Category: Dystonia: Clinical Trials and Therapy
Objective: To determine the safety and efficacy of incobotulinumtoxin-A (BoNT) in musician’s dystonia.
Background: Few published trials of BoNT in upper limb task-specific dystonia are available.
Method: Patients were professional musicians with focal upper extremity task-specific dystonia affecting performance on their instruments either naïve or experienced with BoNT treatment >3 months since last injection. Patients were injected at visit 1, with booster injections at week 2 and 4 at the discretion of the patient/injector. The primary efficacy endpoint was at Week 8 following the final cycle injection. Cycle 2 began at week 12 with similar cross-over visit schedules and repeat injections of either BoNT/placebo. Videotaping during performance, Medical Research Council scale (MRC) rating, dynamometry and subjective patient assessments were performed at each visit. Blood specimens were drawn at baseline/final visit for the presence of neutralizing antibodies. Blinded video segments were randomized to order, rated by two independent experts using a 7-point CGI scale for dystonia severity and musical performance. The primary outcome measure was the change in dystonia rating at week 8 in the active treatment cycle compared to baseline. Secondary outcome measures included patient-rated questionnaires, MRC and dynamometry.
Results: Twenty-one patients were randomized (13 naïve, 8 with prior BoNT treatment)/19 completed both cycles and were included in the analysis. The primary outcome measure for active drug week 8 in comparison to baseline by blinded video rating, yielded P= 0.04 (dystonia severity) and P=0.027 (musical performance). Minimal non-disabling clinical weakness by dynamometry was observed; antibody studies are in progress.
Conclusion: This study demonstrated safety and efficacy of BoNT injection in the treatment of focal upper limb dystonia despite relatively small sample size. Tailoring BoNT injection paradigms to fit the specific needs of elite performers may yield clinically meaningful results that inform future studies.
References: Jankovic J., Ashoori A. Movement Disorders in Musicians. Movement Disorders 2008; 23:1957-1965.Pullman S., Hristova A. Musician’s Dystonia. Neurology 2005;64:186-187.
To cite this abstract in AMA style:S. Frucht, A. Nmashie, MC. George, C. Wu, A. Pantelyat, E. Altenmüller, M. Chen, D. Feng, DM. Simpson. A Double Blind, Placebo Controlled, Crossover Study of Incobotulinumtoxin-A in Musician’s Focal Hand Dystonia [abstract]. Mov Disord. 2021; 36 (suppl 1). https://www.mdsabstracts.org/abstract/a-double-blind-placebo-controlled-crossover-study-of-incobotulinumtoxin-a-in-musicians-focal-hand-dystonia/. Accessed December 5, 2023.
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