[The key problems of diagnosis and treatment of vocal cord paralysis].

Vocal cord paralysis is a common condition that significantly impairs laryngeal function and can even be life-threatening. Over nearly a century, researchers have conducted extensive animal and clinical studies to achieve accurate diagnosis and restore laryngeal function, making significant progress. Approaches have evolved from mechanically narrowing the glottis to restore phonation, to enlarging the glottis to relieve breathing difficulties, and ultimately to the development of surgical techniques aimed at restoring vocal cord mobility, significantly advancing the field. The publication of expert consensus guidelines on the diagnosis and treatment of vocal cord paralysis has standardized the principles and technical standards for managing this condition. However, a vast amount of related knowledge-including the disease's pathogenesis, diagnostic criteria, surgical principles, and techniques-still requires broader dissemination and further refinement. Advancing this knowledge will guide clinical practice and further enhance the diagnosis and treatment of this condition in China.

[Analysis of the efficacy of non-surgical treatment mainly focus on voice therapy and it's influencing factors in patients with unilateral vocal fold paralysis].

Objective:Retrospective analysis of the efficacy and it's influencing factors of non-surgical treatment mainly focus on voice therapy for patients with unilateral vocal fold paralysis. Methods:The retrospective study includes 57 patients who were diagnosed with unilateral vocal fold paralysis and presented with hoarseness as their main complaint at the Department of Voice Medicine, Zhongshan Hospital of Xiamen University from August, 2021 to August, 2023. Judging the efficacy of non-surgical treatment mainly focus on voice therapy through changes in acoustic, aerodynamic, and laryngoscopic parameters; Analyze the relationship between patients' age, gender, duration of disease, cause of nerve injury, type of nerve injury, side of nerve injury and efficacy of non-surgical treatment. Results:After non-surgical treatment mainly focused on voice therapy, there were statistically significant differences（P<0.01） in the changes of vocal fold bow, glottal gap, glottal compression, loudness, Jitter, Shimmer, IC, and NC parameters. There is a statistically significant correlation between the duration of the disease and changes in glottal gap, Shimmer, and IC（P<0.05）, the side of nerve injury can affect changes of glottal gap and NC（P<0.05）. Conclusion:Non-surgical treatment mainly focused on voice therapy has a good efficacy on patients with unilateral vocal fold paralysis. The duration of the disease and the side of nerve injury may affect the efficacy.

Percutaneous Vocal Fold Lateralization in children - a case series of a Brazilian tertiary pediatric hospital (pediatric vocal fold lateralization cases in a Brazilian hospital).

OBJECTIVES: Percutaneous Vocal Fold Lateralization (PVFL) consists of external fixation with non-absorbable percutaneous suture of the vocal fold in a lateral position, under direct glottic visualization. The objective of this study is to determine the effectiveness of PVFL in a university pediatric hospital, as well as to describe the potential risks and complications of the surgery. METHODS: Retrospective cohort study, with data collected from electronic medical records. The study was approved by the Research Ethics Committee of the institution. Surgeries were performed with the modified Lichentenberg technique and data, and outcomes were analyzed. RESULTS: Six patients with Bilateral Vocal Fold Paralysis who underwent Percutaneous Vocal Fold Lateralization were evaluated. Three patients were male. The age at diagnosis ranged from 2 to 132 days (mean 10.5 days). The reason for investigating the upper airway was the presence of increased work of breathing and stridor. Five patients had a favorable clinical evolution, with spontaneous ventilation in room air and absence of stridor or ventilatory effort, without the need for tracheostomy. Surgical results in this series corroborate the findings of other similar cohorts, which showed Percutaneous Vocal Fold Lateralization as a safe and effective procedure in avoiding tracheostomy or allowing decannulation in children with Bilateral Vocal Fold Paralysis. CONCLUSIONS: PVFL seems to be a safe and effective procedure, but it has morbidity, due to immediate, and probably late, non-serious complications. Studies with a larger number of patients, with longer follow-up and using a controlled and randomized clinical design are needed to establish the role of PVFL in the treatment of BVFP in newborns and infants. LEVELS OF EVIDENCE: Level 4 (step 4).

Assessment of Voice Quality and Vocal Cord Paralysis After Endarterectomy.

Introduction: Recurrent laryngeal nerve palsy is a rare but important complication after endarterectomy (CEA). The impact on voice quality after this procedure is also important. The aim of the study was to assess voice quality and vocal cord function after CEA. Material and Methods: 200 patients were enrolled in the study. Inclusion criteria were indications for CEA and patient consent to the procedure. Endoscopic examination of the larynx was performed before the procedure, immediately after the procedure, on the 2nd day after the procedure, then 3 month and 6 months after the procedure. Voice was assessed by maximum phonation time (MPT), GRBAS scale, Voice Handicap Index (VHI) and the Voice-Related Quality of Life (V-RQOL) questionnaire. Results: In the study group, the results on the GRBAS scale were significantly worse and the average MPT was shorter compared to the control group. In the V-RQOL assessment, patients rated their voice as fair or good, significantly more often noticed that they had difficulty speaking loudly and being heard, and that they felt short of air when speaking. In VHI-30, the total score was significantly higher in the study group compared to the control group. Voice disorders after the procedure were reported by 68 patients, while a disorder of the recurrent laryngeal nerve was observed immediately after the procedure in 32 patients. Most vocal cord disorders were transient. Ultimately, 3% of patients were diagnosed with vocal cord paralysis. Conclusion: Cranial nerves paralysis, including the recurrent laryngeal nerve, are a common complication after CEA. Majority the paralysis is transient, but requires appropriate diagnostic and therapeutic procedures. Vocal cord evaluation is a non-invasive and widely available examination and should be performed pre- and postoperatively after all neck surgeries. The incidence of voice disorders after CEA significantly affects the quality of life of patients and requires voice rehabilitation and patient care with psychological support.

Asymmetric triangular body-cover model of the vocal folds with bilateral intrinsic muscle activation.

Many voice disorders are linked to imbalanced muscle activity and known to exhibit asymmetric vocal fold vibration. However, the relation between imbalanced muscle activation and asymmetric vocal fold vibration is not well understood. This study introduces an asymmetric triangular body-cover model of the vocal folds, controlled by the activation of bilateral intrinsic laryngeal muscles, to investigate the effects of muscle imbalance on vocal fold oscillation. Various scenarios were considered, encompassing imbalance in individual muscles and muscle pairs, as well as accounting for asymmetry in lumped element parameters. Measurements of amplitude and phase asymmetries were employed to match the oscillatory behavior of two pathological cases: unilateral paralysis and muscle tension dysphonia. The resulting simulations exhibit muscle imbalance consistent with expectations in the composition of these voice disorders, yielding asymmetries exceeding 30% for paralysis and below 5% for dysphonia. This underscores the relevance of muscle imbalance in representing phonatory scenarios and its potential for characterizing asymmetry in vocal fold vibration.

Association between obstructive sleep apnea and risk of Benign vocal fold lesions: A nationwide 9-year follow-up cohort study.

Since obstructive sleep apnea (OSA) affects various parts of the body, there has been little interest about the effect of OSA on voice. The objective of this study was to evaluate the risk of benign vocal fold lesions (BVFL) in OSA patients. This study used data from the National Health Insurance Service (NHIS) database. The study group was defined as the group diagnosed with OSA between 2008 and 2011. Non-OSA groups were selected based on propensity score (PS) matching. Incidence of BVFL among participants during the follow-up was analyzed. Cox proportional hazard regression analyses were performed to evaluate the association between OSA and incident BVFL. The HR value of the OSA group calculated by considering 8 variables indicates that the risk of developing BVFL is 79% higher than that of the control group. Further, among OSA patients, patients with a history of OP had a 35% lower risk of developing BVFL. The relationships between BVFL and 7 individual variables considered were as follows: For age, HR for the 40 to 59 years group was 1.20 (95%CI, 1.09-1.32). For sex, the HR in the female group was 1.22 (95%CI, 1.10-1.35). For residential areas, the HR values for "Seoul" 1.39 (95%CI, 1.23-1.59). In the high economic status group, the HR was 1.10 (95%CI, 1.01-1.21). This observational study indicated that OSA is associated with an increased incidence of BVFL. The incidence of BVFL increased with older age, female sex, and high SES.

A machine learning approach for vocal fold segmentation and disorder classification based on ensemble method.

In the healthcare domain, the essential task is to understand and classify diseases affecting the vocal folds (VFs). The accurate identification of VF disease is the key issue in this domain. Integrating VF segmentation and disease classification into a single system is challenging but important for precise diagnostics. Our study addresses this challenge by combining VF illness categorization and VF segmentation into a single integrated system. We utilized two effective ensemble machine learning methods: ensemble EfficientNetV2L-LGBM and ensemble UNet-BiGRU. We utilized the EfficientNetV2L-LGBM model for classification, achieving a training accuracy of 98.88%, validation accuracy of 97.73%, and test accuracy of 97.88%. These exceptional outcomes highlight the system's ability to classify different VF illnesses precisely. In addition, we utilized the UNet-BiGRU model for segmentation, which attained a training accuracy of 92.55%, a validation accuracy of 89.87%, and a significant test accuracy of 91.47%. In the segmentation task, we examined some methods to improve our ability to divide data into segments, resulting in a testing accuracy score of 91.99% and an Intersection over Union (IOU) of 87.46%. These measures demonstrate skill of the model in accurately defining and separating VF. Our system's classification and segmentation results confirm its capacity to effectively identify and segment VF disorders, representing a significant advancement in enhancing diagnostic accuracy and healthcare in this specialized field. This study emphasizes the potential of machine learning to transform the medical field's capacity to categorize VF and segment VF, providing clinicians with a vital instrument to mitigate the profound impact of the condition. Implementing this innovative approach is expected to enhance medical procedures and provide a sense of optimism to those globally affected by VF disease.

Consistency of the Signature of Phonotraumatic Vocal Hyperfunction Across Different Ambulatory Voice Measures.

PURPOSE: Although different factors and voice measures have been associated with phonotraumatic vocal hyperfunction (PVH), it is unclear what percentage of individuals with PVH exhibit such differences during their daily lives. This study used a machine learning approach to quantify the consistency with which PVH manifests according to ambulatory voice measures. Analyses included acoustic parameters of phonation as well as temporal aspects of phonation and rest, with the goal of determining optimally consistent signatures of PVH. METHOD: Ambulatory neck-surface acceleration signals were recorded over 1 week from 116 female participants diagnosed with PVH and age-, sex-, and occupation-matched vocally healthy controls. The consistency of the manifestation of PVH was defined as the percentage of participants in each group that exhibited an atypical signature based on a target voice measure. Evaluation of each machine learning model used nested 10-fold cross-validation to improve the generalizability of findings. In Experiment 1, we trained separate logistic regression models based on the distributional characteristics of 14 voice measures and durations of voicing and resting segments. In Experiments 2 and 3, features of voicing and resting duration augmented the existing distributional characteristics to examine whether more consistent signatures would result. RESULTS: Experiment 1 showed that the difference in the magnitude of the first two harmonics (H1-H2) exhibited the most consistent signature (69.4% of participants with PVH and 20.4% of controls had an atypical H1-H2 signature), followed by spectral tilt over eight harmonics (73.6% participants with PVH and 32.1% of controls had an atypical spectral tilt signature) and estimated sound pressure level (SPL; 66.9% participants with PVH and 27.6% of controls had an atypical SPL signature). Additionally, 77.6% of participants with PVH had atypical resting duration, with 68.9% exhibiting atypical voicing duration. Experiments 2 and 3 showed that augmenting the best-performing voice measures with univariate features of voicing or resting durations yielded only incremental improvement in the classifier's performance. CONCLUSIONS: Females with PVH were more likely to use more abrupt vocal fold closure (lower H1-H2), phonate louder (higher SPL), and take shorter vocal rests. They were also less likely to use higher fundamental frequency during their daily activities. The difference in the voicing duration signature between participants with PVH and controls had a large effect size, providing strong empirical evidence regarding the role of voice use in the development of PVH.

Mechanotransduction in the Vocal Fold Microenvironment: A Narrative Review.

PURPOSE: The vocal fold tissues undergo nearly continuous and repeated cycles of injury and repair throughout the course of an individual's lifetime. It is well established that certain individuals are at greater risk of lesion development based on personality and behavioral classification. However, these characteristics alone do not wholly predict or explain lesion development or severity. In this review, we discuss current knowledge of mechanotransduction proteins and their potential relevance to tissue homeostasis in the vocal folds. METHOD: A review of literature surrounding mechanotransduction and tissue homeostasis as it relates to the vocal folds was conducted. Review of the literature included searches of PubMed, Google Scholar, and other various online peer-reviewed sources. Search terms pertained to mechanosensation, mechanotransduction, mechanically activated channels, mechanical cellular regulation, and other associated concepts and terms. Additional literature was identified through the reference lists of identified papers. Findings of this literature review were then applied to known physiology and pathophysiology of the vocal folds in order to speculate on the contribution of mechanically mediated mechanisms within the vocal fold. DISCUSSION AND CONCLUSION: Because the vocal folds are such mechanically active structures, withstanding nearly constant external forces, there is strong support for the idea that mechanically sensitive molecular pathways within the vocal fold tissue play a major role in tissue homeostasis in the presence of these considerable forces. As such, mechanotransduction within the vocal fold should be considered and targeted in future biological studies of vocal fold physiology.

Seven Days of Voice Rest Post-phonosurgery Is Not Better than 3 days: A Prospective Randomized Short-term Outcome Study.

OBJECTIVE: The aim of the study is to compare the short-term effect of 7 versus 3 days of voice rest (VR) on objective vocal (acoustic) parameters following phonosurgery. METHODS: A prospective randomized study conducted at a tertiary referral medical center. Patients with vocal fold nodules, polyps, or cysts and scheduled for phonosurgery were recruited from the Voice Clinic. They were randomized into groups of 7- or 3-day postoperative VR periods and their voices were recorded preoperatively and at 4-week postoperatively. A mixed linear model statistical analysis (MLMSA) was used to compare pre- and postoperative jitter, shimmer, harmonic-to-noise ratio, and maximum phonation time between the two groups. RESULTS: Sixty-five patients were recruited, but only 34 fully complied with the study protocol, and their data were included in the final analysis (19 males, 20 females; mean age: 40.6 years; 17 patients in the 7-day VR group and 16 in the 3-day VR group). The groups were comparable in age, sex, and type of vocal lesion distribution. The preoperative MLMSA showed no significant group differences in the tested vocal parameters. Both groups exhibited significant (p < 0.05) and comparable improvement in all vocal parameters at postoperative week 4. CONCLUSIONS: A VR duration of 7 days showed no greater benefit on the examined vocal parameters than the 3-day protocol 4-week postoperatively. Our results suggest that a 3-day VR regimen can be followed by patients who undergo phonosurgery without compromising the vocal results. Larger-scale and longer-duration studies are needed to confirm our findings. LEVEL OF EVIDENCE: 2 Laryngoscope, 134:4661-4666, 2024.

Long-term stimulation by implanted pacemaker enables non-atrophic treatment of bilateral vocal fold paresis in a human-like animal model.

A wide variety of treatments have been developed to improve respiratory function and quality of life in patients with bilateral vocal fold paresis (BVFP). One experimental method is the electrical activation of the posterior cricoarytenoid (PCA) muscle with a laryngeal pacemaker (LP) to open the vocal folds. We used an ovine (sheep) model of unilateral VFP to study the long-term effects of functional electrical stimulation on the PCA muscles. The left recurrent laryngeal nerve was cryo-damaged in all animals and an LP was implanted except for the controls. After a reinnervation phase of six months, animals were pooled into groups that received either no treatment, implantation of an LP only, or implantation of an LP and six months of stimulation with different duty cycles. Automated image analysis of fluorescently stained PCA cross-sections was performed to assess relevant muscle characteristics. We observed a fast-to-slow fibre type shift in response to nerve damage and stimulation, but no complete conversion to a slow-twitch-muscle. Fibre size, proportion of hybrid fibres, and intramuscular collagen content were not substantially altered by the stimulation. These results demonstrate that 30 Hz burst stimulation with duty cycles of 40% and 70% did not induce PCA atrophy or fibrosis. Thus, long-term stimulation with an LP is a promising approach for treating BVFP in humans without compromising muscle conditions.

Bilateral Vocal Fold Abduction Dysfunction: A Report of Two Neonatal Cases.

Stridor is caused by oscillation of the narrowed upper airway. The most common cause of neonatal stridor is laryngomalacia, followed by vocal fold abduction dysfunction. Herein, we present two neonatal cases of idiopathic dysfunction of vocal fold abduction. A neonate was admitted to the neonatal intensive care unit (NICU) on day 4 of life for inspiratory stridor, intermittent subcostal retraction, and cyanosis. A second neonate was admitted to the NICU on day 7 of life for inspiratory stridor and cyanosis when crying. Neither patient had dysmorphic features or unusual cardiac ultrasonography findings. The diagnosis was confirmed by laryngo-bronchoscopy. Conservative treatment with biphasic positive airway pressure was effective in both cases and symptoms resolved within a few months. Resolution of vocal fold abduction dysfunction was confirmed by repeat endoscopy. Clinical manifestations of vocal fold abduction dysfunction vary widely. Although most cases resolve spontaneously, prolonged tube feeding, or even tracheostomy, is needed in some severe cases. Diagnosis of vocal fold abduction dysfunction requires a laryngo-bronchoscopy study; thus, there may be a large number of undiagnosed patients. Vocal fold abduction dysfunction should be considered in the differential diagnosis for neonatal inspiratory stridor.

Prospective Outcomes of Microlaryngoscopy Versus Office Laser Photoangiolysis for Vocal Fold Polyps.

OBJECTIVE(S): The objective of this study is to compare treatment outcomes for vocal fold polyps (VFPs) between operating room microlaryngoscopy and office-based photoangiolysis with the potassium titanyl phosphate (KTP) laser. METHODS: Prospective nonrandomized cohort study of patients with VFPs undergoing microlaryngoscopy ("OR group") or KTP laser photoangiolysis ("KTP group"). Voice outcomes (patient-reported outcome measures [Voice Handicap Index-10 (VHI-10) and Singing VHI-10 (SVHI-10)], auditory-perceptual measures [Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V)], videostroboscopic characteristics [Voice-Vibratory Assessment of Laryngeal Imaging (VALI)], and acoustic and aerodynamic measures) were performed at baseline and regular intervals after intervention. RESULTS: Forty-four subjects (17 OR group, 27 KTP group) with VFPs were enrolled. Mean VHI-10 significantly improved from baseline to each follow-up interval in both groups, except for the 1-2-week interval in the OR group. Mean SVHI-10 improved for both groups at some intervals. Growth curve models and time-to-event analyses for patient-reported outcomes did not differ between groups. There were significant improvements in all categories of auditory-perceptual voice quality and some categories of videostroboscopic characteristics in both groups. No significant trends were identified in acoustic and aerodynamic measures. Improvements in most outcomes did not significantly differ between groups or based on polyp size. There were no major complications. CONCLUSIONS: Significant improvements in patient-reported voice outcomes measures, auditory-perceptual voice evaluation, and videostroboscopic characteristics occur following surgical treatment of vocal fold polyps with either microlaryngoscopy or office-based KTP laser. Long-term voice outcomes do not significantly differ between treatment modalities. LEVEL OF EVIDENCE: 3 Laryngoscope, 134:S1-S20, 2024.

Investigation of the Position and Angle of the Vocal Fold Projected onto the Thyroid Cartilage.

OBJECTIVE: To perform laryngeal framework surgery for unilateral vocal fold paralysis and obtain favorable voice improvement, it is necessary to accurately determine the vocal fold and arytenoid cartilage positions. Thus, the position and angle of the paralyzed vocal folds and arytenoid cartilage projected onto the affected thyroid plate were measured using computed tomography (CT) before and after surgery. METHODS: Forty-six male patients with thyroid cartilage ossification observed on preoperative CT and vocal fold paralysis were included. Using Adobe Illustrator®, the thyroid plate on the affected side was reconstructed from the continuous images of the sagittal section of the CT examination during participant's quiet breathing (reconstructed affected thyroid plate [RATP]). RESULTS: The anterior commissure mean position was slightly cranial to the midpoint of the thyroid cartilage midline. The paralyzed vocal fold angle was not parallel to the baseline. The average unaffected vocal fold angle during vocalization projected onto the affected thyroid plate was 13.83°, which differed significantly from the average paralyzed vocal fold angle before surgery (19.05°). However, no significant difference was observed in comparison with the average angle of the paralyzed vocal fold after arytenoid adduction. The average distance from the inferior notch of the affected side thyroid cartilage to the affected arytenoid cartilage was 16.7 mm. CONCLUSION: By understanding the positional relationship between the thyroid cartilage plate and internal structure from preoperative CT images, more effective surgery can be performed according to individual differences. LEVEL OF EVIDENCE: IV Laryngoscope, 134:4088-4094, 2024.

Does forced whisper have an impact on voice parameters?

OBJECTIVES: There has been the assumption that whispering may impact vocal function, leading to the widespread recommendation against its practice after phonosurgery. However, the extent to which whispering affects vocal function and vocal fold oscillation patterns remains unclear. METHODS: 10 vocally healthy subjects (5 male, 5 female) were instructed to forcefully whisper a standardized text for 10 min at a sound level of 70 dB(A), measured at a microphone distance of 30 cm to the mouth. Prior to and following the whisper loading, the dysphonia severity index was assessed. Simultaneously, recordings of high speed videolaryngoscopy (HSV), electroglottography, and audio signals during sustained phonation on the vowel /i/ (250 Hz for females and 125 Hz for males) were analyzed after segmentation of the HSV material. RESULTS: The pre-post analysis revealed only minor changes after the intervention. These changes included a rise in minimum intensity, an increase in the glottal area waveform-derived open quotient, and the glottal gap index. However, no statistically significant changes were observed in the harmonic-to-noise-ratio, the glottal- to-noise-excitation-ratio, and the electroglottographic open quotient. CONCLUSION: Overall, the study suggests that there are only small effects on vocal function in consequence of a forced whisper loading.

Effects of Speech Characteristics on Electroglottographic and Instrumental Acoustic Voice Analysis Metrics in Women With Structural Dysphonia Before and After Treatment.

PURPOSE: Literature suggests a dependency of the acoustic metrics, smoothed cepstral peak prominence (CPPS) and harmonics-to-noise ratio (HNR), on human voice loudness and fundamental frequency (F0). Even though this has been explained with different oscillatory patterns of the vocal folds, so far, it has not been specifically investigated. In the present work, the influence of three elicitation levels, calibrated sound pressure level (SPL), F0 and vowel on the electroglottographic (EGG) and time-differentiated EGG (dEGG) metrics hybrid open quotient (OQ), dEGG OQ and peak dEGG, as well as on the acoustic metrics CPPS and HNR, was examined, and their suitability for voice assessment was evaluated. METHOD: In a retrospective study, 29 women with a mean age of 25 years (± 8.9, range: 18-53) diagnosed with structural vocal fold pathologies were examined before and after voice therapy or phonosurgery. Both acoustic and EGG signals were recorded simultaneously during the phonation of the sustained vowels /ɑ/, /i/, and /u/ at three elicited levels of loudness (soft/comfortable/loud) and unconstrained F0 conditions. RESULTS: A linear mixed-model analysis showed a significant effect of elicitation effort levels on peak dEGG, HNR, and CPPS (all p < .01). Calibrated SPL significantly influenced HNR and CPPS (both p < .01). Furthermore, F0 had a significant effect on peak dEGG and CPPS (p < .0001). All metrics showed significant changes with regard to vowel (all p < .05). However, the treatment had no effect on the examined metrics, regardless of the treatment type (surgery vs. voice therapy). CONCLUSIONS: The value of the investigated metrics for voice assessment purposes when sampled without sufficient control of SPL and F0 is limited, in that they are significantly influenced by the phonatory context, be it speech or elicited sustained vowels. Future studies should explore the diagnostic value of new data collation approaches such as voice mapping, which take SPL and F0 effects into account.

Classification of laryngeal diseases including laryngeal cancer, benign mucosal disease, and vocal cord paralysis by artificial intelligence using voice analysis.

Voice change is often the first sign of laryngeal cancer, leading to diagnosis through hospital laryngoscopy. Screening for laryngeal cancer solely based on voice could enhance early detection. However, identifying voice indicators specific to laryngeal cancer is challenging, especially when differentiating it from other laryngeal ailments. This study presents an artificial intelligence model designed to distinguish between healthy voices, laryngeal cancer voices, and those of the other laryngeal conditions. We gathered voice samples of individuals with laryngeal cancer, vocal cord paralysis, benign mucosal diseases, and healthy participants. Comprehensive testing was conducted to determine the best mel-frequency cepstral coefficient conversion and machine learning techniques, with results analyzed in-depth. In our tests, laryngeal diseases distinguishing from healthy voices achieved an accuracy of 0.85-0.97. However, when multiclass classification, accuracy ranged from 0.75 to 0.83. These findings highlight the challenges of artificial intelligence-driven voice-based diagnosis due to overlaps with benign conditions but also underscore its potential.

[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.