I had severe stiff necks before my neck surgery...I had a level 2 in with a compression on my spine....Now I have a nice metal plate in my neck, that bugs me when I turn towards the left...(YUK) Sometimes I wonder what came first? TOS or the neck...they were both caused from a repetitive desk job for 16 years with awful deadlines...perhaps it would best to get another MRI in case it's now compressing on your cord causing the stiffness.....Right before I had my surger, my neck would get so stiff, it reminded me of what whiplash would be.....Just a thought