Thanks for sharing your experience. I agree that B vitamins are generally helpful for people with nerve injuries. There is a forum on this site for "peripheral neuropathy" that has a very long thread about Vit B12. I discovered the benefits of B vits when I drank a Monster energy drink and noticed that my hands were less inflamed and felt a little better. After looking at the ingredients, I saw that it was full of B vits. I then started taking a B vit complex and it helps just llike the monster drink (it works better for me because it doesn't have caffeine like the monster drink ---- caffeine is no bueno for me).
Discovering the benefit of B vits was one of the things that changed my mind about TOS. For a long time I thought TOS was about muscle spasms, trigger points, etc and I spent a lot of time treating that and researching about that. I now believe that TOS is a peripheral nerve injury and the muscle and bloodflow issues are secondary to the nerve injury. Dr. Ellis believes this as well. When I am keeping the neuroinflammation and edema down, then my neck loosens up and blood flow improves.

** This post contains my opinions for my TOS **