Point-touch technique of botulinum toxin injection for the treatment of spasmodic dysphonia

Novel Image-Guided Simulator for Transcervical Intralaryngeal Injection Training

OBJECTIVE(S)

To assess the impact of a novel 3D-printed simulation model with Brainlab Image Guidance on enhancing otolaryngology residents' skills and confidence in performing transcervical intralaryngeal injection (TII) compared with conventional training methods.

METHODS

Utilizing a 3D-printed larynx model derived from computed tomography (CT) scans, this study involved 16 otolaryngology residents divided into two groups for TII training: one with Brainlab Image Guidance (LMIG) and the other without (LM). Pre- and post-training evaluations measured participants' confidence while the Brainlab system measured the accuracy of their needle placements.

RESULTS

After training, participants exhibited a significant increase in confidence with an average rise from 1.56 to 2.75 on a 5-point scale. The LMIG group outperformed the LM group in accuracy achieving statistically significant reductions in target distances after training (3.5 mm right, 3.6 mm left). The LMIG also demonstrated a significantly greater increase in procedural confidence over the LM group after training.

CONCLUSION

The TII laryngeal model with Brainlab Image Guidance significantly improves procedural confidence and accuracy among otolaryngology residents, signifying potential advantage over a more conventional training approach. The model's realistic tactile and live instrument positioning feedback augments the process of surgical skill refinement in a controlled, risk-free, simulation environment.

LEVEL OF EVIDENCE

NA Laryngoscope, 2024.

Treatment Outcome Measures for Spasmodic Dysphonia: A Systematic Review

PURPOSE

This systematic review aims to identify instruments used to evaluate treatment outcomes for people with spasmodic dysphonia.

METHODS

Electronic database (PubMed, Cochrane Library, Embase, and CINAHL) searches and hand-searching identified studies that evaluated treatment approaches for spasmodic dysphonia which included pre and post outcome data.

RESULTS

A total of 4714 articles were retrieved from searching databases; 1165 were duplicates. Titles and abstracts of 3549 were screened, with 171 being selected for full-text review. During full-text review, 101 articles were deemed suitable for inclusion. An additional 24 articles were identified as suitable for inclusion through hand-searching of reference lists. Data was extracted from 125 studies, identifying 220 outcome measures. As per the World Health Organization's International Classification of Functioning (ICF), the majority measured body functions (n = 212, 96%). Outcomes that explored communication and participation in everyday life and attitudes towards communication (ie, activity and participation domains) were infrequent (n = 8; 4%). Quality of life, a paradigm outside of the scope of the ICF, was also captured by four outcome measures. No instruments evaluating communication partners' perspectives were identified.

CONCLUSIONS

Currently there is no unified approach to the measurement of outcomes in SD treatment research. Development and implementation of a core outcome set is recommended to facilitate improved understanding of the efficacy of current and new treatment options.

Thyroarytenoid botulinum toxin injection for refractory laryngeal contact granuloma

BACKGROUND

Although there are many treatments for laryngeal contact granuloma (LCG), some patients still fail treatment. Botulinum toxin A injection vocal cords may be a salvage therapy.

OBJECTIVES

To study the efficacy of thyroarytenoid botulinum toxin A injection for the treatment of refractory LCG.

MATERIAL AND METHODS

From May 2021 to March 2022, 23 male patients with refractory idiopathic LCG were treated by injection of botulinum toxin A into the thyroarytenoid muscle via the thyrohyoid membrane approach. Inspiratory-phase laryngoscopy images were collected before treatment and 3 months after injection treatment. The lesion size was evaluated with the Farwell granuloma endoscopic grading system and Image J software.

RESULTS

The average age of 23 patients was 49 years. The dose of botulinum toxin injection ranged from 2.5 to 5 units. Three months after injection, 17 patients were cured, 2 patients showed marked improvement, and 4 patients did not experience any effect. The total efficacy rate was 82.61% (19/23), and no serious complications occurred. Almost all patients experienced hoarseness within one week after injection; they gradually recovered after one month, and their voice returned to baseline at 3 months.

CONCLUSIONS

Thyroarytenoid botulinum toxin injection is an effective method for resolving refractory LCG.

Low-Dose LEMG-Guided Botulinum Toxin Type A Injection for Intractable Vocal Process Granulomas

OBJECTIVE

Vocal process granuloma (VPG) has a varied treatment success rate and may frustrate patients and physicians due to poor outcomes. There is still a lack of standard protocols to manage VPG. This study aimed to review the efficiency of a standardized low-dose laryngeal electromyographic (LEMG)-guided botulinum toxin A (BTA) injection in intractable vocal granulomas.

METHODS

Twenty-four patients with intractable VPG were recruited. All patients underwent percutaneous LEMG-guided BTA injection on the thyroarytenoid-lateral cricoarytenoid muscle complex in an office setting. The injecting dose was standardized to 1 U in 0.1 mL normal saline at a time. We evaluated the treatment effect by measuring the lesion size with serial laryngoscope evaluations.

RESULTS

The postinjection follow-up time varied from 3 to 23 months. Twenty-one patients (87.5%) experienced complete regression of the granuloma over 1-7 months (median 3 months). No major adverse effects were noted during the follow-up period.

CONCLUSION

For recalcitrant VPG, LEMG-guided low-dose BTA injection has the potential to be a safe, efficient, and effective treatment.

Laryngeal Electromyography-Guided Hyaluronic Acid Vocal Fold Injections for Glottic Insufficiency

OBJECTIVES

To assess voice outcomes using the novel technique of in-office laryngeal electromyography-guided vocal fold injections (LEVFI) with hyaluronic acid to treat glottal insufficiency. Secondary objectives included determining the complication/completion rates and if any factors were associated with improved voice outcomes.

METHODS

Retrospective review of patients who received their first LEVFI from August 2017 to December 2018. Three- and six-month voice outcomes were assessed. Outcomes included voice handicap index-10 (VHI-10), maximum phonation time (MPT), perceptual analysis of voice (GRBAS), fundamental frequency, and stroboscopy.

RESULTS

Of the 121 eligible patients (55.4% male, age 63.7 years), 94 (77.7%) had complete 3-month data and 59 (48.8%) had complete 6-month data. VHI-10 was significantly improved from 25.7 ± 7.5 to 20.9 ± 10.9 at 3 months (P < .001) and to 19.1 ± 11.5 at 6 months (P < .001). MPT improved from 6.2 ± 5.4 seconds to 9.4 ± 7.1 seconds at 3 months (P < .001) and to 11.3 ± 8.2 seconds at 6 months (P < .001). GRBAS was improved in 74.8% of patients ([65.2, 82.8] 95% CI) at 3 months and 80.8% ([69.9, 89.1]) 95% CI) at 6 months. Stroboscopy showed a glottic gap improvement in 74.8% of patients ([65.8, 82.4] 95% CI) at 3 months and in 80.3% ([65.9, 88.5] 95% CI) at 6 months. Fundamental frequency was unchanged, as expected. Multivariate analysis reported that no factors were associated with better voice outcomes. Overall, 177/181 (97.8%) injections were completed. There were no complications.

CONCLUSION

In-office LEVFI is an effective, novel technique to treat glottic insufficiency with improved voice outcomes, high completion rate, and no significant complications.

Vocal fold medialization-A 5-year series of single surgeon consecutive medialization with review of literature

INTRODUCTION

ENT UK released guidelines in 2010 detailing the requisite structure for the creation of a laryngeal intervention clinic. The senior author's practice is the only one regionally that offers this service, and our objective was to review this to determine whether vocal cord medialization injections were showing an improvement in quality of voice for patients.

MATERIALS AND METHODS

Patients were reviewed in a specialist voice clinic prior to being offered vocal cord injection under local anaesthetic in a separate dedicated weekly clinic. They would be assessed by the senior author and a dedicated voice specialist speech and language therapist (SALT). This would include a preinjection grade, roughness, breathiness, asthenia, and strain (GRBAS), Voice Handicap Index (VHI)-10, and the measuring of maximum phonation time (MPT) with the aid of Opera Vox Apple iPad application.

RESULTS

Data were available for 186 injections, on patients with a median age of 66 years (interquartile range [IQR]: 51-75), of whom 61% were male. VHI-10 score improved significantly, from a mean of 26.7 to 12.5 (P < .001). A significant improvement in MPT was also observed, from a median of 3.0 to 6.3 (N = 66, P < .001). Improvements in all components of the GRBAS score were also observed (all P < .001), with between 43% and 88% of cases reporting reductions after the procedure. Patients receiving a repeat procedure saw a significantly smaller improvement in VHI-10 than those where it was the primary treatment (mean reduction: 9.8 vs 15.5, P = .018). Analysis of MPT found a significant correlation between the quantity of injection material used and the degree of improvement observed (rho = 0.355, P = .004).

CONCLUSION

Vocal Cord local anaesthetic medialization injection is a swift, safe, and effective short-term method of improving dysphonia.

Thyrohyoid Approach for Vocal Fold Augmentation

Objectives:

I performed a retrospective chart review to evaluate the patient tolerance and clinical results of a new technique for office-based vocal fold augmentation.

Methods:

Ten patients undergoing the thyrohyoid approach for vocal fold augmentation were asked to rate their tolerance of the procedure using a 10-point rating scale (1 = “no problem” and 10 = “very uncomfortable”). The patients also filled out a quality-of-life survey (Voice Handicap Index-10) immediately before and 1 month after the procedure. I reviewed the preprocedure and postprocedure stroboscopic findings. The findings analyzed included changes in wave symmetry and glottal closure, and evidence of implant migration.

Results:

All patients successfully underwent the procedure. The mean patient tolerance score was found to be 2.1. The average score on the Voice Handicap Index-10 improved from 21.3 before the procedure (SD, 9.23) to 7.5 after the procedure (SD, 5.77). These values were compared by use of a paired t-test, and the difference was found to be significant, with a p value of .01. The analysis of stroboscopic results revealed “improvement” or “no change” in the wave symmetry, “improvement” in glottal closure, and “no evidence of migration” after the procedure in all cases.

Conclusions:

The study findings demonstrate that the thyrohyoid approach can be used successfully in patients who need vocal fold augmentation, and that it is generally well tolerated.

Treatment efficacy of electromyography versus fiberscopy-guided botulinum toxin injection in adductor spasmodic dysphonia patients: a prospective comparative study

INTRODUCTION

This study prospectively evaluates and compares the treatment efficacy of botulinum toxin injection under electromyography guidance (EMG group) and percutaneous botulinum toxin injection under flexible fiberscopic guidance (fiberscopy group).

METHODS

Thirty patients with adductor spasmodic dysphonia (ADSD), who had never received treatment, were randomly allocated into EMG- or fiberscopy-guided botulinum toxin injections between March 2008 and February 2010. We assessed acoustic and aerodynamic voice parameters, and the voice handicap index (VHI) before injection and at 1, 3, and 6 months after injection.

RESULTS

The mean total dosage of botulinum toxin was similar for both groups: 1.7 ± 0.5 U for the EMG group and 1.8 ± 0.4 U for the fiberscopy group (P > 0.05). There were no significant differences in outcomes between the two groups in either the duration of effectiveness or complications such as breathy voice and aspiration.

CONCLUSION

Botulinum toxin injection under fiberscopic guidance is a viable alternative to EMG-guided botulinum toxin injection for the treatment of adductor spasmodic dysphonia when EMG equipment is unavailable.

Treatment of spasmodic dysphonia with a neuromodulating electrical implant

OBJECTIVES/HYPOTHESIS

To investigate the feasibility of an implantable electrical stimulation device to treat spasmodic dysphonia (SD) by neuromodulation of the muscle spindle gamma loop.

STUDY DESIGN

Prospective case series.

METHOD

Five subjects underwent daily stimulation of the left thyroarytenoid muscle (TA) below the level of α-motor neuron activation (AMNA) for 5 consecutive days. Professional and patient voice evaluations were performed. Transcartilagenous placement of an implantable stimulation device lead was investigated in anesthetized porcine and cadaveric human models.

RESULTS

Three of 5 subjects improved in all categories of evaluation. One subject improved in three of four categories. These four subjects described significant carryover of effect after treatment. The fifth subject evidenced improvement until contracting an upper respiratory infection on day 3. Transcartilagenous electrode placement into the porcine TA with muscle stimulation was successful. The electrode lead was passed from the cadaveric larynx to the mastoid tip in the subplatysma layer with an absence of tension.

CONCLUSION

The symptoms of SD improve after electrical stimulation of the TA at levels below AMNA. This is likely through neuromodulation of the muscle spindle gamma loop. Implantation of an electrode into the TA with a postauricular implanted stimulator is feasible with modifications of an already existing device. With further investigation, such a device has the potential to deliver an alternative treatment for SD.

LEVEL OF EVIDENCE

4.

Office-based botulinum toxin injections

Botulinum toxin injections are an effective treatment option for several laryngeal disorders. This article reviews the indications, procedural techniques, potential complications, and outcomes of Botox injections for laryngeal disorders.

Surgery or Botulinum Toxin for Adductor Spasmodic Dysphonia: A Comparative Study

Objectives:

Currently, botulinum toxin (Botox) injection is the standard of treatment for adductor spasmodic dysphonia (ADSD). We sought to compare the outcome of selective laryngeal adductor denervation-reinnervation (SLAD-R) surgery for ADSD to that of Botox injections.

Methods:

Patient-oriented measures (VHI-10) and objective single-blinded gradings of digital voice recordings were utilized as outcome measures. The surgical cohort, recruited by retrospective patient selection, consisted of 77 patients with a mean follow-up time of 7.54 ± 2.55 years (range, 2.2 to 14.2 years). The injection cohort, recruited prospectively, included 28 patients with a mean follow-up time of 46.37 ± 5.51 days (range, 36 to 54 days).

Results:

As measured by the VHI-10, the surgical patients had significantly improved voice handicap outcome scores (mean, 14.4 ± 13.6) as compared to the patients who had Botox injection (mean, 26.5 ± 12.1; p = 0.001). Aside from VHI-10 item 2, the surgical group demonstrated significantly improved voice-related function on each VHI-10 component (p = 0.01). Within the injection subgroup, 88% agreed that Botox successfully treats their ADSD, yet only 63% agreed that Botox improves their speech consistently. Within the surgical subgroup, 82% would recommend this surgery to others, and 78% agreed that their voice was actually better after surgery than after Botox. Objective voice ratings demonstrated similar levels of breathiness and overall voice quality in the treatment subgroups.

Conclusions:

When indicated, the SLAD-R surgery for ADSD demonstrates outcomes equal to or superior to those of the current standard of Botox injections.

Efficacy of laryngeal botulinum toxin injection: comparison of two techniques

OBJECTIVES/HYPOTHESIS

It is hypothesized that there is no difference in the effectiveness of botulinum toxin (BTX) injection between electromyography (EMG)-guided and non-EMG guided "point-touch" techniques in the treatment of adductor spasmodic dysphonia.

STUDY DESIGN

Retrospective chart review.

METHODS

Patients selected for evaluation underwent sequential treatment by one or both of the senior authors using two different injection techniques with similar BTX dilution and preparation. Data gathered included dose injected, injection effect, and presence and duration of breathiness and dysphagia after injection. Statistical analysis was performed used a generalized estimating equations model.

RESULTS

A total of 417 injections in 64 patients were analyzed. There was no difference in the rate of successful injections between the EMG-guidance group and the non-EMG guidance group (94.4% and 93.2%, respectively; P = .7).

CONCLUSIONS

This unique study demonstrates that efficacy of BTX does not necessarily depend on the method of injection used. In experienced hands, excellent clinical results can be achieved with either EMG-guided or non-EMG guided injection techniques.

Efficacy of laryngeal botulinum toxin injection: comparison of two techniques

OBJECTIVES/HYPOTHESIS

It is hypothesized that there is no difference in the effectiveness of botulinum toxin (BTX) injection between electromyography (EMG)-guided and non-EMG guided "point-touch" techniques in the treatment of adductor spasmodic dysphonia.

STUDY DESIGN

Retrospective chart review.

METHODS

Patients selected for evaluation underwent sequential treatment by one or both of the senior authors using two different injection techniques with similar BTX dilution and preparation. Data gathered included dose injected, injection effect, and presence and duration of breathiness and dysphagia after injection. Statistical analysis was performed used a generalized estimating equations model.

RESULTS

A total of 417 injections in 64 patients were analyzed. There was no difference in the rate of successful injections between the EMG-guidance group and the non-EMG guidance group (94.4% and 93.2%, respectively; P = .7).

CONCLUSIONS

This unique study demonstrates that efficacy of BTX does not necessarily depend on the method of injection used. In experienced hands, excellent clinical results can be achieved with either EMG-guided or non-EMG guided injection techniques.

The point-touch technique for botulinum toxin injection in adductor spasmodic dysphonia: quality of life assessment

Background:

Botulinum toxin injection under electromyographic guidance is the ‘gold standard’ for adductor spasmodic dysphonia treatment. The point-touch technique, an alternative injection method which relies on anatomical landmarks, is cheaper, quicker and more accessible, but has not yet gained widespread acceptance due to concerns about patient satisfaction.

Objective:

To assess swallowing and voice-related quality of life following point-touch botulinum toxin injection in adductor spasmodic dysphonia patients.

Setting:

Stanford University Voice and Swallowing Center.

Design:

Prospective case series (evidence level four).

Methods:

Consecutive adductor spasmodic dysphonia patients with a stable botulinum toxin dose–response relationship were recruited prospectively. The Eating Assessment Tool and Voice-Related Quality of Life questionnaires were completed pre-treatment and at 10 and 30 per cent completion of the injection cycle, respectively.

Results:

Thirty-seven patients completed follow up. The mean total botulinum toxin dose was 0.88 units. Pre-treatment Voice-Related Quality of Life questionnaire results reflected the burden of disease. Post-treatment Eating Assessment Tool and Voice-Related Quality of Life questionnaire results were collected at 2.53 and 7.84 weeks, respectively; the former showed an increase in dysphagia, albeit statistically insignificant, while the latter showed significantly improved scores (both domain and total).

Conclusion:

The point-touch technique is a viable alternative for botulinum toxin injection in the treatment of adductor spasmodic dysphonia.

Percutaneous injection laryngoplasty in the management of acute vocal fold paralysis

OBJECTIVES/HYPOTHESIS

To evaluate the clinical outcome of patients with acute vocal fold paralysis treated with bovine collagen via percutaneous injection laryngoplasty under simple topical anesthesia.

STUDY DESIGN

Retrospective case series.

METHODS

The charts of 38 consecutive patients with acute unilateral vocal fold paralysis who underwent percutaneous injection laryngoplasty under simple topical anesthesia were reviewed. Symptoms and laryngeal function were assessed pre- and postinjection using the Glottal Function Index (GFI), GRBAS Dysphonia Scale, Functional Outcome Swallowing Scale (FOSS), and maximum phonation time (MPT).

RESULTS

Mean GFI, GRBAS, FOSS, and MPT improved from 13.71 to 7.68, 7.24 to 3.95, 3.70 to 2.20, and 12.87 to 16.45, respectively (P < or = .0001). There were no complications related to the procedure. In seven patients requiring tube feeding secondary to dysphagia and aspiration, injection was successful in restoring oral alimentation in only three patients, with the four failures occurring in patients with multiple cranial neuropathies.

CONCLUSIONS

Percutaneous injection laryngoplasty is a viable option for immediate rehabilitation of acute vocal fold paralysis, and can be performed in the inpatient setting. With dysphagia and aspiration secondary to multiple cranial nerve palsies, medialization of the paralyzed cord alone may be insufficient to restore safe oral alimentation.

Anatomic direction of entry for botulinum toxin injection to treat the adductor spasmodic dysphonia in Thais

Background: Botulinum toxin injections into the thyroarytenoid (TA) muscle of the larynx is the most popular treatment for adductor spasmodic dysphonia. Injection is usually done by percutaneous transcricothyroid membrane with either electromyography (EMG) or fiberoptic laryngoscopy (FOL) to verify placement of the needle within the TA muscle. This procedure requires a working knowledge of three-dimensional anatomy of the larynx to establish the direction for the accurate placement of the needle. Objective: Find out the appropriate angles and depth of the needle for placement of percutaneous transcricothyroid membrane method of botulinum toxin injection by means of studying the larynges of Thai cadavers. Methods: The descriptive study was performed in 45 Thai freshly thawed cadavers. The angle of the needle from midline sagittal plane, the angle in superior relation to tracheal plane, and the depth from midline cricothyroid (CT) membrane to midlength of TA muscle were measured from the two views of photographs, anteroposterior and lateral. Results: The mean angle of 24.2±6.76° (mean±SD) from the midline sagittal plane in male and 24.9±7.6° in female were worked out. A mean angle in superior relation to the tracheal plane was 47.7±7.8° and 51.4±9.6° in male and female, respectively. The mean depth was 1.7±0.2 and 1.4±0.1 cm in male and female, respectively. Conclusion: The mean angles and depth of the needle insertion from the midline of CT membrane to the center of TA muscle in Thai laryngeal specimens were evaluated. These values were different from the studies in Caucasians, but it could provide a direct relationship to the build of the races. This knowledge may help laryngologists do this procedure more accurately with better outcome, especially in hospitals that have no EMG or FOL guide.

Comparative Analysis of Efficiency of Injection Laryngoplasty Technique for with or without Neck Treatment Patients: A Transcartilaginous Approach Versus the Cricothyroid Approach

Objectives

These days, the main injection laryngoplasty technique is cricothyroid (CT) approach. However, patients who have previously undergone other neck treatments, such as thyroidectomy or neck dissection have distorted anatomical landmark makes this approach more difficult. The aim of this study is to determined the efficiency of transcartilaginous (TC) approah as compared with CT approach for unilateral vocal fold paralysis patients, especially for previously neck treated patients.

Methods

From March 2005 to February 2008, 137 consecutive injection laryngoplasties were performed in patients with unilateral glottic insufficiency. Percutaneous injection was performed under local anesthesia into the vocalis muscle, using disposable 25 G 4 cm long needles through the cricothyroid membrane or directly through the thyroid cartilage. Of the 137 patients, 124 completed acoustic, perceptual, stroboscopic, and subjective evaluations prior to the injection and at 3 months after the injection.

Results

In the 124 patients, the CT and TC approaches were used in 94 and 30 patients, respectively. Acoustic and perceptual parameters (GRBAS, MPT, jitter, shimmer), voice handicap index, and grades of mucosal waves and glottic closure were significantly improved after the injection in both the CT and TC groups (P<0.05). Only two patients (6.6%) had penetration difficulties, because of ossification of the thyroid cartilage. The overall success rates of the CT and TC approaches were 86.2%, 93.3%, respectively. However, the success rate of the TC approach in patients who had previously undergone neck treatments was significantly higher than that of the CT approach (100% vs. 65% P<0.05).

Conclusion

Based on the preliminary results of this trial, injection laryngoplasty using a TC approach was an effective alternative to the CT approach, especially in patients who had previously undergone neck surgeries.

Recommendations of the Neurolaryngology Study Group on laryngeal electromyography

The Neurolaryngology Study Group convened a multidisciplinary panel of experts in neuromuscular physiology, electromyography, physical medicine and rehabilitation, neurology, and laryngology to meet with interested members from the American Academy of Otolaryngology Head and Neck Surgery, the Neurolaryngology Subcommittee and the Neurolaryngology Study Group to address the use of laryngeal electromyography (LEMG) for electrodiagnosis of laryngeal disorders. The panel addressed the use of LEMG for: 1) diagnosis of vocal fold paresis, 2) best practice application of equipment and techniques for LEMG, 3) estimation of time of injury and prediction of recovery of neural injuries, 4) diagnosis of neuromuscular diseases of the laryngeal muscles, and, 5) differentiation between central nervous system and behaviorally based laryngeal disorders. The panel also addressed establishing standardized techniques and methods for future assessment of LEMG sensitivity, specificity and reliability for identification, assessment and prognosis of neurolaryngeal disorders. Previously an evidence-based review of the clinical utility of LEMG published in 2004 only found evidence supported that LEMG was possibly useful for guiding injections of botulinum toxin into the laryngeal muscles. An updated traditional/narrative literature review and expert opinions were used to direct discussion and format conclusions. In current clinical practice, LEMG is a qualitative and not a quantitative examination. Specific recommendations were made to standardize electrode types, muscles to be sampled, sampling techniques, and reporting requirements. Prospective studies are needed to determine the clinical utility of LEMG. Use of the standardized methods and reporting will support future studies correlating electro-diagnostic findings with voice and upper airway function.

Botulinum toxin as adjunctive therapy in refractory laryngeal granuloma

Objective:

This study evaluated the role of botulinum toxin type A in the treatment of refractory laryngeal granulomas.

Study design and setting:

Retrospective clinical review at a tertiary care hospital. Seven patients with vocal process granulomas underwent percutaneous injection of botulinum toxin into both vocal folds, performed in an office setting. Total doses ranged from 10 to 25 U, divided between both vocal folds.

Results:

All patients experienced resolution of their granulomas over two to seven weeks. No patient developed aspiration pneumonia. All patients experienced hoarseness secondary to the injections, but voice quality returned to baseline in all patients as the toxin was degraded.

Conclusions:

Botulinum toxin is safe and effective therapy in resolving vocal process granulomas in patients refractory to traditional therapy. The optimal treatment dose remains to be determined.

Significance:

Percutaneous botulinum toxin injection is helpful in resolving laryngeal granulomas.

Evidence for the effectiveness of botulinum toxin for spasmodic dysphonia from high-quality research designs

The practice of evidence-based medicine promotes use of the knowledge ascertained from high quality research designs. The objective of this review was to determine what evidence has been provided from high quality research designs (e.g., randomized control trials or high quality prospective, matched group cohort studies), through December of 2006, relative to the effectiveness of botulinum toxin for treating spasmodic dysphonia. Results of the review indicated that no new high quality (Class I or Class II) studies have been published since 2001. One Class I study has been published since 1973, which found significant treatment effects for acoustic and perceptual variables of vocal function. Four Class II studies have been published during this same time frame, all finding significant treatment effects, though the nature of studied factors was variable between investigations. Based on the quality of evidence scale used, botulinum toxin can be considered an effective treatment for adductor spasmodic dysphonia.

Botulinum toxin: Clinical use

Since its development for the use of blepharospasm and strabismus more than 2.5 decades ago, botulinum neurotoxin (BoNT) has become a versatile drug in various fields of medicine. It is the standard of care in different disorders such as cervical dystonia, hemifacial spasm, focal spasticity, hyperhidrosis, ophthalmological and otolaryngeal disorders. It has also found widespread use in cosmetic applications. Many other indications are currently under investigation, including gastroenterologic and urologic indications, analgesic management and migraine. This paper is an extensive review of the spectrum of BoNT clinical applications.

Botulinum toxin for treating spasmodic dysphonia (laryngeal dystonia): a systematic Cochrane review

BACKGROUND

Spasmodic dysphonia is a neurological voice disorder characterized by involuntary adductor (towards midline) or abductor (away from midline) vocal fold spasms during phonation which result in phonatory breaks. Botulinum toxin is currently the gold standard of treatment.

OBJECTIVE

To determine the efficacy of botulinum toxin therapy for the treatment of spasmodic dysphonia.

DESIGN

Systematic Cochrane review.

SEARCH STRATEGY

The search strategy for this review complied with Cochrane standards. We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (1966 to February 2005), EMBASE (1974 to February 2005), CINAHL (through February 2005), Dissertation Abstracts International (1975 to February 2005) and PsycINFO (1975 to February 2005). The search engine FirstSearch was also used (February 2005). Reference lists for all the obtained studies and other review articles were examined for additional studies.

SELECTION CRITERIA

All randomized control trials where the participants were randomly allocated prior to intervention and in which botulinum toxin was compared to an alternative treatment, placebo or non-treated control group were included.

DATA COLLECTION AND ANALYSIS

Two reviewers independently evaluated all potential studies meeting the selection criteria noted above for inclusion.

MAIN RESULTS

Only one study in the literature met the inclusion criteria. This was the only study identified which reported a treatment/no treatment comparison. It reported significant beneficial effects for fundamental frequency (Fo), Fo range, spectrographic analysis, independent ratings of voice severity and patient ratings of voice improvement.

REVIEWER'S CONCLUSIONS

The evidence from randomized controlled trials supporting the effectiveness of botulinum toxin for management of spasmodic dysphonia is deficient. The lack of supporting evidence from randomized controlled trials results in an inability to draw unbiased generalized conclusions regarding the effectiveness of botulinum toxin for all types of spasmodic dysphonia.

Botulinum toxin therapy of laryngeal muscle hyperactivity syndromes: comparing different botulinum toxin preparations

Spasmodic dysphonia (SD) is a focal dystonia characterized by a strained, strangled voice. Botulinum toxin is a symptomatic treatment for SD and has become the mainstay of therapy over the last two decades. In this manuscript, we briefly review different laryngeal muscle hyperactivity syndromes, their injection techniques and toxins currently available. Adductor SD is the most common indication for botulinum toxin treatment in the larynx. All studies report similar results with regard to improvement, patient satisfaction and side effects. We describe different injection techniques to treat this disorder such as the percutaneous, transoral, transnasal, point-touch techniques. In abductor SD, a subtype of SD, the treatment is aimed at the posterior cricoarytenoid muscle. Other applications of botulinum toxin in the larynx include spasmodic laryngeal dyspnea and voice tremors. We also review injection techniques, the different toxin types used, and toxin doses.

Thyrohyoid Approach to Cidofovir Injection: A Case Study

Various techniques for injection into the larynx have been well described, including transoral injection with indirect laryngoscopy or direct laryngoscopy and transcutaneous injection through the thyroid cartilage or cricothyroid membrane. We describe a case not amenable to these techniques, in which entry through the thyrohyoid membrane for injection of cidofovir was successfully performed with a thyrohyoid approach. This technique is described, and comparisons are made with currently available techniques.

Speech intelligibility in severe adductor spasmodic dysphonia

This study compared speech intelligibility in nondisabled speakers and speakers with adductor spasmodic dysphonia (ADSD) before and after botulinum toxin (Botox) injection. Standard speech samples were obtained from 10 speakers diagnosed with severe ADSD prior to and 1 month following Botox injection, as well as from 10 age- and gender-matched healthy adults. This yielded 3 speaking conditions: pre-Botox injection, post-Botox injection, and normal control. Thirty phrases were extracted from the speech samples and arranged in a counterbalanced listening experiment. Thirty students, reporting little experience with distorted speech, served as listeners. Each listener's response was scored for words correctly identified using a liberal scoring criterion yielding a percentage of words correctly identified for each speaker. The results indicated that the speakers with ADSD were significantly more intelligible in the post-Botox condition than in the pre-Botox condition. The results also indicated that healthy speakers were significantly more intelligible than the speakers in both the pre- and post-Botox conditions. In general, these results indicated that intelligibility is affected in severe ADSD and that the use of Botox injection in ADSD improves intelligibility scores. However, the results also indicated that the use of Botox injection does not result in speech intelligibility similar to that of normal, non-ADSD speakers.

Botulinum toxin injections for the treatment of spasmodic dysphonia

BACKGROUND

The use of botulinum toxin for the treatment of spasmodic dysphonia is currently the treatment of choice for management of this neurological voice disorder. Over the past 20 years, botulinum toxin has been used to treat both adductor and abductor forms of the disorder, with vocal improvement noted after treatment for both. A large number of studies have attempted to document the efficacy of botulinum toxin for improvement of vocal symptoms in individuals with spasmodic dysphonia.

OBJECTIVES

To determine the effectiveness of botulinum toxin for treating spasmodic dysphonia.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (1966 to July 2003), EMBASE (1974 to July 2003 ), CINAHL (through July 2003), Dissertation Abstracts International (1975 to July 2003) and PsycINFO (1975 to July 2003). The search engine FirstSearch was also used (July 2003). Reference lists for all the obtained studies and other review articles were examined for additional studies.

SELECTION CRITERIA

All studies in which the participants were randomly allocated prior to intervention and in which botulinum toxin was compared to either an alternative treatment, placebo or non-treated control group were included.

DATA COLLECTION AND ANALYSIS

Two reviewers independently evaluated all potential studies meeting the selection criteria noted above for inclusion. One study met the inclusion criteria and was included in the final analysis.

MAIN RESULTS

Only one study in the literature met the inclusion criteria. This was the only study identified which reported a treatment/no treatment comparison. It reported significant beneficial effects for fundamental frequency (Fo), Fo Range, spectrographic analysis, independent ratings of voice severity and patient ratings of voice improvement.

REVIEWERS' CONCLUSIONS

The evidence from randomized controlled trials does not allow firm conclusions to be drawn about the effectiveness of botulinum toxin for all types of spasmodic dysphonia, or for patients with different behavioral or clinical characteristics.

Office-based treatment of laryngeal papillomatosis with percutaneous injection of cidofovir

OBJECTIVE

Our aim was to report our experience with office-based treatment of severe laryngeal papillomatosis with percutaneous injection of cidofovir in a case series of 5 patients.

STUDY DESIGN AND SETTING

We conducted a retrospective review of a case series in a tertiary academic care voice disorders clinic. Adult patients with papillomas of the vocal cords and anterior commissure received percutaneous injection using a point-touch technique. Clinical improvement or remission of the papillomatosis was noted.

RESULTS

Before initiation of office treatments, patients required direct laryngoscopy and CO(2) laser ablation of papillomas on average every 2.8 months. There were no complications related to the injection technique. During a treatment period of 7 to 16 months (mean 12 months), a significant reduction in the volume of papillomatosis was achieved in all patients. One patient received 2 treatments and another received 1 treatment in the operating room for final clearance of papillomas.

CONCLUSION

Office-based treatment of adult patients with anterior laryngeal papillomatosis using percutaneous injection of cidofovir reduces the need for repeated direct laryngoscopy and laser ablation under general anesthesia.

SIGNIFICANCE

Percutaneous injection treatment with cidofovir is a useful adjunct to direct laryngoscopy and laser ablation in the treatment of laryngeal papillomatosis.

Botox treatment in adductor spasmodic dysphonia: a meta-analysis

Over the years many studies have been conducted to document the treatment effects of Botulinum toxin type A in adductor spasmodic dysphonia. The results of these studies have led to the view that overall Botulinum toxin treatment is moderately effective. This study reviews efficacy research qualitatively and quantitatively to determine the extent to which this conclusion is fully supported by the data. Although the data indicate moderate overall improvement as a result of Botulinum toxin treatment, they also suggest significant variation across patients, measurements, and treatment conditions. This result, together with methodological limitations and lack of standardization in BT efficacy research, justifies caution when making inferences regarding BT treatment benefit in adductor spasmodic dysphonia.

Botulinum toxin: basic science and clinical uses in otolaryngology

The role of botulinum toxin as a therapeutic agent is expanding rapidly in otolaryngology. Botulinum toxin is a protease that blocks the release of acetylcholine from nerve terminals. Its effects are transient and nondestructive, and largely limited to the area in which it is administered. These effects are also graded according to dose, allowing for individualized treatment of patients and disorders. Botulinum toxin has been used primarily to treat disorders of excessive or inappropriate muscle contraction. In the field of otolaryngology, these include spasmodic dysphonia, oromandibular dystonia, and blepharospasm; vocal tics and stuttering; cricopharyngeal achalasia; various tremors and tics; hemifacial spasm; temporomandibular joint disorders; and a number of cosmetic applications. Botulinum toxin treatment has recently begun to show some benefit in the control of pain from migraine and tension headache. It may also prove useful in the control of autonomic dysfunction, as in Frey syndrome, sialorrhea, and rhinorrhea. In over 20 years of use in humans, botulinum toxin has accumulated a considerable safety record, and in many cases represents relief for thousands of patients unaided by other therapy.

Treatment of Parkinson hypophonia with percutaneous collagen augmentation

OBJECTIVES

It has been estimated that more than 70% of patients with Parkinson disease experience voice and speech disorders characterized by weak and breathy phonation, and dysarthria. This study reports on the efficacy of treating Parkinson patients who have glottal insufficiency.

STUDY DESIGN AND METHODS

Thirty-five patients underwent collagen augmentation of the vocal folds for hypophonia associated with Parkinson disease, using a new technique of percutaneous injection with fiberoptic guidance. Patient response to the collagen augmentation was determined by telephone survey.

RESULTS AND CONCLUSIONS

The procedure required minimal patient participation and was safely performed on all the patients who were studied. Results of the survey indicated that 75% of patient responses demonstrated satisfaction with the technique, compared with 16% of patient ratings reflecting dissatisfaction. These results were moderately correlated with the duration of improvement of the dysphonia. Results of this preliminary evaluation demonstrate that voice deficits in Parkinson disease are amenable to vocal fold augmentation. Because this procedure requires minimal patient participation and can be safely performed in an office setting, it may also be useful in other severely debilitating neuromotor diseases that result in glottal insufficiency and hypophonia.

Treatment of vocal fold granuloma using botulinum toxin type A

Contact granuloma of the vocal folds has been associated with abnormal use of the voice, and acid reflux may exacerbate the inflammatory process. Treatments have included voice therapy and antireflux measures. Surgical excision is considered in patients who do not respond to medical management. Localized injections of botulinum toxin type A (BOTOX) have been effective in patients with disorders of muscular control in the head and neck. In this study, granulomas resolved in six patients who underwent injection of the affected vocal folds. Botulinum toxin type A is probably successful because it prevents forceful closure of the arytenoids during phonation and coughing. Localized injection of this neurotoxin is promising both as an initial treatment and as an alternative treatment in patients who do not respond to standard therapy or who are poor surgical candidates.

Technique for injection of botulinum toxin through the flexible nasolaryngoscope

A new endoscopic method of injecting botulinum toxin into the thyroarytenoid muscles for treatment of adductor spasmodic dysphonia was evaluated. Twelve patients with adductor spasmodic dysphonia were given injections in the thyroarytenoid muscle under video visualization with a flexible catheter needle that was passed through the working channel of a flexible nasolaryngoscope. Six patients received unilateral injections, and six received bilateral injections. Preinjection and postinjection speech samples were compared by use of spectrographic analysis. Significant decreases in voice breaks and sentence duration were found after treatment with both unilateral and bilateral injections. Patient interviews and diaries documented the reported degree and duration of symptom reduction. All 12 patients reported that the injections were of significant benefit and that the endoscopic procedure was tolerable. We concluded that this is a safe and effective technique for injecting botulinium toxin into laryngeal muscles for treatment of spasmodic dysphonia.

Botulinum A toxin stimulates neurite branching in nerve-muscle cocultures

In addition to skeletal muscle paralysis, type A botulinum toxin commonly causes sprouting of motor axons in various experimental whole-animal systems. The use of type A botulinum toxin in clinical treatment of muscle spasm disorders is becoming increasingly popular. The eventual, unwanted return of involuntary activity in the treated muscles may be a consequence of such axon sprouting. We have developed a coculture model allowing the quantification of botulinum toxin-induced sprouting that shows promise for future studies on its mechanism and control. Chick embryo ciliary ganglion motor neurons were cocultured with chick leg muscle cells. The presence of type A botulinum toxin in the coculture medium was correlated with significantly increased branching frequency of neurites. Toxin-increased branching frequency occurred even when the neurons and muscle cells were separated from each other on the culture dishes, suggesting a presynaptic effect of toxin. Cocultures incubated in the presence of curare, a post-synaptic blocker, had control levels of neurite branching, ruling out the possibility that simple synaptic blockade causes sprouting but again supporting the hypothesis of a pre-synaptic activity of botulinum toxin.