Musicians with Dystonia Bulletin Board

I haven't had FD appearing in the other hand, but I have had it transferring to other tasks/functions, and was initially just as surprised as you. See my link - which you've probably seen - but details my thoughts and how I overcame this. I think the principles are important.

If the circumstances/approach that brought on FD in the first place are still there, or you have re-introduced them, it is no surprise that symptoms will also reappear. I think you need to ask yourself some searching questions about how you approach your playing/practising, whether you are over practising, working on repetitive drills and focussing on controlling movement rather than making music, whether you play with a light graceful touch or whether you play with a lot of tension in your arm, the sort of techniques you work on with the left hand and whether you work too much on stressful techniques (big stretches, high speed fingering etc), I am sure you know all this.