Botulinum toxin therapy for spamodic dysphonia: Retrospective data analysis of 349 treatments in 48 patients

Objectives:

Botulinum toxin A (BoNT-A) poses the standard therapy in spasmodic dysphonia (SpD). Aim of this retrospective study was to analyze the duration of effect and evolution of dosage of BoNT-A during 16 years in our department.

Methods:

The charts of patients, who were treated for SpD from 1998 to 2014, were assessed. Three brands of BoNT-A were available for therapy. Constant amount of BoNT-A was injected in both vocalis muscles, either endoscopically controlled or transcervically EMG-controlled. Patients consulted our department for the next treatment as soon as they felt disturbed by recurring symptoms. Time intervals between treatments and injected toxin dosages were assessed.

Results:

During 16 years, 48 patients with SpD underwent 349 treatments. SpD was the third leading diagnosis in our consultation (12%; 48/438 patients). In 36/48 patients BoNT was injected more than twice, in average 7,4 ± 11,1 times per patient (median 3,5). The median time interval between treatments was stable with 5,5 ± 7,0 months (p = 0,69). Onabotulinumtoxin A (Botox) was injected in 38%, Abotulinumtoxin A (Dysport) in 52% and Incobotulinumtoxin A (Xeomin) in 11% of all treatments. We observed a significant increase in dosage of Botox (mean 5,1 ± 3,2U per side; p = 0,002), and a significant decrease in dosage of Dysport (mean 20,0 ± 44U per side; p < 0,0001) during the 16 years. There was no significant change in dosage for Xeomin (mean 6,6 ± 2,5U per side; p = 0,27).

Conclusion:

Duration of effect of BoNT-A for treatment for SpD was stable with no significantly different time intervals between treatments. The dose of BoNT-A varied significantly between different brands.

Publication History

Publication Date:
18 April 2018 (online)