Have you had a MRI or xrays of the c spine yet?

If nothing shows up as a clear cause for those symptoms then possibly it could be due to soft tissue problems as well as other things like trigger points and adhesions/sticky tissues - those causes usually don't show up on imaging tests.

You might read a bit on our Thoracic outlet syndrome (TOS) forum to see if those symptoms fit for you.
TOS useful sticky thread - lots of various therapy info too.
http://neurotalk.psychcentral.com/thread84.html