The video above shows very clearly the curling up of the finger that is charcteristic of focal dystonia sufferers.
There have been many high profile pianists who have suffered, or have been suspected of suffering, from focal dystonia. Leon Fleischer is probably the most documented, but strong evidence also suggest Glenn Gould and Robert Schumann were also afflicted.
Concert pianist Hung-Kuan Chen, who rehabilitated himself from focal dystonia has written an article about his journey. In it he shares lots of insights into dealing with, and eventually conqueirng the condition. Chen is an active member of the Musicians with Dystonia Bulletin Board. I also have an updated version of the rehab methods of pianist Paul, also from the Musicians BB, and you can download that here
New Zealand based pianist Michael Houstoun has also managed to rehablitate himself and has a story online.