What is musician's dystonia?
Dystonia, motor dystonia, and focal dystonia are all similar terms to describe a condition of cramping just like "writer's cramp." Muscles of the fingers and hands contract and don't let go causing twisting and abnormal positioning that prevents the musician from playing his or her instrument.
This condition affects pianists, violinists, and woodwind (e.g., flute, clarinet, saxophone) players most often. There may be a genetic predisposition to the condition but in most cases involving musicians there is an element of repetitive overuse. Stiffness, cramping, and involuntary movements seem to come on slowly at first.
These symptoms often only occur while playing the instrument. The symptoms disappear when the person is at rest. This phenomenon can make it appear as though there is an emotional or psychologic cause (i.e., the person doesn't really want to play), but this is not the case most times.
With retraining and sometimes a little medical help (e.g., Botox injections, anticholingergic medications), a more normal motor pattern can be re-established. Deep brain stimulation is a newer treatment for this problem that is under investigation. Since there may be excessive excitability in some areas of the brain, this approach may provide another safe and effective treatment option.
Reference: Andrew J. Rosenbaum, MD, et al. Injuries Complicating Musical Practice and Performance: The Hand Surgeon's Approach to the Musician-Patient. In The Journal of Hand Surgery. June 2012. Vol. 37A. No. 6. Pp. 1269-1272.