I agree with Mark whole heartedly; I was actually waiting for him to reply to what you posted about your neurologist's beliefs because he can include so much more information about it than I could.
There are new studies with something called a Diffusion Tensor Imaging to help determine what's going in inside someone's brain after a mTBI. It measures the white matter, or axonal damage or something like that.
http://www.ninds.nih.gov/news_and_ev..._biomarker.htm
The CT and MRI are not adequate tests to indicate mTBI and often even MTBI.
I actually asked for it when I was still really bad off over a year ago and even my neurologist (who teaches neurology at USC) didn't seem to be aware of the studies or what I was actually asking for. But my communication skills were very poor and my cognitive functioning greatly degraded at that time so I'm not sure I was able to ask in the right way - My stepmom typed it out on a piece of paper with a lot of other concerns we had and I brought it to her and pointed to it and she thought it was a request for an MRI and I wasn't able to clarify because I was doing so poorly.
Frankly, I don't think your neuro knows what they are talking about and I hope you get a second opinion/find another neurologist.