http://www.wemove.org/dys/dys.html (scroll down to dystonia on the left)
http://www.dystonia.org.uk/about-dys...page32250.html
http://emedicine.medscape.com/article/1145318-overview (it talks about nail changes about 2/3 way down. It also mentions the jerking movements earlier in the article.)

I hope this gives you a little help. It probably already mentions a lot of what I'm sure you already know, but maybe you could print these articles out to take to your DOCTOR!! Keep us posted on how you're doing!!