Botulinum Toxin Treatment in Musician's Dystonia: Long-Term-Effects and Influencing Factors

Musician's Dystonia (MD) is a task-specific movement disorder that occurs while playing an instrument and severely limits a musician's ability to perform. While currently no causal therapies are available, symptomatic therapies, particularly the injection of botulinum toxin (BoNT), offer a therapeutic option. The present study presents a 30-year longitudinal evaluation of the clinical course of 156 patients with MD treated with BoNT at a specialist outpatient facility. The evaluation took into account known risk factors, such as family history, time to treatment, initial severity of symptoms, gender, and age at the onset of playing an instrument and the onset of symptoms. The study showed that more severe initial symptoms, which entailed a larger number of muscles requiring treatment, predicted a poorer long-term outcome. Furthermore, a longer interval between symptom onset and the commencement of BoNT treatment was also associated with a poorer outcome. These results highlight the importance of rapid diagnosis and the early initiation of BoNT therapy in MD patients.