Incobotulinum Toxin A (Xeomin®) As A Treatment For Focal Task-Specific Dystonia Of The Musician's Hand

The investigational drug being studied in this protocol is Incobotulinumtoxin A (Xeomin®). Botulinum toxin (BoNT) prevents the release of the acetylcholine from peripheral nerves, inhibiting muscle contractions. BoNT is effective in relaxing overactive muscles. In musician's dystonia, the ability to reduce abnormally overactive muscles in the hand can be critical for the musical professional to continue his or her career. With the use of EMG/electrical stimulation and/or ultrasound guidance, the injector can precisely localize the individual muscles that are affected in this condition with great accuracy. Prior studies have shown that BoNT injections produce beneficial effects in forearm muscles, and less effect in shoulder or proximal arm muscles. Possible risks in treating patients with BoNT include excessive weakness of the injected muscles. The drug may also affect non-targeted muscles. However these risks will be minimized during the screening period by carefully targeting the affected muscles and by administering low doses of BoNT. Small booster doses may be given at follow up visit (2, 4, 14 and 16-weeks after the primary injection date) if the initial injection was insufficient to produce sufficient efficacy in relief of the focal dystonia and did not produce excess weakness of the targeted muscle.