Voice Therapy Outcome Post Transoral Thyroarytenoid Myoneurectomy in Adductor Spasmodic Dysphonia: A Case Series.

OBJECTIVES: Postoperative evaluations of patients, who undergo of transoral thyroarytenoid myoneurectomy using CO2 laser for the treatment of Adductor Spasmodic Dysphonia (ASD), reveal some residual laryngeal symptoms such as intermittent spasms, vocal effort, and stiffness in laryngeal muscles which can be identified on videolaryngo-stroboscopy (VLS) by patterns of Muscle Tension Dysphonia (MTD) and mucosal wave, and as deviations in acoustic perceptual measures. This study aims to document these vocal symptoms observed postoperatively, and most importantly highlight the need for voice therapy postoperatively and report the short-term vocal outcomes post-therapy. STUDY DESIGN: Retrospective case series. METHOD: The case series includes five patients, three females and two males, in the age range of 40 to 76years, who underwent transoral thyroarytenoid myoneurectomy using CO2 laser for severe ASD. The assessment protocol to document pretherapy (3-week postop) and post-therapy (after 1month of therapy) findings included VLS, Maximum Phonation Time (MPT), VHI-10 GRBAS, and Multi-Dimensional Voice Profile (MDVP) (acoustic voice analysis). Voice therapy regimen included Resonant Voice Therapy, semi-occluded vocal tract exercises, Vocal Function Exercises, and/or breath support exercises customized for individual symptoms. RESULT: MTD of varying grades, MPT less than 10 seconds, deviant F0, mild to moderate degrees of perceptually rough and predominantly strained voice were noted in the pretherapy evaluation. Following 1month of voice therapy, changes noted were a reduction in strained and rough voice quality and an increase in MPT and muscle tension. Improvement of almost all parameters of MDVP tended towards normative as compared to pretherapy including F0. CONCLUSION: Voice therapy initiated at the earliest recovery stage postoperatively does lead to positive short-term vocal outcomes in patients with severe ASD. It is necessary to have long-term follow-ups and aim for the maintenance of satisfactory vocal outcomes.

Probing the inhibitory motor circuits in adductor laryngeal dystonia during a dystonia-unrelated task.

BACKGROUND: The pathophysiology of adductor laryngeal dystonia (AdLD) remains unknown; however, there is growing evidence that dystonia is associated with disruptions in the inhibitory regulation of sensorimotor cortical areas. Using functional MRI (fMRI) and transcranial magnetic stimulation (TMS) complementarily, we previously demonstrated an overly activated laryngeal motor cortex and revealed correlations between blood-oxygen-level dependent (BOLD) activation and intracortical inhibition in a phonation (dystonia-related) task in adductor laryngeal dystonia (AdLD). OBJECTIVE: Here, we aimed to characterize the brain-based findings in the primary motor cortex (M1) during a dystonia-unrelated (finger tapping) task in AdLD and controls (CTL). METHODS: We examined the between-group differences in task-dependent BOLD activation and intracortical inhibition, measured by the TMS-evoked cortical silent period (cSP), in the M1. The correlations between fMRI and TMS responses were assessed. RESULTS: There is more broadly dispersed BOLD activation, not confined to the hand motor cortex, and reduced intracortical inhibition in AdLD compared to CTL. Further, there are more positive correlations between cSP and BOLD activation in a task unrelated to dystonic symptoms in AdLD compared with CTL. This is in contrast to our previous work that demonstrated fewer positive correlations in AdLD during a dystonic phonation task. CONCLUSIONS: In unaffected musculature activation, there is dispersed BOLD activation that is correlated with intracortical inhibition suggesting a possible compensatory strategy in the non-dystonic muscles.

Comparison of Botulinum Toxin Injections and Type 2 Thyroplasty for Adductor Spasmodic Dysphonia.

OBJECTIVES: Injection of botulinum toxin type A (BTX) into intrinsic laryngeal muscles is the current gold standard therapy for adductor spasmodic dysphonia (AdSD). However, a surgical procedure could potentially offer more stable and long-lasting voice quality to AdSD patients. Here, we report the long-term results of type 2 thyroplasty (TP2) with TITANBRIDGE® (Nobelpharma, Tokyo, Japan) compared with those of BTX injections. METHODS: In total, 73 AdSD patients visited our hospital between August 2018 and February 2022. Patients were provided the option of BTX injections or TP2. They were assessed via the Voice Handicap Index (VHI)-10 before treatments and at scheduled clinical follow-ups at 2, 4, 8, and 12 weeks for BTX and at 4, 12, 26, and 52 weeks for TP2. RESULTS: Overall, 52 patients selected the BTX injection and had a pre-injection mean VHI-10 score of 27.3 ± 8.8. Following injections, the scores significantly improved to 21.0 ± 11.1, 18.6 ± 11.5, and 19.4 ± 11.7 at 2, 4, and 8 weeks, respectively. There were no significant differences between the pre-injection scores and the 12-week scores (21.5 ± 10.7). Alternately, 32 patients opted to be treated with TP2 and had a pre-treatment mean VHI-10 score of 27.7. All patients reported an improvement in their symptoms. Additionally, the mean VHI-10 score significantly improved to 9.9 ± 7.4 at 52 weeks following treatment. There was a significant difference between the two treatment groups at 12 weeks. Some patients received both treatments. CONCLUSION: These preliminary results provide important insights into the value of TP2 as a potential permanent treatment for AdSD patients. LEVEL OF EVIDENCE: 3 Laryngoscope, 133:3443-3448, 2023.

Durability of Titanium Implants Following Type II Thyroplasty for Adductor Type Spasmodic Dysphonia.

OBJECTIVE: To determine the durability of current titanium implants (TI) used in voice improvement surgery for adductor spasmodic dysphonia (ADSD), which is type II thyroplasty (T2T), and identify the effects of their fractures on vocal functions. METHODS: A total of 36 ADSD patients who underwent T2T had the following exams: The CT scans of the larynx were performed 1 year after the surgery to assess the fractures of TI. The improvement in the mean voice handicap index 10 (VHI-10) scores and the success rate between nonfractured (NFR) and fractured (FR) groups were compared. RESULTS: It was indicated that TI was broken in 21 cases (58.3%). In one case (2.7%), a fracture on the part of the bridge that connects both sides of the plates was observed, and fractures at holes placed on the plates in the other 35 cases (55.6%). The mean VHI-10 score improved from 27.2 ± 8.1 to 11.4 ± 7.9 in the NFR group and from 26.3 ± 4.9 to 9.7 ± 7.9 in the FR group. The success rates were 66.6% in the NFR group and 71.5% in the FR group. No statistical difference was observed in the improvement in the mean VHI-10 scores, and the success rate between the two groups. However, two cases resulted in failure in the FR group, whereas no worsened case was observed in the NFR group. CONCLUSION: The current TI used in T2T has low durability and could result in the worsening of vocal symptoms after the surgery. LEVEL OF EVIDENCE: 4 Laryngoscope, 133:3028-3033, 2023.

Laryngeal Imaging Study of Glottal Attack/Offset Time in Adductor Spasmodic Dysphonia during Connected Speech.

Adductor spasmodic dysphonia (AdSD) disrupts laryngeal muscle control during speech and, therefore, affects the onset and offset of phonation. In this study, the goal is to use laryngeal high-speed videoendoscopy (HSV) to measure the glottal attack time (GAT) and glottal offset time (GOT) during connected speech for normophonic (vocally normal) and AdSD voices. A monochrome HSV system was used to record readings of six CAPE-V sentences and part of the "Rainbow Passage" from the participants. Three raters visually analyzed the HSV data using a playback software to measure the GAT and GOT. The results show that the GAT was greater in the AdSD group than in the normophonic group; however, the clinical significance of the amount of this difference needs to be studied further. More variability was observed in both GATs and GOTs of the disorder group. Additionally, the GAT and GOT time series were found to be nonstationary for the AdSD group while they were stationary for the normophonic voices. This study shows that the GAT and GOT measures can be potentially used as objective markers to characterize AdSD. The findings will potentially help in the development of standardized measures for voice evaluation and the accurate diagnosis of AdSD.

Abnormal Laryngopharyngeal Sensation in Adductor Laryngeal Dystonia Compared to Healthy Controls.

BACKGROUND/OBJECTIVES: Laryngeal sensory abnormality has been implicated as a component of adductor laryngeal dystonia (AdLD). The study objective was to assess laryngopharyngeal sensation in AdLD utilizing a calibrated, tactile aesthesiometer to deliver differential stimuli to lateral pyriform sinus (LPS), aryepiglottic fold (AEF), and false vocal fold (FVF). METHODS: Patients with known Botox-responsive AdLD underwent sensory testing using a previously-validated methodology involving calibrated tactile stimuli (6-0, 5-0, 4.5-0, 4-0 nylon monofilaments). Laryngeal adductor reflex (LAR) and participant-rated perceptual strength of stimulI were evaluated. Responses were compared to normative controls (n = 33). Two-samples, Mann-Whitney and Fisher exact tests compared mean strength ratings and LAR between AdLD and control groups. Mixed-effects logistic regression and linear models assessed association of filament size, stimulus site, age, sex, and LD status on LAR and perceptual strength rating respectively. RESULTS: Thirteen AdLD patients (nine women, mean age 60+/-15 years) completed testing. Average LAR response rates were higher amongst all filament sizes in AdLD versus controls at LPS (56.3% vs. 35.7%) and AEF (96.1% vs. 70.2%) with comparable rates at FVF (90.2% vs. 91.7%). AdLD had 3.3 times the odds of observed LAR compared to controls (p = 0.005), but differences in subjective detection of stimuli, perceptual strength ratings, and cough/gag rates were insignificant on multivariate modeling (p > 0.05). CONCLUSIONS: This is the first study to objectively assess laryngopharyngeal sensation in AdLD. Findings demonstrated increased laryngopharyngeal sensation in AdLD compared to controls. The identification of increased laryngeal hypersensitivity in these patients may improve understanding of AdLD pathophysiology and identify future targets for intervention. LEVEL OF EVIDENCE: 2 Laryngoscope, 133:2271-2278, 2023.

Spasmodic dysphonia: introductory phonetic analyses.

Adductor spasmodic dysphonia (ADSD) is a neurological dystonia characterised by involuntary adductor spasms of the larynx during speech. Spasm frequency is often reported to increase during syllables that begin with voiced speech sounds, especially glottal stops. Because of its underlying physical and acoustic complexities, the voicing contrast in American English (AE) appears unlikely to interact consistently with a singular physical phenomenon like laryngeal spasm. This retrospective study investigated additional phonetic contrasts and their relationship to spasm frequency. Standardised, 144-word recordings of 36 participants with adductor spasmodic dysphonia were analysed. Productions were coded for rater-perceived syllable stress, voiced/voiceless onset, vowel/consonant onset, and word-onset place and manner of production. Phonetic contexts were compared using independent sample t-tests and Kruskal-Wallis statistics. Contexts in which spasm varied significantly included stressed/unstressed syllables, content/function words, and multisyllabic/monosyllabic words. Study results reaffirm the clinical usefulness of standardised ADSD/ABSD sentences during differential diagnosis but conflict with previous studies that report a connection between ADSD spasm and phoneme voicing.

Pre- and Postoperative High-Speed Videolaryngoscopy Findings in Adductor Spasmodic Dysphonia Following Transoral CO2 LASER-Guided Thyroarytenoid Myoneurectomy.

INTRODUCTION: Vocal cord vibration after transoral CO2 LASER-guided thyroarytenoid (TA) myoneurectomy in adductor spasmodic dysphonia (AdSD) patients is unclear to date. The precise vibratory patterns in AdSD patients are difficult to evaluate with routine videolaryngostroboscopy. High-speed videolaryngoscopy (HSV) is an ideal choice to evaluate such patients. This study was performed to compare pre- and postoperative, after 6 months, vocal fold vibratory onset delay (VFVOD) and closed phase glottal cycle (CPGC) in AdSD patients following transoral CO2 LASER-guided TA myoneurectomy using the HSV. MATERIALS AND METHODS: Retrospective study, conducted from January, 2016 to January, 2019, of the AdSD patients who underwent transoral CO2 LASER-guided TA myoneurectomy using the HSV. Patient data were acquired from the hospital database to evaluate VFVOD and CPGC from HSV recordings of the patients. VFVOD was calculated as sum of prephonatory delay (PPD) and steady-state delay (SSD). The PPD and SSD were evaluated and compared separately for each patient. The MedCal Version 19.2.6 was used for data analysis. Paired sample t test was performed to compute the significance of the difference between the mean of the dataset. A P value less than 0.05 was considered significant. RESULTS: A total of nine patients were included in the study, out of which three were females and six were males. The average age was 45.5 ± 6.9 years. The mean of postoperative PPD (166.8 ± 22.1), SSD (76.5 ± 8.6), and CPGC (62.6 ± 4.8) were significantly less than mean of preoperative PPD (222.6 ± 22.1), SSD (97.7 ± 9.5), and CPGC (71.6 ± 5 %), with P values of 0.0007, 0.0001, and 0.0001, respectively. CONCLUSIONS: There was a significant decrease in VFVOD and CPGC posttransoral CO2 LASER-guided TA myoneurectomy in AdSD patients after 6 months follow-up. This study also establishes efficiency of the HSV to measure the vocal cord vibration in the patients with AdSD. The primary limitations of the study were the small sample size and its retrospective nature. Future prospective studies with increased sample size can further substantiate the findings of the work performed here.

Optimizing Botox regimens in patients with adductor spasmodic dysphonia and essential tremor of voice: A 31-year experience.

Objective: The purpose of this study was to quantitatively compare the effectiveness of unilateral and bilateral botulinum toxin A (BTX-A) injections for mitigating undesirable weak/breathy voice quality and dysphagia for patients with adductor spasmodic dysphonia and/or essential tremor of voice (ETV). Methods: Data were collected from the medical records of 319 patients, yielding three treatment cohorts: patients who received an equal dose bilateral injection regimen (BL=) throughout their course of treatment at VUMC, patients who switched to a unilateral injection regimen (UL), and patients who switched to an unequal dose bilateral injection regimen (BL≠). Changes in length of improvement, duration of weak/breathy voice, and dysphagia severity were compared. Results: The BL = treatment group reported the longest duration of improved voice. Shorter periods of improved voice were reported at baseline by patients who later switched to UL or BL ≠ injection regimens. Patients receiving UL injections reported significantly reduced weak/breathy voice and dysphagia. Patients receiving BL ≠ injections reported increased length of improved voice; however, dysphagia symptoms increased. Ninety-two percent of patients with ETV switched to a UL regimen, with 61% of patients transitioning within the first three injections. Conclusions: Patients with pronounced dysphagia and extended periods of weak/breathy voice may benefit from a UL injection approach to mitigate side effects from BTX-A without sacrificing improved voice outcomes. For patients seeking to extend their length of improved voice, a BL ≠ injection regimen may be effective provided the adverse side effects from BTX-A are minimal. Patients with ETV may benefit from a UL injection approach at the outset of their course of treatment with BTX-A. Level of evidence: III.

Deep-Learning-Based Representation of Vocal Fold Dynamics in Adductor Spasmodic Dysphonia during Connected Speech in High-Speed Videoendoscopy.

OBJECTIVE: Adductor spasmodic dysphonia (AdSD) is a neurogenic dystonia, which causes spasms of the laryngeal muscles. This disorder mainly affects production of connected speech. To understand how AdSD affects vocal fold (VF) movements and hence, the speech signal, it is necessary to study VF kinematics during the running speech. This paper introduces an automated method for analysis of VF vibrations in AdSD using laryngeal high-speed videoendoscopy (HSV) in running speech. METHODS: A monochrome HSV system was used to obtain video recordings from vocally normal individuals and AdSD patients during production of the six CAPE-V sentences and the "Rainbow Passage." A deep neural network was designed based on the UNet architecture. The network was developed for glottal area segmentation in HSV data providing a tool for quantitative analysis of VF vibrations in both norm and AdSD. The network was trained and validated using the manually labeled HSV frames. After training the network, the segmentation quality was quantitatively evaluated against visual analysis results of a test dataset including segregated HSV frames and a short sequence of VF vibrations in consecutive frames. RESULTS: The developed convolutional network was successfully trained and demonstrated an accurate segmentation on the testing dataset with a mean Intersection over Union (IoU) of 0.81 and a mean Boundary-F1 score of 0.93. Moreover, the visual assessment of the automated technique showed an accurate detection of the glottal edges/area in the HSV data even with challenging image quality and excessive laryngeal maneuvers of AdSD patients during the running speech. CONCLUSION: The introduced automated approach provides an accurate representation of the glottal edges/area during connected speech in HSV data for norm and AdSD patients. This method facilitates the development of HSV-based measures to quantify VF dynamics in AdSD. Using HSV to automatically analyze VF vibrations in AdSD can allow for understanding AdSD vocal mechanisms and characteristics.

Detection of Vocal Fold Image Obstructions in High-Speed Videoendoscopy During Connected Speech in Adductor Spasmodic Dysphonia: A Convolutional Neural Networks Approach.

OBJECTIVE: Adductor spasmodic dysphonia (AdSD) is a neurogenic voice disorder, affecting the intrinsic laryngeal muscle control. AdSD leads to involuntary laryngeal spasms and only reveals during connected speech. Laryngeal high-speed videoendoscopy (HSV) coupled with a flexible fiberoptic endoscope provides a unique opportunity to study voice production and visualize the vocal fold vibrations in AdSD during speech. The goal of this study is to automatically detect instances during which the image of the vocal folds is optically obstructed in HSV recordings obtained during connected speech. METHODS: HSV data were recorded from vocally normal adults and patients with AdSD during reading of the "Rainbow Passage", six CAPE-V sentences, and production of the vowel /i/. A convolutional neural network was developed and trained as a classifier to detect obstructed/unobstructed vocal folds in HSV frames. Manually labelled data were used for training, validating, and testing of the network. Moreover, a comprehensive robustness evaluation was conducted to compare the performance of the developed classifier and visual analysis of HSV data. RESULTS: The developed convolutional neural network was able to automatically detect the vocal fold obstructions in HSV data in vocally normal participants and AdSD patients. The trained network was tested successfully and showed an overall classification accuracy of 94.18% on the testing dataset. The robustness evaluation showed an average overall accuracy of 94.81% on a massive number of HSV frames demonstrating the high robustness of the introduced technique while keeping a high level of accuracy. CONCLUSIONS: The proposed approach can be used for efficient analysis of HSV data to study laryngeal maneuvers in patients with AdSD during connected speech. Additionally, this method will facilitate development of vocal fold vibratory measures for HSV frames with an unobstructed view of the vocal folds. Indicating parts of connected speech that provide an unobstructed view of the vocal folds can be used for developing optimal passages for precise HSV examination during connected speech and subject-specific clinical voice assessment protocols.

Titanium bridge modification for type 2 thyroplasty to improve device mechanical & safety performance.

OBJECTIVE: Titanium bridges are used to separate the thyroid ala during type 2 thyroplasty for adductor spasmodic dysphonia. Revision surgeries have adventitiously indicated that bridge wing failure occurs in the area of the medial hole in some cases. This study investigated the rate and cause of device malfunctions and developed an improved device. METHODS: We conducted a questionnaire survey to determine the number of surgeries performed in Japan up to the end of 2014, and to obtain information about revision cases. In addition, damage analyses were performed on the fracture surfaces of recovered titanium bridges through use of scanning electron microscopy (SEM). RESULTS: Between 2002 and 2014, titanium bridges were used in 385 patients. Revision surgery was performed in 19 cases. Revision surgeries revealed that in 11 cases breakage occurred in the wings of the device in the region of the medial hole. However, such fractures were not associated with any signs of recurrence or any adverse events. SEM analyses of fracture surfaces confirmed that fatigue fractures were caused by repeated bending stress in the area of the medial hole. Based on these results, the shape of the hole was changed from round to oval and the wing thickness was increased to prevent breakage. CONCLUSIONS: The wings of titanium bridges may break without any associated signs, symptoms or tissue damage. Based on the malfunctions detected and analyses of the devices recovered following malfunction, changes to the specification were made for commercial development of the titanium bridge.

Post-treatment clinical course following botulinum toxin injection therapy for adductor spasmodic dysphonia: Analysis of data from a placebo-controlled, randomized, double-blinded clinical trial in Japan.

OBJECTIVE: Botulinum toxin (BT) therapy is a first-line treatment for spasmodic dysphonia (SD). However, a detailed chronological course and clinical factors that affect the therapeutic effect have been vague. In this study, we analyzed the data from our placebo-controlled, randomized, double-blinded parallel-group comparison/open-label clinical trial of BT (Botox) to clarify these. METHODS: A total of 22 patients with abductor SD (ADSD) were enrolled. The female-to-male ratio was 20:2 with a mean age of 40.0 ± 10.3 years and a median duration of symptoms of 7.5 years. The therapeutic effect was evaluated based on the change in the number of aberrant morae (phonemes), GRBAS scale, Voice Handicap Index (VHI), and Visual Analogue Scale (VAS). RESULTS: The change in the number of aberrant morae peaked at 2 weeks and lasted for 12 weeks in the BT group with significance (P < .01) compared to the placebo group. Objective improvement (number of aberrant morae and [S] element in GRBAS) preceded subjective improvement (VHI and VAS). The change in number of aberrant morae and VHI showed a significant correlation (P < .01). The changes in the number of aberrant morae, VHI, and VAS in younger subjects were greater than in older subjects. Patients who presented with post-treatment breathy hoarseness or dysphagia showed better therapeutic effects. CONCLUSIONS: BT therapy was effective for ADSD based on both objective and subjective assessments. Improvements in subjective parameters were delayed compared to objective measures due to post-treatment breathy hoarseness. However, this adverse event was believed to reflect the treatment effect. LEVEL OF EVIDENCE: 1b.

Effects and Differences of Voice Therapy on Spasmodic Dysphonia and Muscle tension dysphonia: A Retrospective Pilot Study.

OBJECTIVES: Laryngeal and voice findings of adductor spasmodic dysphonia (AdSD) and muscle tension dysphonia (MTD) are similar, and it is difficult to distinguish between both disorders. The purpose of this study is to ascertain the effect of voice therapy on MTD and AdSD and clarify their difference. METHODS: A total of 49 patients, including 22 patients with MTD (MTD group) and 27 patients with AdSD (SD group), were included in the study. The MTD scores were evaluated, and aerodynamic analysis (maximum phonation time [MPT], mean airflow rate [MFR], highest pitch, lowest pitch, and pitch range), perceptual evaluation (Strangulation, Interruption, and Tremor), acoustic analysis (PPQ, APQ, NHR, and DVB), and subjective assessment (voice handicap index-10 [VHI-10]) were performed before and after voice therapy. RESULTS: The MTD score, highest pitch, pitch range, strangulation, PPQ, APQ, NHR, and VHI-10 showed significant improvement after treatment in the MTD groups. On the other hand, the effect of voice treatment on AdSD was poor despite the improvement in the MTD score. CONCLUSIONS: This study could serve as a basis for conducting prospective studies to verify the effects of voice therapy on MTD and AdSD.

Proposal for a Core Outcome Set of Measurement Instruments to Assess Quality of Voice in Adductor Spasmodic Dysphonia Based on a Literature Review.

OBJECTIVES: Uniform evaluation of treatment effect on the quality of voice in adductor spasmodic dysphonia (AdSD) is challenging due to the broad variety of available outcome measurement instruments (OMIs). The European Laryngological Society categorized five types of measurement domains for voice quality evaluations: patient-reported outcome measures, perceptual analyses, acoustic analyses, visual analyses, and aerodynamic measurements. The aim of this study was to propose a core outcome set (COS) for these domains, enabling systematic assessments of treatment effects on the quality of voice in patients with AdSD. METHODS: The PubMed, Embase, and Cochrane databases were searched for eligible studies published before July 2019. The results were systematically analyzed following the protocol of the COnsensus-based Standards for the selection of health Measurement INstruments/Core Outcome Measures in Effectiveness Trials initiative. The proposed COS is based on the prevalence of OMIs, quality of the included studies, criteria for good measurement properties, and correlations to other OMI domains. RESULTS: A total of 76 articles were included, with nearly all studies and OMIs found to be of moderate or low quality. The 19 studies that reported on the correlation of OMIs demonstrated conflicting results. Appraising the best available evidence, our proposed COS consisted of patient-reported outcome measures (voice handicap index), perceptual measurements (grade, roughness, breathiness, strain, and voice breaks) and acoustic measurements (voice breaks, voice onset time, aperiodicity, and multiparameter algorithms). CONCLUSION: A review of OMIs evaluating treatment effects in AdSD was conducted. Based on this review, a uniform COS was proposed. However, evidence for the selected instruments was limited. Further exploration into the validity and reliability of OMIs for AdSD is recommended.

Quality of Life After Botulinum Toxin Injection in Patients With Adductor Spasmodic Dysphonia; a Systematic Review and Meta-analysis.

INTRODUCTION: Adductor spasmodic dysphonia is an extremely disabling voice disorder that negatively impacts a patient's quality of life (QOL). We performed a systematic review to determine if Botulinum Toxin (BT) injections improved voice related QOL in patients with this disorder. METHODS: PubMed, EMBASE, Web of Science, Cochrane Library, ProQuest, and Scopus from 2000, to and including November 1st, 2018, were searched. We identified randomized controlled trials, controlled trials, and observational studies of the effects of BT injections on the QOL in patients with adductor spasmodic dysphonia. The two authors, separately and individually chose the studies based on inclusion criteria, assessed study quality, and relevant extracted data. RESULTS: Nine studies used the Voice Handicap Index (VHI). The results showed significant changes pre- to post-BT injection (SMD = -0.357; 95% CI: -0.579, -0.136; z = 3.16; P = 0.002; I-squared = 0.000%). Five studies used the Voice-Related QOL; their results also showed a significant improvement pre- to postinjection (SMD = -2.99; 95% CI: -3.27, -1.32; z = 4.61; P < 0.001; I-squared = 87%). Three other studies used other, shortened versions of the VHI, VHI-10. They also showed significant results (SMD = -0.145; 95% CI: -0.349, 0.06; z = 1.38; P = 0.17; I-squared = 0.000). CONCLUSION: BT injections positively affect patients' QOL. However, patients' QOL scores may never be normalized, in line with perceptual voice quality and acoustic parameters.

Quantitative laryngeal electromyography parameters may correlate with improved outcomes following botulinum toxin injection for spasmodic dysphonia.

BACKGROUND: Despite use of qualitative laryngeal electromyography (LEMG) guided botulinum toxin A (BoNT-A) injection for treatment of adductor spasmodic dysphonia (AdSD), unsatisfactory injections and complete "misses" remain problematic. We aimed to determine if the quantitative LEMG measure of number of small segments (NSS) correlates with voice outcomes following (BoNT-A injection for AdSD. METHODS: Automated quantitative LEMG analysis was performed during electromyography (EMG) -guided BoNT-A injection into the thyroarytenoid-lateral cricoarytenoid muscle complex for treatment of AdSD. Pre-injection phonatory NSS values were correlated with clinical voice outcomes and patient reported injection results. RESULTS: Quantitative LEMG measures were obtained for 45 AdSD patients (28 female, mean age 60.8 ± 12.8 years) during EMG-guided BoNT-A injection. Mean sampled NSS during phonation immediately prior to BoNT-A injection was 524 ± 323 (range: 2-904). Mean follow up was 36.5 ± 9.4 days; one patient was lost to follow-up. In comparison to their previous BoNT-A injection, the current injection was rated as worse, same, and better by 13 (29.5%), 25 (56.8%), and 6 (13.6%) patients, respectively. All 4 (9.1%) patients with NSS < 200 rated their BoNT-A injection result as worse than previous, and change in Voice Handicap Index-10 (VHI-10) scores were worse or without change. CONCLUSIONS: Aiming for an NSS value greater than 200 during phonation prior to BoNT-A toxin injection for AdSD may reduce unfavorable voice outcomes.

Impacto en la calidad de vida del tratamiento de disfonía espasmódica aductora con toxina botulínica A / Impact on the quality of life of the treatment of adductor spasmodic dysphonia with botulinum toxin A

Introducción. La distonía laríngea o disfonía espasmódica se caracteriza por con-tracciones involuntarias de los músculos laríngeos internos que se desencadenan al hablar, siendo la forma aductora la más frecuente. La inyección de toxina botulínica es el manejo de elección. Para evaluar la respuesta a la terapia existen varios instru-mentos validados, uno de ellos es el cuestionario Voice Handicap Index-10 (VHI-10). El objetivo de este estudio es caracterizar a los pacientes con disfonía espasmódica aductora y evaluar el impacto de la toxina en su calidad de vida.Método. Éste se centró en un estudio retrospectivo descriptivo en pacientes adultos con diagnóstico de disfonía espasmódica aductora tratados con toxina botulínica A, en el Hospital Clínico Universidad de Chile (HCUC), en el periodo comprendido en-tre 2013 y 2021. El mismo permitió la obtención de los datos epidemiológicos de los pacientes, a quienes se les solicitó responder la encuesta VHI-10 previo y posterior a un mes de cada inyección de la toxina.Resultados. Se incluyeron 55 pacientes (218 procedimientos). La dosis promedio utilizada fue de 9,18 UI con un intervalo promedio de 7,4 meses. El puntaje VHI-10 promedio en la evaluación inicial fue de 29,4 y posinfiltración de 14,96, siendo esta diferencia significativa (p < 0,000001). En nuestra serie casi un tercio tiene asociada alguna patología neurológica, y se reportó un 3,67% de complicaciones leves y transitorias.Conclusión. La disfonía espasmódica aductora tiene un gran impacto en la calidad de vida de los pacientes, que se reduce significativamente mediante la inyección de toxina botulínica A, procedimiento que ha demostrado ser seguro y eficaz

Introduction. Laryngeal dystonia or spasmodic dysphonia is characterized by in-voluntary contractions of internal laryngeal muscles that are triggered when speak-ing, being the adductor form the most frequent. Botulinum toxin injection is the management of choice. There are several validated instruments to assess response to therapy, one of them is the Voice Handicap Index-10 (VHI-10) questionnaire. The objective of this study is to characterize patients with adductor spasmodic dysphonia and evaluate the impact of the toxin in their quality of life.Method. A descriptive retrospective study was carried out in adult patients with a diagnosis of adductor spasmodic dysphonia treated with botulinum toxin A, between 2013-2021 at the Hospital Clínico Universidad de Chile. The epidemiological data of the patients and the VHI-10 survey were obtained before and after one month of each toxin injection was requested.Results. 55 patients (218 procedures) were included. The average dose used was 9.18 IU with an average interval of 7.4 months. The average VHI-10 score in the initial evaluation was 29.4 and post-infiltration was 14.96, being this difference sig-nificant (p <0.000001). In our series, almost a third had an associated neurological pathology, and 3.67% of mild and transitory complications were reported.Conclusion. Adductor spasmodic dysphonia has a great impact on the quality of life of patients, which is significantly reduced by injecting botulinum toxin A, a pro-cedure that has been shown to be safe and effective

Transcranial magnetic stimulation and functional magnet resonance imaging evaluation of adductor spasmodic dysphonia during phonation.

BACKGROUND: Reduced intracortical inhibition is a neurophysiologic finding in focal dystonia that suggests a broader problem of impaired cortical excitability within the brain. A robust understanding of the neurophysiology in dystonia is essential to elucidate the pathophysiology of the disorder and develop new treatments. The cortical silent period (cSP) is a reliable, non-invasive method to measure intracortical inhibition in the primary motor cortex associated with a muscle of interest. In adductor spasmodic dysphonia (AdSD), cSP of the laryngeal motor cortex (LMC) which directly corresponds to the affected musculature, the thyroarytenoid (TA), has not been examined. OBJECTIVE: This work evaluated the cSP of the LMC and the relationship between cSP and functional magnetic resonance imaging (fMRI) blood-oxygen-level dependent (BOLD) activation in people with AdSD (n = 12) compared to healthy controls (CTL, n = 14). RESULTS: Shortened LMC cSP were observed bilaterally in people with AdSD vs CTL (F(1, 99) = 19.5226, p < 0.0001), with a large effect size (η2 = 0.1834). Between-group fMRI analysis revealed greater activation in bilateral LMC in the AdSD > CTL contrast as compared to CTL > AdSD contrast. Correlation analysis showed that people with AdSD have positive correlation of left LMC BOLD activation and the cSP. Further, the right LMC cSP lacks either positive or negative associations with BOLD activation. CTL individuals displayed both positive and negative correlations between cSP and BOLD activation in the left LMC. In CTL, the LMC cSP and BOLD activation showed exclusively negative correlations in both hemispheres. CONCLUSION: In AdSD, the cortical activation during phonation may not be efficiently or effectively associated with inhibitory processes, leading to muscular dysfunction. These findings may give insight into the maladaptive cortical control during phonation in people with AdSD.

Adductor spasmodic dysphonia: Botulinum toxin a injections or laser thyroarytenoid myoneurectomy? A comparison from the patient perspective.

OBJECTIVES/HYPOTHESIS: The current gold standard of therapy for adductor spasmodic dysphonia (AdSD) is injection of botulinum toxin A (BTX) in the adductor musculature. A surgical procedure could potentially offer more stable and long-lasting voice quality. In this study, we report the long-term results of endoscopic laser thyroarytenoid (TA) myoneurectomy versus BTX treatment in the same patients with AdSD. STUDY DESIGN: Retrospective case series. METHODS: Between July 2013 and September 2016, a total of 22 patients with AdSD were included. Voice outcomes were measured using the Voice Handicap Index and a Likert-scale patient-reported voice questionnaire. Data were obtained for each patient at four time points: preoperatively with and without BTX and twice postoperatively at 3 months (short term) and 12 months (long term). RESULTS: No statistically significant differences were found between voice outcome after BTX injection and the short- and long-term postoperative voice outcomes for the group as a whole. During postoperative follow-up, 10 of the 22 patients (45%) needed a second procedure after an average of 18 months (interquartile range, 13-22 months) due to recurrence of their original voice problem. CONCLUSIONS: The TA myoneurectomy showed encouraging results, comparable to BTX after follow-up of 12 months for the group as a whole. However, after good results initially, voice deterioration was seen in 45% of the patients who all underwent a second procedure. These preliminary results provide important insights into the value of TA myoneurectomy as a potential definite treatment for a select group of patients with AdSD. Further research might explore long-term results after revision surgery. LEVEL OF EVIDENCE: 4 Laryngoscope, 130:741-746, 2020.