A few years ago I developed a tremor in my right thumb, no pain but a bleeding nuisance. I have to steady my right hand when I try and write, if not it looks like the 'dead sea scrolls'. However, what really irritates is the fact that I cannot rely on it when finer-picking, as a result I do not finger-pick when playing in front of anybody.   I end up just strumming, but some songs I no longer do because of it. I have seen a number of consultants over the years who advise that it is 'focal dystonia' and they cannot cure it.