Efficacy of Botulinum A Injection to the Laryngeal Adductor Compartment for Treatment of Cough

Objectives: Studies examining electromyography (EMG)-guided laryngeal onobotulinumtoxinA (BTxA) injection for chronic cough reveal promising efficacy, however, are limited by small cohorts and absent quantifiable outcomes. It further remains unclear if pulmonary disease limits efficacy, or if vagal motor neuropathy prognosticates response. We hypothesize BTxA injection results in qualitative improvement in cough, decrease in Cough Severity Index (CSI), no change in Voice Handicap Index-10 (VHI-10), and complication rates comparable to historical data. We also examine the correlation of pulmonary comorbidities and vocal fold hypomobility with treatment efficacy.Study design: Retrospective review.Methods: Charts for patients receiving percutaneous adductor compartment BTxA injection for cough were reviewed for the binary outcome of patient-reported presence or absence of improvement. Generalized estimating equations regression models were used to analyze the change in CSI (Delta CSI) and the correlation of Delta CSI with qualitative outcomes. Multivariable analyses were used to examine correlation of vocal fold hypomobility and pulmonary disease with qualitative outcomes and Delta CSI.Results: Forty-seven patients underwent 197 BTxA injections from June 2012 to June 2022. A statistical proportion of 0.698 (0.599-0.813, p < 0.0001) or 69.8% of injections resulted in subjective improvement. Mean Delta CSI was -2.12 (0.22-4.02, p < 0.05), indicating overall improvement. With and without subjective improvement, estimated Delta CSI was -4.43 and +2.68, respectively (p < 0.0001). VHI-10 did not change (0.69, p = 0.483). Neither pulmonary disease nor vocal fold hypomobility correlated with subjective improvement or Delta CSI. Dysphagia occurred following 15 (7.6%) injections with no aspiration pneumonia or hospitalization.Conclusions: BTxA injection to the laryngeal adductors may effectively treat cough with limited risk for serious complications.

Automated summary

This study aimed to investigate the efficacy and related factors of electromyography (EMG)-guided laryngeal onobotulinumtoxinA (BTxA) injection for chronic cough. The results showed that BTxA injection effectively improved cough quality and reduced Cough Severity Index (CSI), with minimal risk of complications. Pulmonary disease and vocal fold hypomobility were not significantly correlated with treatment efficacy.