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.

Recovery of Recurrent Laryngeal Nerve Function With Neoadjuvant Treatment: Neural Characterization.

OBJECTIVES: Neoadjuvant targeted therapy has emerged as a promising treatment strategy for locally aggressive thyroid cancer. Its impact on tumor and adjacent tissues remains a nascent area of study. Here we report on a series of six subjects with locally advanced thyroid cancer and recurrent laryngeal nerve (RLN) paralysis who experienced recovery of RLN function with neoadjuvant treatment and describe the morphologic and electrophysiologic characteristics of these recovered nerves. METHODS: This is a multicenter retrospective review. Descriptive analysis was conducted to examine the following parameters for recovered nerves: (1) nerve morphology, characterized as Type A (involving epineurium only) versus Type B (extending beyond epineurium); (2) proximal stimulability (normal vs. abnormal vs. absent); and (3) surgical management (resection vs. preservation). RESULTS: Six subjects with unilateral VFP were identified. Median time to return of VF mobility was 3 months (range 2-13.5). All nerves (100%) were noted to have Type A morphology at surgery. Proximal stimulability was normal in four subjects (66.7%), abnormal in one (16.7%), and absent in one (16.7%). Nerves that had improvement of function through neoadjuvant therapy were able to be surgically preserved in five subjects (83.3%). CONCLUSIONS: This represents the first characterization of RLNs that have recovered function with neoadjuvant treatment of locally advanced thyroid cancer. Although much remains unknown, our findings indicate carcinomatous neural invasion is a reversible process and recovered nerves may demonstrate normal morphology and electrophysiologic activity. LEVEL OF EVIDENCE: 4 Laryngoscope, 134:3415-3419, 2024.

Immediate effect of recurrent laryngeal nerve stimulation in patients with idiopathic unilateral vocal fold paralysis.

BACKGROUND: There is a lack of effective treatment for idiopathic unilateral vocal fold paralysis (IUVFP). A better phonation was reported by patients after laryngeal nerve stimulation during our clinical examination. OBJECTIVES: This study aims to investigate immediate effect of recurrent laryngeal nerve (RLN) stimulation on phonation in patients with IUVFP. MATERIAL AND METHODS: Sixty-two patients with clinically identified IUVFP underwent RLN stimulation with needle electrodes. Laryngoscopy, acoustic analysis, and voice perception assessment were performed for quantitative comparison of vocal function and voice quality before and after the intervention. RESULTS: Laryngoscopic images showed a larger motion range of the paralyzed vocal fold (p < .01) and better glottal closure (p < .01) after RLN stimulation. Acoustic analysis revealed that the dysphonia severity index increased significantly (p < .01) while the jitter and shimmer decreased after the intervention (p < .05). According to perceptual evaluation, RLN stimulation significantly increased RBH grades in patients with IUVFP (p < .01). Furthermore, the improvement in voice perception had a moderate positive correlation with the decrease in the glottal closure. CONCLUSIONS AND SIGNIFICANCE: This study shows a short-term improvement of phonation in IUVFP patients after RLN stimulation, which provides proof-of-concept for trialing a controlled delivery of RLN stimulation and assessing durability of any observed responses.

Anti-IgLON5 Disease Showing an Improvement in Dysautonomia, Including Vocal Cord Palsy, via Combined Immunotherapy.

Anti-IgLON5 disease shows various neurological manifestations, of which dysautonomia is one of the major symptoms and is rarely improved by immunotherapy. We herein report a patient with anti-IgLON5 disease who showed several autonomic failures, including vocal cord palsy for four months. The patient presented with cognitive impairments, bulbar symptoms accompanied by myorhythmia in the pharynx and tongue, cerebellar ataxia with tremor, motor neuron symptoms in the limbs, gastrointestinal dysfunction, orthostatic hypotension, non-rapid eye movement sleep disorder on polysomnography, and severe vocal cord palsy. Combined immunotherapy improved his symptoms, including vocal cord palsy, suggesting that combined immunotherapy might improve dysautonomia in anti-IgLON5 disease.

Early Changes in Porcine Larynges Following Injection of Motor-Endplate Expressing Muscle Cells for the Treatment of Unilateral Vocal Fold Paralysis.

OBJECTIVES: No curative injectable therapy exists for unilateral vocal fold paralysis. Herein, we explore the early implications of muscle-derived motor-endplate expressing cells (MEEs) for injectable vocal fold medialization after recurrent laryngeal nerve (RLN) injury. METHODS: Yucatan minipigs underwent right RLN transection (without repair) and muscle biopsies. Autologous muscle progenitor cells were isolated, cultured, differentiated, and induced to form MEEs. Three weeks after the injury, MEEs or saline were injected into the paralyzed right vocal fold. Outcomes including evoked laryngeal electromyography (LEMG), laryngeal adductor pressure, and acoustic vocalization data were analyzed up to 7 weeks post-injury. Harvested porcine larynges were examined for volume, gene expression, and histology. RESULTS: MEE injections were tolerated well, with all pigs demonstrating continued weight gain. Blinded analysis of videolaryngoscopy post-injection revealed infraglottic fullness, and no inflammatory changes. Four weeks after injection, LEMG revealed on average higher right distal RLN activity retention in MEE pigs. MEE-injected pigs on average had vocalization durations, frequencies, and intensities higher than saline pigs. Post-mortem, the MEE-injected larynges revealed statistically greater volume on quantitative 3D ultrasound, and statistically increased expression of neurotrophic factors (BDNF, NGF, NTF3, NTF4, NTN1) on quantitative PCR. CONCLUSIONS: Minimally invasive MEE injection appears to establish an early molecular and microenvironmental framework to encourage innate RLN regeneration. Longer follow-up is needed to determine if early findings will translate into functional contraction. LEVEL OF EVIDENCE: NA Laryngoscope, 134:272-282, 2024.

Association of Sociodemographic Factors on the Presentation and Management of Unilateral Vocal Fold Immobility.

OBJECTIVE: To determine the association of social determinants of health (SDOH) on the presentation and management of unilateral vocal fold immobility (UVFI). METHODS: Retrospective chart review of 207 adult UVFI patients evaluated at a tertiary-care hospital between 2018 and 2019 was performed. Sociodemographic factors including gender, median household income, preferred language, and insurance type were recorded. Confounding clinical factors including etiology of UVFI, Voice Handicap Index-10 (VHI-10) score, laryngoscopic findings, and intervention history were extracted from medical records. Multivariable logistic regression was performed using sociodemographic and clinical factors. RESULTS: Patient demographics and socioeconomic status were not associated with time to presentation. Patients presenting with glottic insufficiency and UVFI due to malignancy or recurrent laryngeal nerve (RLN) sacrifice had a shorter time to presentation. Higher household income was associated with greater number of interventions (p = 0.02), but neither income nor insurance type affected intervention type or timing. Female patients were less likely to undergo injection medialization laryngoplasty (odds ratio [OR] 0.25, p = 0.005). Older patients were more likely to undergo injection (OR 1.04, p = 0.027). Patients with large glottic gaps (OR 21.2, p = 0.014) and higher VHI-10 scores (OR 1.06, p = 0.047) were more likely to undergo surgery. CONCLUSION: Higher household income was associated with greater number of interventions and longer duration of care at a private tertiary-care hospital. RLN sacrifice, known malignancy, and glottic insufficiency significantly reduced the time to presentation. Type of intervention received was a complex interplay of both demographic and clinical factors. Large prospective studies should examine the role of SDOH in the presentation and management of UVFI. LEVEL OF EVIDENCE: 4 Laryngoscope, 134:297-304, 2024.

Electrical Stimulation of Vocal Fold Adduction Triggered by Laryngeal Electromyography Using a Custom Implant.

PURPOSE: Medialization procedures for unilateral vocal fold (VF) paralysis generally improve voice but do not fully replace dynamic VF adduction. Paralyzed VFs typically experience synkinetic reinnervation, which makes it feasible to elicit movement through electrical stimulation. We tested a novel laryngeal pacing implant capable of providing closed-loop (automatic) stimulation of a VF triggered by electromyography (EMG) potentials from the contralateral VF. METHOD: A custom, battery-powered, microprocessor-based stimulator was tested in eight dogs with bipolar electrodes implanted for recording EMG from the left VF and stimulating adduction of the right VF. A cuff electrode on the left recurrent laryngeal nerve (RLN) stimulated unilateral VF adduction, modeling voluntary control in anesthetized animals. Closed-loop stimulation was tested in both acute and chronic experiments. Synkinetic reinnervation was created in two animals by right RLN transection and suture repair to model unilateral VF paralysis. RESULTS: In all animals, left VF activation through RLN stimulation generated a robust EMG response that rapidly triggered stimulation of contralateral thyroarytenoid and lateral cricoarytenoid muscles, causing nearly simultaneous bilateral adduction. Optimal triggering of VF stimulation from elicited EMG was achieved using independent onset and offset thresholds. Real-time artifact blanking allowed closed-loop stimulation without self-perpetuating feedback, despite the proximity of recording and stimulation electrodes. CONCLUSIONS: Using a custom implant system, we demonstrated real-time closed-loop stimulation of one VF triggered by the activation of the contralateral VF. This approach could potentially restore dynamic glottic closure for reflexive behaviors or phonation in cases of unilateral VF paralysis with synkinetic reinnervation. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.24492133.

[The consensus among experts on the diagnosis and treatment of pediatric vocal cord paralysis].

Pediatric vocal ford paralysis is a vocal cord movement disorder caused by damage to the pediatric laryngeal motor nerves.It is mainly characterized by voice, breathing,and swallowing difficulties,and in severe cases,it can lead to choking in affected children. Currently, the diagnosis and treatment of this condition pose a significant challenge for pediatric otolaryngologists, as the goal is to minimize damage to the vocal folds and laryngeal framework.In order to standardize the diagnosis and treatment of pediatric vocal cord paralysis, the Pediatric Otolaryngology Committee of the Chinese Medical Association,in collaboration with multiple children's medical centers nationwide, have formulated this consensus document.

Variations in Practices and Preferences of Vocal Fold Injection Materials: A National Survey.

BACKGROUND: Vocal fold injection augmentation (VFI) is a common procedure for the treatment of glottic insufficiency. Material options for VFI and decisions regarding material selection are not standardized and often based on clinician preference. OBJECTIVE: This study aims to understand the variations in provider preference and utilization of injectable materials for VFI. METHODS: A 40-question survey was sent to 158 academic laryngologists. Questions pertained to the type of injectable materials used including brand preferences and rationale for preferences. RESULTS: Ninety-seven of the 158 laryngologists contacted participated in the survey (61.4%). The most frequently used injectable materials were Hyaluronic Acid (HA)-based products. Carboxymethylcellulose (CMC)-based products were preferred for trial augmentation (57.2%), HA-based products were preferred for acute/subacute vocal fold paralysis, presbyphonia, and sulcus/scar (54.2%, 61.5%, 44.7%, 41.7% respectively), and Calcium Hydroxyapatite (CaHA)-based products were preferred for long-term paralysis (28.1%). CMC-based products were discontinued by 21.8% of participants, largely due to quick material resorption. 17.8% of participants discontinued HA-based products largely due to adverse events and 26.0% abandoned CaHA-based products mostly due to inflammatory properties causing vocal fold stiffness and material unpredictability. Over 30% of respondents reported wanting to reinitiate micronized alloderm Cymetra® as an available injectable. CONCLUSION: Our survey demonstrated that there are significant variations in practice and preferences in regard to injectable material selection for VFI. As there is limited data on the direct material comparison, understanding the rationale behind these variations is crucial to guide new providers in material selection and provide information to patients undergoing these procedures. LEVEL OF EVIDENCE: 5 Laryngoscope, 133:1176-1183, 2023.

Voice Improvement after Voice Therapy in Female Patients with Unilateral Vocal Fold Paralysis after Thyroid Surgery.

INTRODUCTION: Dysphonic voice is present in patients with unilateral vocal fold paralysis (UVFP). The aim of this study was to present outcomes following rehabilitation of patients with UVFP, performed according to a voice therapy protocol. METHODS: This prospective study comprised 27 women with UVFP who underwent pre- and post-voice therapy assessment. The mean age of patients was 53.19 ± 10.06 years. The protocol included the following: (1) multidimensional assessment of voice quality before treatment; (2) digital laryngeal manipulation voice therapy; (3) voice therapy evaluation which implied repeated multidimensional assessment of voice. RESULTS: The results showed improvement in voice quality following voice therapy with regard to the parameters of the objective voice analysis (maximum fundamental frequency of voice, minimum intensity of voice, jitter, shimmer, harmonics-to-noise ratio, and signal-to-noise ratio, p ˂ 0.05), maximum phonation time, subjective analysis of voice, as well as self-assessment of voice quality on all the subscales and overall score (p ˂ 0.001). CONCLUSION: Implementing a protocol provides clear guidelines at each stage of the treatment. Voice therapy performed using digital laryngeal manipulation improves the majority of the acoustic and perceptual characteristics of the voice.

Laryngology Outcomes Following Implantable Vagus Nerve Stimulation.

Importance: Vagus nerve stimulation (VNS) devices have gained widespread acceptance for treatment of resistant epilepsy and depression. The increasing number of procedures has resulted in an increasing number of iatrogenic injuries to the vagus nerve, which can have a significant effect on vocalization and quality of life. Objective: To determine the relative frequency of laryngeal adverse effects reported to the US Food and Drug Administration (FDA) after VNS implantation and to analyze associated VNS device problems. Design, Setting, and Participants: This retrospective cross-sectional analysis queried the FDA Manufacturer and User Facility Device Experience database of adverse events in the US between 1996 and 2020. Main Outcomes and Measures: The primary outcome was the percent of adverse events reported to the FDA that included patients who received VNS with laryngeal adverse effects and the associated proportion of device problems after VNS surgery. Results: A total of 12 725 iatrogenic vagus nerve issues were documented after VNS implantation, with apnea (n = 395; 3.1%) being the most common patient problem. Overall, 187 reports of laryngeal adverse effects associated with VNS devices were identified and represented the eighth most common iatrogenic vagus nerve problem reported to the FDA. Laryngeal adverse effects included 78 reports of voice alteration and 57 reports of paresis/paralysis. The VNS device problems frequently associated with laryngeal adverse effects were high impedance (n = 15, 8.02%), incorrect frequency delivery (n = 10, 5.35%), and battery problems (n = 11, 5.88%). The number of laryngeal adverse effect reports per year peaked in 2012 with 43 cases. Conclusions and Relevance: This cross-sectional study found that although the literature demonstrates that vocal changes occur with nearly all VNS devices, the FDA receives adverse event reports of voice changes. Our results emphasize a potential need to improve patient counseling prior to VNS surgery to better set patient expectations regarding vocal changes and to prevent unnecessary patient concern. In addition, reports of vocal fold paresis/paralysis potentially suggest that patients may benefit from preoperative laryngeal assessment to differentiate preexisting vocal fold paralysis from that caused by VNS surgery.

A Very Rare Complication of Vocal Fold Augmentation With Calcium Hydroxylapatite: Neck Abscess.

INTRODUCTION: Vocal fold injection augmentation is performed routinely for the treatment of glottic insufficiency especially due to unilateral vocal fold paralysis. There are numerous materials that are used for injection laryngoplasty, calcium hydroxylapatite being one of them. CASE REPORT: We present an interesting case of a 64-year-old male patient with metastatic acinic cell carcinoma of the right parotid gland, who underwent right vocal cord injection laryngoplasty with calcium hydroxylapatite for right vocal cord paralysis with glottal insufficiency and developed a neck abscess. DISCUSSION: This is the first report in the literature of neck abscess following vocal fold injection laryngoplasty using calcium hydroxylapatite. It seems that over injection of the vocal fold gave rise to extravasation of the injected material outside the laryngeal framework which later became a nidus for infection. CONCLUSIONS: We present the first case in the literature of neck abscess following vocal fold injection laryngoplasty using calcium hydroxylapatite. Clinicians should be aware of this rare but dangerous complication.

Varicella Zoster Virus Reactivation Involving the Vagus Nerve.

OBJECTIVES: To characterize the presentation, clinical course and functional outcomes of patients with varicella zoster virus (VZV) reactivation involving the vagus nerve. To highlight the role of otolaryngology in acute and long-term management of laryngopharyngeal VZV and its sequelae. METHODS: Retrospective review of 3 patients with laryngopharyngeal VZV, managed at a tertiary referral center. RESULTS: All cases presented with vesicular lesions involving mucosa of the laryngopharynx. Each experienced vocal fold hypomobility, among other otolaryngologic sequelae. All were treated with systemic antivirals and corticosteroids. Mucosal lesions resolved within 7 days of treatment initiation; functional deficits persisted for months to years. Dysphonia improved to a plateau at 3 months, while dysphagia took longer to resolve. One patient with disseminated disease experienced bilateral vocal fold paralysis requiring temporary tracheostomy. CONCLUSIONS: Vagal neuropathy secondary to VZV reactivation is a rare clinical entity with a variety of laryngeal manifestations. Early initiation of systemic therapy and serial endoscopic evaluations are critical components of acute management when laryngopharyngeal involvement is suspected. Otolaryngologists should plan for long-term phonatory and deglutitive therapy in these cases, as neurologic sequelae can persist for months to years following initial insult. LEVEL OF EVIDENCE: Level 4 (Case-series).

The Regenerative Effects of c-Met Agonistic Antibodies in Vocal Fold Atrophy.

BACKGROUND: Atrophy of the vocal folds and the accompanying glottic insufficiency affect the quality of life. Although growth factors have been used to treat muscle atrophy, their effectiveness is limited by their short half-life. METHODS: In total, 15 rabbits and 24 rats were used for the study. The right recurrent laryngeal nerves of all animals were transected. One month following nerve transection, PBS (PBS group), rHGF (HGF group), or a c-Met agonistic antibody (c-Met group) was injected into the paralyzed vocal folds. The larynges of the rabbits were harvested from each group for histologic examination and subjected to PCR analysis. RESULTS: Cross-sectional areas (CSAs) of thyroarytenoid muscles were evaluated. The c-Met group had increased CSAs compared to the PBS and HGF groups, but there were no significant differences compared to normal controls. The expression levels of myogenesis-related genes were evaluated three weeks after the injection. The expression levels of myosin heavy chain IIa were significantly increased in the PBS group, while the expression levels of MyoD were increased in the c-Met group. CONCLUSIONS: The c-Met agonistic antibody showed promise for promoting muscle regeneration in a vocal fold palsy model.

Lipoinjection for Unilateral Vocal Fold Paralysis Treatment: A Systematic Review and Meta-Analysis.

INTRODUCTION: Lipoinjection is one of the available treatments for unilateral vocal fold paralysis. OBJECTIVE: To evaluate lipoinjection predictability, and analyze the differences in safety and efficacy of the different techniques. STUDY DESIGN: Systematic review and meta-analysis. METHODS AND RESULTS: A systematic review on Medline, Cochrane, and Scopus databases included 49 articles analyzing the data of 1,166 patients, concerning technical details and voice parameters changes. Lipoinjection used a mean volume of 1.3 mL, 95% confidence interval (CI) (0.92, 1.69)-average overcorrection of 30%. Meta-analysis of pre- and postoperative voice parameters' means showed a significant improvement at 6 months of mean phonation time (preoperative: 5.12, 95% CI [4.48, 5.76]-6 months: 10.46, 95% CI [9.18, 11.75]), Jitter (preoperative: 2.71, 95% CI [2.08, 3.33])-6 months: 1.37, 95% CI [1.05, 1.70]), Shimmer (preoperative: 4.55, 95% CI [3.04, 6.07]-6 months: 2.57, 95% CI [1.69, 3.45]), grade (preoperative: 2.15, 95% CI [1.73, 2.57]-6 months: 0.12, 95% CI [0.97, 1.43]), breathiness (preoperative: 2.012, 95% CI [1.48, 2.55]-6 months: 0.99, 95% CI [0.58, 1.40]), and asthenia (preoperative: 1.90, 95% CI [1.33, 2.47]-6 months: 0.75, 95% CI [0.17, 1.33]) of GRBAS (Grade, Roughness, Breathiness, Asthenia and Strain), and Voice Handicap Index-30 (preoperative: 72.06, 95% CI [54.35, 89.76]-6 months: 26.24, 95% CI [19.58, 32.90]). Subgroup analysis by harvesting technique concluded in no statistically significant difference between them. Few complications were reported. Reintervention was only required for 86 patients. CONCLUSION: Lipoinjection seems a safe therapeutic option for unilateral vocal fold paralysis, with available data showing an efficacy lasting 6 months to 1 year. Laryngoscope, 132:1630-1640, 2022.

Intermittent Vagal Nerve Stimulation-Associated Vocal Fold Movement Impairment.

OBJECTIVES: Implanted vagal nerve stimulators (VNS) are an accepted therapy for refractory seizures. However, VNS have been shown to affect vocal fold function, leading to voice complaints of hoarseness. We present a case of intermittent VNS-related vocal fold paralysis leading to dysphonia and dysphagia with aspiration in a pediatric patient. METHODS: This is a case report of a patient at a tertiary hospital evaluated in pediatric swallow and voice clinics. Patient and mother gave verbal consent to be included in this case report. RESULTS: Indirect laryngeal stroboscopy was performed demonstrating full vocal fold mobility with VNS off and left vocal fold paralysis in lateral position and glottic gap with VNS on. Voice measures were performed demonstrating decreased phonation time, lower pitch, and decreased intensity of voice with VNS on. Flexible endoscopic evaluation of swallowing demonstrated deep penetration alone with VNS off and deep penetration with concern for aspiration with VNS on. CONCLUSIONS: While the majority of cases of vocal fold movement impairment associated with VNS have been noted to have a medialized vocal fold with VNS activation, we describe a case of intermittent vocal fold lateralization associated with VNS activation with resultant voice changes and aspiration.

Supporting Direct Breastfeeding in a Tracheostomy-Dependent Neonate: A Case Report.

OBJECTIVES: There are numerous well-described benefits to breastfeeding to both infant and mother. Even in healthy children with an uncomplicated perinatal course, there may be significant struggles maintaining a breastfeeding relationship. Infants with a complicated clinical course have been shown to benefit even more from the provision of breastmilk, however they are seldom encouraged to feed directly at the breast. There are no reports of successful direct breastfeeding in an infant with a tracheostomy. METHODS AND RESULTS: We present the case of a breastfeeding dyad including a trach-dependent infant with congenital idiopathic bilateral vocal fold immobility who successfully initiated and maintained an inclusive breastfeeding relationship. CONCLUSION: This case illustrates that successful direct breastfeeding can be achieved in an infant with a tracheostomy. If a patient is felt to be capable of oral feeding via bottle, there is no reason that there should not be a trial of direct feeding at the breast, for the benefit of both members of the breastfeeding dyad.

Effects of Voice Therapy for Dysphonia due to Tension Imbalance in Unilateral Vocal Fold Paralysis and Paresis.

OBJECTIVES: Medialization procedures, such as type I thyroplasty, arytenoid adduction, and vocal fold injection, are popular treatments for dysphonia due to unilateral vocal fold paralysis (UVFP). However, dysphonia occasionally persists after medialization procedures owing to tension imbalance. This tension imbalance causes diplophonia, asymmetry and aperiodic vibrational flutter in travelling wave motion. Currently, there is no established treatment for tension imbalance. We herein report two cases with residual dysphonia due to tension imbalance following medialization for chronic UVFP, and another case presenting with dysphonia due to tension imbalance following chronic unilateral vocal fold paresis. METHODS: Three patients underwent voice therapy using flow phonation to facilitate increased airflow management in speech as well as forward oral resonance by focusing on balanced airflow. Phonatory outcomes were evaluated using stroboscopic findings, aerodynamic and acoustic measures, as well as self-rating. RESULTS: Aerodynamic assessments, acoustic findings and self-ratings improved in all three cases after voice therapy. Stroboscopic findings prior to voice therapy showed asymmetric vibration with glottic gap, which was improved after voice therapy. Fundamental frequency (F0) also increased post-therapy. CONCLUSIONS: In a previous canine study, it was shown that enhanced breath support with expiratory airflow resulted in increased F0, suggesting that enhanced breath support could increase vocal fold tension. The increased F0 achieved in the present cases following voice therapy may increase vocal fold tension with breath support. Thus, voice therapy using flow phonation may be effective for supporting vocal fold tension and improving dysphonia due to tension imbalance following UVFP and paresis.