Validity and reliability of the Group for Learning Useful and Performant Swallowing (GLUPS) tool.

INTRODUCTION: To validate the Group for Learning Useful and Performant Swallowing (GLUPS), a clinical tool dedicated to videofluoroscopy swallowing study (VFSS). METHODS: Forty-five individuals were recruited from January 2022 to March 2023 from the Department of Otolaryngology Head and Neck Surgery of University Hospital Saint-Pierre (Brussels, Belgium). Subjects underwent VFSS, which was rated with GLUPS tool by two blinded otolaryngologists and one speech-therapist. VFSS were rated twice with GLUPS within a 7-day period to assess test-retest reliability. RESULTS: Twenty-four patients and twenty-one controls completed the evaluations. The internal consistency (α = 0.745) and the test-retest reliability (rs = 0.941; p = 0.001) were adequate. GLUPS reported a high external validity regarding the significant correlation with the Penetration-Aspiration Scale (rs = 0.551; p = 0.001). Internal validity was adequate, because GLUPS score was significant higher in patients compared to controls (6.21 ± 4.42 versus 2.09 ± 2.00; p = 0.001). Interrater reliability did not report significant differences in the GLUPS sub- and total score among the independent judges. The mean GLUPS score of individuals without any evidence of VFSS abnormalities was 2.09/23 (95% CI 1.23-2.95), which supported that a GLUPS score ≥ 3.0 is suggestive of pathological VFSS. CONCLUSIONS: GLUPS is a clinical instrument documenting the abnormal findings of oral and pharyngeal phases at the VFSS. GLUPS demonstrated high reliability and excellent criterion-based validity. GLUPS may be used in clinical practice for the swallowing evaluation at the VFSS.

Impact of Dysphonic Schoolteachers' Voices on Children's Reaction Times according to Phonemic Contrasts.

INTRODUCTION: This paper aimed at observing the impact of dysphonic voice on children's reception of a linguistic message by evaluating their reaction times (RTs) to instructions given by functional dysphonic and control female schoolteachers (STs). METHODS: French minimal pairs such as /muʃ/ ("mouche" fly) versus /buʃ/ ("bouche" mouth) embedded in a carrier sentence "click on the drawing of…" were produced by two groups of 10 dysphonic and control female ST, matched in age and year of experience. The phonemical contrasts observed are voicing, nasality, consonantal place of articulation, vowel roundedness, and vowel place of articulation. The experimentation was presented in the form of a computer game to children from 7 to 10 years old. Two images illustrating the target words were presented, accompanied by the oral instructions recorded by ST. With a two-button box created for the experiment, children had to click as quickly as possible on the image corresponding to the instruction. RESULTS: Our results show that the RTs of all children are affected by the ST's dysphonia, regardless of their age and that they have significantly longer RT when discriminating minimal pairs contrasting in voicing when the instruction is given by a dysphonic speaker compared to the same instruction given by a control speaker. CONCLUSION: These observations could be explained by the fact that functional dysphonia is associated with improper use of the vocal folds and thus an alteration of voicing.

Henri IV of France's larynx 3D reconstitution.

OBJECTIVES: King Henri IV of France (reign from 1589 to 1610) was one of the most important kings of France. Embalmed and buried in Saint-Denis, his remains were beheaded in 1793. His head (including his larynx) survived in successive private collections until its definitive identification in 2010. The purpose of the study was to provide a morphologic study of the larynx with a 3D reconstitution. METHODS: A flexible endoscopy was performed via the mouth and via the trachea. Measures of the larynx (vocal folds lengths, thickness, width, larynx height) were collected from the CT-scan by a panel of experts blind each other. The segmentation of the laryngeal anatomical components (vocal folds, cartilages) was performed using 3DSlicer®. Mesh smoothing and 3D reconstitution were performed using Fusion 360®. Reconstitution was discussed between the experts. Decision was made by consensus after discussion. RESULTS: Cricoid, thyroid, arytenoid cartilages, vocal folds and hyoid bone were identified and a computed 3D reconstitution of the larynx was made. The laryngeal 3D model appeared morphologically similar to a living subject. Measures were similar but smaller than those of a modern subject. CONCLUSIONS: The 3D reconstitution of the larynx of Henri IV of France was conducted from the CT-scan of his mummified head. This work constitutes a first valuable morphologic analysis of a larynx from an embalmed individual. This anatomical work is the first step towards the reconstruction of the voice of this historical character, which we hope to concretize with computer modeling tools in a second step. LEVEL OF EVIDENCE: V based on experiential and non-research evidence.

Tele-rehabilitation in voice disorders during the pandemic: a consensus paper from the French Society of Phoniatrics and Laryngology.

OBJECTIVES: To establish a consensus protocol for telerehabilitation in speech therapy for voice disorders. METHODS: The study was conducted according to a modified Delphi method. Twenty speech therapist or laryngologist experts of the French Society of Phoniatrics and Laryngology assessed 24 statements of voice telerehabilitation with a 10-point visual analog scale ranging from 1 (totally disagree) to 10 (totally agree). The statements were accepted if more than 80% of the experts rated the item with a score of ≥ 8/10. The statements with ≥ 8/10 score by 60-80% of experts were improved and resubmitted to voting until they were validated or rejected. RESULTS: The French Society of Phoniatrics and Laryngology experts validated 10, 6, and 2 statements after the first, second and third voting round, respectively. Seven statements did not reach agreement threshold and were rejected. The validated statements included recommendations for setting (N = 4), medical/speech history (N = 2), subjective voice evaluations (N = 3), objective voice quality measurements (N = 3), and voice rehabilitation (N = 5). The experts agreed for a follow-up consisting of combined telerehabilitation and in-office rehabilitation. The final protocol may be applied in context of pandemic but could be assessed out of pandemic period for patients located in rural regions. CONCLUSIONS: This Delphi study established the first telerehabilitation protocol of the French Society of Phoniatrics and Laryngology for patients with voice disorders. Future controlled studies are needed to assess its feasibility, reliability, and the patient perception about telerehabilitation versus in-office rehabilitation.

Consensus for voice quality assessment in clinical practice: guidelines of the European Laryngological Society and Union of the European Phoniatricians.

INTRODUCTION: To update the European guidelines for the assessment of voice quality (VQ) in clinical practice. METHODS: Nineteen laryngologists-phoniatricians of the European Laryngological Society (ELS) and the Union of the European Phoniatricians (UEP) participated to a modified Delphi process to propose statements about subjective and objective VQ assessments. Two anonymized voting rounds determined a consensus statement to be acceptable when 80% of experts agreed with a rating of at least 3/4. The statements with ≥ 3/4 score by 60-80% of experts were improved and resubmitted to voting until they were validated or rejected. RESULTS: Of the 90 initial statements, 51 were validated after two voting rounds. A multidimensional set of minimal VQ evaluations was proposed and included: baseline VQ anamnesis (e.g., allergy, medical and surgical history, medication, addiction, singing practice, job, and posture), videolaryngostroboscopy (mucosal wave symmetry, amplitude, morphology, and movements), patient-reported VQ assessment (30- or 10-voice handicap index), perception (Grade, Roughness, Breathiness, Asthenia, and Strain), aerodynamics (maximum phonation time), acoustics (Mean F0, Jitter, Shimmer, and noise-to-harmonic ratio), and clinical instruments associated with voice comorbidities (reflux symptom score, reflux sign assessment, eating-assessment tool-10, and dysphagia handicap index). For perception, aerodynamics and acoustics, experts provided guidelines for the methods of measurement. Some additional VQ evaluations are proposed for voice professionals or patients with some laryngeal diseases. CONCLUSION: The ELS-UEP consensus for VQ assessment provides clinical statements for the baseline and pre- to post-treatment evaluations of VQ and to improve collaborative research by adopting common and validated VQ evaluation approach.

Intelligibility of pseudo-whispered speech after total laryngectomy.

This study aimed to assess the intelligibility of so-called 'pseudo-whispered speech' (pseudo-WS), as produced without voice nor pulmonic airstream by some alaryngeal patients prior to rehabilitation. Several perception tests were submitted to three experienced clinicians and three naive listeners, relying on the speech samples of 20 French native speakers: 10 alaryngeal speakers, solely using pseudo-WS when starting speech therapy up to six months after total laryngectomy, and 10 control speakers, recorded in the closest speech mode available, whispered speech (WS). Experts were asked to identify consonants (C) in the /a/+C+/a/ context and to rate intelligibility, unintended additive noise, and fluency on a likert-scale, while naive listeners completed a quantitative test of intelligibility. Intelligibility of WS was found to be high, with scores ranging from 46.33/54 to 53.67/54 (median 52.5, interquartile range 2.33) for the quantitative test, and segmental intelligibility ranging from 68.75% to 94.79% (median 87.5, interquartile range 17.71). Segmental confusion affected voicing in favour of unvoiced consonants, as previously reported in the literature. By contrast, intelligibility of pseudo-WS was found to be poor, with scores ranging from 1/54 (unintelligibility) to 28.33/54 (median 8.66, interquartile range 14.67) for the quantitative test, and segmental intelligibility ranging from 3.13% to 28.13% (median 9.24, interquartile range 14.58). Segmental intelligibility was not uniformly affected: stops, labials and unvoiced consonants were better identified than other categories. Finally, a significant correlation was found between global intelligibility and articulatory precision, while unintended additive noise and fluency seemed to play no role.

Transoral robotic cordectomy for glottic carcinoma: a rapid review.

OBJECTIVE: The objective of this study was to investigate feasibility, surgical, oncological, and functional outcomes of transoral robotic cordectomy (TORS-Co) and whether TORS-Co reported comparable outcomes of transoral laser microsurgery (TLM). METHODS: PubMed, Scopus, and Cochrane Library were searched by three laryngologists for studies investigating feasibility, surgical, oncological, and functional outcomes of patients benefiting from TORS-Co. The following outcomes were investigated according to the PRISMA statements: age; cT stage; types of cordectomy; surgical settings; complications; and functional and feasibility features. RESULTS: Nine studies published between 2009 and 2021 met our inclusion criteria, accounting for 114 patients. There was no controlled study. TORS-Co was performed in cT1 or cT2 glottic cancer through types II, III, IV, V, or VI cordectomies. The exposure was inadequate in 4% of cases, leading to conversion in transoral laser cordectomy. Margins were positive in 4.5% and local recurrence occurred in 10.7% (N = 8/75). Tracheotomy and feeding tube requirement varied across studies, depending on the types of TORS-Co. The mean duration of robot installation/vocal cord exposure and operative times ranged from 20 to 42 min and 10 to 40 min, respectively. The mean duration of hospital stay ranged from 2 to 7 days. Complications included dyspnea, bleeding, granuloma, synechia, and tongue hematoma and dysesthesia. CONCLUSION: The current robotic systems do not appear adequate for TORS-Co. TORS-Co was associated with higher rates of complications and tracheotomy than TLM.

Acoustic measurements are useful therapeutic indicators of patients with dysphonia-related to reflux.

OBJECTIVES: The objective is to study the usefulness of acoustic measurements as therapeutic outcomes for patients with dysphonia related to laryngopharyngeal reflux (LPR). METHODS: From September 2019 to April 2021, 120 patients with LPR at the hypopharyngeal-esophageal multichannel intraluminal impedance pH-monitoring (HEMII-pH) were prospectively recruited from three University Hospitals. They were divided in two groups regarding the presence of dysphonia. The treatment consisted of a combination of diet, proton-pump inhibitors, magaldrate and alginate for 3-6 months. The following clinical and acoustic evaluations were studied regarding groups at baseline, 3- and 6-month posttreatment: reflux symptom score (RSS), reflux sign assessment (RSA), percent jitter, percent shimmer and noise-to-harmonic ratio (NHR). RESULTS: A total of 109 patients completed the evaluations, accounting for 49 dysphonic and 60 non-dysphonic individuals. HEMII-pH, gastrointestinal endoscopy, baseline clinical and acoustic features were comparable between groups. RSS and RSA significantly improved from pre- to 3-month posttreatment in both groups. Jitter, Shimmer and NHR significantly improved from pre- to 3-month posttreatment in dysphonic patients, without additional 3- to 6-month posttreatment changes. Acoustic parameters did not change throughout treatment in patients without dysphonia. CONCLUSION: Acoustic measurements may be an interesting indicator of treatment in LPR patients who reported dysphonia. In this group of individuals, the evolution of acoustic parameters was consistent with the evolution of symptoms and findings.

European white paper: oropharyngeal dysphagia in head and neck cancer.

PURPOSE: To develop a European White Paper document on oropharyngeal dysphagia (OD) in head and neck cancer (HNC). There are wide variations in the management of OD associated with HNC across Europe. METHODS: Experts in the management of specific aspects of OD in HNC across Europe were delegated by their professional medical and multidisciplinary societies to contribute to this document. Evidence is based on systematic reviews, consensus-based position statements, and expert opinion. RESULTS: Twenty-four sections on HNC-specific OD topics. CONCLUSION: This European White Paper summarizes current best practice on management of OD in HNC, providing recommendations to support patients and health professionals. The body of literature and its level of evidence on diagnostics and treatment for OD in HNC remain poor. This is in the context of an expected increase in the prevalence of OD due to HNC in the near future. Contributing factors to increased prevalence include aging of our European population (including HNC patients) and an increase in human papillomavirus (HPV) related cancer, despite the introduction of HPV vaccination in various countries. We recommend timely implementation of OD screening in HNC patients while emphasizing the need for robust scientific research on the treatment of OD in HNC. Meanwhile, its management remains a challenge for European professional associations and policymakers.

Stroboscopic assessment of unilateral vocal fold paralysis: a systematic review.

PURPOSE: To review the relevant basic stroboscopic evaluations in unilateral vocal fold paralysis (UVFP). Our aim was twofold: (1) to determine the frequency of use of stroboscopic parameters in outcome evaluation after surgical treatment of UVFP using a Pareto diagram; and (2) to select the most relevant parameters in terms of a significant difference between pre- and post-surgical intervention for UVFP. METHODS: A systematic review in PUBMED includes studies on stroboscopic evaluation in combination with UVFP and surgical treatment. The review was limited to English studies published between 1990 and March 2018. The most frequently used stroboscopic parameters were identified using a Pareto diagram. Then, 'the percentage of significance' for the most frequently stroboscopic parameters was identified by comparing the number of studies that showed a statistically significant change in pre- and post-treatment results with the total number of studies using the same parameters. RESULTS: Seven stroboscopic parameters were nominated using the Pareto diagram. In decreasing order of citation frequency, periodicity, edge bowing, mucosal wave, glottic gap, position of vocal fold, amplitude, and symmetry have respective percentages of significance of 87.5%, 83.3%, 77.7%, 64.5%, 60%, 57.1%, and 50%. Five pertinent scales were selected for the most frequent and significant stroboscopic parameters. CONCLUSIONS: The results indicate that periodicity, edge bowing, mucosal wave, glottic gap, and position of vocal fold represent the five most frequently used and relevant stroboscopic parameters in UVFP evaluation. The current review outlines a proposal scale of these stroboscopic parameters. PROSPERO REGISTRATION NUMBER: CRD42019126786.

Development of scores assessing the refluxogenic potential of diet of patients with laryngopharyngeal reflux.

OBJECTIVE: To develop clinical tools assessing the refluxogenic potential of foods and beverages (F&B) consumed by patients with laryngopharyngeal reflux (LPR). METHODS: European experts of the LPR Study group of the Young-Otolaryngologists of the International Federation of Oto-rhino-laryngological societies were invited to identify the components of Western European F&B that would be associated with the development of LPR. Based on the list generated by experts, four authors conducted a systematic review to identify the F&B involved in the development of esophageal sphincter and motility dysfunctions, both mechanisms involved in the development of gastroesophageal reflux disease and LPR. Regarding the F&B components and the characteristics identified as important in the development of reflux, experts developed three rational scores for the assessment of the refluxogenic potential of F&B, a dish, or the overall diet of the patient. RESULTS: Twenty-six European experts participated to the study and identified the following components of F&B as important in the development of LPR: pH; lipid, carbohydrate, protein composition; fiber composition of vegetables; alcohol degree; caffeine/theine composition; and high osmolality of beverage. A total of 72 relevant studies have contributed to identifying the Western European F&B that are highly susceptible to be involved in the development of reflux. The F&B characteristics were considered for developing a Refluxogenic Diet Score (REDS), allowing a categorization of F&B into five categories ranging from 1 (low refluxogenic F&B) to 5 (high refluxogenic F&B). From REDS, experts developed the Refluxogenic Score of a Dish (RESDI) and the Global Refluxogenic Diet Score (GRES), which allow the assessment of the refluxogenic potential of dish and the overall diet of the LPR patient, respectively. CONCLUSION: REDS, RESDI and GRES are proposed as objective scores for assessing the refluxogenic potential of F&B composing a dish or the overall diet of LPR patients. Future studies are needed to study the correlation between these scores and the development of LPR according to impedance-pH study.

The Mechanism and Representation of Korean Three-Way Phonation Contrast: External Photoglottography, Intra-Oral Air Pressure, Airflow, and Acoustic Data.

This paper aims to refine our understanding of the speech mechanism and laryngeal features involved in the Korean lenis (/p t k/), aspirated (/ph th kh/), and fortis (/p' t' k'/) plosives. For this purpose we made measurements using a new noninvasive technique called external lighting and sensing photoglottography (ePGG) as well as intra-oral air pressure (Pio) above the glottis, airflow, and acoustic data. From simultaneous recordings of the experimental data, we were ableto quantify the laryngeal-oral coordination of glottal opening and a consonant release, and the covariance of airflow peak and duration of aspiration with glottal opening. The phasing of glottal opening and the 3-way phonation contrast occurs in the order, from early to late, fortis, lenis < aspirated plosives, and the glottal opening peak ranges from low to high in the same order. We also found that a Pio peak, the durations of a high Pio plateau and an oral closure, and F0 are independent of the glottal opening mechanism, varying in the order lenis < aspirated and fortis plosives. From these findings, we propose that the 2 independent patterns are accounted for by the articulator-based features [±spread glottis] and [±tense], respectively.

Reduced survival in patients with ALS with upper airway obstructive events on non-invasive ventilation.

INTRODUCTION: Non-invasive ventilation (NIV) is part of standard care in amyotrophic lateral sclerosis (ALS). Intolerance or unavailability of NIV, as well as the quality of correction of nocturnal hypoventilation, has a direct impact on prognosis. OBJECTIVES: We describe the importance of NIV failure due to upper airway obstructive events, the clinical characteristics, as well as their impact on the prognosis of ALS. METHODS: Retrospective analysis of the data of 190 patients with ALS and NIV in a single centre for the period 2011-2014. 179 patients tolerating NIV for more than 4 h per night without leaks were analysed. RESULTS: Among the 179 patients, after correction of leaks, 73 remained inadequately ventilated at night (defined as more than 5% of the night spent at <90% of SpO2), as a result of obstructive events in 67% of cases (n=48). Patients who remained inadequately ventilated after optimal adjustment of ventilator settings presented with shorter survival than adequately ventilated patients. Unexpectedly, patients with upper airway obstructive events without nocturnal desaturation and in whom no adjustment of treatment was therefore performed also presented with shorter survival. On initiation of NIV, no difference was demonstrated between patients with and without upper airway obstructive events. In all patients, upper airway obstruction was concomitant with reduction of ventilatory drive. CONCLUSIONS: This study shows that upper airway obstruction during NIV occurs in patients with ALS and is associated with poorer prognosis. Such events should be identified as they can be corrected by adjusting ventilator settings.

Laryngeal microsurgery under Transnasal Humidified Rapid Insufflation Ventilatory Exchange.

Objective: Since 2015, Transnasal Humidified Rapid Insufflation Ventilatory Exchange (THRIVE) has been used in general anesthesia for preoxygenation or difficult exposure airway management. Its use offers new opportunities in laryngology. THRIVE increases apnea time and frees the access to the upper airway. However, its use may be less stable than orotracheal intubation. The main objective of this work was to evaluate the feasibility of laryngeal microsurgery under THRIVE including using Laser. Study Design: Retrospective. Setting: A total of N = 99 patients with laryngeal microsurgery (with or without CO2 laser) under THRIVE were included successively from January 1, 2020 to January 30, 2022. Method: Medical history, comorbidities, clinical and surgical data were extracted and analyzed. Two groups were constituted regarding the "success" (use of THRIVE along all the procedure) or the "failure" (need for an endotracheal tube) of the use of THRIVE during the procedure. Results: A failure occurred in N = 15/99 patients (15.2%) mainly due to refractory hypoxia. The odd ratios (OR) for THRIVE failure were: OR = 6.6 [2.9-35] for overweight (BMI >25 kg/m2); OR = 3.8 [1.7-18.7] for ASA score >2; OR = 4.7 [2.3-24.7] for the use of CO2 laser. Elderly patients and patients with pulmonary pathology were not statistically at greater risk of THRIVE failure. No adverse event was described. Conclusion: This work confirms the feasibility of laryngeal microsurgery under THRIVE, including with CO2 laser. Overweight, ASA >2 and lower fraction of inspired oxygen during CO2 laser use increased the risk for orotracheal intubation.

One hundred fifty years of total laryngectomies.

The inaugural total laryngectomy in history was conducted by Billroth in 1873. Nevertheless, significant enhancements to the technique were achieved through the contributions of Gluck, Sorensen, and various other surgeons. Throughout the twentieth century, advancements in anesthesia, infectious disease, hospital hygiene, antibiotic therapy, resuscitation, and the expertise of numerous laryngologists elevated total laryngectomy to a pivotal surgical intervention in head and neck surgery. The latter half of the twentieth century witnessed a paradigm shift with the emergence of organ preservation protocols. Total laryngectomy became the preferred choice for patients experiencing radiotherapy failure. However, the widespread use of laryngeal conservative treatments appears to be correlated with a decline in overall survival rates in the United States and Europe. The evolution of new minimally invasive surgical approaches in the twenty-first century may usher in a revolutionary era in the management of laryngeal carcinoma, offering the potential for improved survival and functional outcomes.

The Dubai Definition and Diagnostic Criteria of Laryngopharyngeal Reflux: The IFOS Consensus.

OBJECTIVE: The objective of this work was to gather an international consensus group to propose a global definition and diagnostic approach of laryngopharyngeal reflux (LPR) to guide primary care and specialist physicians in the management of LPR. METHODS: Forty-eight international experts (otolaryngologists, gastroenterologists, surgeons, and physiologists) were included in a modified Delphi process to revise 48 statements about definition, clinical presentation, and diagnostic approaches to LPR. Three voting rounds determined a consensus statement to be acceptable when 80% of experts agreed with a rating of at least 8/10. Votes were anonymous and the analyses of voting rounds were performed by an independent statistician. RESULTS: After the third round, 79.2% of statements (N = 38/48) were approved. LPR was defined as a disease of the upper aerodigestive tract resulting from the direct and/or indirect effects of gastroduodenal content reflux, inducing morphological and/or neurological changes in the upper aerodigestive tract. LPR is associated with recognized non-specific laryngeal and extra-laryngeal symptoms and signs that can be evaluated with validated patient-reported outcome questionnaires and clinical instruments. The hypopharyngeal-esophageal multichannel intraluminal impedance-pH testing can suggest the diagnosis of LPR when there is >1 acid, weakly acid or nonacid hypopharyngeal reflux event in 24 h. CONCLUSION: A global consensus definition for LPR is presented to improve detection and diagnosis of the disease for otolaryngologists, pulmonologists, gastroenterologists, surgeons, and primary care practitioners. The approved statements are offered to improve collaborative research by adopting common and validated diagnostic approaches to LPR. LEVEL OF EVIDENCE: 5 Laryngoscope, 134:1614-1624, 2024.

Glottic bamboo nodules from systemic lupus erythematosus.

Bamboo nodules of the glottis are of late being described as a distinct entity seen in patients with autoimmune diseases. We report the symptoms, clinical features, and management of a case of bamboo nodules of the glottis in a patient with systemic lupus erythematosus. We discuss the pathogenesis and management of this condition on the basis of a review of the medical literature.

Endoscopic laser medial arytenoidectomy for treatment of bilateral vocal fold paralysis.

Endoscopic laser medial arytenoidectomy for bilateral vocal fold paralysis has the advantage of preserving the structure and the position of the vocal fold, contrary to a transverse cordotomy or total arytenoidectomy. Our objective was to evaluate the functional results of this procedure. This is a prospective non-randomized study. Twenty patients were included: five patients had a tracheotomy preoperatively and 15 patients had dyspnea on exertion. Acoustic voice measurements, spirometric parameters and the voice handicap index 120 (VHI), were evaluated 1 week before surgery and 3 months after. All the five patients with tracheotomy were successfully decannulated. Acoustic records and VHI were available for eight patients. Jitter and shimmer were worse (p = 0.0078), whereas the VHI was not significantly different after surgery. Spirometric records, available for six patients, were not modified. Endoscopic laser medial arytenoidectomy allowed decannulation and subjective improvement of quality of life in patients with bilateral vocal fold paralysis.