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.

Successful emergency Lichtenberger lateralisation for immediate bilateral laryngeal immobility after total thyroidectomy: a CARE case report

OBJECTIVE

This case report discusses a successful emergency Lichtenberger lateralisation procedure after immediate bilateral laryngeal immobility, occurring after total thyroidectomy.

METHODS

A 63-year-old female with right-sided vocal fold paralysis due to compression by a multinodular thyroid goitre underwent total thyroidectomy, which resulted in immediate post-operative bilateral vocal fold immobility. The patient had acute-onset post-operative dyspnoea, was promptly re-intubated, and an emergency lateralisation Lichtenberger suture was placed over the right vocal fold and fixated on the outer surface of the neck.

RESULTS

After two weeks, her right vocal fold recovered first, with the suture still in place. At four weeks, both vocal folds regained function and the suture was extracted.

CONCLUSION

The take-away message is that an emergency lateralisation suture may be a viable option in maintaining airway patency, while allowing for normal deglutition, in patients who would otherwise be candidates for prolonged intubation, posterior cordotomy, medial arytenoidectomy or tracheostomy.

Current opinion in otolaryngology and head and neck surgery: the role of the otolaryngologist in the management of pediatric dysphagia

PURPOSE OF REVIEW

Dysphagia affects at least 1% of the pediatric population. This prevalence further increases in patients who are born prematurely or who have underlying neuromuscular or cardiopulmonary disorders. A multidisciplinary team approach, including an Otolaryngologist, can help promote an expedited diagnosis and therapeutic regimen, ensuring that the patient receives adequate nutrition needed for growth and development.

RECENT FINDINGS

The development and growth of multidisciplinary aerodigestive clinics have improved outcomes in pediatric patients with dysphagia. If a structural concern is noted on examination, there remain a multitude of medical and surgical options to help improve patient outcomes and swallow. These treatment options are usually multimodality and specific interventions may be employed to target a specific and notable abnormality.

SUMMARY

Pediatric dysphagia is a complex concern. For the otolaryngologist, etiologies with surgical targets may include ankyloglossia, tonsillar hypertrophy, laryngomalacia, laryngo-esophageal cleft, vocal fold movement impairment, and cricopharyngeal achalasia. The development and formalization of a multidisciplinary approach has streamlined and broadened treatment options for these patients. An otolaryngologist is integral as part of the treatment team of these patients.

Impact of Rehydration Following Systemic Dehydration on Vocal Fold Gene Expression

OBJECTIVE

Biological data on the beneficial effects of vocal fold rehydration are lacking. This study aimed to examine the effects of acute systemic dehydration on vocal fold gene expression and determine whether rehydration would reverse these changes.

METHODS

Male New Zealand White rabbits (N = 24, n = 8/group) provided the animal model. Systemic dehydration was induced by 5 days of water volume restriction. Rehydration was provided by ad-lib water for 3 days following dehydration. Euhydrated rabbits were used as the control group. Vocal fold tissue was dissected. Seventeen genes were selected based on physiological function and role in supporting vocal fold structure, oxidative stress, hemodynamics, and extracellular matrix turnover. Relative gene expression was assessed by RT-qPCR.

RESULTS

Rehydration following systemic dehydration can modulate gene expression, with expression patterns suggesting that rehydration reverses dehydration-induced changes in over half of the tested genes. CLIC5 (chloride intracellular channel 5) and EFEMP1 (EGF containing fibulin extracellular matrix protein 1) genes were significantly upregulated in the dehydration group compared with the euhydrated control. A1BG (alpha-1B-glycoprotein) and IL1RAP (interleukin 1 receptor accessory protein) were downregulated by rehydration compared with the dehydration group.

CONCLUSION

This study provides molecular evidence for a transcriptional response to rehydration following acute systemic dehydration in the vocal folds. These data are the first to study gene expression following realistic dehydration and rehydration paradigms and provide biological data to support clinical recommendations to increase water intake after acute dehydration.

LEVEL OF EVIDENCE

NA Laryngoscope, 133:3499-3505, 2023.

Lipoid proteinosis; a rare pathology, requiring multidisciplinary input

A male patient in his early childhood presented to rheumatology with a hoarse voice and recurrent oral and cutaneous ulceration. Serological investigation revealed persistently elevated inflammatory markers. Despite compliance to treatment, flare-ups persisted, prompting the use of further treatment. An airway endoscopy revealed cystic changes to the left vocal cord. Referral to ophthalmology revealed multiple, waxy, skin-coloured, beaded papules on thickened, irregular eyelid margins with distichiasis, in keeping with moniliform blepharosis. Enrolment into the 100 000-genome project helped clinch the diagnosis of lipoid proteinosis. Although this case highlights the diagnostic power of genetics, it also sheds light on the importance of targeted clinical referral. When one considers the typical symptoms and signs of lipoid proteinosis, referral to a centre of rare diseases would have proven effective in not only avoiding polypharmacy but also reducing the psychological burden of several years of uncertainty must have had on our patient.

Influence of Reduced Saliva Production on Phonation in Patients With Ectodermal Dysplasia

OBJECTIVE

Patients with ectodermal dysplasia (ED) suffer from an inherited disorder in the development of the ectodermal structures. Besides the main symptoms, i.e. significantly reduced formation/expression of teeth, hair and sweat glands, a decreased saliva production is objectively accounted. In addition to difficulties with chewing/swallowing, ED patients frequently report on the subjective impression of rough and hoarse voices. A correlation between the reduced production of saliva and an affliction of the voice has not yet been investigated objectively for this rare disease.

METHODS

Following an established measurement protocol, a study has been conducted on 31 patients with ED and 47 controls (no ED, healthy voice). Additionally, the vocal fold oscillations were recorded by high-speed videoendoscopy (HSV@4 kHz). The glottal area waveform was determined by segmentation and objective glottal dynamic parameters were calculated. The generated acoustic signal was evaluated by objective and subjective measures. The individual impairment was documented by a standardized questionnaire (VHI). Additionally, the amount of generated saliva was measured for a defined period of time.

RESULTS

ED patients displayed a significantly reduced saliva production compared to the control group. Furthermore, the auditory-perceptual evaluation yielded significantly higher ratings for breathiness and hoarseness in the voices of male ED patients compared to male controls. The majority of male ED patients (67%) indicated at least minor impairment in the self-evaluation. Objective acoustic measures like Jitter and Shimmer confirmed the decreased acoustic quality in male ED patients, whereas none of the investigated HSV parameters showed significant differences between the test groups. Statistical analysis did not confirm a statistically significant correlation between reduced voice quality and amount of saliva.

CONCLUSIONS

An objective impairment of the acoustic outcome was demonstrated for male ED patients. However, the vocal folds dynamics in HSV recordings seem unaffected.

The effects of vocal tract constrictions on aerodynamic measures in a synthetic vocal fold model

According to nonlinear source-filter theory, as the strength of the coupling between the source and filter increases, typically by a decrease in the vocal tract cross-sectional area, the resultant increase in the inertance of the vocal tract yields an increase in the interactions between acoustic pressures within the vocal tract and the changing glottal airflow and/or the vibratory pattern of the vocal folds as noted in Titze [(2008). J. Acoust. Soc. Am. 123(4), 1902-1915]. The purpose of the current research was to examine the effects of parametric vocal tract constrictions mimicking epilaryngeal tube and lip narrowing on aerodynamic measures in a dynamic self-oscillating physical model of the vocal folds and vocal tract. Multilayered silicone vocal fold models were created based on Murray and Thomson [(2011). J. Visualized Exp. 58, e3498] and Murray and Thomson [(2012). J. Acoust. Soc. Am. 132(5), 3428-3438] and mounted to a simple synthetic trachea and supraglottal vocal tract model. Four constriction cross-sectional areas were examined at two locations (i.e., at the epilarynx and lip regions). Phonation threshold pressure and flow were measured at phonation onset and offset using four M5-CONV vocal fold models. Results indicated that both constriction magnitude and location are relevant factors in determining glottal aerodynamics. In general, a narrow epilarynx tube or lip constriction resulted in the lowest onset pressures and airflows while the no vocal tract condition resulted in the highest onset pressures and airflows.

An Old Myth: Prediction of the Correct Singing Voice Classification. True or not?

OBJECTIVE

Predicting the correct singing voice classification based on laryngoscopy is an old myth. The aim of this study was to evaluate if a professional phoniatrician/laryngologist can predict the correct singing voice classification only from laryngoscopy and to analyze different anatomical parameters between professional sopranos and altos to determine whether a multivariate analysis of anatomical parameters can predict the singing register.

STUDY DESIGN

Prospective study METHODS: We included 49 professional female singers (25 sopranos, 24 altos). Laryngoscopic images were shown to professional phoniatricians/laryngologists to rate whether it they show a soprano or an alto. In addition, a high-resolution computer tomography (HRCT) scan was performed during singing of ƒ0 by each singer. DICOM scan data were rendered and 3D-visualized using the software MIMICS. In all singers, we measured the length of the vocal folds of the glottis, the distance from the anterior commissure orthogonally to the vertebral spine, and the antero-posterior distance of the subglottis/trachea 1 cm and 2 cm below the glottis. We also measured the length and volume of the resonance space.

RESULTS

It was not possible to predict the singing voice classification only from laryngoscopy. In the HRCT images, sopranos had significantly shorter vocal folds, a shorter glottal length, a shorter distance from the anterior commissure to the spine, and a shorter resonance space. When combining all parameters, the chance of correctly predicting a soprano was 74.1% and an alto 68.2%.

CONCLUSION

Although there are anatomical differences between sopranos and altos, prediction of the singing voice classification from laryngoscopy or HRCT is not reliable enough for clinical use.

Characterization of Vocal Fold Pathology in Military Drill Instructors

OBJECTIVE

Military drill instructors have extreme vocal demands that place them at risk for phonotrauma. Characterization of laryngeal pathology and vibratory characteristics among drill instructors presenting for specialized voice care is lacking.

METHODS

A retrospective review in a specialized voice clinic over a two-year period was conducted. Patients identified as current drill instructors between the ages of 28-43 with a diagnosis of dysphonia were included. Laryngeal pathology was diagnosed by a fellowship trained laryngologist and vibratory characteristics were evaluated utilizing the Voice-Vibratory Assessment with Laryngeal Imaging (VALI) rating form. All patients were also evaluated by a speech-language pathologist. Patient reported outcome measures were collected along with perceptual voice evaluations utilizing the Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V).

RESULTS

Twelve current drill instructors were identified, and all had phonotraumatic lesions. Lesions were categorized as vocal fold hemorrhage (8%), ectasia (25%), unilateral epithelial thickening (33.3%), bilateral epithelial thickening (58.3%), ventricular cyst (8%), polyp (25%), and sulcus vocalis (25%). Vibratory abnormalities were assessed with the VALI rating scale and correlated to CAPE-V perceptual ratings with 83% having reduced mucosal wave, 75% reduced amplitude of lateral excursion, 50% aperiodic vibrations, 50% asymmetric or chasing wave, 58% glottal insufficiency, 100% supraglottic hyperfunction, and an average CAPE-V overall severity of 50% with severe perceptual dysphonia. The average Voice Handicap Index (VHI-10) and Reflux Symptom Index (RSI) score was 15.5 and 14.7, respectively.

CONCLUSION

Phonotraumatic lesions were universally present in drill instructors complaining of hoarseness, suggesting early referral, and intervention may be warranted in this population.

LEVEL OF EVIDENCE

4.

Functional Analysis of Injectable Substance Treatment on Surgically Injured Rabbit Vocal Folds

OBJECTIVES

The objective of this study was to evaluate the efficacy of immediate injection treatments of dexamethasone, hyaluronic acid (HA)/gelatin (Ge) hydrogel and glycol-chitosan solution on the phonatory function of rabbit larynges at 42 days after surgical injury of the vocal folds, piloting a novel ex vivo phonatory functional analysis protocol.

METHODS

A modified microflap procedure was performed on the left vocal fold of 12 rabbits to induce an acute injury. Animals were randomized into one of four treatment groups with 0.1 mL injections of dexamethasone, HA/Ge hydrogel, glycol-chitosan or saline as control. The left mid vocal fold lamina propria was injected immediately following injury. The right vocal fold served as an uninjured control. Larynges were harvested at Day 42 after injection, then were subjected to airflow-bench evaluation. Acoustic, aerodynamic and laryngeal high-speed videoendoscopy (HSV) analyses were performed. HSV segments of the vibrating vocal folds were rated by three expert laryngologists. Six parameters related to vocal fold vibratory characteristics were evaluated on a Likert scale.

RESULTS

The fundamental frequency, one possible surrogate of vocal fold stiffness and scarring, was lower in the dexamethasone and HA/Ge hydrogel treatment groups compared to that of the saline control (411.52±11.63 Hz). The lowest fundamental frequency value was observed in the dexamethasone group (348.79±14.99 Hz). Expert visual ratings of the HSV segments indicated an overall positive outcome in the dexamethasone treatment group, though the impacts were below statistical significance.

CONCLUSION

Dexamethasone injections might be used as an adjunctive option for iatrogenic vocal fold scarring. An increased sample size, histological correlate, and experimental method improvements will be needed to confirm this finding. Results suggested a promising use of HSV and acoustic analysis techniques to identify and monitor post-surgical vocal fold repair and scarring, providing a useful tool for future studies of vocal fold scar treatments.

Nasal Breathing Through a Damp Gauze Enhances Surface Hydration of the Vocal Folds and Optimizes Vocal Function

OBJECTIVE

The present study proposes a direct surface hydration system based on nasal breathing through a damp gauze. The goal is to observe whether such direct hydration procedure positively modifies vocal fold functionality by improving voice quality and enhancing the mobility and pliability of the vocal fold mucosa.

METHODS

Sixty-one young adults without voice problems were enrolled and were randomly divided into three double-blinded treatment groups. In the first group (the gauze group), participants breathed through the nose wrapped in a damp gauze for 10 minutes while doing vocal warm-up exercises to facilitate water penetration into the mucosal layers of the vocal folds. The second group (the exercise group) performed the same warm-up exercises as the gauze group for 10 minutes without hydration procedures. The third group (the control group) talked using their normal speaking voice for 10 minutes. The participants were evaluated before and after the treatment tasks with three tests: a laryngostroboscopic examination (ie, the glottic closure, the amplitude of the mucosal wave, and the maximum opening of the glottic space); voice acoustic analysis (multidimensional voice program); and a perceptual voice evaluation (GRBAS scale).

RESULTS

Results showed that after the use of a damp gauze, glottic closure, the amplitude of the mucosal wave, the maximum opening of the glottic space, the shimmer, and the B of GRBAS all improved.

CONCLUSION

Findings showed significantly better vocal results for the participants of the gauze group, suggesting the damp gauze procedure to be an effective, fast, and economical procedure to improve and optimize vocal fold functionality. It can be hypothesized that the obtained results are related to an improvement in vocal folds surface hydration and viscoelasticity.

[Advances in application research on assessment methods of vocal fatigue]

Vocal fatigue（VF） is the common clinical symptom of voice diseases. It can also be a separate symptom and is considered to be a signal for the body to rest and to avoid pathological damage to the vocal cords. Therefore, the early identification and evaluation of vocal fatigue is of great value to the early prevention and treatment of vocal diseases. In recent years, there are many researches on the evaluation methods of vocalization fatigue. We searched the relevant literature and summarized the application status of vocal fatigue assessment methods, in order to provide reference for the selection and development of vocal fatigue assessment tools in clinical practice.

Long-term voice evaluation after arytenoid adduction surgery in patients with unilateral vocal fold paralysis

PURPOSE

Laryngeal framework surgery, including medialization laryngoplasty and arytenoid adduction (AA), is expected to have a lasting or permanent effect in patients with unilateral vocal fold paralysis (UVFP); however, there are few reports about the long-term outcomes of AA. This study aimed to evaluate the long-term postoperative effects of AA surgery and examine its stability and reliability.

METHODS

This study collected the voice handicap index (VHI) questionnaire from patients with UVFP who underwent AA more than 2 years previously. The VHI values preoperatively and 3 months postoperatively (early postoperative evaluation) were retrospectively calculated, and VHI values more than 2 years after surgery (late postoperative evaluation) were collected by mailing a sheet to the patients and asking to fill and return it. Possible influenced subscales such as age, sex, causes of UVFP, affected side, and surgeons were also analyzed.

RESULTS

A total of 77 patients with UVFP who underwent AA had significantly lower early and late postoperative evaluations than preoperative evaluations. In 38 patients with no missing values, there were no significant differences between early and late postoperative evaluations, measured at a median of approximately 5 years. There were also no significant differences between early and late postoperative evaluations in any of the subscale groups.

CONCLUSION

Patients with UVFP who underwent AA surgery achieved stable voice improvement in the long term after surgery.

I-gel Plus acts as a superior conduit for fiberoptic intubation than standard i-gel

The supraglottic airway (SGA) is widely used. I-gel Plus is a next-generation i-gel with some improvements, including facilitation of fiberoptic tracheal intubation (FOI). To compare the performance of i-gel Plus and standard i-gel as conduits for FOI, a Thiel-embalmed cadaveric study was conducted. Twenty-two anesthesiologists were enrolled as operators in Experiment 1. The i-gel Plus and standard i-gel were inserted into one cadaver, and the FOI was performed through each SGA. The primary outcome was time required for FOI. The secondary outcomes were the number of attempts and visual analog scale (VAS) score for difficulty in FOI. Moreover, fiberoptic views of the vocal cords in each SGA were assessed by an attending anesthesiologist using nine cadavers in Experiment 2. The percentage of glottic opening (POGO) score without fiberscope tip upward flexion and upward angle of the fiberscope tip to obtain a 100% POGO score were evaluated as secondary outcomes. The time for FOI through i-gel Plus was significantly shorter than that through standard i-gel (median (IQR), i-gel Plus: 30.3 (25.4-39.0) s, vs standard i-gel: 54.7 (29.6-135.0) s; median of differences, 24.4 s; adjusted 95% confidence interval, 3.0-105.7; adjusted P = 0.040). Although the number of attempts for successful FOI was not significantly different, the VAS score for difficulty in the i-gel Plus group was significantly lower (easier) than that in the standard i-gel group. Moreover, i-gel Plus required a significantly smaller upward angle of the fiberscope tip to obtain a 100% POGO score. FOI can be performed more easily using i-gel Plus than using standard i-gel because of the improved fiberoptic visibility of vocal cords.

Vocal fold restoration after scarring: biocompatibility and efficacy of an MSC-based bioequivalent

BACKGROUND

There is growing interest to application of regenerative medicine approaches in otorhinolaryngological practice, especially in the framework of the therapy of vocal fold (VF) scar lesions. The used conservative and surgical methods, despite the achieved positive outcomes, are frequently unpredictable and do not result in the restoration of the VF's lamina propria's structure, which provides the mechanical properties necessary for vibration. In this connection, the aim of this study was to ascertain the safety and efficacy of a bioequivalent in the treatment of VF scars using a rabbit model of chronic damage.

METHODS

The bioequivalent consisted of a hydrogel system based on a PEG-fibrin conjugate and human bone marrow-derived MSC. It was characterized and implanted heterotopically into rats and orthotopically into rabbits after VF scar excision.

RESULTS

We showed that the fabricated bioequivalent consisted of viable cells retaining their metabolic and proliferative activity. While being implanted heterotopically, it had induced the low inflammatory reaction in 7 days and was well tolerated. The orthotopic implantation showed that the gel application was characterized by a lower hemorrhage intensity (p = 0.03945). The intensity of stridor and respiratory rate between the groups in total and between separate groups had no statistically significant difference (p = 0.96 and p = 1; p = 0.9593 and p = 0.97…1, respectively). In 3 days post-implantation, MSC were detected only in the tissues closely surrounding the VF defect. The bioequivalent injection caused that the scar collagen fibers were packed looser and more frequently mutually parallel that is inherent in the native tissue (p = 0.018). In all experimental groups, the fibrous tissue's ingrowth in the adjacent exterior muscle tissue was observed; however, in Group 4 (PEG-Fibrin + MSC), it was much less pronounced than it was in Group 1 (normal saline) (p = 0.008). The difference between the thicknesses of the lamina propria in the control group and in Group 4 was not revealed to be statistically significant (p = 0.995). The Young's modulus of the VF after the bioequivalent implantation (1.15 ± 0.25 kPa) did not statistically significantly differ from the intact VF modulus (1.17 ± 0.45 kPa); therefore, the tissue properties in this group more closely resembled the intact VF.

CONCLUSIONS

The developed bioequivalent showed to be biocompatible and highly efficient in the restoration of VF's tissue.

Dynamic vocal cord behavior and stridor during emergence from general anesthesia in small children with supraglottic airway

PURPOSE

Stridor during emergence from anesthesia is not rare in children managed with supraglottic airway (SGA). However, we know little about the mechanisms of stridor and behavior of the vocal cords (VC). This study aimed to clarify patterns of VC movement and laryngeal airway maintenance function during recovery from anesthesia in children with SGA.

METHODS

This is a secondary analysis of data collected from an observational study involving 27 anesthetized children. Using a multi-panel recording system, endoscopic VC image, vital sign monitor, multi-channel tracings of respiratory variables and respiratory sound and patient's view were simultaneously captured in one monitor. Inspiratory and expiratory VC angles formed by lines connecting anterior and posterior commissures were measured at the first spontaneous breath and the breath one minute after the first breath. VC narrowing and dilation were assessed by differences of VC angles.

RESULTS

Inspiratory VC narrowing (median (IQR): 5.3 (2.7, 9.1) degree at the first breath) and dilation (- 2.7 (- 3.8, - 1.7) degree at the first breath) were observed in 15 and 12 out of 27 children, respectively. The former group achieved greater tidal volume compared to the latter in one minute. Five children (19%) temporarily developed stridor-like sound from outside with inspiratory VC narrowing. The stridor-like sound was captured by microphones attached to the neck and anesthesia circuit, but was not evident from the chest.

CONCLUSION

Laryngeal narrowing occurs in half of the children with SGA during emergence from anesthesia, and temporal stridor-like sound is relatively common.

CLINICAL TRIAL REGISTRATION

UMIN (University Hospital Information Network) Clinical Registry: UMIN000025058 ( https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000028697 ).

Assessment of Laryngeal Sensory Function using a Tactile Aesthesiometer in Healthy Adults

INTRODUCTION

Laryngeal sensory function in healthy adults was assessed through the delivery of tactile stimuli using Cheung-Bearelly monofilaments.

METHODS

37 healthy adults were recruited with 340 tactile stimuli analyzed. Four calibrated tactile stimuli were delivered to three laryngeal sites: false vocal fold (FVF), aryepiglottic fold (AEF), and lateral pyriform sinus (LPS). Primary outcome was the elicitation of laryngeal adductor reflex (LAR). Secondary outcomes were gag, patient-reported laryngeal sensation (PRLS), and perceptual strength. Analysis was performed with mixed effects logistic regression modeling.

RESULTS

Positive LAR was observed in 35.7%, 70.2%, and 91.2% of stimuli at LPS, AEF, and FVF respectively. LAR rates were significantly associated with laryngopharyngeal subsite (p < 0.001), tactile force (p = 0.001), age (p = 0.022) and sex (p = 0.022). LAR, gag, PRLS, and perceptual strength significantly increased as a more medial laryngeal subsite was stimulated and as stimulus force increased. Each of the ten years of age increase was associated with 19% reduction in odds of LAR (aOR = 0.81, 95% CI [0.68, 0.97]; p = 0.022). Male gender was associated with a 55% reduction in odds of LAR (aOR = 0.45, 95% CI [0.23, 0.89]; p = 0.022).

CONCLUSION

LAR elicitation capability decreases in the male gender, aging, and a more lateral subsite. This study provides insight into the pathophysiology of hypo- and hyper-sensitive laryngeal disorders and is paramount to making accurate diagnostic assessments and finding novel treatment options for various laryngological disorders. Laryngoscope, 133:2525-2532, 2023.

Recurrent laryngeal motor nerve conduction studies in a rat model: Establishing an objective measure for investigating laryngeal innervation

INTRODUCTION/AIMS

Disease or injury can cause neuromuscular changes to the larynx that can affect voice, breathing, and swallowing. Motor nerve conduction studies have had limited use in the study of laryngeal neurophysiology, despite their importance in other anatomic sites. The aim of this study was to explore the feasibility of performing recurrent laryngeal motor nerve conduction studies (rlMNCS) in a rat model.

METHODS

rlMNCS were performed in 15 rats under anesthesia. A bipolar stimulating electrode was placed on the recurrent laryngeal nerve (RLN) 5 mm below the cricoid cartilage. Via direct laryngoscopy, a recording electrode was placed transorally into the thyroarytenoid muscle. The RLN was maximally stimulated to determine the compound muscle action potential (CMAP). Three consecutive trials were averaged.

RESULTS

The mean stimulating threshold to the RLN to achieve a CMAP from the thyroarytenoid was 1.7 ± 0.6 mA. RLN stimulation caused a visible adductor twitch of the vocal fold in all animals. The mean negative amplitude was 2.0 ± 0.8 mV, and the total area was 1.0 ± 0.4 mV ms. The CMAP latency and negative duration were 1.0 ± 0.1 ms and 0.9 ± 0.2 ms, respectively.

DISCUSSION

rlMNCS are feasible and may be useful in understanding laryngeal neurophysiology with disease or injury. This work could provide a tractable animal model for studying and monitoring treatment of neuromuscular conditions affecting voice, breathing, and swallowing.

Acoustic Screening of the "Wet voice": Proof of Concept in an ex vivo Canine Laryngeal Model

BACKGROUND

Current protocols for bedside swallow evaluation have high rates of false negative results. Though experts are not consistently able to screen for aspiration risk by assessing vocal quality, there is emerging evidence that vocal acoustic parameters are significantly different in patients at risk of aspiration. Herein, we aimed to determine whether the presence of material on the vocal folds in an excised canine laryngeal model may have an impact on acoustic and aerodynamic measures.

METHODS

Two ex vivo canine larynges were tested. Three liquids of different viscosities (1:100 diluted glycerin, pure glycerin, and honey-thick Varibar) were placed on the vocal folds at a constant volume. Acoustic and aerodynamic measures were obtained in both adducted and abducted vocal fold configurations. Intraglottal high-speed imaging was used to approximate the maximum divergence angle of the larynges in the studied conditions and examine its relationship to vocal efficiency (VE) and acoustic measures.

RESULTS

In glottic insufficiency conditions only, we found that several acoustic parameters could predict the presence of material on the vocal folds. Based on the combination of the aerodynamic and acoustic data, we found that decreased spectral energy in the higher harmonics was associated with decreased VE in the presence of material on the vocal folds and/or glottic insufficiency.

CONCLUSION

Decreased spectral energy in the higher harmonics of the voice was found to be a potential biomarker of swallowing dysfunction, as it correlates with decreased vocal efficiency due to material on the vocal folds and/or glottic insufficiency, both of which are known risk factors for aspiration.

LEVEL OF EVIDENCE

NA Laryngoscope, 133:2517-2524, 2023.

Diagnosis of vocal cord dysfunction/inducible laryngeal obstruction: An International Delphi Consensus Study

BACKGROUND

Vocal cord dysfunction/inducible laryngeal obstruction (VCD/ILO) is characterized by breathing difficulties in association with excessive supraglottic or glottic laryngeal narrowing. The condition is common and can occur independently; however, it may also be comorbid with other disorders or mimic them. Presentations span multiple specialties and misdiagnosis or delayed diagnosis is commonplace. Group-consensus methods can efficiently generate internationally accepted diagnostic criteria and descriptions to increase clinical recognition, enhance clinical service availability, and catalyze research.

OBJECTIVES

We sought to establish consensus-based diagnostic criteria and methods for VCD/ILO.

METHODS

We performed a modified 2-round Delphi study between December 7, 2021, and March 14, 2022. The study was registered at ANZCTR (Australian New Zealand Clinical Trials Registry; ACTRN12621001520820p). In round 1, experts provided open-ended statements that were categorized, deduplicated, and amended for clarity. These were presented to experts for agreement ranking in round 2, with consensus defined as ≥70% agreement.

RESULTS

Both rounds were completed by 47 international experts. In round 1, 1102 qualitative responses were received. Of the 200 statements presented to experts across 2 rounds, 130 (65%) reached consensus. Results were discussed at 2 international subject-specific conferences in June 2022. Experts agreed on a diagnostic definition for VCD/ILO and endorsed the concept of VCD/ILO phenotypes and clinical descriptions. The panel agreed that laryngoscopy with provocation is the gold standard for diagnosis and that ≥50% laryngeal closure on inspiration or Maat grade ≥2 define abnormal laryngeal closure indicative of VCD/ILO.

CONCLUSIONS

This Delphi study reached consensus on multiple aspects of VCD/ILO diagnosis and can inform clinical practice and facilitate research.

Preoperative lymphocyte count, neutrophil to lymphocyte and platelet to lymphocyte ratio predict the recurrence with progression and cancerization in vocal fold lesions-retrospective study

Backgrounds

This study explored the contribution of peripheral blood markers in diagnosis and prognosis estimation of different stages of laryngeal dysplasia and early glottic cancer.

Methods

Retrospective analysis of clinical, histopathological and laboratory data of 220 patients including hemoglobin, neutrophil, lymphocyte, monocyte and platelet counts, neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR).

Results

The mean hemoglobin level and platelets count showed differences between histopathological stages of lesions (p = 0.041 and 0.046, respectively). In patients with recurrent lesions mean level of lymphocyte count, NLR and PLR were significant in assessing progression and cancerization (p = 0.005, 0.028 and 0.023, respectively). The univariate analysis recognized level of PLR ≥ 141.74 as significant risk factor of the recurrence of vocal fold hypertrophic lesions (OR = 1.963).

Conclusions

The levels of blood cells and their ratios seem to be effective in predicting the recurrence of lesion and even more their potential role in indicating malignant progression.

[An autopsied patient with palatal tremor and fatal bilateral vocal cord abduction paralysis associated with bilateral cerebellar dentate nucleus infarction]

A 74-year-old male patient developed multiple infarcts of the brainstem and cerebellum, followed 14 months later by palatal tremor and bilateral vocal cord abduction paralysis, resulting in death due to type 2 respiratory failure. Pathologic analysis revealed old infarcts extending from the bilateral cerebellar cortices to the dentate nucleus, being more extensive on the right side, accompanied by Wallerian degeneration involving the left red nucleus, right central tegmentum tract, and inferior cerebellar peduncle, followed by pseudohypertrophy of the bilateral inferior olivary nuclei. These lesions, involving the Guillain-Mollaret triangle, may have been responsible for the palatal tremor. On the other hand, there were no evident causative lesions for the vocal cord abduction, including any in the nucleus ambiguus or posterior cricoarytenoid muscles. In this case it is possible that the dysfunction responsible for the palatal tremor may have affected the pathway from the central tegmentum tract, which is part of the Guillain-Mollaret triangle, to the vagus nerve arising from the nucleus ambiguus, which plays a role in vocal cord abduction, thus affecting the vocal cords and resulting in abduction paralysis.

Is Immobile vocal fold Related to the Spinal Accessory Nerve Agenesis?: A Case Report

The spinal accessory nerve innervates the sternocleidomastoid and trapezius muscles, but the internal branch from the spinal accessory nerve is also contributing to the motor innervation of the larynx. For the first time, we report a case of an impairment of sternocleidomastoid, trapezius, and thyroarytenoid muscles from the same side. In our case, the anatomical variant that can explain this situation implies the cranial roots and some fibers from the spinal roots of the spinal accessory nerve to form the internal branch. In the case of agenesis of these spinal roots, the muscles reliant on it would be missing. For this reason, it is advisable to rule out laryngeal problems in patients with sternocleidomastoid and/or trapezius muscles impairment.

Using a vertical three-mass computational model of the vocal folds to match human phonation of three adult males

Computer models of phonation are used to study various parameters that are difficult to control, measure, and observe in human subjects. Imitating human phonation by varying the prephonatory conditions of computer models offers insight into the variations that occur across human phonatory production. In the present study, a vertical three-mass computer model of phonation [Perrine, Scherer, Fulcher, and Zhai (2020). J. Acoust. Soc. Am. 147, 1727-1737], driven by empirical pressures from a physical model of the vocal folds (model M5), with a vocal tract following the design of Ishizaka and Flanagan [(1972). Bell Sys. Tech. J. 51, 1233-1268] was used to match prolonged vowels produced by three male subjects using various pitch and loudness levels. The prephonatory conditions of tissue mass and tension, subglottal pressure, glottal diameter and angle, posterior glottal gap, false vocal fold gap, and vocal tract cross-sectional areas were varied in the model to match the model output with the fundamental frequency, alternating current airflow, direct current airflow, skewing quotient, open quotient, maximum flow negative derivative, and the first three formant frequencies from the human production. Parameters were matched between the model and human subjects with an average overall percent mismatch of 4.40% (standard deviation = 6.75%), suggesting a reasonable ability of the simple low dimensional model to mimic these variables.

Low-grade malignant myofibroblastic sarcoma of the larynx: a case report

Low-grade myofibroblastic sarcoma (LGMS) is a rare malignant mesenchymal tumor derived from myofibroblasts. It is commonly identified in the head and neck, and particularly in the oral cavity, but rarely in the larynx. In this case report, we describe a patient who presented with hoarseness and underwent electronic fiber laryngoscopy, which revealed a neoplasm on the surface of his left vocal cord. The vocal cord tumor was resected under general anesthesia, and a malignant LGMS was diagnosed on postoperative pathologic examination. The results of immunohistochemical staining of the sections for vimentin (diffuse +), actin (partial +), and desmin (-) were consistent with this diagnosis. The patient recovered well after the surgery, and there was no recurrence of the neoplasm.

Vocal Fold Pathologies Among Undergraduate Singing Students In Three Different Genres

OBJECTIVE

This study aimed to compare the prevalence and incidence of vocal fold pathologies among undergraduate classical, musical theatre, and contemporary commercial music (CCM) students over two-time points.

METHODS

This study is part of a longitudinal investigation. Videostroboscopic examinations were rated, with consensus among three of four expert blinded raters confirming the presence of pathology. Association between genre of singer and the presence of pathology, interrater reliability, and intra-rater reliability were calculated. Prevalence and incidence of pathologies were compared across genres.

RESULTS

During first-year evaluations, 32% of musical theatre, 18% of CCM, and 0% of classical students had vocal pathologies. The prevalence at third-year evaluations showed 22% of classical, 39% of musical theatre, and 27% of CCM participants having vocal fold pathologies. The incidence of pathologies was 67% of musical theatre students compared to 22% of classical students and 27% of CCM students. The four raters demonstrated fair to moderate interrater agreement. Singing Voice Handicap Index-10 scores were normal for CCM singers at both time points but elevated for musical theatre and classical singers.

CONCLUSION

No classical singers were found to have pathology during first-year evaluations, although CCM and musical theatre singers showed evidence of vocal fold pathologies. At third-year evaluations, all three genres had an apparent increase in prevalence of pathologies. Implications of this study suggest that more time in the field and intense voice usage may lead to a greater risk of pathology for all singers, regardless of genre.

LEVEL OF EVIDENCE

2 Laryngoscope, 133:2317-2324, 2023.

The effect of the auditory signal on videolaryngostroboscopy ratings and interpretation

OBJECTIVE

The primary aim of this study was to examine the effect of the videolaryngostroboscopic auditory signal on videolaryngostroboscopy (VLS) ratings and interpretation in normophonic and dysphonic speakers.

STUDY DESIGN

Prospective repeated measures design METHOD: Eight speech-language pathologists evaluated rigid VLS exams obtained from 12 dysphonic speakers with vocal fold pathology and 4 normophonic speakers with normal VLS exams. VLS exams were evaluated with the auditory signal present and absent with a washout period between rating sessions. VLS measures were obtained using the Voice-vibratory Assessment of Laryngeal Imaging (VALI) and a 100mm visual analog scale (VAS). The effects of the auditory signal and its interaction with voice quality severity on 9 VLS ratings, diagnostic billing codes, and treatment recommendations were examined.

RESULTS

There was no effect of auditory information on VLS measures or overall severity of laryngeal function evaluated using the VAS (ps > 0.05). There was a main effect of auditory information and a significant interaction with voice quality severity for only one VLS measure (non-vibrating portion-left) evaluated using the VALI (P = 0.05). Post-hoc analysis for this rating showed significant increases (t-test adjusted P < 0.05) when voice quality severity was moderate-severe (M = 4.8%; SD = 1.65%) and auditory information was present. Agreement in individual clinician's selection of diagnostic codes (73%) and treatment recommendations (65.6%) when auditory cues were present and absent was moderate to high.

CONCLUSION

The presence of the videolaryngostroboscopic auditory signal had a minimal effect on VLS ratings, treatment recommendations, or diagnostic billing codes.

The Influence of Fiber Orientation of the Conus Elasticus in Vocal Fold Modeling

While the conus elasticus is generally considered a part of continuation of the vocal ligament, histological studies have revealed different fiber orientations that fibers are primarily aligned in the superior-inferior direction in the conus elasticus and in the anterior-posterior direction in the vocal ligament. In this work, two continuum vocal fold models are constructed with two different fiber orientations in the conus elasticus: the superior-inferior direction and the anterior-posterior direction. Flow-structure interaction simulations are conducted at different subglottal pressures to investigate the effects of fiber orientation in the conus elasticus on vocal fold vibrations, aerodynamic and acoustic measures of voice production. The results reveal that including the realistic fiber orientation (superior-inferior) in the conus elasticus yields smaller stiffness and larger deflection in the coronal plane at the junction of the conus elasticus and ligament and subsequently leads to a greater vibration amplitude and larger mucosal wave amplitude of the vocal fold. The smaller coronal-plane stiffness also causes a larger peak flow rate and higher skewing quotient. Furthermore, the voice generated by the vocal fold model with a realistic conus elasticus has a lower fundamental frequency, smaller first harmonic amplitude, and smaller spectral slope.

An Endoscopic Cap Electrode for Posterior Cricoarythenoid Muscle Stimulation in a Porcine Model

OBJECTIVE

Laryngeal pacing (LP) is a highly anticipated therapeutic option for patients suffering from bilateral vocal fold paralysis with synkinesis. Identification of candidate patients requires confirmation of a stimulable posterior cricoidarythenoid muscle (PCA) by neuromuscular electrical stimulation (NMES). A silicone endoscopic cap electrode (ECE50) was designed to be operated as an endoscopic extension tip for selective PCA stimulation and confirmation of a glottic opening movement in a setting comparable to a gastroscopy procedure.

METHODS

A porcine animal model (n = 6) was applied to develop and test endoscopic cap prototypes in general anesthesia and sedation at a biomedical research center. Two ENT endoscopy experts evaluated and refined the cap design and performance in regard to procedure safety, endoscope handling, accessibility of the PCA by the transoral approach and selective muscle stimulation.

RESULTS

Vocal fold opening movements could be evoked by the investigators in 9 of 12 PCA muscles to stimulate with similar electric parameters. The endoscopic approach using the ECE50 proved to be atraumatic and sufficiently controlled under sedation to locate the required hotspot for NMES of the PCA.

CONCLUSION

The functionality of the novel endoscopic cap concept has been proven in a porcine model. It can be expected to be transferable to human application and to be of diagnostic importance in the screening and identification of LP candidate patients in future.

LEVEL OF EVIDENCE

NA Laryngoscope, 133:2279-2284, 2023.

Predictive Outcomes of Deep Learning Measurement of the Anterior Glottic Angle in Bilateral Vocal Fold Immobility

OBJECTIVE

(1) To compare maximum glottic opening angle (anterior glottic angle, AGA) in patients with bilateral vocal fold immobility (BVFI), unilateral vocal fold immobility (UVFI) and normal larynges (NL), and (2) to correlate maximum AGA with patient-reported outcome measures.

METHODS

Patients wisth BVFI, UVFI, and NL were retrospectively studied. An open-source deep learning-based computer vision tool for vocal fold tracking was used to analyze videolaryngoscopy. Minimum and maximum AGA were calculated and correlated with three patient-reported outcomes measures.

RESULTS

Two hundred and fourteen patients were included. Mean maximum AGA was 29.91° (14.40° SD), 42.59° (12.37° SD), and 57.08° (11.14° SD) in BVFI (N = 70), UVFI (N = 70), and NL (N = 72) groups, respectively (p < 0.001). Patients requiring operative airway intervention for BVFI had an average maximum AGA of 24.94° (10.66° SD), statistically different from those not requiring intervention (p = 0.0001). There was moderate negative correlation between Dyspnea Index scores and AGA (Spearman r = -0.345, p = 0.0003). Maximum AGA demonstrated high discriminatory ability for BVFI diagnosis (AUC 0.92, 95% CI 0.81-0.97, p < 0.001) and moderate ability to predict need for operative airway intervention (AUC 0.77, 95% CI 0.64-0.89, p < 0.001).

CONCLUSIONS

A computer vision tool for quantitative assessment of the AGA from videolaryngoscopy demonstrated ability to discriminate between patients with BVFI, UVFI, and normal controls and predict need for operative airway intervention. This tool may be useful for assessment of other neurological laryngeal conditions and may help guide decision-making in laryngeal surgery.

LEVEL OF EVIDENCE

III Laryngoscope, 133:2285-2291, 2023.

Multidimentional assessment of voice quality in patients with laryngopharyngeal reflux disease

<b><br>Introduction:</b> Gastroesophageal Reflux Disease (GERD) is a common disorder in world population. As a result of the regurgitation of acid content from the stomach to laryngopharynx and larynx, secondary damage of laryngeal mucosa occur, which is highly sensitive to hydrochloric acid, and morphological changes are observed. Symptomatology of laryngopharyngeal reflux is varied which makes differential diagnosis difficult.</br> <b><br>Aim:</b> The aim of the study was the assessment of voice quality, morphological changes in larynx as well as etiology of Laryngopharyngeal Reflux Disease.</br> <b><br>Material and method:</b> The severity of dysphonia was classified using perceptual and acoustic methods as well as RSI. Morphological control was performed using HSDI technique and RFS. Etiological factors were examined basing on barofunction of upper esophageal sphincter and 24-hour pH-metry of air exhaled expressed in Ryan score.</br> <b><br>Results:</b> In the majority of patients with Laryngopharyngeal Reflux, dysphonia was recognized, intensified especially in women (G3R2B0A0S3), which was confirmed in Yanagihara classification (type III) and parameters of acoustic analysis. Voice disorders were the most frequently the result of edema and congestion of interarytenoid area, aytenoids and vocal folds. Those symptoms were caused by the decrease of upper esophageal sphincter tension and acidity of exhaled air which was confirmed in 24-hour pHmetry.</br> <b><br>Conclusions:</b> It is important to educate physicians and patients about the possibilty of negative impact of reflux disease on the occurrence of voice quality disorders. Current diagnostic methods for dysphonia guarantee accurate recognition and therapeutic success improving the prognoses of patients with Laryngopharyngeal Reflux.</br>.

Convolutional neural network-based vocal cord tumor classification technique for home-based self-prescreening purpose

BACKGROUND

In this study, we proposed a deep learning technique that can simultaneously detect suspicious positions of benign vocal cord tumors in laparoscopic images and classify the types of tumors into cysts, granulomas, leukoplakia, nodules and polyps. This technique is useful for simplified home-based self-prescreening purposes to detect the generation of tumors around the vocal cord early in the benign stage.

RESULTS

We implemented four convolutional neural network (CNN) models (two Mask R-CNNs, Yolo V4, and a single-shot detector) that were trained, validated and tested using 2183 laryngoscopic images. The experimental results demonstrated that among the four applied models, Yolo V4 showed the highest F1-score for all tumor types (0.7664, cyst; 0.9875, granuloma; 0.8214, leukoplakia; 0.8119, nodule; and 0.8271, polyp). The model with the lowest false-negative rate was different for each tumor type (Yolo V4 for cysts/granulomas and Mask R-CNN for leukoplakia/nodules/polyps). In addition, the embedded-operated Yolo V4 model showed an approximately equivalent F1-score (0.8529) to that of the computer-operated Yolo-4 model (0.8683).

CONCLUSIONS

Based on these results, we conclude that the proposed deep-learning-based home screening techniques have the potential to aid in the early detection of tumors around the vocal cord and can improve the long-term survival of patients with vocal cord tumors.

A 4-Week Straw Phonation in Water Exercise Program for Aging-Related Vocal Fold Atrophy

PURPOSE

This study evaluated the efficacy of a 4-week straw phonation in water (SPW) exercise program on aging-related vocal fold atrophy (VFA), with a secondary objective to examine the immediate effects of SPW exercises.

METHOD

Thirty-eight older adults aged 60 years and above formally diagnosed with aging-related VFA were randomly assigned into an experimental group undergoing SPW exercises with an 8-cm depth of straw submersion into water for 4 weeks plus vocal hygiene practice (n = 20), and a control group with only vocal hygiene practice (n = 18). Outcome measures included laryngeal endoscopic measures of glottal gap, auditory-perceptual ratings of voice quality, acoustic measures, aerodynamic measures, and standardized self-assessment questionnaire scores. An additional round of acoustic and aerodynamic assessment following 20 min of SPW exercises was conducted to examine the immediate effects.

RESULTS

Significant improvements in normalized glottal gap area, perceptual rating of breathiness, smoothed cepstral peak prominence, harmonics-to-noise ratio (HNR), mean oral airflow, subglottal pressure and laryngeal airway resistance at comfortable loudness, Voice-related Quality of Life scores, and Chinese Vocal Fatigue Index Factor 3 scores were observed in the experimental group relative to the control group. There were also significant immediate effects for HNR, mean oral airflow, subglottal pressure, and laryngeal airway resistance.

CONCLUSIONS

These findings suggested significant immediate improvements in vocal function following SPW exercises, with additional significant improvements in vocal function as well as significant improvements in quality of life following the 4-week SPW exercise program. Further studies with more long-term follow-up are recommended to better understand the efficacy of SPW exercises with deep levels of straw submersion into water as an effective clinical option for the management of hypofunctional dysphonia associated with aging-related VFA.

Trends and In-Hospital Outcomes in Patients with Vocal Fold Paralysis after Ischemic and Intracerebral Hemorrhagic Stroke: A Propensity Matched 20-Year Analysis of the Nationwide Inpatient Sample

OBJECTIVE

Laryngeal manifestations of stroke have been sparsely described in the literature, specifically vocal fold paralysis (VFP). This study aimed to identify the prevalence, characteristics, and in-hospital outcomes of patients presenting with VFP after acute ischemic stroke (AIS) and intracranial hemorrhage (ICH).

METHODS

A query of the 2000-2019 Nationwide Inpatient Sample was performed for patients admitted with AIS (International Classification of Diseases, Ninth Revision 433, 43,401, 43,411, 43,491, International Classification of Diseases, Tenth Revision I63) and ICH (International Classification of Diseases, Ninth Revision 431, 432.9, International Classification of Diseases, Tenth Revision I61, I62.9). Demographics, comorbidities, and outcomes were identified. Univariate analysis with t-tests or χ2 performed as appropriate. A 1:1 nearest neighbor propensity score matched cohort was generated. Variables with standardized mean differences > 0.1 used in multivariable regression to generate adjusted odds ratios (AOR)/β-coefficients for VFP on outcomes. Significance was set at an alpha level of < 0.001. All analysis were performed in R version 4.1.3.

RESULTS

A total of 10,415,286 patients with AIS were included; 11,328 (0.1%) had VFP. Of 2,000,868 patients with ICH 2132 (0.1%) had in-hospital VFP. Multivariable analysis revealed that patients with VFP after AIS were less likely to be discharged home (AOR 0.32; 95% confidence interval {CI}: 0.18-0.57; P < 0.001) and elevated total hospital charges (β coefficient = 59,684.6; 95% CI = 18,365.12-101,004.07; P = 0.005). Patients with VFP after ICH were less likely to experience in-hospital mortality (AOR 0.53; 95% CI: 0.34-0.79; P = 0.002) with longer hospital stays (1.99 days; 95% CI: 1.78-2.21; P < 0.001) and elevated total hospital charges (β coefficient = 53,905.35; 95% CI = 16,352.84-91,457.85; P = 0.005)..

CONCLUSIONS

VFP in patients with ischemic stroke and ICH; although an infrequent complication is associated with functional impairment, longer hospital stay, and higher charges.

Fundamental frequency disturbances in female and male singers' pitch glides through long tube with varied resistances

Source-filter interaction can disturb vocal fold vibration frequency. Resonance frequency/bandwidth ratios (Q-values) may affect such interaction. Occurrences of fundamental frequency (fo) disturbances were measured in ascending pitch glides produced by four female and five male singers phonating into a 70 cm long tube. Pitch glides were produced with varied resonance Q-values of the vocal tract + tube compound (VT + tube): (i) tube end open, (ii) tube end open with nasalization, and (iii) with a piece of cotton wool in the tube end (conditions Op, Ns, and Ct, respectively). Disturbances of fo were identified by calculating the derivative of the low-pass filtered fo curve. Resonance frequencies of the compound VT+tube system were determined from ringings and glottal aspiration noise observed in narrowband spectrograms. Disturbances of fo tended to occur when a partial was close to a resonance of the compound VT+tube system. The number of such disturbances was significantly lower when the resonance Q-values were reduced (conditions Ns and Ct), particularly for the males. In some participants, resonance Q-values seemed less influential, suggesting little effect of source-filter interaction. The study sheds light on factors affecting source-filter interaction and fo control and is, therefore, relevant to voice pedagogy and theory of voice production.

Difficult glottis: Diagnostic dilemma in viewof the clinical presentation

<br><b>Introduction:</b> The taxonomy of vocal fold lesions has been refined, and it serves as a common descriptive language for diagnosis, treatment algorithms, and reporting of outcomes. However, we observe rare cases when numerous pathologies overlap, resulting in an unclear and complicated clinical presentation of the glottis.</br> <br><b>Aim:</b> The aim of this paper is to present cases of overlapping etiopathological factors which poses a challenge when making a diagnosis and referring a patient for adequate treatment.</br> <br><b>Material and method:</b> The study presents different photographs of the glottis, including some unique and unusual images in which overlapping pathologies were captured. The photographs are accompanied by case descriptions, comments, and pathological analyses.</br> <br><b>Results:</b> Four selected photographs showed a bunch of exophytic growth lesions with foci of whitish plaques, covered by yellowish crusts, with thinned, reddened vocal folds presenting foci of leukoplakia. The study discussed possible causes of vocal folds edema, diffuse erythema, presence of crusts or exudate, whitish debris/plaques or development of leukoplakia, non-neoplastic ulceration, as well as injected and reddened mucous membrane. Chronic infectious laryngitis, idiopathic ulcerative laryngitis, and drug-induced laryngitis were also mentioned. The study also raised the issues concerning diabetics and patients treated with inhaled corticosteroids, including candidiasis and primary aspergillosis of the larynx.</br> <br><b>Conclusions:</b> To conclude, everyday clinical practice involves encountering cases of unclear onset and course, with complicated presentation of the glottis. Therefore, comprehensive history-taking and thorough investigation of systemic causes are of immense importance. Recommended management includes conducting the most meticulous differential diagnosis, implementing treatment for the most likely cause, and, whenever possible, refraining from biopsy in order to avoid permanent damage to vocal cords.</br>.

Systematic Review of Literature on Vocal Demand Response: Understanding Physiology, Measurements, and Associated Factors

PURPOSE

Considering the conceptual migration from vocal load and vocal loading to vocal demand and vocal demand response, this review of literature aimed to identify physiological explanations, reported measurements, and associated factors (vocal demands) reported in the literature when considering the phonatory response to a vocal demand.

METHODS

A systematic review of literature, following the PRISMA Statement, was conducted using Web of Science, PubMed, Scopus, and ScienceDirect. Data were analyzed and presented in two parts. First, a bibliometric analysis, co-occurrence analysis, and content analysis were performed. Three criteria that got article inclusion were defined: (1) written in English, Spanish, and Portuguese; (2) published between 2009 and 2021; and (3) focused on vocal load and loading, vocal demand response, and voice assessment parameters. A total of 54 publications met the criteria and were included in this review. The second part included a conceptual framework based on the content analysis of three aspects of vocal demand response: (1) physiological explanations, (2) reported measurements, and (3) vocal demands.

RESULTS AND CONCLUSION

As would be expected since vocal demand response is a relatively new term and not yet commonly used in literature when discussing way that the speakers respond to communicative scenarios, most of the studies reviewed (both historical and recent) still use the term of vocal load and vocal loading. Although there is a broad variety of literature discussing a wide range of vocal demands and voice parameters used to characterize the vocal demand response, results show that there is consistency across the studies. While vocal demand response is unique and intrinsic to the talker, associated factors that contribute to this response include both internal talker and external talker factors. Internal factors include muscle stiffness, viscosity in the phonatory system, vocal fold tissue damage, elevated sound pressure levels during occupational voice demands, extended periods of voice use, suboptimal body posture, difficulties in breathing technique, and sleep disturbances. Associated external factors include the working environment (noise, acoustics, temperature, humidity). In conclusion, although vocal demand response is intrinsic to the speaker, the speaker's response is affected by external vocal demands. However, due to the wide methods to evaluate vocal demand response, it has been difficult to establish its contribution to voice disorders in the general population and, specifically, among occupational voice users. This literature review identified commonly reported parameters and factors that may help clinicians and researchers define vocal demand response.

Voice Onset Time in Children With and Without Vocal Fold Nodules

PURPOSE

Voice onset time (VOT) of voiceless consonants provides information on the coordination of the vocal and articulatory systems. This study examined whether vocal-articulatory coordination is affected by the presence of vocal fold nodules (VFNs) in children.

METHOD

The voices of children with VFNs (6-12 years) and age- and gender-matched vocally healthy controls were examined. VOT was calculated as the time between the voiceless stop consonant burst and the vocal onset of the vowel. Measures of the average VOT and VOT variability, defined as the coefficient of variation, were calculated. The acoustic measure of dysphonia, cepstral peak prominence (CPP), was also calculated. CPP provides information about the overall periodicity of the signal, with more dysphonic voices having lower CPP values.

RESULTS

There were no significant differences in either average VOT or VOT variability between the VFN and control groups. VOT variability and average VOT were both significantly predicted by the interaction between Group and CPP. There was a significant negative correlation between CPP and VOT variability in the VFN group, but no significant relationship was found in the control group.

CONCLUSIONS

Unlike previous studies with adults, there were no group differences in average VOT or VOT variability in this study. However, children with VFNs who were more dysphonic had increased VOT variability, suggestive of a relationship between dysphonia severity and control of vocal onset during speech production.

High-Speed Videoendoscopic and Acoustic Characteristics of Inspiratory Phonation

PURPOSE

Given the importance of inspiratory phonation for assessment of vocal fold structure, the aim of this investigation was to evaluate and describe the vocal fold vibratory characteristics of inspiratory phonation using high-speed videoendoscopy in healthy volunteers. The study also examined the empirical relationship between cepstral peak prominence (CPP) and glottal area waveform measurements derived from simultaneous high-speed videoendoscopy and audio recordings.

METHOD

Vocally healthy adults (33 women, 28 men) volunteered for this investigation and completed high-speed videoendoscopic assessment of vocal fold function for two trials of an expiratory/inspiratory phonation task at normal pitch and normal loudness. Twelve glottal area waveform measures and acoustic CPP values were extracted for analyses.

RESULTS

Inspiratory phonation resulted in shorter closing time, longer duration of the opening phase, and faster closing phase velocity compared to expiratory phonation. Sex differences were elucidated. CPP changes for inspiratory phonation were predicted by changes in the glottal area index and waveform symmetry index, whereas changes in CPP during expiratory phonation were predicted by changes in asymmetry quotient, glottal area index, and amplitude periodicity.

CONCLUSIONS

Vocal fold vibratory differences were identified for inspiratory phonation when compared to expiratory phonation, the latter of which has been studied more extensively. This investigation provides important basic inspiratory phonation data to better understand laryngeal physiology in vivo and provides a basic model from which to further study inspiratory phonation in a larger population representing a broader age range.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.22223812.

Analysis of Dysphagia and Cough Strength in Patients with Unilateral Vocal Fold Paralysis

The association between swallowing function and cough strength in patients with unilateral vocal fold paralysis (UVFP) is unknown. We evaluated the relationship between voluntary cough strength and dysphagia among patients with UVFP (UVFP group) by comparing their data with that of corresponding healthy participants (healthy control [HC] group) in a prospective observational study. From February 1st, 2018 to March 30th, 2019, we recruited patients with a voice disorder due to UVFP, who were referred to our university hospital. Patients with a history of laryngeal surgery, vagal nerve paralysis, or cardiac and respiratory failure were excluded. Descriptive and clinical data regarding swallowing, voice, and cough peak flow (CPF) were collected as a measure of cough strength. The UVFP group comprised six women and seven men (median age, 68.0 years), and the HC group comprised six women and eight men (median age 65.5 years). The groups differed significantly in the Eating Assessment Tool (EAT)-10 scores and CPF rates (P < 0.001). Among patients with UVFP, 84.6% had an abnormal EAT-10 score of ≥ 3. Additionally, 16.7% of the patients exhibited liquid aspiration with contrast medium on a videofluorographic swallowing study (VFSS). There was no correlation between the CPF values, EAT-10 scores, or the VFSS results. Therefore, patients with severe UVFP, whose condition had been fixed, had difficulties when swallowing (85% of cases), and some even presented with aspiration on VFSS (20% of cases), while receiving a regular diet.

Vocal Cord Dysfunction During the COVID-19 Pandemic

BACKGROUND

Vocal cord dysfunction is an upper-airway disorder characterized by exaggerated and transient glottic constriction causing respiratory and laryngeal symptoms. Common presentation is with inspiratory stridor often in the context of emotional stress and anxiety. Other symptoms include wheezing (which may be on inspiration), frequent cough, choking sensation, or throat and chest tightness. This is seen commonly in teenagers, particularly in adolescent females. The COVID-19 pandemic has been a trigger for anxiety and stress with an increase in psychosomatic illness. Our objective was to find out if the incidence of vocal cord dysfunction increased during COVID-19 pandemic.

METHODS

We performed a retrospective chart review of all the subjects with a new diagnosis of vocal cord dysfunction who were seen at the out-patient pulmonary practice at our children's hospital between January 2019-December 2020.

RESULTS

The incidence of vocal cord dysfunction in 2019 was found to be 5.2%, (41/786 subjects seen) compared to 10.3% (47/457 subjects seen) in 2020, which is a nearly 100% increase in incidence (P < .001).

CONCLUSIONS

It is important to recognize that vocal cord dysfunction has increased during the COVID-19 pandemic. In particular, physicians treating pediatric patients, as well as respiratory therapists, should be aware of this diagnosis. It is imperative to avoid unnecessary intubations and treatments with bronchodilators and corticosteroids as opposed to behavioral and speech training to learn effective voluntary control over the muscles of inspiration and the vocal cords.

Differences in Glottal Closure and Visibility of the Anterior Commissure during Rigid-90°, Rigid-70°, and Flexible Laryngostroboscopy

INTRODUCTION

The conventional rigid-90° and rigid-70° laryngostroboscopy has been so far considered the gold standard in assessing the vibratory behavior of the vocal folds and the glottal closure configuration during phonation. Meanwhile, this rigid laryngostroboscopy is more and more replaced by flexible chip-on-tip systems. The aim of this study was to evaluate the influence of these different endoscopic techniques on glottal closure configuration and on visibility of the complete focal fold length including anterior commissure during phonation.

METHODS

Twenty-one euphonic subjects were enrolled (mean age 34.6 ± 9.5; m = 10, f = 11). They were examined with the three laryngoscopic techniques (conventional rigid-90°, rigid-70°, and flexible chip-on-tip laryngoscopy during low and high voice pitch with soft and loud voice intensity). For evaluating the degree of glottal closure, a modified classification of Södersten et al. was applied and the visibility of the anterior commissure was evaluated. The correlation of the three endoscopic techniques was assessed with Cohen and Fleiss' kappa.

RESULTS

In even low loud phonation, the rigid-90° and rigid-70° endoscopies revealed a complete closure of the glottis in only 47.6% of subjects but with flexible endoscopy in 81%. The complete vocal fold length with anterior commissure was best visible with flexible endoscopy in 90.5% in low-soft and high-soft phonation. The rigid-90° endoscopy showed a slight agreement in comparison with the flexible endoscopy in regard to the types of vocal fold closure with a Cohen's kappa coefficient k = 0.199. The rigid-90° endoscopy showed an almost perfect agreement with k = 0.84 when compared to the rigid-70° endoscopy. The flexible endoscopy compared to the rigid-70° endoscopy showed a fair agreement with k = 0.346.

CONCLUSION

We found mainly corresponding results in both rigid-90° and rigid-70° endoscopic techniques which can be explained by the same transoral approach with the tongue pulled out, whereas the flexible transnasal endoscopy mainly gives a better view on the anterior commissure. The influence of transorally or transnasally guided endoscopic techniques needs to be considered in interpretation of laryngostroboscopic parameters like vocal fold closure and supraglottal hyperactivity.

Change in glottic view during intubation using a KoMAC videolaryngoscope: A retrospective analysis

Intubation with videolaryngoscopy has become popular in various clinical settings. However, despite the use of a videolaryngoscope, difficult intubation still exists and intubation failure has been reported. This retrospective study assessed the efficacy of the 2 maneuvers in improving the glottic view during videolaryngoscopic intubation. The medical records of patients who underwent videolaryngoscopic intubation and whose glottal images were stored in electronic medical charts were reviewed. The videolaryngoscopic images were divided into 3 categories according to the applied optimization techniques as follows: conventional method, with the blade tip located in the vallecular; backward-upward-rightward pressure (BURP) maneuver; and epiglottis lifting maneuver. Four independent anesthesiologists scored the visualization of the vocal folds using the percentage of glottic opening (POGO, 0-100%) scoring system. A total of 128 patients with 3 laryngeal images were analyzed. The glottic view was the most improved in the epiglottis lifting maneuver among all the techniques. The median POGO scores were 11.3, 36.9, and 63.1 in the conventional method, BURP, and epiglottis lifting maneuver, respectively (P < .001). There were significant differences in the distribution of POGO grades according to the application of BURP and epiglottis lifting maneuvers. In the POGO grades 3 and 4 subgroups, the epiglottis lifting maneuver was more effective than the BURP maneuver in improving the POGO score Inadequate visualization of the vocal folds occurred even when intubation was performed using a videolaryngoscope. The application of optimization maneuvers, such as BURP and epiglottis lifting by the blade tip, could improve the glottic view.

An Ex-vivo Model Examining Acoustics and Aerodynamic Effects Following Medialization With and Without Arytenoid Adduction

OBJECTIVES/HYPOTHESIS

Quantify differences in acoustics and intraglottal flow fields between Thyroplasty Type 1 (TT1) with and without arytenoid adduction (AA) using excised canine larynx model.

STUDY DESIGN

Basic science experiments using excised larynges.

METHODS

Surgical procedures were implemented in eight excised canine larynges. Acoustics and intraglottal flow measurements were taken at low and high subglottal pressures in each experimental setup.

RESULTS

In all larynges, vocal efficiency (VE) and cepstrum peak prominence (CPP) were higher, and the mean phonatory flow rate was lower in TT1 with AA than without AA. The glottal asymmetry is reduced with AA and promotes the formation of stronger vortices in the glottal flow during the closing phase of the vibrating folds.

CONCLUSIONS

Findings suggest a clear acoustic and aerodynamic benefit to the addition of AA when performing TT1. It shows significant improvement in CPP, translating to decreased breathiness and dysphonia and increased VE, leading to easier and more sustainable phonation. Stronger intraglottal vortices are known to be correlated with the loudness of voice produced by phonation.

LEVEL OF EVIDENCE

N/A Laryngoscope, 133:621-627, 2023.