Neurogenic although the artery to my arm was compressed along with the nerve bundle in the brachial plexus. I never asked the Docter if he considered my case to be arterial TOS as well. In my case, I had grown an extra scalene muscle that was wrapped around the nerves and artery to my arm on the right side. The 1st rib was also causing compression. On my left side, the extra scalene muscle cradled the nerves and artery so if that muscle went into spasm or swelled, my elbow, pinky and ring fingers would hurt.

I think my anatomy predisposed me to the condition. I am 5'3 with a petite, yet athletic build. I played a lot of sports growing up and seemed to have more muscle mass then other women my size and age. That along with the extra scalene muscle that shouldn't have developed didn't leave enough room for everything that needs to pass through the area. That's my best guess based upon the post surgical information I got from the Docter.