Practice makes perfect—and it rewires the brain, as many studies have shown. But sometimes hours of practice can take these brain changes too far, as happens in musician’s dystonia, when the boundaries between muscles blur in the brain and precise movements are no longer possible. In pianists, for example, the fingers might clutch inward involuntarily every time they attempt to strike a key. This condition takes years to develop, but new research suggests a treatment that takes only 15 minutes can reorganize the brain and allow musicians to play again.
A team led by Karin Rosenkranz of University College London applied vibrations to individual hand muscles in pianists with dystonia, giving each muscle several rounds of a two-second vibration followed by a two-second rest. The 15-minute protocol immediately improved playing to match that of pianists without dystonia.
The team investigated the brain changes underlying the improvement using transcranial magnetic stimulation (TMS), a noninvasive technology that ramps up activity in a precisely targeted area of the brain. The researchers stimulated an area corresponding to one muscle in the hand as they measured the electrical signals in that muscle to see how these signals changed when they applied vibrations to each of the other hand muscles. In dystonia, activating one muscle accidentally activates other muscles around it, because the brain areas for each muscle are not distinct. After treatment, the researchers confirmed that more distinct boundaries were carved out between the neural territories devoted to each muscle.
Although dystonia may return if old practice habits are resumed, the temporary improvement offered by the new treatment may give sufferers a chance to learn new techniques or change their habits so they can avoid a relapse. “You’ve got to retrain the brain to manage this [disorder],” says Nancy Byl, a physical therapist at the University of California, San Francisco, who was not involved in the study. Byl treats dystonia in musicians, athletes, assembly-line workers and people who type intensively, such as software engineers or writers. She notes that overpracticing alone may lead to repetitive strain injury, but it usually takes the addition of anxiety, stress or genetic factors to tilt someone toward dystonia.