Neurectomy and Myomectomy for Treatment of Spasmodic Dysphonia

Spasmodic dysphonia (SD) is a debilitating neurological disorder affecting the muscles of voice production. Sudden involuntary movements of the vocal folds lead to phonatory breaks and to forced, strained, and strangled voice quality in adductor SD, or breathy breaks in abductor SD. There is currently no cure for spasmodic dysphonia, and the gold standard for treatment is the injection of botulinum toxin in small amounts to the intrinsic laryngeal musculature.1 However, botulinum treatment requires periodic reinjection, produces vocal instability immediately after injection, lacks uniform results among patients, and patients can develop antibodies to botulinum toxin. Long-term or permanent symptom relief would be ideal. We present four patients with adductor and one patient with abductor spasmodic dysphonia who underwent neurectomy and myomectomy for treatment. The mean age was 64 years (age range 45-83). The mean duration of adductor spasmodic dysphonia was 11.8 years. The duration of abductor spasmodic was 4 years. All patients had previously been treated with voice therapy and botulinum toxin A. The mean duration of follow up was 1.7 years. Four patients had subjective and objective improvement after surgery. One patient had subjective improvement.

Assessment of Patients Receiving Short-Interval Botulinum Toxin Chemodenervation Treatment for Laryngeal Dystonia and Essential Tremor of the Vocal Tract

Importance

The gold-standard treatment for laryngeal dystonia (LD) and essential tremor of the vocal tract (ETVT) is botulinum toxin (BoNT) chemodenervation. Although safe and effective, it is not curative, and periodic injections are required. Some medical insurance companies only cover injections at a 3-month interval, though some patients benefit from injections more frequently.

Objective

To determine the proportion and characteristics of patients who receive BoNT chemodenervation treatment in intervals shorter than 90 days.

Design, Setting, and Participants

This retrospective cohort study across 3 quaternary care neurolaryngology specialty practices in Washington and California recruited patients who underwent at least 4 consecutive laryngeal BoNT injections for LD and/or ETVT in the past 5 years. Data were collected from March through June 2022 and analyzed from June through December 2022.

Exposure

Laryngeal BoNT treatment.

Main Outcomes and Measures

Biodemographic and clinical variables, injection characteristics, evolution during the 3 interinjection intervals, and lifetime laryngeal BoNT treatment data were collected from patient medical records. Logistic regression was used to assess association to the short-interval outcome, defined as an average injection interval shorter than 90 days.

Results

Of 255 patients included from the 3 institutions, 189 (74.1%) were female, and the mean (SD) age was 62.7 (14.3) years. The predominant diagnosis was adductor LD (n = 199 [78.0%]), followed by adductor dystonic voice tremor (n = 26 [10.2%]) and ETVT (n = 13 [5.1%]). Seventy patients (27.5%) received short-interval injections (<90 days). The short-interval group was younger than the long-interval group (≥90 days), with a mean (SD) age of 58.6 (15.5) years and 64.2 (13.5) years, respectively, and a mean difference of -5.7 years (95% CI, -9.6 to -1.8 years). There were no patient-related differences between the short- and long-interval groups in terms of sex, employment status, or diagnosis.

Conclusions and Relevance

This cohort study demonstrated that while insurance companies often mandate a 3-month or greater interval for BoNT chemodenervation financial coverage, there is a considerable subset of patients with LD and ETVT who receive short-interval treatment to optimize their vocal function. Short-interval chemodenervation injections demonstrate a similar adverse effect profile and do not appear to predispose to resistance through antibody formation.

Clinical Observation of Botulinum Toxin Injection in the Treatment of Focal Dystonia and Muscle Spasm

Dystonia and muscle spasms are a group of common and unfavorable clinical neurological symptoms. The use of botulinum toxin (BTX-A) abroad has achieved good results in the treatment of various movement disorders characterized by involuntary or abnormal muscle contractions. It is expected to open up a new field for the treatment of myelodysplastic syndromes (MDs) such as focal dystonia and muscle spasm. There are theoretical and practical implications for the diagnosis and development of some effective neurological treatments. The efficacy of BTX-A in the treatment of various focal dystonia and muscle spasm disorders is as follows: symptoms were improved to varying degrees after injection of Botox or botulinum toxin type A (CBTX-A), but Botox or CBTx. There was no significant difference in the efficacy of A. 30.4% of patients had complete remission, 57.8% had significant remission, and 8.9% had partial remission. Among them, HFS and BS had the best curative effect, and the symptoms were significantly improved by 95.3% and 89.4%, respectively. The efficacy of CD was also satisfactory, with 75.5% of the patients showing significant improvement in symptoms, followed by Meg/OMD (OMD) with 73.3% and SD with 3.3%. The efficacy of WC is poor, and functional improvement is uncertain. Other forms of focal dystonia and spasticity also showed significant functional improvement in 60% of patients. Most patients start to see effects within 1 week after BTX-A injection, symptoms gradually improve, and the bridge of curative effect is reached in 2-4 weeks, and the healing effect lasts for about 3-5 months on average. The overall severity of adverse effects was not severe and resolved spontaneously within a few days to ten weeks, with the most concerning complications being ptosis and dysphagia.

Transoral radiofrequency of the terminal branches of the recurrent nerve in the treatment of adductor spasmodic dysphonia: our experience over 11 patients

PURPOSE

Spasmodic dysphonia (SD) or laryngeal dystonia is as a rare vocal disorder characterized by involuntary action-induced endolaryngeal contraction. In the last decade, botulin toxin injection has become the standard treatment in adductor spasmodic dysphonia necessitating repetitive injections. The purpose of this study is to analyze retrospectively data from patients treated with the minimal-invasive transoral radiofrequency-induced thermotherapy (RFITT) of the terminal branches of the recurrent nerve.

METHODS

Between 2009 and 2015, 11 patients (six females and five males aged from 32 to 91 years) with adductor SD were treated with RFITT. Pre-operative and post-operative vocal assessments (VHI-30, GRBASI, and acoustic-aerodynamics measurements), number of surgical revisions, delay between procedures, and post-operative complications were recorded. Statistical analyses were carried out on the first vocal assessment performed 2-8 weeks after the first procedure.

RESULTS

Based on available data from ten patients, voice handicap index (VHI) showed improvement with a mean value of -17.7 points (p-value (pval) = 0.014, adjusted p-value (adj pval) = 0.21); instability has also revealed improvement in six patients (pval = 0.05, adj pval = 0.31). Four patients underwent only one procedure including one patient showing still long-term beneficial results after 5 years of follow-up. Other patients required one to three new procedures with an average time between procedures of 15.3 months. Over 24 surgeries performed on a total of 11 patients, one definitive treatment-related severe adverse event was reported.

CONCLUSION

Thanks to long-lasting effect, repetitive treatments are less frequent compared to botulin toxin therapy. In our opinion, RFITT is a promising alternative to botulin toxin as a second-step procedure in case of toxin resistance or patient's lack of compliance.

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.

Non-aesthetic uses of botulinum toxin in the head and neck

INTRODUCTION

The use of botulinum toxin in the specialty of aesthetic surgery in the head and neck is well known. However, it has also been used for other conditions affecting the head and neck, and in recent years its use, as well as the number of relevant applications, has expanded enormously.

REVIEW

This article presents a summary of the current range of uses in the laryngeal, pharyngeal, cervical, oromandibular and facial muscles and salivary glands. We highlight particular conditions focusing on dystonia (laryngeal, craniocervical, oromandibular and cervical), multiple system atrophy, migraines, facial nerve palsy, post-laryngectomy, cricopharyngeal dysphagia, Zenker's diverticulum, retrograde cricopharyngeal dysfunction disorder, sialorrhea and gustatory sweating (Frey's syndrome).

CONCLUSION

This article should aid the ear, nose and throat surgeon garner knowledge about the range of uses for botulinum toxin in the head and neck.

Factors influencing long-term treatment response to botulinum toxin injection for spasmodic dysphonia

OBJECTIVE

The purpose of this study was to evaluate the outcomes of long-term botulinum toxin type A (BoNTA) treatment for adductor spasmodic dysphonia (AdSD) and to determine the factors predictive of treatment response by investigating dose stability and average intervals.

DESIGN

Retrospective cohort study.

SETTING

Academic tertiary medical centre.

EXPOSURES

A total of 470 patients with adductor spasmodic dysphonia, who received electromyography-guided BoNTA injections over 12 years, were retrospectively enrolled in this study.

MAIN OUTCOMES AND MEASURES

The patients' demographic data, baseline voice dynamics and treatment profiles (dose, frequency and intervals) were evaluated. Factors correlating with the dose adjustment ratio (number of increasing dosing/total number of BoNTA toxin injections) and changes in intervals between injections were statistically analysed.

RESULTS

A total of 122 patients, who received ≥ 4 injections and whose average treatment interval was < 240 days, were finally evaluated. Of them, 115 (94.3%) were female and seven (5.7%) were male, and the mean age at initial treatment was 34.89 ± 13.07 and 41.14 ± 12.71 years, respectively. On average, patients received 18.00 ± 13.33 injections (1.67 ± 0.60 U/injection) to alternating unilateral vocal folds. The treatment period was 65.07 ± 43.28 months and the mean interval between injections was 4.16 ± 1.28 months. The mean dose adjustment ratio among patients who received ≥ 4 injections was 0.15 ± 0.13, and dose changes occurred 4.36 times/patient. The patients' age and gender significantly affected the treatment response, where younger or female patients showed greater dosing variability and shorter intervals between injections. However, the baseline voice dynamics (voice handicap index, fundamental frequency, jitter, shimmer, noise-to-harmonic ratio, maximum phonation time and degree of voice breaks) did not predict the dose adjustment ratio or interval changes. In addition, patients with fluctuating doses showed lower age and higher VHI subscale scores, and patients with short-treatment interval (< 100 days) showed higher SDF0.

CONCLUSIONS

Almost all patients received stable low doses of BoNTA over time, irrespective of the baseline results. Patients' age, gender and VHI scores were correlated with poor treatment responses, such as frequent dose changes and shorter intervals between injections.

Methodological Quality of Systematic Reviews and Meta-analyses Published in High-Impact Otolaryngology Journals

OBJECTIVE

To assess the methodological quality of intervention-focused systematic reviews (SRs) and meta-analyses (MAs) published in high-impact otolaryngology journals.

DATA SOURCES

Ovid Medline, Embase, and Cochrane Library.

REVIEW METHODS

A comprehensive search was performed for SR and MA citations from 2012 to 2017 in the 10 highest impact factor otolaryngology journals. Abstracts were screened to identify published manuscripts in which the authors indicated clearly that they were performing an SR or MA. Applying a modified typology of reviews, 4 reviewers characterized the review type as SR, MA, or another review type. A simplified version of the AMSTAR 2 (A MeaSurement Tool to Assess systematic Reviews 2) tool was used to assess the reporting and methodological quality of the SRs and MAs that were focused on interventions.

RESULTS

Search and abstract screening generated 499 manuscripts that identified themselves as performing an SR or MA. A substantial number (85/499, 17%) were review types other than SRs or MAs, including 34 (7%) that were literature reviews. In total, 236 SRs and MAs focused on interventions. Over 50% of these SRs and MAs had weaknesses in at least 3 of the 16 items in the AMSTAR 2, and over 40% had weaknesses in at least 2 of the 7 critical domains. Ninety-nine percent of SRs and MAs provided critically low confidence in the results of the reviews.

CONCLUSION

Intervention-focused SRs and MAs published in high-impact otolaryngology journals have important methodological limitations that diminish confidence in the results of these reviews.

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.

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

Laryngeal Botulinum Toxin Injection for Vocal Tremor: Utility of Concurrent Strap Muscle Injection

OBJECTIVES/HYPOTHESIS

Vocal tremor is a neurologic disorder that can be treated with laryngeal botulinum toxin injections (LBTX). We sought to describe our experience with thyroarytenoid and concurrent strap muscle injection.

STUDY DESIGN

Retrospective chart review.

METHODS

A chart review was performed of all patients with a primary diagnosis of vocal tremor treated with LBTX from 2012 through 2017.

RESULTS

Twenty-one patients were included (mean age 69 years, 100% female). Thirteen patients (62%) had a minor component of spasmodic dysphonia in addition to their tremor. Fourteen patients had vertical and horizontal components to their tremor, and two had horizontal tremor alone. The remaining five patients did not have clear characterization of their tremor. A total of 49 injections were reviewed (25 thyroarytenoid [TA], 24 thyroarytenoid and strap muscle [TA+S]), and patients reported subjective voice benefit with 48 (96%) of these (92% TA, 100% TA+S). When available, the postprocedural change from baseline Voice Handicap Index-10 and Consensus Auditory Perceptual Evaluation of Voice scores were calculated (mean overall: -1.9, -7.8; TA: -2.7, -3.5; TA+S: -1.4, -10.3, respectively). Subjective patient improvement ratings (scale 0%-100%) were obtained for 46 injections, with a mean of 70% improvement per injection. Of patients with both horizontal and vertical tremor, outcomes were improved with TA+S injection versus TA alone (mean improvement 74% vs. 35%, P < .005).

CONCLUSIONS

There is utility in the characterization of vertical and horizontal components of vocal tremor. Patients with both appear to have increased benefit with injection of strap muscles in addition to thyroarytenoid muscles.

LEVEL OF EVIDENCE

4 Laryngoscope, 129:1433-1437, 2019.

Chemodenervation of the Larynx

Botulinum neurotoxin (BoNT) has existed for thousands of years; however, it was not medically utilized until investigations into its therapeutic use began in sincerity during the late 1970s and 1980s. This, coupled with the reclassification of spasmodic dysphonia as a focal dystonia, led to the use of chemodenervation for this disorder, which has since become a refined technique. Indeed, due to its safety and efficacy, BoNT has been investigated in multiple neurolaryngology disorders, including spasmodic dysphonia, vocal tremor, and muscle tension dysphonia. BoNT has been shown to be a useful and safe adjunct in the treatment for these disorders and may reduce or eliminate oral pharmacotherapy and/or prevent the need for a surgical intervention. We present the historical background, development, proposed mechanisms of action, uses, and techniques for administering BoNT for laryngeal disorders, with a particular focus on spasmodic dysphonia.