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.

[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.

A Retrospective Study of Acoustic Measures of Glottal Stop Production to Assess Vocal Function in Unilateral Vocal Fold Paresis/Paralysis Patients.

PURPOSE: The aim of this study was to determine (a) diagnostic accuracy of acoustic measures of glottal stop production (GSP; intensity differences, slopes, complete voicing cessation) to distinguish between unilateral vocal fold paresis/paralysis (UVFP) patients and controls; (b) if acoustic measures of GSP significantly correlated with an acoustic measure of voice disorder severity, acoustic voice quality index (AVQI); and (c) if acoustic measures from another type of voicing cessation, voiceless consonant production, also significantly differed between groups. METHOD: Ninety-seven patients with unilateral paresis/paralysis and 35 controls with normal laryngostroboscopic signs produced two sets of five repeated [i] and four repeated [isi]. Tokens were randomized by type between groups and analyzed blinded using a customized Praat program that computed intensity differences and slopes between vowel maxima and glottal stop minima for inter-[i] tokens and vowel maxima and voiceless consonant minima for intra-[isi] tokens. The number of voicing cessations for inter-[i] tokens was obtained. RESULTS: Onset and offset intensity differences and number of voicing cessations from inter-[i] tokens had the greatest areas under the curve (.854, .856, and .835, respectively). Correlation coefficients were significant (p < .01) between AVQI and all GSP acoustic measures with weak/medium effect sizes. No significant differences were found between controls and participants with UVFP for acoustic measures from intra-[isi]. CONCLUSIONS: Acoustic GSP measures demonstrated good diagnostic accuracy and some relationship to severity of voice disorder. No significant differences in acoustic measures for medial voiceless fricative consonants between controls and participants with UVFP suggested that voicing cessation for voiceless fricatives differs from voicing cessation for GSP.

Dysphagia as a predictor of voice handicap and voice restoration in unilateral vocal fold immobility.

OBJECTIVE: Dysphagia is multifactorial in unilateral vocal fold immobility (UVFI). Severe dysphagia could indicate greater functional deficits in UVFI. The purpose of this study is to evaluate the association of dysphagia with the need for surgical voice restoration in patients with UVFI. STUDY DESIGN: Retrospective chart review. SETTING: Single-institution, tertiary referral center. METHODS: Records of UVFI patients from 2008 to 2018 were examined. Dysphagia severity was extracted from patient history. Etiology of UVFI and other relevant variables were analyzed to determine their association with dysphagia. Dysphagia severity and other clinical variables were then analyzed for their association with surgical voice restoration. RESULTS: Eighty patients met selection criteria out of 478 patients with UVFI. There was significant concordance between dysphagia severity extracted from patient history and patient-reported EAT-10 scores (R = 0.59, p = 0.000035). Patients' EAT-10 scores were correlated with VHI-10 scores (R = 0.45, p = 0.011). Severe dysphagia (p = 0.037), high VHI-10 score on presentation (p = 0.0009), and longer duration of hoarseness before presentation (p = 0.008) were associated with surgical voice restoration in UVFI patients. CONCLUSION: In this pilot study, severe dysphagia and increased voice handicap on presentation were associated with the need for surgical voice restoration in UVFI patients. Presenting dysphagia may be an additional variable for clinicians to consider for management of UVFI.

Noticeable effect of lower baseline amplitude on the predictive accuracy of intraoperative amplitude changes for postoperative vocal cord palsy: a prospective cohort study.

BACKGROUND: To explore the effect of lower baseline amplitude on its predictive accuracy of postoperative vocal cord paralysis (VCP) in monitored thyroid surgery. MATERIALS AND METHODS: Clinical and electrophysiological data were collected during thyroid surgeries performed between November and December 2021 at China-Japan Union Hospital. Univariate/multivariate regression analysis were applied to these data to examine a possible correlation. A receiver operating characteristic curve was used to evaluate predictive efficacy. RESULTS: A total of 631 nerves-at-risk (NAR) were identified in 460 patients who were divided into two groups according to postoperative development of VCP. The VCP group included a higher percentage of NAR with V1<1000 (68.2 vs. 40.7%, respectively; P =0.014) and NAR with R1<1400 (77.3 vs. 47.0%, respectively; P =0.005) compared with the non-VCP group. Multivariate regression analysis further identified V1<1000 [odds ratio (OR)=2.688, P =0.038], R1<1400 (OR=3.484, P =0.018) as independent risk factors for postoperative temporary VCP. The receiver operating characteristic curve showed the AUC value of V signal decline for predicting VCP was 0.87. The diagnostic efficiency of R signal decline reached as high as 0.973. A multivariate logistic regression analysis identified independent risk factors for V1<1000 and these included: higher BMI (OR=1.072, P =0.013), hypertension (OR=1.816, P =0.015), smoking (OR=1.814, P =0.031), and male sex (OR=2.016, P =0.027). CONCLUSION: In our cohort, lower baseline amplitude was an independent risk factor for developing transient postoperative VCP. It also affected the predictive efficacy of intraoperative amplitude changes on VCP. Higher BMI, hypertension, smoking, and male sex may also be closely associated with lower initial amplitude. Thus, maintaining a higher initial amplitude is critical for patient safety during thyroid surgery.

Comparison of 24-month voice outcomes after injection laryngoplasty with calcium hydroxylapatite or hyaluronic acid in patients with unilateral vocal fold paralysis.

PURPOSE: The objective was to evaluate the long-term voice outcomes in pa-tients with unilateral vocal fold paralysis treated with injection laryngoplasty using either cal-cium hydroxylapatite (CaHA) or hyaluronic acid (HA). METHODS: A single-centre retrospective study was performed. There were 75 patients with dysphonia due to unilateral vocal fold paralysis: injected with CaHA or injected with HA. We analysed Voice Handicap Index-30 (VHI), videostroboscopic images, auditory-perceptual (GRBAS), and acoustic measures (MDVP) in 6, 12, and 24 months after augmentation. RESULTS: The mean change in VHI 24 months after augmentation was 29.14 in the CaHA group, and 22.88 in the HA group. There was an improvement of glottal gap 6, 12, and 24 months after augmentation in both groups. The GRBAS parameters were similar in both groups throughout the whole period. The MDVP pa-rameters decreased 6 and 12 months after augmentation and were similar in both groups. There were 4 patients augmented with CaHA (12.5%) who needed reintervention within 2 years of surgery and another 4 (9.3%) augmented with HA. CONCLUSION: This study demonstrates that there are no long-term differences in voice outcomes or number of reaugmentations for injection laryn-goplasty with CaHA compared to HA.

Cord medialisation in unilateral vocal fold paralysis improves forced vital capacity.

OBJECTIVES: The lateralised vocal fold of unilateral vocal fold paralysis (ULVFP) is unphysiological for expiration wherein vocal folds normally adduct to increase expiratory resistance and prevent small airway collapse. ULVFP may therefore impair ventilatory function and ventilatory volume. This study seeks to test whether vocal fold medialisation improves forced vital capacity (FVC). DESIGN: Prospective inception cohort intervention study. SETTING: Academic Tertiary Care Institution. PARTICIPANTS: Twenty-five patients of ULVFP with a phonatory gap ranging from 2 to 6 mm. MAIN OUTCOME MEASURES: Vocal fold medialisation was undertaken with autologous fat injection. Forced vital capacity (FVC) assessments by spirometry were undertaken pre-treatment and 1-month post-treatment. RESULTS: Improvement in FVC was noted in all patients with the quantum of improvement ranging from 0.1 to 0.6 litres. Mean FVC improved from 3.10 L pre-injection to 3.45 L post-injection. (p < .001). A moderate correlation was noted between the degree of medialisation and improvement in FVC (r = .33, Pearson's correlation coefficient). CONCLUSIONS: Objective improvement in FVC is consistently noted in post vocal fold medialisation for ULVFP and is probably mediated by increased glottic expiratory resistance and consequent improvement in intrinsic PEEP.

New Developments in Anterior Laryngeal Recording Technique During Neuromonitored Thyroid and Parathyroid Surgery.

A recurrent laryngeal nerve (RLN) injury resulting in vocal fold paralysis and dysphonia remains a major source of morbidity after thyroid and parathyroid surgeries. Intraoperative neural monitoring (IONM) is increasingly accepted as an adjunct to the standard practice of visual RLN identification. Endotracheal tube (ET) surface recording electrode systems are now widely used for IONM; however, the major limitation of the clinical use of ET-based surface electrodes is the need to maintain constant contact between the electrodes and vocal folds during surgery to obtain a high-quality recording. An ET that is malpositioned during intubation or displaced during surgical manipulation can cause a false decrease or loss of electromyography (EMG) signal. Since it may be difficult to distinguish from an EMG change caused by a true RLN injury, a false loss or decrease in EMG signal may contribute to inappropriate surgical decision making. Therefore, researchers have investigated alternative electrode systems that circumvent common causes of poor accuracy in ET-based neuromonitoring. Recent experimental and clinical studies have confirmed the hypothesis that needle or adhesive surface recording electrodes attached to the thyroid cartilage (transcartilage and percutaneous recording) or attached to the overlying neck skin (transcutaneous recording) can provide functionality similar to that of ET-based electrodes, and these recording methods enable access to the EMG response of the vocalis muscle that originates from the inner surface of the thyroid cartilage. Studies also indicate that, during surgical manipulation of the trachea, transcartilage, percutaneous, and transcutaneous anterior laryngeal (AL) recording electrodes could be more stable than ET-based surface electrodes and could be equally accurate in depicting RLN stress during IONM. These findings show that these AL electrodes have potential applications in future designs of recording electrodes and support the use of IONM as a high-quality quantitative tool in thyroid and parathyroid surgery. This article reviews the major recent developments of newly emerging transcartilage, percutaneous, and transcutaneous AL recording techniques used in IONM and evaluates their contribution to improved voice outcomes in modern thyroid surgery.

Value of Neurostimulation Plus Laryngeal Palpation to Predict Postoperative Vocal Fold Motility.

BACKGROUND: The aim of this study was to evaluate the reliability of intraoperative neuromonitoring through recurrent laryngeal nerve stimulation and simultaneous laryngeal palpation (NSLP) in predicting postoperative vocal cord palsy and in providing useful information in the decision to perform a staged surgery in initially planned total thyroidectomy. MATERIALS AND METHODS: A retrospective review was performed involving 552 patients for whom a total thyroidectomy was planned. In all patients, preoperative and postoperative laryngoscopy was performed. The incidence of vocal cord palsy was calculated on 1104 nerves at risk. RESULTS: Sensitivity and specificity of NSLP were 0.9411 and 0.9925 respectively. The positive predictive value was 0.7804, the negative predictive value was 0.9981, the false positive rate was 0.8%. In 41 patients (7.4%) the initial surgical strategy was changed into a staged procedure. Nine patients (21.9%) were false positive, 32 patients (78.1%) were true positive. Finally, a two-stage thyroidectomy was performed in 27 of 41 patients. CONCLUSIONS: High sensitivity and specificity confirm the validity of NSLP in predicting postoperative vocal cord palsy and in driving a possible staged thyroidectomy, both in benign thyroid disease and in differentiated thyroid carcinoma.

Perceptual Evaluation of Vocal Fold Vibratory Asymmetry.

OBJECTIVES: Laryngeal vibratory asymmetry occurring with paresis may result in a perceptually normal or abnormal voice. The present study aims to determine the relationships between the degree of vibratory asymmetry, acoustic measures, and perception of sound stimuli. STUDY DESIGN: Animal Model of Voice Production, Perceptual Analysis of Voice. METHODS: In an in vivo canine model of phonation, symmetric and asymmetric laryngeal vibration were obtained via graded unilateral recurrent laryngeal nerve (RLN) stimulation simulating near paralysis to full activation. Phonation was performed at various contralateral RLN and bilateral superior laryngeal nerve stimulation levels. Naïve listeners rated the perceptual quality of 182 unique phonatory samples using a visual sort-and-rate task. Cepstral peak prominence (CPP) was calculated for each phonatory condition. The relationships among vibratory symmetry, CPP, and perceptual ratings were evaluated. RESULTS: A significant relationship emerged between RLN stimulation and perceptual rating, such that sound samples from low RLN levels were preferred to those from high RLN levels. When symmetric vibration was achieved at mid-RLN stimulation, listeners preferred samples from symmetric vibration over those from asymmetric vibration. However, when symmetry was achieved at high RLN levels, a strained voice quality resulted that listeners dispreferred over asymmetric conditions at lower RLN levels. CPP did not have a linear relationship with perceptual ratings. CONCLUSIONS: Laryngeal vibratory asymmetry produces variable perceptual differences in phonatory sound quality. Though CPP has been correlated with dysphonia in previous research, its complex relationship with quality limits its usefulness as clinical marker of voice quality perception. LEVEL OF EVIDENCE: NA, basic science Laryngoscope, 131:2740-2746, 2021.

Pediatric Vocal Fold Paresis and Paralysis: A Narrative Review.

Importance: Vocal fold paralysis (VFP) results from the disruption of neural motor outputs to laryngeal muscles. Children with VFP manifest various degrees of difficulties in phonation, breathing, and swallowing. Although the etiologic characteristics and symptoms of VFP are well established in adults, corresponding clinical profiles are notably different in children. Clinical management of VFP is particularly challenging in children because their larynges are still actively developing and the recovery of disrupted laryngeal nerves is often unpredictable. This review discusses the neurologic conditions and diagnostic and treatment considerations in pediatric VFP. Observations: Injury to the peripheral laryngeal nerves and certain central nervous system diseases, such as Arnold-Chiari malformation type II, can result in VFP in infants and children. The incidence of unilateral vs bilateral VFP is variable across pediatric studies. Most reported VFP cases are associated with injury of the recurrent laryngeal nerve. Laryngeal electromyography requires needle insertion that must be performed under anesthesia with special care in the pediatric setting. Neither normative values nor standardized procedures of laryngeal electromyography are currently established for the pediatric population. Laryngeal reinnervation, endoscopic arytenoid abduction lateropexy, and laryngeal pacing are plausible treatment options for pediatric VFP. Despite these new advances in the field, no corresponding efficacy data are available for clinicians to discern which type of patients would be the best candidates for these procedures. Conclusions and Relevance: The neuroanatomy and neurophysiology of VFP remain more elusive for the pediatric population than for adults. Basic and clinical research is warranted to fully comprehend the complexity of this laryngeal movement disorder and to better inform and standardize clinical practice.

Vocal fold injection material does not preclude interpretation of laryngeal electromyography.

INTRODUCTION/AIMS: Temporary vocal fold injection (VFI) is a common treatment for acute and subacute vocal fold paralysis (VFP). Laryngeal electromyography (LEMG) is useful for diagnosing neurogenic causes of VFP. This study evaluated whether the presence of VFI material prevents interpretation of LEMG in patients with acute and subacute VFP. METHODS: Patients with acute and subacute unilateral VFP (onset ≤6 mo) who underwent temporary VFI within 3 mo preceding LEMG were evaluated. A matched control group that did not undergo VFI was also studied. The LEMG team (laryngologist and electromyographer) performed and interpreted LEMG using a pre-specified protocol, including qualitative and quantitative motor unit analysis. RESULTS: Eighteen patients with VFI underwent LEMG successfully with interpretation of spontaneous activity and motor unit recruitment. Fourteen patients were seen in follow-up to determine accuracy of established LEMG prognosis. Seven of seven subjects with poor LEMG prognosis did not recover vocal fold motion. Five of seven subjects with fair LEMG prognosis recovered vocal fold motion. Findings were similar for the control group. DISCUSSION: VFI augmentation material did not prevent interpretation of meaningful LEMG data in patients with acute and subacute VFP, and accurate prognoses of vocal fold motion recovery were established.

Quantitative laryngeal electromyography (LEMG) in unilateral vocal fold paralysis: Developing normative values using the opposite normal mobile vocal fold.

OBJECTIVE: Laryngeal electromyography (LEMG) is used to confirm neuropathy; traditionally, it is evaluated qualitatively. This study aimed to develop normative values for the thyroarytenoid-lateral cricoarytenoid (TA-LCA) muscle complex by determining the mean turns (MT) and mean amplitudes (MA) using the opposite normal mobile vocal fold in unilateral vocal fold paralysis (VFP). This study also compared the MT and MA of the paralyzed vocal fold with that of the normal side and analyzed their correlations. METHODS: This is a cross-sectional study in which 77 patients (18 males, 59 females, mean age of 48) with unilateral VFP with an opposite normal mobile vocal fold underwent LEMG with a standardized protocol. Koufman gradings and MT and MA were used for the qualitative and quantitative evaluations. Mann-Whitney U test was performed to compare the median of the turns and amplitudes between the opposite normal mobile vocal fold and the paralyzed side. A linear-scale graphical "cloud" of the normal TA-LCA muscle complex was generated using logarithmic regression analysis. The qualitative and quantitative parameters were analyzed using multiple analysis of variance and Kruskall-Wallis test. Post-hoc analysis was performed to further determine the differences of the significance between both parameters. The correlation between the qualitative and quantitative parameters was analyzed using Spearman correlation. RESULTS: The MT and MA were significantly higher for the normal TA-LCA muscle complex than the paralyzed side (582 vs. 336; 412 vs. 296, respectively) and the median of the turns and amplitudes were significantly lower in the paralyzed side with p-values <0.001. A significant difference was observed between the Koufman grading and the combination of MT and MA [F (8,144) = 73.254] and between the Koufman grading and MT and MA individually [H (4, 72) = 18.3 and H (4, 72) =33.4], in which both had p-values <0.001. A moderate negative linear relationship was seen between the Koufman grading and MT and MA. On further analysis, it was revealed that only certain pairs of Koufman grading were statistical significant. CONCLUSIONS: This study was the first to present the quantitative normative values and "cloud" of the TA-LCA muscle complex using the opposite normal mobile vocal fold in patients with unilateral VFP in which it is comparable to healthy controls. We concluded that quantitative LEMG supports the qualitative Koufman grading method however it cannot be used independently to determine the severity of neuropathy.

Different types of dysphagia alleviated by the chin-down position.

OBJECTIVE: Retrospective videofluoroscopic swallowing study (VFSS) evaluations of pharyngeal swallowing were used to evaluate the types of dysphagia alleviated by the chin-down maneuver. MATERIALS AND METHODS: The study population consisted of 64 patients who underwent VFSS evaluations during neutral and chin-down maneuvers presenting specifically penetration or aspiration. The assessment of the VFSS movie clips of each maneuver was performed using parameters of the Modified Barium Swallow Impairment Profile (MBSImP) and the presence and degree of airway invasion(PDAI) by three blinded raters in the following five subcategorized groups, 1. patietns presenting penetration or aspiration during swallow 2. after swallow, patients of 3. head and neck, 4. digestive and 5. neuromuscular disorders, respectively. The scores registered for the two maneuvers were statistically compared. Additionally, we examined statistically which factors had the impact on the improvement of the PDAI using fisher's exact test. RESULTS: Compared with the neutral position, PDAI, pharyngeal constriction, anterior hyoid movement, pharyngeal constriction, laryngeal elevation, laryngeal closure, upper esophageal sphincter opening, initiation of the pharyngeal swallow, and pharyngeal clearance in pyriform sinus were significantly (p < 0.01-0.05) improved with the chin-down maneuver. In a subcategory comparison with group 1, 3 and 4, the PDAI improved significantly (p < 0.01) with the chin-down maneuver, in which laryngeal elevation and laryngeal closure had statistically the impact (p < 0.01-0.05) on improvement of PDAI. CONCLUSION: The chin-down maneuver was most effective in improving swallow function when the impairment included penetration and aspiration during swallow caused by inadequate laryngeal elevation and laryngeal closure.

Application of a Computer Vision Tool for Automated Glottic Tracking to Vocal Fold Paralysis Patients.

OBJECTIVES: (1) Demonstrate true vocal fold (TVF) tracking software (AGATI [Automated Glottic Action Tracking by artificial Intelligence]) as a quantitative assessment of unilateral vocal fold paralysis (UVFP) in a large patient cohort. (2) Correlate patient-reported metrics with AGATI measurements of TVF anterior glottic angles, before and after procedural intervention. STUDY DESIGN: Retrospective cohort study. SETTING: Academic medical center. METHODS: AGATI was used to analyze videolaryngoscopy from healthy adults (n = 72) and patients with UVFP (n = 70). Minimum, 3rd percentile, 97th percentile, and maximum anterior glottic angles (AGAs) were computed for each patient. In patients with UVFP, patient-reported outcomes (Voice Handicap Index 10, Dyspnea Index, and Eating Assessment Tool 10) were assessed, before and after procedural intervention (injection or medialization laryngoplasty). A receiver operating characteristic curve for the logistic fit of paralysis vs control group was used to determine AGA cutoff values for defining UVFP. RESULTS: Mean (SD) 3rd percentile AGA (in degrees) was 2.67 (3.21) in control and 5.64 (5.42) in patients with UVFP (P < .001); mean (SD) 97th percentile AGA was 57.08 (11.14) in control and 42.59 (12.37) in patients with UVFP (P < .001). For patients with UVFP who underwent procedural intervention, the mean 97th percentile AGA decreased by 5 degrees from pre- to postprocedure (P = .026). The difference between the 97th and 3rd percentile AGA predicted UVFP with 77% sensitivity and 92% specificity (P < .0001). There was no correlation between AGA measurements and patient-reported outcome scores. CONCLUSIONS: AGATI demonstrated a difference in AGA measurements between paralysis and control patients. AGATI can predict UVFP with 77% sensitivity and 92% specificity.

Arytenoid asymmetry: Is it the most predictive parameter for arytenoid adduction in unilateral vocal fold paralysis?

OBJECTIVE: The aim of this study was to establish arytenoid asymmetry as a pre-operative predictive parameter for arytenoid adduction surgery in unilateral vocal fold paralysis and thereafter identify the most predictive parameter for arytenoid adduction among the established parameters. METHODS: A retrospective comparative study was undertaken. The 'arytenoid asymmetry angle' formed between skewed 'glottic' and 'interarytenoid' axes (traced along the plane of closure of the membranous and cartilaginous glottis, respectively) was quantified in pre-operative laryngoscopic images of 85 adults with unilateral vocal fold paralysis who underwent either type 1 thyroplasty (group 1) or type 1 thyroplasty with arytenoid adduction (group 2). The need for arytenoid adduction was determined intra-operatively based on subjective voice improvement and laryngoscopic results. RESULTS: Arytenoid asymmetry (p < 0.0001), posterior phonatory gap (p = 0.001) and vertical level difference (p = 0.004) were significantly greater in group 2 (descending order of parameters). Arytenoid asymmetry angle showed a significant positive correlation with the latter two parameters. CONCLUSION: Arytenoid asymmetry is the most predictive parameter for arytenoid adduction. An arytenoid asymmetry angle of more than or equal to 33.9° is an indication for arytenoid adduction. This aids in pre-operative planning of arytenoid adduction.

Combined Transverse Cordotomy- Anteromedial Arytenoidectomy for Isolated Glottic Stenosis.

OBJECTIVES/HYPOTHESIS: Glottic stenosis is a discrete cause of airway compromise. We aimed to determine the surgical outcomes of transverse cordotomy with anteromedial arytenoidectomy (TCAMA), performed in the setting of isolated glottic stenosis resulting from two discrete etiologies: bilateral vocal fold paralysis (BVFP) and posterior glottic stenosis (PGS). STUDY DESIGN: Retrospective, analytic cohort study. METHODS: Twenty-six patients with isolated glottic stenosis were treated with TCAMA between 2006 and 2019. A retrospective analysis determined decannulation rates and intervals, voice outcomes, swallowing outcomes, and reoperation rates postoperatively. Outcomes between the two etiologic cohorts were compared. RESULTS: Of the 26 patients, 16/26 patients were diagnosed with PGS and 10/26 with BVFP. Eighteen patients required tracheotomies during their clinical course (11/16 PGS, and 7/10 BVFP), and 100% were ultimately decannulated. The PGS cohort required two-sided interventions more frequently than the BVFP cohort (45.5% vs. 0%, P = .066). Trach-dependent PGS patients required a longer time to achieve decannulation than BVFP patients by a factor of 2.38, although the difference was not statistically significant (102.3 days vs. 42.9 days, respectively, P = .113). Patients demonstrated a significant change in maximum phonation time but no statistically significant differences with preoperative versus postoperative voice outcomes like voice-related quality of life. All patients ultimately returned to their baseline swallow function postoperatively. CONCLUSION: TCAMA is an effective treatment for surgical rehabilitation of glottic stenosis caused by both BVFP and PGS. Patient-reported outcomes of postoperative vocal function remain consistent following surgical intervention. Additional, prospective studies with greater power are warranted to validate the contrasting outcomes observed when applying this discrete surgical technique across two distinct diagnostic cohorts in this retrospective study. LEVEL OF EVIDENCE: 4. Laryngoscope, 131:2305-2311, 2021.

Bilateral vocal cord paralysis in Miller Fisher syndrome/Guillain-Barre overlap syndrome and a review of previous case series.

Miller Fisher syndrome (MFS), an acute demyelinating neuropathy, is characterised by a triad of areflexia, ataxia and ophthalmoplegia. It is the most common variant of Guillain-Barre Syndrome (GBS). In about 5.6%-7.1% of MFS cases, patients also suffer from progressive motor weakness of the limbs. This condition is termed MFS/GBS overlap syndrome. Whether it is in MFS or GBS, bilateral vocal cord paralysis (BVCP) is a rare manifestation with limited cases reported in the literature. We report an extremely rare case where a 65-year-old man developed BVCP in an MFS/GBS overlap syndrome. We have also reviewed previous case reports in the literature for comparison.

Pre- and post-operative high-speed videolaryngoscopy in unilateral vocal cord paralysis following autologous fat augmentation.

PURPOSE: To compare high-speed videolaryngoscopy (HSV) parameters such as open quotient (OQ), amplitude symmetry index (ASI), phase symmetry index (PSI), and frequency symmetry index (FSI), of the unilateral vocal cord paralysis (UVCP) patients pre and post (after 6 months) autologous fat augmentation. MATERIALS AND METHODS: This retrospective study evaluated all age and gender patients with UVCP that underwent autologous fat augmentation from July 2016 to July 2019. The OQ, ASI, PSI, and FSI were calculated from the HSV recordings by using the montage and fast Fourier transform point analysis. The pre-and post-operative means were compared using a paired student t-test, with a p-value less than 0.05 considered significant. RESULT: A total of 37 patients, age 41.2 ± 11.3 years (21 to 67 years), 59.4% females and 40.6% males, were included in the study. The average duration of symptom onset was 2.3 ± 0.87 months. The post-operative mean values of OQ, ASI, PSI, and FSI following the fat augmentation were significantly improved compared to the pre-operative mean values with p-values <0.0001, 0.0018, 0.0011, and 0.0006, respectively. CONCLUSION: There was a significant improvement in the OQ, ASI, PSI, and FSI in UVCP patients after 6 months of autologous fat augmentation, signifying an enhanced vibratory function. The ability of HSV to measure the minute details of vocal cord vibration by providing quantitative measurements has also been highlighted. The need for future prospective research with an increased sample size and longer duration of follow up is recommended.