Glottal Closure Research Articles

Influence of etiology on the efficacy of ansa cervicalis anterior root-recurrent laryngeal nerve anastomosis in the treatment of unilateral vocal ford paralysis

Objective: To explore the efficacy of ansa cervicalis anterior root-recurrent laryngeal nerve (RLN) anastomosis in the treatment of unilateral vocal fold paralysis (UVFP) and to analyze the effect of different pathogenic factors on efficacy. Methods: From January 2010 to January 2022, 428 patients (187 males and 241 females) at Changhai Hospital with UVFP who underwent ansa cervicalis anterior root-RLN anastomosis due to thyroid surgery, thoracic surgery, idiopathic vocal ford paralysis or high cranial base injury were analyzed. The course of nerve injury ranged from 6 to 24 months. Videostroboscopy, auditory perceptual evaluation parameters (GRBAS including Grade, Roughness, Breathiness, Asthenia, Strain), Voice Handicap Index (VHI-10), acoustic analysis including Jitter, Shimmer and noise to harmonic ratio (NHR), maximum phonation time (MPT) and laryngeal electromyography were used to evaluate the surgery efficacy, and the therapeutic difference of the above 4 different etiology patients receiving the operation was compared. Data processing was performed using SPSS 26.0 statistical software, and Wilcoxon signed rank test was used. Kruskal Wallis one-way ANOVA was used for those with equal variance. Results: At 12 months after operation, the affected vocal ford position, vocal ford edge, glottal closure, symmetry and regularity of vocal ford vibration were significantly improved in all four groups (P<0.01). G, R, B, A, S, VHI-10, Jitter, Shimmer and NHR were significantly lower than those before operation, while, MPT was significantly longer (P<0.01). Also, the maximum voluntary motor unit recruitment (VMUR) in the affected thyroarytenoid muscles and posterior cricoarytenoid muscles was significantly improved after surgery (P<0.01). However, the results of thyroid surgery group, thoracic surgery group and idiopathic vocal ford paralysis group were better than those of high cranial base injury group respectively, and the differences were statistically significant (P<0.05). Conclusion: Ansa cervicalis anterior root-RLN anastomosis has an obvious efficacy on the recovery of phonatory function in UVFP patients with different causes, but the high cranial base injury is significantly worse than that of vocal ford paralysis caused by other causes.

Acoustic and perceptual profiles of american english social affective expressions

This pilot study reports on acoustic and perceptual profiles of two American female speakers’ productions of six American English social affective expressions: Authority, Declaration, Irritation, Sincerity, Uncertainty and walking on eggs as spoken in the linguistic sentence frame, Mary was dancing. The acoustic profile describes the prosodic characteristics of the utterances as a whole, as well as the voice quality characteristics of the nuclear stress syllable in the utterances. The perceptual profiles describe listeners’ 3 dimensional VAD emotional ratings, i.e., Valence, Arousal, and Dominance, of the utterances and listeners’ auditory impressions of the nuclear stress syllable. Multifactorial Analyses were applied to examine the relation between the prosodic characteristics and the VAD scales, and also the relationship between voice quality measurements on the nuclear stress vowel and auditory perceptions. The prosodic MFA results indicate that for these two American English speakers, a soft / noisy voice, with weak harmonics and irregular rhythm with pauses and hesitations, as in the expressions of Uncertainty and WOEG, is perceived by listeners as accommodating and not positive. Loud, tense voices with energy in the upper frequencies, as in theexpression of Irritation, are perceived as Aroused. Expressions of Authority, Declaration, and Sincerity tend to have comparatively regular rhythm and relatively flat intonation. The MFA analysis of voice quality measurements and auditory perceptions suggests that Normalized Amplitude Quotient may indeed be a good estimate for tense voice due to glottal closing behavior, Cepstral Peak Prominence, a good estimation for strong non-noisy harmonics, Peak Slope, a good estimate of spectral related tense voice, and Hammarberg Index, for distribution of spectral energy, i.e., strong or weak energy in the upper frequencies.

Using High-Speed Videoendoscopy to Analyze Laryngeal Closure Parameters During Normal Swallow.

This pilot study was designed to test the tolerability of a lower scope position and feasibility of custom-designed MATLAB graphical user interface (GUI) used to analyze playback review of laryngeal high-speed videoendoscopy (laryngeal HSV) during healthy volitional dry swallows. We hypothesized this method would conceptually provide time resolution for glottic closure events compared with standard (30 frames per second, fps), and enable a means to measure timing, sequence, and duration of laryngeal movements during swallowing not otherwise visualized. A total of 14 healthy adults (4 male, 22-80 years) participated. We performed laryngeal HSV at 500fps. Measurements included: (i) feasibility and tolerability of the procedure; (ii) identification of a swallowing segment of interest (SOI) for the peak of the swallow; and (iii) description of laryngeal swallowing movements using a GUI. Fourteen subjects tolerated the procedure without discomfort and swallow images were able to be analyzed in 12. Using our GUI, mean SOI was 260 ms, yielding 130 frames for analysis (compared with seven in standard laryngoscopy). Vocal fold adduction, vocal fold medialization, and anterior-posterior arytenoid compression to the epiglottis prior to whiteout could be identified and sequenced. Participants tolerated a low position of the endoscope during dry volitional swallows. The output of our GUI demonstrated a novel technique for identifying, describing, and sequencing a swallowing SOI. Future studies should investigate laryngeal closure and arytenoid positioning with a bolus and in a range of ages, genders, and etiologies in both healthy and abnormal populations to better understand swallowing physiology. NA Laryngoscope, 2024.

Influence of flow rate and fiber tension on dynamical, mechanical and acoustical parameters in a synthetic larynx model with integrated fibers.

The human voice is generated by the oscillation of the vocal folds induced by exhalation airflow. Consequently, the characteristics of these oscillations and the primary sound signal are controlled by the longitudinal tension of the vocal folds, the flow rate, and their prephonatoric position. To facilitate independent control of these parameters, a synthetic larynx model was developed, as detailed in a previous publication. This study aims to statistically analyze the influence of airflow and fiber tension on phonation characteristics, such as periodicity and symmetry, glottis closure during vocal fold oscillations, as well as tissue elasticity and generated sound. A total of 76 experiments were conducted and statistically analyzed with a systematic variation of flow rate and longitudinal tension within the vocal folds.During these experiments, vocal fold motion, subglottal pressure, and emitted sound were meticulously measured and analyzed. Groupwise statistical testing identified the flow rate as the main influencing parameter on nearly all phonation characteristics. However, the fundamental frequency, stiffness parameters, and quality parameters of the primary sound signal are predominantly controlled by the longitudinal tension within the vocal folds. The results demonstrated a complex interplay between the flow rate and tension, resulting in different characteristics of the produced sound signal.

Aerodynamic Threshold Measures for Reflecting Glottal Closure in Voice Disorders.

Previous work suggested that phonation threshold pressure (PTP), phonation threshold flow (PTF), and phonation threshold power (PTW) could be effective aerodynamic measures for quantifying glottal incompetence. This study examined how these measures could reflect varying extent of incomplete glottal closure in individuals with voice disorders. Thirty individuals formally diagnosed with glottal incompetence, including 10 with hypofunctional disorders (hypo group) and 20 with hyperfunctional disorders (hyper group), and 30 individuals with normal voice (control group) participated in the study. PTP was measured indirectly by intra-oral pressure during production of bilabial stop consonant-vowel syllables, PTF was measured during the sustained vowel /a/, and PTW was obtained as the product of PTP and PTF. The extent of incomplete glottal closure was quantified by normalized glottal gap (NGG) and normalized glottal gap area (NGGA) based on image analysis of videostroboscopic recordings of sustained /i/. Significant differences in all threshold measures (p < .05) were found among three participant groups with medium-to-large effect sizes (ηp2 = .128-.220), with significantly higher values for the hypo group than the control group and no significant differences between the hyper and control groups. Receiver operating characteristic (ROC) analysis showed the highest diagnostic or classification accuracy contrasting between the hypo and control groups (area under the ROC curve = .717-.757), with the highest classification accuracy for PTW. There were significant, moderate-to-strong positive correlations with NGG and NGGA for the disorders group (Pearson's r = .4244-.6226) and the hypo group (r = .5689-.8949). These measures could be effective for identifying glottal incompetence, especially for hypofunctional disorders. PTW could be more sensitive than PTP and PTF in reflecting the extent of incomplete glottal closure, consistent with theoretical predictions. Their relative sensitivities for quantifying distinct incomplete glottal closures specific to different voice disorders should be evaluated in future studies.

Early injection laryngoplasty for acute unilateral vocal fold paralysis after thoracic aortic surgery

ObjectiveUnilateral vocal fold paralysis (UVFP) following open thoracic aortic surgery increases pulmonary complications and hospital stays. An intervention protocol with early injection laryngoplasty (IL) and swallowing maneuvers was developed for acute UVFP following thoracic aortic surgery. This study aimed to compare the incidence of complications and length of medical care between the non-VFP and the IL-UVFP group managed under this protocol. MethodsPatients who underwent open thoracic aortic surgery from March 2020 to February 2023 were included, excluding those with preoperative VFP or postoperative bilateral VFP. Under the protocol, patients with UVFP and incomplete glottic closure received IL and swallowing maneuvers within one week after diagnosis, while those without a glottic gap started a soft diet along with swallowing maneuvers. Postoperative complications, including reintubation, ICU re-transfer, pneumonia, stroke, delirium, wound infection, and bleeding, as well as hospital and ICU stay, were assessed. ResultsOf the 355 patients included in the study, 51 (14.4%) developed postoperative UVFP, while 304 (85.6%) had normal VF function. In the UVFP group, 42 patients underwent IL, while 9 patients without a glottic gap did not undergo IL. The incidence of complications and length of medical care were analyzed in the non-VFP and the IL-UVFP groups. The IL-UVFP group had a longer median hospital stay compared to the non-VFP group (20.5 vs. 16.0 days), though this difference was not statistically significant (P = .0681). ICU stay (P = .5396) and ICU re-transfer rates (P = 1.00) were also comparable between the groups. There was no significant difference in the incidence of pneumonia between the IL-UVFP group (4.8%) and the non-VFP group (9.5%) (P = .4003). Additionally, no significant differences were observed in the incidence of stroke, delirium, wound infection, or bleeding between the groups. No IL-related complications were reported. ConclusionsThe protocol with early IL appears to help reduce complication rates in acute UVFP patients following thoracic aortic surgery to levels comparable to those in patients without VFP. This protocol could serve as a guideline for otolaryngologists in managing UVFP patients. Level of evidence2b/Individual cohort study.

Analysis of therapeutic effect of fibrocystic degeneration of vocal folds

Objective:To explore the differences in clinical presentation and therapeutic outcomes between vocal fold fibrocystic degeneration and other common benign lesions, such as vocal fold polyp and cyst. Methods:Vocal function was assessed before and after surgery in 10 cases of vocal fold fibrocystoids, 30 cases of vocal fold polyps and 10 cases of vocal fold cysts at Department of Voice Medicine, Xiamen University Zhongshan Hospital. The voice Assessments included GRBAS（G-scale）, VHI-10 scale, Reflux Symptom Index（RSI） scale, stroboscope, acoustic objective analysis, and aerodynamics measurements. The acoustice analysis parameters included fundamental frequency（F0）, fundamental frequency perturbation（Jitter）, amplitude perturbation（Shimmer） and voice disturbance severity index（DSI）, while the maximum phonation time（MPT） was assessed for aerodynamics. Stroboscopic parameters included vocal fold straightness, vocal fold color, glottic closure and mucosal wave. All three groups underwent phonomicrosurgery and a follow-up review was conducted one month later. Pre-and post-operative function assessment parameters were compared across the three groups. Results:Significant differences were founded in the G grade, Jitter, Shimmer, DSI, glottic closure and mucosal wave between the vocal fold fibrocystic degeneration group and the vocal fold polyp and vocal fold cyst group（P<0.05）. Most voice function parameters in all three groups showed significant improvement after surgery（P<0.05）. The improvement of VHI（10）, RSI and mucosal wave scores in the vocal fold fibrocystic lesion group was significantly different from that of the vocal fold polyp group（P<0.05）. Conclusion:Vocal fold fibrocystic degeneration is a more severe than that of vocal fold polyps and cysts, which are two common benign vocal fold lesions. Phonomicrosurgery is an effective treatment for vocal fold fibrocystic degeneration, but its curative effect are less favorable compared to those for vocal fold polyps and vocal fold cysts. Therefore, a detailed preoperative evaluation is essential for predicting surgical outcomes.

A Methodology to Quantify the Effective Vertical Thickness of Prephonatory Vocal Fold Medial Surface

ObjectiveThe shape of the vocal fold medial surface, particularly its vertical thickness, has been shown in computational and physical modeling studies to be highly influential in regulating glottal closure during phonation. However, because of the difficulty to quantify the vertical thickness in real vocal folds, this influence has often been overlooked in clinical contexts. Therefore, the goal of this study is to present a method to calculate an effective vertical thickness of the medial surface that is predictive of the glottal closure pattern during phonation. MethodsAn effective vertical thickness of the medial surface is calculated as a weighted integral of the medial surface contour along the vertical dimension. The weight is one for the part of the medial surface within a fixed threshold distance from the most medial point, and decays exponentially otherwise. The influence of the threshold distance value on the effective thickness value is investigated. Additionally, the sensitivity of the calculated effective thickness to slight misidentification of the vertical glottal midline is also studied. The methodology is validated on the vocal fold medial surface data from a canine hemilarynx at different levels of thyroarytenoid muscle activation. ResultsFor most threshold distances, the thickness follows an expected sigmoid-like trend with respect to the thyroarytenoid muscle activation level. A threshold distance of 0.05 mm appears optimal as it produced thickness changes in a range comparable to previous computational and experimental studies. The methodology is relatively robust to slight misidentification of the vertical glottal midline. ConclusionsA methodology to estimate the effective vocal fold vertical thickness from medial surface contours is proposed. The methodology can be applied in future studies to correlate medial surface shape to relevant parameters characterizing vocal fold vibration as well as clinical evaluation of treatment effectiveness.

Clinical Effects of Voice Therapy on Vocal Outcomes in Unilateral Vocal Fold Paralysis: Proof-of-Concept Study for Two SOVT-Based Treatment Protocols

BackgroundStudies on treatment efficacy in unilateral vocal fold paralysis (UVFP) often lack a predetermined treatment protocol, and little is known about the effects of specific vocal techniques on vocal outcomes and quality of life in UVFP patients. The purpose of this preliminary proof of concept study is to investigate the effects and feasibility of two intensive treatment protocols based on water-resistance therapy (WRT) and vocal function exercises (VFE). MethodsTen participants with acute or chronic UVFP/paresis were recruited in the study and randomly assigned to the WRT or VFE group. Three of these participants presented with aphonia and could not complete the program as prescribed. The remaining participants completed an intensive therapy program with the assigned vocal technique. Before, during, and after the program, a multidimensional voice assessment was performed. Maximum phonation time, acoustic, perceptual, and patient-reported outcome measures were obtained. ResultsWRT and VFE had positive clinical effects on instrumental and auditory-perceptual voice quality, glottal closure, and patient-reported outcome measures, but inter-individual variability was high. Studies with larger sample sizes are necessary to confirm or refute these findings. ConclusionThe WRT- and VFE-based therapy programs are both feasible and seem to elicit positive clinical changes in UVFP patients. Suggestions on how to improve the programs are provided, as well as considerations for implementation in clinical practice. Follow-up research is needed to examine the efficacy of both programs on group level.

Voice Type Component Profile Model of Glottal Gap Voice in Ex Vivo Canine Larynges

This paper aimed to create a voice type component profile (VTCP) to model a glottal gap during phonation. VTCP was generated from phonation from eight excised canine larynges with induced posterior glottal gaps. Glottal gaps were induced using metal shims with widths ranging from 0.5 to 3.5mm, in 0.5 mm increments. Acoustic data was collected under each gap condition, and a custom MATLAB software was used to analyze the data for VTCP. The trends of each VTC were analyzed with changes in glottal gap size. Increasing glottal gap led to a decrease in VTC1 and an increase in VTC4. Post-Hoc Tukey tests found that for both VTC4 and VTC1, The 1.5mm group differed from the 2, 2.5, and 3.5mm group. Additionally, in both VTC1 and VTC4 there was a significant difference between both the control and 0.5mm shim groups and the 2, 2.5, 3, and 3.5mm shim groups. VTC2 followed a similar trend as VTC1. Average VTC3 was highest at control, and the 1, 2, 2.5, 3, and 3.5mm shim groups significantly differed from the control group. Kendall correlation tests showed that there was a significant weak inverse relationship with glottal gap size and VTC1, VTC2, and VTC3 and a significant weak positive correlational relationship with glottal gap size and VTC4. As glottal gap width increased, phonation exhibited increased turbulence associated with increased breathiness. Periodicity decreased as turbulence increased. Increased turbulence was shown to be derived from the glottal level. The size of the induced glottal gap was the cause of the turbulent signals. The study highlights the potential of VTCP analysis in detecting subtle changes in glottal closure and suggests avenues for further research in diagnosing voice disorders.

Efficacy analysis of ansa cervicalis anterior root-recurrent laryngeal nerve anastomosis in the treatment of unilateral vocal cord paralysis

Objective:Investigates the application and clinical efficacy of ansa cervicalis anterior root-recurrent laryngeal nerve（RLN） anastomosis in the treatment of unilateral vocal fold paralysis（UVFP）. Methods:A prospective study was conducted with 92 UVFP patients admitted to our department from January 2018 to January 2022 who received ansa cervicalis anterior root-RLN anastomosis. The course of nerve injury ranged from 6 to 24 months. Videostroboscopy, voice subjective auditory perceptual assessment（GRBAS）, Voice Handicap Index（VHI-10）, voice objective acoustic analysis and laryngeal electromyography（EMG） were used to evaluate the efficacy of the operation. Results:Videostroboscopy showed that although the movement of vocal cords did not return to normal 12 months after operation, their volume and muscle tension were significantly improved and their positions were adducted to the median or near-median. Also the glottic closure, vocal cord position, vocal cord edge, symmetry and regularity of vocal cord vibration were significantly improved than pre-operation（P<0.01）. The five indexes of GRBAS（Grade, Roughness, Breathiness, Asthenia, Strain） and VHI-10, as well as voice acoustic parameters（Jitter, Shimmer, NHR） post-operation were significantly reduced, while the maximum phonation time（MPT） was significantly longer（P<0.01）. The results of laryngeal EMG indicated that the maximum voluntary motor unit recruitment（VMUR） post-operation was significantly recovered（P<0.01）, which confirmed that the affected laryngeal muscle obtained effective nerve reinnervation. Conclusion:Ansa cervicalis anterior root-RLN anastomosis can effectively improve the voice function of patients which is safe and satisfactory. It is an ideal method for the treatment of unilateral RLN injury.

Evaluation of the effect of endoscopic CO₂laser arytenoidectomy on re-operation for failed posterior cordotomy

Objective:To analyze the efficacy of endoscopic CO₂ laser arytenoidectomy in treating bilateral vocal cord paralysis. Methods:Ninety-five patients who underwent endoscopic CO₂ laser arytenoidectomy for bilateral vocal cord paralysis at the First Affiliated Hospital of Naval Medical University（Changhai Hospital） of Shanghai from January 2009 to December 2022 were included in this study. Among them, 59 patients underwent endoscopic CO₂ laser arytenoidectomy as their first glottic enlargement surgery（Group A）, while 36 patients, who had previously undergone two unsuccessful CO₂ laser-assisted posterior cordotomies, underwent endoscopic CO₂ laser arytenoidectomy as a subsequent surgery（Group B）. Swallowing function, electronic laryngoscopy, perceptual voice evaluation, and objective voice analysis indicators were statistically analyzed before and after surgery to evaluate clinical efficacy. Results:The extubation rate after the first surgery was 84.75% in Group A and 86.11% in Group B, with total extubation rates of 94.92% and 94.44%, respectively. There were no significant differences between the two groups in preoperative and postoperative swallowing function, glottic size, or various voice evaluation indicators（P>0.05）. Within-group comparisons showed that postoperative swallowing function, glottic closure during phonation, perceptual evaluations of G（grade of hoarseness）, A（asthenia）, and B（breathiness） significantly worsened, with increased grades. The maximum transverse diameter of the posterior glottis during inspiration significantly increased, and the VHI-10 score was significantly higher postoperatively. Jitter, shimmer, and the harmonics-to-noise ratio significantly deteriorated, and maximum phonation time significantly shortened（P<0.05）. No significant differences were observed in postoperative R（roughness） and S（strain） compared to preoperative values（P>0.05）. Conclusion:Endoscopic CO₂ laser arytenoidectomy can impair voice quality to some extent but effectively alleviates breathing difficulties in patients with bilateral vocal cord paralysis. For patients who did not achieve successful extubation with CO₂ laser-assisted posterior cordotomy, endoscopic CO₂laser arytenoidectomy is an effective reoperative method, ensuring a high extubation rate while preserving certain voice functions.

Application of placing the anterior end of endotracheal tube at the glottis in laryngeal mask airway positive ventilation during general anesthesia: A prospective, randomized, controlled trial.

Glottic contraction and closure causes ventilation obstruction and laryngeal mask airway (LMA) leakage during positive pressure ventilation using LMA. This study aimed to assess the effect of placing the anterior end of the endotracheal tube (ET) at the glottis through the LMA ventilation conduit on treating LMA leakage following glottic contraction and closure. In this prospective, randomized, controlled trial, patients with non-minor surgery using LMA ventilation were randomly allocated to the i-gel group (group L) and the i-gel combined with ET group (group LE). The tip of ET was placed 2 cm under glottis guided by fiberoptic bronchoscope through i-gel ventilation conduit in group LE. The perioperative incidence of i-gel leakage, the changes of systolic blood pressure (SBP) and heart rate (HR) following artificial airway insertion, and adverse events were recorded. Perioperative i-gel leakage was observed in 7 of 48 patients (14.6%) in group L and 1 of 49 patients (2.0%) in group LE. There was significant difference in the incidence of leakage between the 2 groups (P = .031). SBP and HR after ET insertion in group LE increased significantly compared to those in group L (P < .05/5). The values of both SBP and HR after ET insertion did not exceed the basic values in group LE (P > .05/4). There were no significant differences in the incidence and severity of postoperative sore pain and hoarseness, cough during i-gel and ET removal between the 2 groups (P > .05). Placing the anterior end of ET at the glottis reduced LMA air leakage related to glottic contraction and closure in non-minor surgery. The ET placing had low stress response and did not significantly increase postoperative complications.

Identifying PTSD sex-based patterns through explainable artificial intelligence in biometric data

Post-Traumatic Stress Disorder (PTSD) is a mental health condition that arises from exposure to traumatic events, affecting various aspects of human well-being. The complexity and variability of symptoms pose challenges for accurate diagnosis and monitoring, exacerbated by accessibility barriers. In response, alternative methodologies leveraging biometric data have emerged, such as facial movements, speech, or voice-to-text transcriptions, and analyzing them using Explainable Artificial Intelligence (XAI) techniques. Numerous studies have explored the presence or absence of PTSD, yet few have concentrated on either explicable indicators or distinctions among these indicators, such as the patient’s sex. This research used an XAI algorithm to identify patterns related to PTSD in three biometric data sets: facial movements, speech, and voice-to-text transcriptions. Such biometric data are grouped by sex. Utilizing the DAIC-WOZ database, this study involves feature selection and characterization. Experiment configurations addressed participant segmentation, feature reduction, and standardization. Training phases employed machine-learning classification algorithms with their corresponding performance evaluation. The interpretability stage explored the relationship between input features and class output. The findings reveal that among the three biometric data sets evaluated in this work (facial movements, speech, and voice-to-text transcriptions), speech characterization is the most effective in identifying PTSD indicators, suggesting a uniform speech pattern associated with breathy and tense voice and weak phonation in PTSD patients. Sex-specific analysis enhances prediction performance, revealing distinctions in the associated speech features. The Women’s model prioritizes tense voice and vocal volume variations, reduced glottal closure, and interrupted phonation. Conversely, the Speech-Men model reflects reduced resonance, making the voice thinner and weaker, indicating altered vocal quality. As for facial movements, sex-specific characteristics are not evident, but some features focused on lips are associated with PTSD. Similarly, PTSD is related to alertness, determination, and anxiety in both women and men. In conclusion, using an XAI algorithm to differentiate sex-based patterns in biometric data contributes to a better understanding of PTSD indicators, offering potential advancements in personalized diagnostic strategies.

Vocal Fold Injury Produces Similar Biomechanical Outcomes in Male and Female Rabbits

Sex differences in response to trauma and physiologic stressors have been identified in numerous organ systems but have not yet been defined in the larynx. The objective of this study was to develop an endoscopic vocal fold injury model in rabbits and to compare structural and functional outcomes between male and female subjects. Basic science study. Two male and two female rabbits underwent unilateral endoscopic cordectomy. Animals were intubated with a size 3-0 neonatal endotracheal tube, and laryngoscopy was performed with a 4mm Hopkins rod telescope. While visualizing, a 2mm cupped forceps grasped and resected the mid-membranous portion of the right true vocal fold. Larynges were then harvested after 8weeks. Excised larynx phonation with high-speed videography and kymography was used to assess vibrational quality. Tissue elastic (Young's) modulus was measured by indentation. Injured larynges phonated with fundamental frequencies between 237-415Hz. In both males and females, the scarred vocal fold exhibited an increased Young's modulus compared to the contralateral nonoperated vocal fold. There were no notable differences in glottal closure pattern or vocal fold oscillation symmetry between sexes. We have demonstrated a model for vocal fold scarring in rabbits. Vibrational and structural outcomes were similar between the examined male and female larynges.

Exploring Biomechanical Correlates in Voice Analysis of Multiple Sclerosis Patients.

The predominant alterations in voice of patients with multiple sclerosis (MS) are phonatory instability, vocal asthenia and roughness, shortness of breath, hypophonia, and hypernasality. However, research on alterations of acoustic parameters has few studies and disparate results. The objective of this study was to investigate voice disturbances in patients with MS, both with objective measures (analysis of biomechanical) and subjective measures (scales and questionnaires). This is an experimental study with a total of 20 participants with MS. Voice samples were collected, and biomechanical correlates were analyzed through the Clinical Voice Systems program, Online Lab App. The VHI-30 (Voice Handicap Index) questionnaire, the GRBAS (grade, roughness, breathiness, asthenia, strain) scale, and the Hospital Anxiety and Depression Scale were used as subjective measures. Ninety-five percentages of participants feel and describe dysphonic difficulties. Self-perception of vocal disability correlated with auditory vocal perceptual analysis in the sample of women. The biomechanical parameters showed alterations in the strength of the glottic closure, the efficiency index, and the structural imbalance index.

Utility of Ultrahigh-Resolution Computed Tomography for Laryngeal Reconstructive Surgery.

Unilateral vocal fold paralysis (UVFP) presents as incomplete glottal closure and leads to breathy hoarseness. Various treatments, including laryngeal framework surgery (type 1 thyroplasty [TP1] and arytenoid adduction [AA]), have been devised to correct this condition. Ultrahigh-resolution computed tomography (U-HRCT) allows detailed three-dimensional imaging of the larynx, which aids our understanding of vocal fold motion disorders. This study assessed whether U-HRCT is beneficial for correct diagnosis and surgical planning. The participants were 26 UVFP patients who underwent laryngeal framework surgery (TP1 and/or AA). U-HRCT was used to measure the vocal fold volume (VFV) and level difference (LD). The need to combine AA with TP1 to obtain satisfactory surgical outcomes was evaluated by U-HRCT and various voice function tests. VFV was smaller in paralyzed folds than in unaffected folds. LD correlated strongly with voice parameters and showed high intra-rater and inter-rater reliability. The surgical outcome of the laryngeal framework surgery performed was judged to be excellent for improving voice function. Comparison of LD between the TP1 group and TP1 + AA group indicated that LD is an excellent parameter to determine the need to combine AA with TP1. These findings underscore the value of preoperative U-HRCT, especially LD, in surgical decision-making and afford insights for optimal phonosurgery and individualized intervention. Patients with LD >1.0 mm may benefit from thyroplasty with AA. 3 (case-control study) Laryngoscope, 134:4667-4673, 2024.

CO2 laser in benign vocal fold lesions: an observational study

BackgroundTo evaluate the clinical and functional outcome of patients having benign vocal fold lesions who were treated with carbon dioxide laser.MethodsFor this Study a total of 41 Patients who had hoarseness of voice and satisfied the inclusion criteria were included. A detailed medical history and a thorough ENT examination was performed. Voice evaluation was done using (G)rade, (R)oughness, (B)reathiness, (A)sthenia….weakness (S)train (GRBAS), voice handicap index (VHI), and maximum phonation time scores.ResultsAll 41 patients reported hoarseness of voice as their primary complaint, and most of them developed their symptoms gradually. The following causes seem to have contributed to the presence of hoarseness of voice: LPR in 8 patients, smoking in 25 patients, voice abuse in 14 patients, and irritation exposure in 6 patients. The most frequent lesion in 25 (60.97 percent) of the subjects was a vocal polyp. This study showed majority of patients 35 (85.4%) had posterior phonatory gap and six (14.6%) had anterior gap preoperatively. All patients had incomplete glottic closure preoperatively, whereas glottic closure was complete at first follow-up postoperatively. The mean preoperative GRBAS score in study subjects was 10.972 with an SD (standard deviation) of 2.1724 and a median of 10.000. The mean postoperative GRBAS score at six months was 0.268 with an SD of 0.4486, median 0.000, Z score − 5.618, and p value < 0.001 which is statistically significant.ConclusionPrecision, hemostasis, and minimal postoperative edema are benefits of using carbon dioxide laser. This research therefore supports the idea that benign vocal fold lesions might be successfully treated with the super-pulsed microspot carbon dioxide laser, which offers good voice outcomes.

Streamlining quantification of age‐related vocal atrophy

AbstractObjectivesAge‐related vocal atrophy (ARVA) has a significant impact on voice, communication, and quality of life. Vocal folds are bowed with incomplete glottic closure during phonation. Efficient quantification of vocal fold atrophy and collection of voice recordings in clinic remains challenging. The primary focus of this study is to describe a novel method for quantifying vocal atrophy and obtaining voice recordings in clinic among patients with ARVA.MethodsPatients with ARVA were included. Voice recordings were collected during the clinic visit, and acoustic analysis was subsequently performed. A novel mobile application was used to quantify the bowing index (BI).ResultsThe study included 10 patients with ARVA, with a mean age of 72.7 ± 6.8 years and body mass index (BMI) of 24.9 ± 2.4 kg/m2. Calculation of BI was feasible with a mean of 9.9 ± 1.8 units. On average, the audio recording took 2.6 ± 0.4 min, and subsequent analysis required 7.1 ± 1.8 min. Mean continuous speech f0 was 212.1 ± 10.1 and 134.2 ± 31.5 Hz for male and female patients, respectively. Smoothed cepstral peak prominence was 8.9 ± 1.5 dB (male) and 8.5 ± 0.3 dB (female), and maximum phonation time between male and female patients was 16.7 ± 9.8 and 13.8 ± 1.9 s, respectively.ConclusionWe present a feasible and streamlined method for quantification of vocal fold atrophy in the clinic among patients with ARVA. The accuracy and reliability of this new method are areas of ongoing investigation. Quantification of vocal atrophy may help with clinical decisions, including diagnosing vocal atrophy and tracking treatment progress. Moreover, this method may improve research data acquisition without burdening patients and clinicians with additional time‐consuming tasks.Level of evidence: 4.

Analysis of vocal fold movement characteristics in patients with laryngeal neurogenic injury

Objective:To analyze the characteristics of vocal fold movement and glottic closure in patients with laryngeal neurogenic injury. Methods:A total of 185 patients with vocal fold paralysis diagnosed by laryngeal electromyography as neurogenic damage to cricothyroid muscle, thyreoarytenoid muscle and posterior cricoarytenoid muscle were enrolled, they were divided into unilateral vocal fold paralysis group and bilateral vocal fold paralysis group, respectively, and superior laryngeal paralysis group, recurrent laryngeal nerve paralysis group and vagal nerve paralysis group according to nerve injury. The characteristics of vocal fold movement and glottic closure were analyzed under strobe laryngoscope. The qualitative evaluation of vocal fold movement was fixed vocal fold, reduced vocal fold movement and normal vocal fold movement, and the qualitative evaluation of glottic closure was glottic closure and glottic imperfection. The results were analyzed statistically. Results:The proportion of normal, reduced and fixed vocal fold motion in bilateral vocal fold paralysis group was significantly different from that in unilateral vocal fold paralysis group（P<0.05）, the composition of normal and reduced vocal fold motion in bilateral vocal fold paralysis group（47.70%） was significantly greater than that in unilateral vocal fold paralysis group（12.27%）. There was no significant difference between the proportion of glottic closure and glottic imperfecta in bilateral vocal fold paralysis group and unilateral vocal fold paralysis group（P<0.05）. The proportion of decreased vocal fold motion in superior laryngeal nerve paralysis group（50.00%） was higher than that in recurrent laryngeal nerve paralysis group（9.32%） and vagal nerve paralysis group（9.00%）. The proportion of decreased and fixed vocal fold motion in superior laryngeal nerve paralysis group, recurrent laryngeal nerve paralysis group and vagal nerve paralysis group was statistically significant（P<0.05）.There was no significant difference in glottic closure among the three groups（P<0.05）. Conclusion:Vocal fold movement characteristics of patients with laryngeal neurogenic injury were mainly vocal fold fixation, or normal or weakened vocal fold movement. There may be missed diagnosis of unilateral vocal fold paralysis in clinical practice. In half of the patients with superior laryngeal nerve palsy, vocal fold movement is characterized by vocal fold fixation.