Spasmodic Dysphonia Patients' Perception of Pain with Botulinum Toxin Injections

OBJECTIVES

To evaluate spasmodic dysphonia patients' perception of pain associated with laryngeal botulinum toxin (BTX) injections and to determine factors associated with higher pain scores relative to other included patients.

METHODS

Prospective cohort study. Adult patients with adductor spasmodic dysphonia that presented to a tertiary laryngology practice for BTX injections were recruited from March to July 2022. Patients completed the visual analog scale (VAS) pre-procedure to quantify predicted pain. Ten minutes post-procedure they completed VAS and the short form McGill Pain Questionnaire (SF-MPQ). Factors that may affect pain were extracted from charts. Descriptive statistics, univariate, and multivariate analyses were conducted (alpha = 0.05).

RESULTS

One hundred and nineteen patients were included (63 ± 14 yo, 26% Male). SF-MPQ reported mild pain (4.12 ± 4.05 out of 45) with a pain intensity of none to mild (0.70 ± 0.89 out of 5). Bilateral injections yielded significantly higher SF-MPQ scores (5.19 ± 4.66) than unilateral injections (3.30 ± 3.30) (p = 0.012). There was a significant VAS reduction from pre 28.9 ± 24.6 mm (out of 10 mm) to post 24.5 ± 22.3 (p < 0.001). On multiple regression analyses, receiving a bilateral injection significantly (p < 0.05) contributed to a model that predicted higher pre-VAS (p = 0.013). Bilateral injections (p < 0.05) and higher VHI-10 (p < 0.05) contributed to a model that predicted higher total SF-MPQ (p = 0.001) and affective SF-MPQ (p = 0.001) scores. Not being a professional voice user (PVU) significantly (p < 0.05) contributed to a model that predicted higher post-VAS (p = 0.008) scores.

CONCLUSIONS

BTX injections were well tolerated with low pain scores. Factors associated with higher relative predicted or experienced pain included bilateral versus unilateral injection, PVU status, and higher VHI-10.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:240-246, 2024.

Comparison of Outcome Measures (Subjective, Objective, and Patient-Based) in Laryngeal Dystonia Treatment With Botulinum Toxin A Injection

BACKGROUND

Outcome assessment in laryngeal dystonia is hindered by lack of consensus on a core set of outcome measures to quantify treatment effect and disease severity on quality of life. Potential outcome measure domains include objective voice, clinician reported, and patient reported outcome measures (PROMs) for determining treatment success and longitudinal disease tracking. We aim to determine correlations between a selections of outcome measure tools following Botulinum toxin injection.

METHODS

A selection of instruments were administered to assess adductor laryngeal dystonia patient outcomes before and after Botulinum toxin injection. Voice samples recorded using a cellular telephone application were used for objective acoustic measures (CPPS, acoustic voice quality index) and speech language pathologist perceptual analysis (CAPE-V). Additionally, patients completed a PROMs battery consisting of the Voice Handicap Index-10, Communicative Participation Item Bank-10, OMNI-Vocal Effort Scale, 3 visual analog scale (VAS) questions. Changes in these outcome measures pre-post treatment were compared between each other and with a global rating of change questionnaire (GRCQ) using Spearman's rank correlation coefficients.

RESULTS

Twenty six patients (20 female, mean age 57.7 years) participated. Using an anchor based GRCQ, patients reported Botox efficacy was the only outcome measure found to have significant correlation (r = 0.54, P = 0.022); all other outcome measures did not meet statistically significant correlation. Amongst the selected outcome tools, several moderate-strong correlations were identified, largely for outcome measures within the same domain. Most notable were correlations between the patient reported OMNI-VES and VAS questions (r > 0.68, P < 0.05), clinician CAPE-V strain and overall severity (r = 0.900, P < 0.001), and acoustic voice quality index with sustained vowel CPPs (r = -0.797, P = 0.002).

CONCLUSION

Correlation between outcome measures instruments used for patients with adductor laryngeal dystonia requires further attention. Weak correlations with an anchor based GRCQ were found for this study's selected outcome instruments. A select number of correlations were found between outcome instruments within each of the individual outcome measure domains (patient perception, clinical perception, objective acoustics), but there was largely a lack of correlation found for instruments between these three separate domains.

Treatment of relapsing functional and organic dysphonia: a narrative literature review

Information about failure and relapses is critical in deciding whether and how to treat a given condition, as well as during patient counselling before therapy. This paper aims to perform a non-systematic review of relapses and failure of dysphonia treatment in the adult population. Studies on failure and relapses after treatment of benign vocal fold lesions, functional dysphonia and neurogenic dysphonia were analysed. The frequency and the duration of follow-up were heterogeneous, and the management of relapses was reported in only a portion of the studies. Relapses after surgical treatment of benign vocal fold lesions ranged between 1% and 58% of cases, and their management was mainly surgical. Rates of relapse after voice therapy for functional dysphonia and spasmodic dysphonia were 12%-88% and 8%-63%, respectively. Rates of relapse after surgical treatment for unilateral and bilateral vocal fold paralysis were 10%-39% and 6%-25%, respectively; treatment was mainly represented by surgical revision. In conclusion, failure and relapses of functional and organic dysphonias after therapy are not rare, but treatment modalities are seldomly reported. The data from this non-systematic review stresses the need for further research in this area.

Botulinum Neurotoxin Therapy in the Clinical Management of Laryngeal Dystonia

Laryngeal dystonia (LD), or spasmodic dysphonia (SD), is a chronic, task-specific, focal movement disorder affecting the larynx. It interferes primarily with the essential functions of phonation and speech. LD affects patients' ability to communicate effectively and significantly diminishes their quality of life. Botulinum neurotoxin was first used as a therapeutic agent in the treatment of LD four decades ago and remains the standard of care for the treatment of LD. This article provides an overview of the clinical application of botulinum neurotoxin in the management of LD, focusing on the classification for this disorder, its pathophysiology, clinical assessment and diagnosis, the role of laryngeal electromyography and a summary of therapeutic injection techniques, including a comprehensive description of various procedural approaches, recommendations for injection sites and dosage considerations.

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.