx. A presumptive diagnosis of SLE was made 3 years before meeting the clinical criteria of overt SLE. The VFP debut of SLE is extremely rare, and a literature review includes a handful of case reports (4 of a total of 37) since 1959. Only partial recovery of laryngeal function using glucocorticoids and Plaquenil was accomplished in the current case.

Manufacturing Process for Non-Adhesive Super-Soft Vocal Fold Models

This study aims to develop super-soft, non-sticky vocal fold models for voice research. The conventional manufacturing process of silicone-based vocal fold models results in models with undesirable properties, such as stickiness and reproducibility issues. Those vocal fold models are prone to rapid aging, leading to poor comparability across different measurements. In this study, we propose a modification to the manufacturing process by changing the order of layering the silicone material, which leads to the production of non-sticky and highly consistent vocal fold models. We also compare a model produced using this method with a conventionally manufactured vocal fold model that is adversely affected by its sticky surface. We detail the manufacturing process and characterize the properties of the models for potential applications. The outcomes of the study demonstrate the efficacy of the modified fabrication method, highlighting the superior qualities of our non-sticky vocal fold models. The findings contribute to the development of realistic and reliable vocal fold models for research and clinical applications.

Glottal Voice Distortions: Nasolaryngoscopic and Spectral Analysis of Anatomophysiologic Changes in Singing Voice

The distorted voices, commonly called vocal drives in Brazil and in some other South American countries, are vocal ornaments belonging to the aesthetics of popular singing and desired by singers of different styles. The advances in vocal sciences have allowed the demystification of this type of technique in the last four decades, classifying them as glottal, supraglottic or mixed distortions/drives. The interdisciplinary approach in the evaluation of singers who use glottal distortions is fundamental for a broad understanding of the particularities of each case. The present study has as main objective to describe the anatomophysiological and spectral findings of the glottal distortions, identified in the practice of many singers. A sample of three singers in a sung emission with and without vocal distortions was collected. PreSonus® AudioBox Studio One kit was used to record the voice during the nasolaryngoscopic evaluation. The singers underwent vocal warm-up and functional evaluation of the larynx based on two studies on contemporary singers. The singers performed the Snarl Voice and Phaser distortions and both showed particular anatomophysiological behaviors. The larynx was low in the first distortion and the level of the clean voice in the second, with the posterior opening of the glottis in both distortions being observed, with opening of the middle third of the glottis for the first as well. Formants vary according to the vocal tract settings used for the distortions. The glottic distortions present a complex anatomophysiological behavior in their composition, with fundamental participation of the transverse interarytenoid muscle and lateral cricoarytenoids, as well as the the participation of the vocal fold in the frequency break. F3 varied according to the longitudinal length and F4 with the diameter, both being related to the three-dimensional adjustments of the vocal tract.

Association of Sociodemographic Factors on the Presentation and Management of Unilateral Vocal Fold Immobility

OBJECTIVE

To determine the association of social determinants of health (SDOH) on the presentation and management of unilateral vocal fold immobility (UVFI).

METHODS

Retrospective chart review of 207 adult UVFI patients evaluated at a tertiary-care hospital between 2018 and 2019 was performed. Sociodemographic factors including gender, median household income, preferred language, and insurance type were recorded. Confounding clinical factors including etiology of UVFI, Voice Handicap Index-10 (VHI-10) score, laryngoscopic findings, and intervention history were extracted from medical records. Multivariable logistic regression was performed using sociodemographic and clinical factors.

RESULTS

Patient demographics and socioeconomic status were not associated with time to presentation. Patients presenting with glottic insufficiency and UVFI due to malignancy or recurrent laryngeal nerve (RLN) sacrifice had a shorter time to presentation. Higher household income was associated with greater number of interventions (p = 0.02), but neither income nor insurance type affected intervention type or timing. Female patients were less likely to undergo injection medialization laryngoplasty (odds ratio [OR] 0.25, p = 0.005). Older patients were more likely to undergo injection (OR 1.04, p = 0.027). Patients with large glottic gaps (OR 21.2, p = 0.014) and higher VHI-10 scores (OR 1.06, p = 0.047) were more likely to undergo surgery.

CONCLUSION

Higher household income was associated with greater number of interventions and longer duration of care at a private tertiary-care hospital. RLN sacrifice, known malignancy, and glottic insufficiency significantly reduced the time to presentation. Type of intervention received was a complex interplay of both demographic and clinical factors. Large prospective studies should examine the role of SDOH in the presentation and management of UVFI.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:297-304, 2024.

Early Changes in Porcine Larynges Following Injection of Motor-Endplate Expressing Muscle Cells for the Treatment of Unilateral Vocal Fold Paralysis

OBJECTIVES

No curative injectable therapy exists for unilateral vocal fold paralysis. Herein, we explore the early implications of muscle-derived motor-endplate expressing cells (MEEs) for injectable vocal fold medialization after recurrent laryngeal nerve (RLN) injury.

METHODS

Yucatan minipigs underwent right RLN transection (without repair) and muscle biopsies. Autologous muscle progenitor cells were isolated, cultured, differentiated, and induced to form MEEs. Three weeks after the injury, MEEs or saline were injected into the paralyzed right vocal fold. Outcomes including evoked laryngeal electromyography (LEMG), laryngeal adductor pressure, and acoustic vocalization data were analyzed up to 7 weeks post-injury. Harvested porcine larynges were examined for volume, gene expression, and histology.

RESULTS

MEE injections were tolerated well, with all pigs demonstrating continued weight gain. Blinded analysis of videolaryngoscopy post-injection revealed infraglottic fullness, and no inflammatory changes. Four weeks after injection, LEMG revealed on average higher right distal RLN activity retention in MEE pigs. MEE-injected pigs on average had vocalization durations, frequencies, and intensities higher than saline pigs. Post-mortem, the MEE-injected larynges revealed statistically greater volume on quantitative 3D ultrasound, and statistically increased expression of neurotrophic factors (BDNF, NGF, NTF3, NTF4, NTN1) on quantitative PCR.

CONCLUSIONS

Minimally invasive MEE injection appears to establish an early molecular and microenvironmental framework to encourage innate RLN regeneration. Longer follow-up is needed to determine if early findings will translate into functional contraction.

LEVEL OF EVIDENCE

NA Laryngoscope, 134:272-282, 2024.

The vocal cords are predominantly closed in preterm infants <30 weeks gestation during transition after birth; an observational study

AIM

Studies in animals have shown that vocal cords (VCs) close during apnoea before and after birth, thereby impairing the effect of non-invasive ventilation. We tested the feasibility of visualising VCs using ultrasonography (US) and investigated the position and movement of the VCs during non-invasive respiratory support of preterm infants at birth.

METHODS

In an observational study, VCs were visualised using US in infants <30 weeks gestation during both stabilisation after birth and at one hour after birth. Respiratory efforts were simultaneously recorded. The percentage of time the VCs were closed in the first ten minutes was determined from videoframes acquired at 15 Hz and compared with respiratory flow patterns measured using a respiratory function monitor.

RESULTS

US of the VCs could be performed in 20/20 infants included (median (IQR) gestational age 27+6 (27+1-28+6) weeks) without interfering with stabilisation, of whom 60% (12/20) were initially breathing and 40% (8/20) were apnoeic at birth. In breathing infants, the VCs closed between breaths and during breath holds, which accounted for 57% (49-66) of the time. In apnoeic infants receiving positive pressure ventilation, the VCs were closed for 93% (81-99) of the time. US at one hour after birth could be performed in 14/20 infants, VCs were closed between breaths and during breath holds, accounting for 46% (27-52) of the time.

CONCLUSION

Visualising VCs in preterm infants at birth using US is feasible. The VCs were closed during apnoea, in between breaths and during breath holds, impairing the effect of ventilation given.

E-Cigarette Vaping-Related Vocal Fold Injury: A Case Report

E-cigarettes heat a solution into an aerosol that is inhaled. This paper demonstrates that vaping can cause vocal fold injury such as the mucosal burn seen in the case presented.

High Speed Video Observations of Vocal Fold Kinematics While Playing a Clarinet

INTRODUCTION

In this pilot study, flexible high-speed video (HSV) technology with synchronized audio is used to visualize vocal fold behavior in a wind instrumentalist. Specifically, this study aims to contribute to describing the vocal fold behavior of a professional clarinet musician playing varying tones and melodies.

METHOD

Vocal folds of a healthy 26-year-old professional clarinet musician were recorded utilizing a HSV camera coupled to a flexible endoscope, which allowed the synchronous recording of audio with vocal fold movement at the onset, playing, and offset of playing. Two raters experienced with analyzing vocal folds described vocal fold motion of each sample. Samples were processed through a software model to determine the vocal fold movement relative to their position at rest. Digital kymograms (DKGs) were additionally obtained to visualize vocal fold micromovements throughout each sample.

RESULTS

At the onset of playing, the raters observed the vocal folds moving to a paramedian position. Vocal fold adduction varied according to the task performed and ranged from 58% to 77% of the original resting glottis width. The calculated changes in glottis width and DKGs were consistent with the descriptions by the raters.

CONCLUSION

This study demonstrates the utility of flexible HSV in observing vocal fold motion before, during, and after events other than sustained phonation. The incomplete adducted vocal fold postures observed while playing the clarinet not only differ from phonation but also differ depending on task. These various postures may contribute to voice fatigue in wind instrumentalists or to various disorders experienced during their careers.

Efficacy of platelet-rich plasma (PRP) in benign vocal fold lesions: a systematic review and meta-analysis

OBJECTIVES

To evaluate the efficacy of platelet-rich plasma (PRP) in benign vocal fold lesions.

METHODS

MEDLINE, Cochrane Central, Web of Science, and Scopus databases were searched in April 2023 for relevant clinical trials. Inclusion criteria were clinical trials evaluating the efficacy of PRP in benign vocal fold lesions. We conducted a comparative double-arm analysis using the pooled mean difference (MD) and 95% confidence interval (CI). Outcomes of interest included the vocal handicap index (VHI), the Jitter and Shimmer percentages, and the noise-to-harmonic ratio (NHR).

RESULTS

Six studies matched the inclusion criteria. The pooled analysis shows that PRP was associated with significantly lower VHI scores compared with the control (MD = - 5.06, p < 0.01). Regarding the Jitter percentage, the PRP group was not superior to the control group at 2 and 4 weeks. However, the results revealed that PRP significantly reduced the Jitter percentage at 3 months (MD = - 0.61, p = 0.0008). The overall analysis favored the PRP arm significantly (p < 0.001). As for the Shimmer percentage, the combined effect estimate favored the PRP group (MD = - 1.22, p = 0.002). Subgroup analysis according to the time did not reveal any significant differences between studies at 2 weeks, 4 weeks, and 3 months. The analysis of the NHR outcome revealed a significant difference between both groups (MD = -1.09, p = 0.01). However, at 4 weeks, the treatment group had a significantly lower NHR % compared to the control group (MD = - 0.61, p = 0.02). There was no significant difference at 3 months (MD = - 2.14, p = 0.14).

CONCLUSIONS

Platelet-rich plasma is effective in reducing VHI scores, Jitter and Shimmer percentages, and NHR values. This effect is more evident after follow-up, especially 3 months.

Extramedullary plasmacytoma of the larynx - Case report

Extramedullary plasmacytoma of the larynx is an extremely rare entity accounting for 0.04-0.45% of malignant tumours of the larynx. The objective of this clinical case report is to highlight the diagnosis and management of a unique case such as this. A 77-year-old gentleman presented with complaints of hoarseness for 1 year. Computed tomography image revealed a soft tissue mass lesion involving the right true vocal cord. Direct laryngoscopic biopsy was performed and subjected to histopathological examination, which showed collection of plasma cells. Immunohistochemistry confirmed the presence of Kappa and Lambda cells. Multiple myeloma (MM) was ruled out. The patient received radical intent radiation therapy using 3DCRT technique with a dose of 50Gy in 25# over 5 weeks. He experienced improvement in hoarseness on subsequent follow-up visits. At 1-year follow up, positron emission tomography computed tomography showed near total resolution of disease with no progression to MM. Radiation therapy alone is known to achieve good local control, recurrence free survival, and organ preservation in such cases.

Unilateral vocal fold paralysis as a port complication

Unilateral vocal fold paralysis (UVFP) is a frequent finding in otorhinolaryngology practice, but its occurrence as a port complication was very rarely described in English Literature. The authors report a 55-year-old woman with a pancreatic adenocarcinoma who presented a left vocal fold paralysis that occurred concurrently with a venous thrombosis of the left subclavian vein, where a totally implantable venous-access had been previously placed. Although the patient's oncologic disease, that could mislead to a neoplastic cause of the UVFP, the authors came across with an unusual etiology and to their best knowledge, it is the first case of irreversible UVFP associated with onsite thrombosis of the vessel where a port was implanted. The objective of this article is to present and discuss this rare case of UVFP secondary to a port complication and to review the main mechanisms of iatrogenic vocal fold paralysis related to these devices.

Immediate effect of recurrent laryngeal nerve stimulation in patients with idiopathic unilateral vocal fold paralysis

BACKGROUND

There is a lack of effective treatment for idiopathic unilateral vocal fold paralysis (IUVFP). A better phonation was reported by patients after laryngeal nerve stimulation during our clinical examination.

OBJECTIVES

This study aims to investigate immediate effect of recurrent laryngeal nerve (RLN) stimulation on phonation in patients with IUVFP.

MATERIAL AND METHODS

Sixty-two patients with clinically identified IUVFP underwent RLN stimulation with needle electrodes. Laryngoscopy, acoustic analysis, and voice perception assessment were performed for quantitative comparison of vocal function and voice quality before and after the intervention.

RESULTS

Laryngoscopic images showed a larger motion range of the paralyzed vocal fold (p < .01) and better glottal closure (p < .01) after RLN stimulation. Acoustic analysis revealed that the dysphonia severity index increased significantly (p < .01) while the jitter and shimmer decreased after the intervention (p < .05). According to perceptual evaluation, RLN stimulation significantly increased RBH grades in patients with IUVFP (p < .01). Furthermore, the improvement in voice perception had a moderate positive correlation with the decrease in the glottal closure.

CONCLUSIONS AND SIGNIFICANCE

This study shows a short-term improvement of phonation in IUVFP patients after RLN stimulation, which provides proof-of-concept for trialing a controlled delivery of RLN stimulation and assessing durability of any observed responses.

Cricothyroid Muscle Dysfunction Affects Aerodynamic Performance in Patients with Unilateral Vocal Fold Paralysis

BACKGROUND

Emerging evidence has revealed that cricothyroid (CT) muscle dysfunction in unilateral vocal fold paralysis (UVFP) further impairs patients' voices. Given that CT muscle dysfunction does not influence vocal fold position, the mechanism of voice dysfunction induced by dysfunction of CT muscle in UVFP patients remains controversial. This study compares aerodynamics between UVFP patients with and without CT muscle involvement.

METHODS

This cross-sectional study recruited patients with UVFP manifesting dysphonia, and UVFP was confirmed with videolaryngoscopy and laryngeal electromyography (LEMG). Voice analysis and aerodynamic tests were further performed. Patients with (CT+ group) and without (CT- group) CT muscle involvement were compared.

RESULT

A total of 175 patients (40 in the CT+ group and 135 in the CT- group) with UVFP were analyzed. The CT+ group showed lower maximal sound pressure level (SPL) (P=0.039), mean SPL (P=0.042), peak air pressure (P<0.001), mean peak air pressure (P<0.001) and aerodynamic power (P=0.004) than the CT- group.

CONCLUSION

The decrease in SPL, peak air pressure, and aerodynamic power in UVFP patients with CT muscle dysfunction suggests that the effect of CT muscle dysfunction is mediated by a change in aerodynamics.

Radiotherapy result of a case of Kaposi's sarcoma located on the vocal cord

Kaposi's sarcoma (KS) is an angiogenic tumor. KS lesions frequently develop in the skin and oral cavity mucosa in the head and neck regions, and pure laryngeal localization is extremely rare. We reported a 64-year-old male patient without HIV, HBV, and HCV positivity presented with a hemangiomatous lesion detected incidentally in the right vocal cord. Biopsy was taken for histopathological and immunohistochemical evaluation. Examination revealed that spindle cells were of vascular origin and expressed HHV-8, a specific marker associated with Kaposi's sarcoma-associated herpesvirus. Positron emission tomography-computed tomography (PET/CT) demonstrated an increased fluorodeoxyglucose (FDG) uptake in the vocal cord. The patient was treated with a 30 Gy volumetric arc plan. Disease-free follow-up continues in the first year after low-dose definitive RT. This is the first case report of KS in the vocal cord in which the most detailed data about RT were shared.

Vocal cord movement: can it be accurately graded?

INTRODUCTION

Flexible nasendoscopy (FNE) is the principal assessment method for vocal cord movement. Because the procedure is inherently subjective it may not be possible for clinicians to grade the degree of vocal cord movement reliably. The aim of this study was to assess the accuracy and consistency of grading vocal cord movement as viewed via FNE.

METHODS

Thirty FNE videos, without sound or clinical information, were assessed by six consultant head and neck surgeons. The surgeons were asked to assess and grade right and left vocal cord movement independently, based on a five-category scale. This process was repeated three times on separate occasions. Agreement and reliability were assessed.

RESULTS

Mean overall observed inter-rater agreement was 67.7% (sd 1.9) with the five-category scale, increasing to 91.4% (sd 1.9) when a three-category scale was derived. Mean overall observed intra-rater agreement was 78.3% (sd 9.7) for five categories, increasing to 93.1% (sd 3.3) for three categories. Discriminating vocal cord motion was less reliable using the five-category scale (k = 0.52) than with the three-category scale (k = 0.68).

CONCLUSIONS

This study demonstrates quantitatively that it is challenging to accurately and consistently grade subtle differences in vocal cord movement, as proven by the reduced agreement and reliability when using a five-point scale instead of a three-point scale. The study highlights the need for an objective measure to help in the assessment of vocal cord movement.

Voice Changes Without Laryngeal Nerve Alterations After Thyroidectomy: The Need For Prospective Trials - A Review Study

BACKGROUND

Thyroidectomy is a commonly performed surgical procedure that is offered for different thyroid pathologies. The most frequent complication after total thyroidectomy is transient or permanent hypoparathyroidism followed by transient or permanent recurrent laryngeal nerve palsy. Patients may experience voice impairment despite intact laryngeal nerve function. These patients are of special interest because they experience subjective symptoms which are difficult to measure and therefore to treat.

SUMMARY

The Voice Handicap Index (VHI) and VHI-10 are the most commonly used subjective questionnaires. Their results correlate with objective findings. Female sex, in particular after menopause, is a dominant factor for developing voice impairment after thyroidectomy. The extent of neck surgery and the weight and volume of the removed thyroid correlates directly with both objective and subjective voice impairment after surgery. Videolaryngostroboscopy should be considered to examine vocal cord pathologies in this patient group. Surprisingly, there are no studies showing that speech and voice therapy are beneficial for patients with voice alterations but with intact laryngeal nerves.

CONCLUSIONS

While recurrent laryngeal nerve (RLN) paralysis can be evaluated by objective exams postoperatively, we are still left with the issue of possible partial or complete external branch of superior laryngeal nerve (EBSLN) injury. It is therefore quite difficult to segregate neural (RLN and EBSLN) and non-neural voice change populations, regardless of the method of literature evaluation. Perhaps patients' perspectives on how they experience voice functionality should play a superior role in deciding which patients should be investigated further with laryngoscopy, acoustic or perceptual analysis, and which patients should be offered treatment.

Electrical Stimulation of Vocal Fold Adduction Triggered by Laryngeal Electromyography Using a Custom Implant

PURPOSE

Medialization procedures for unilateral vocal fold (VF) paralysis generally improve voice but do not fully replace dynamic VF adduction. Paralyzed VFs typically experience synkinetic reinnervation, which makes it feasible to elicit movement through electrical stimulation. We tested a novel laryngeal pacing implant capable of providing closed-loop (automatic) stimulation of a VF triggered by electromyography (EMG) potentials from the contralateral VF.

METHOD

A custom, battery-powered, microprocessor-based stimulator was tested in eight dogs with bipolar electrodes implanted for recording EMG from the left VF and stimulating adduction of the right VF. A cuff electrode on the left recurrent laryngeal nerve (RLN) stimulated unilateral VF adduction, modeling voluntary control in anesthetized animals. Closed-loop stimulation was tested in both acute and chronic experiments. Synkinetic reinnervation was created in two animals by right RLN transection and suture repair to model unilateral VF paralysis.

RESULTS

In all animals, left VF activation through RLN stimulation generated a robust EMG response that rapidly triggered stimulation of contralateral thyroarytenoid and lateral cricoarytenoid muscles, causing nearly simultaneous bilateral adduction. Optimal triggering of VF stimulation from elicited EMG was achieved using independent onset and offset thresholds. Real-time artifact blanking allowed closed-loop stimulation without self-perpetuating feedback, despite the proximity of recording and stimulation electrodes.

CONCLUSIONS

Using a custom implant system, we demonstrated real-time closed-loop stimulation of one VF triggered by the activation of the contralateral VF. This approach could potentially restore dynamic glottic closure for reflexive behaviors or phonation in cases of unilateral VF paralysis with synkinetic reinnervation.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.24492133.

[Clinical comprehensive evaluation of Jinsang Sanjie Pills/Capsules in treatment of vocal nodule/polyp of vocal cord]

This study used health technology assessment methods and multi-criteria decision analysis(MCDA) model, according to the guideline for clinical comprehensive evaluation of Chinese patent medicine, we developed this assessment tool. The comprehensive evaluation score of Jinsang Sanjie Pills/Capsules is calculated based on the additive model. This score is calculated by "quantitative evaluation software v1.0 for clinical comprehensive evaluation of Chinese patent medicines" which developed by the project team. The evaluation yielded the following results.(1)Effectiveness: compared with the control group, Jinsang Sanjie Pills/Capsules can improve the total effectiveness rate of vocal nodule/polyp of vocal cord, and improve the symptoms and signs.(2)Safety: Jinsang Sanjie Pills/Capsules did not show acute toxicity and long-term toxicity. The most common adverse reaction was gastrointestinal system damage, all of the adverse reactions were either improved or cured.(3)Economy: from the perspective of the health system, evaluating the single use or combination of Jinsang Sanjie Pills/Capsules with conventional medication in the treatment of vocal nodule/polyp of vocal cord is relatively effective and cost-effective compared to conventional medication, with a stable cost-effectiveness advantage.(4) Innovation: Jinsang Sanjie Pills/Capsules are used for the treatment of slow throat paralysis(vocal nodules, polyp of vocal cord, thickening of vocal mucosa) caused by heat toxin accumulation, Qi stagnation and blood stasis, and the resulting hoarseness. Jinsang Sanjie Pills/Capsules have good innovation and targeted indications.(5) Suitability: the investigated doctors, pharmacists and patients all believed that Jinsang Sanjie Pills/Capsules have good suitability.(6)Accessibility: Jinsang Sanjie Pills/Capsules are included in the category B of the National Basic Medical Insurance, Work Injury Insurance, and Maternity Insurance Drug Catalogue(2021 edition), which have good cost-effectiveness and affordability for medical insurance and self-paid patients. Jinsang Sanjie Pills/Capsules do not contain endangered animals and plants. The supply of raw materials can meet the demand of production at present. The comprehensive evaluation score is 76.06 points. Based on all dimensions of evidence, 71.4% experts consensus on Jinsang Sanjie Pills/Capsules is class A, which can be directly converted into decision making. This study comprehensively evaluated the clinical application value of Jinsang Sanjie Pills/Capsules in the treatment of vocal nodule/polyp of vocal cord, so as to provide evidence for their rational clinical use and regulatory decision-making.

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

BACKGROUND/OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

LEVEL OF EVIDENCE

3 Laryngoscope, 133:3449-3454, 2023.

The effect of swelling on vocal fold kinematics and dynamics

Swelling in the vocal folds is caused by the local accumulation of fluid, and has been implicated as a phase in the development of phonotraumatic vocal hyperfunction and related structural pathologies, such as vocal fold nodules. It has been posited that small degrees of swelling may be protective, but large amounts may lead to a vicious cycle wherein the engorged folds lead to conditions that promote further swelling, leading to pathologies. As a first effort to explore the mechanics of vocal fold swelling and its potential role in the etiology of voice disorders, this study employs a finite-element model with swelling confined to the superficial lamina propria, which changes the volume, mass, and stiffness of the cover layer. The impacts of swelling on a number of vocal fold kinematic and damage measures, including von Mises stress, internal viscous dissipation, and collision pressure, are presented. Swelling has small but consistent effects on voice outputs, including a reduction in fundamental frequency with increasing swelling (10 Hz at 30 % swelling). Average von Mises stress decreases slightly for small degrees of swelling but increases at large magnitudes, consistent with expectations for a vicious cycle. Both viscous dissipation and collision pressure consistently increase with the magnitude of swelling. This first effort at modeling the impact of swelling on vocal fold kinematics, kinetics, and damage measures highlights the complexity with which phonotrauma can influence performance metrics. Further identification and exploration of salient candidate measures of damage and refined studies coupling swelling with local phonotrauma are expected to shed further light on the etiological pathways of phonotraumatic vocal hyperfunction.

Predicting Airflow from Measures Sensitive to Mid-cord Glottal Gap During the COVID-19 Pandemic

OBJECTIVES

To determine if trans-laryngeal airflow, important in assessing vocal function in paresis/paralysis and presbylarynges patients with mid-cord glottal gaps, could be predicted by other measures sensitive to mid-cord glottal gap size but with smaller risks of spreading COVID-19, and if any patient factors need consideration.

METHODS

Four populations were: unilateral vocal fold paresis/paralysis (UVFP, 148), aging and UVFP (UVFP plus aging, 22), bilateral vocal fold paresis/paralysis without airway obstruction (BVFP, 49), and presbylarynges (66). Five measures were selected from the initial clinic visit: mean airflow from repeated /pi/ syllables, longer of 2 /s/ and 2 /z/ productions, higher of 2 cepstral peak prominence smoothed for vowel /a/ (CPPSa), and Glottal Function Index (GFI). S/Z ratios were computed. Stepwise regression models used 3 measures and 5 patient factors (age, sex, etiology, diagnosis, and potentially impaired power source for voicing) to predict airflow.

RESULTS

Log-transformations were required to normalize distributions of airflow and S/Z ratio. The final model revealed age, sex, impaired power source, log-transformed S/Z ratio, and GFI predicted log-transformed airflow (R2 = .275, F[5,278] = 21.1; P < .001).

CONCLUSIONS

The amount of variance explained by the model was not high, suggesting adding other predictive variables to the model might increase the variance explained.