Embouchure dystonia--Portrait of a task-specific cranial dystonia.

Focal task-specific dystonia (FTSD) is an unusual disorder of motor control, which typically affects the hand but may also involve the face, jaw, and tongue. We report 89 musicians with dystonia of the embouchure (ED), the muscles of the lower face, jaw, and tongue used to control the flow of air into the mouthpiece of a woodwind or brass instrument. Symptoms of ED began at an average age of 36, were typically painless and only rarely were preceded by trauma. Specific musical techniques commonly triggered dystonia, often in one instrumental register. Task-specific embouchure tremor and lip-pulling ED phenotypes were common among high-register brass players (trumpet and French horn), whereas lip-locking occurred exclusively in low-register brass players (trombone and tuba). Jaw and tongue ED phenotypes occurred predominantly in woodwind players, and once present, frequently spread to speaking or eating. Six percent of all ED patients had coincident writer's cramp, suggesting a possible genetic predisposition to develop dystonia. We assessed two-point sensory discrimination in the upper lip, lower lip, and hand in ED patients, normal musicians, and nonmusician age-matched controls--there were no differences between groups. Once present, symptoms of ED did not remit and often disrupted careers and livelihoods. Better treatments are urgently needed for this unusual disorder of oral motor control.