I've never been diagnosed with dystonia but your post has similarities that I have experienced. When I was around 10 I had turned my head to speak to someone but then couldn't move it back. My muscles and neck were just stiff and frozen. A GP doctor painfully turned my head back forward, threw a neck brace on me for over 6 weeks. Well, in my early twenty's I experienced another episode w/my neck. I awakened one morning thinking I must have slept wrong but it became worse as time passed. I ended up with my neck frozen in a sideways position w/a small tilt forward - It took extensive therapy for over 4 months to get my neck upright and muscles loosened.
I know this is not directly answering your question; however, my neuro believes that I've had MS since I was a juvenile based on history. So my "neck" experiences could have been connected to my MS. Unless it happens again I'll never know for sure.
Please keep me posted if you find that there is a connection with MS and dystonia.
Pray without ceasing. In every thing give thanks: for this is the will of God in Christ Jesus concerning you. 1 Thessalonians 4:17,18
Just started Copaxone 06/2009
Monthly IV Solumedrol since 03/2009
Diagnosed RRMS October 2008
ACDF C6/C7 May 2008
ACDF C5/C6 May 2005