EMG's are rarely positive for TOS. So you can still have neurogenic TOS as it is the more common form. My physiatrist told me earlier this year that he's probably only seen 5 to maybe 10 positive EMGs for TOS in his practice. I am one of those 5 to 10 positive cases. He dxd me with TOS in 2004. I've had surgery for that side and it's doing great. Since then, I've developed TOS on the other side and went back to see him.