First, here is a list of notables (sorry, source is Wikipedia!) with focal dystonia, from Wikipedia. Some have recovered. I only read about Leisner and Paraskevas, guitarists with long periods of disability who recovered through a program of their own invention:
Andrew Dawes, noted violinist and co-founder of the Orford String Quartet.[9]
Christian Münzner, lead guitar of progressive extreme metal band Obscura
Leon Fleisher, an international concert pianist, suffered from this affliction in his right hand beginning in the 1960s and switched to only left hand playing. In the 2000s, he regained use of his right hand and recommenced performing and recording with two hands.
Alex Klein, formerly the first oboist of the Chicago Symphony
Ernestine Whitman, former member of the Atlanta Symphony and currently a professor of flute at Lawrence University
Keith Emerson, pianist and keyboard player
Warren Deck, tubist and former member of the New York Philharmonic, was diagnosed with focal dystonia in his upper lip, which ended his playing career.
Dominic Frasca, Guitarist
Gary Graffman, pianist, who changed to performing only with his left hand.
Billy McLaughlin, guitarist, switched to playing left-handed when afflicted with dystonia.
Liona Boyd, Canadian classical guitarist, known as the “First Lady of the Guitar”, retired from the concert stage for six years in 2003, due to focal dystonia that affected her right hand. She worked to retrain her right hand and since 2009 she has been performing again as a guitarist, singer and songwriter.[10]
Andy Billups, bass guitarist with British rock group, The Hamsters, has made a partial recovery; he plays by using modified guitar plectrums.
David Leisner, classical guitarist, has recovered the full use of his hand after a decade of disability.
Badi Assad, Brazilian singer-guitarist, was diagnosed with focal dystonia in 1999; she eventually recovered and resumed her career.[11]
Tom Adams, bluegrass banjo player, has focal dystonia in his right hand, and has switched to the guitar.
Scott Adams, the writer of the Dilbert comics, has focal dystonia of the right hand, which impedes his artwork.[12]
Scott Devine, bass player and founder of Scott’s Bass Lessons has focal dystonia which requires him to wear a glove on his left hand when playing bass.
Stuart Cassells, founder of the bagpipe rock group Red Hot Chilli Pipers, announced focal dystonia in September 2011; he has left the band.[13]
Apostolos Paraskevas, Greek-American classical guitarist-composer, was struck by focal dystonia to his right hand in 2009. He fully recovered in 2013 after 7,000 hours of personal work in re-constructing his technique. He was able to decode the condition as an unconscious behavioral habit and returned to performing professionally again. His rehabilitation was based on reducing tension in his hand and retraining his brain through proper, relaxed hand movements, practiced extensively. His article A Classical Guitarist’s Story of Recovery from Focal Dystonia will be published in London on the Classical Guitar Magazine.
Steve Dilling, bluegrass banjo player and founding member of the group, IIIrd Tyme Out. He was forced to retire from the group due to focal dystonia.
Jang Jae-in, korean singer-songwriter and guitarist diagnosed with dystonia in her left hand in 2012. in 2015 in You Hee-yeol’s Sketchbook she announced that she quit playing guitar.