I've been having a lot of discussions on this with a couple of Neuropsychs that I see at the concussion clinic I'm currently attending. It is both of their views that individuals who experience sensitivity/over-stimulation issues can make a 100% recovery. The issue is finding an effective way to push/increase your tolerance to whatever it is your sensitive. In fact, their philosophy is that you push quite hard regardless of what symptoms you experience during, after on the same day, or in the days/weeks to come.

Note, I'm not endorsing this philosophy, but this is how their program runs.

The other thing to consider is that for many with chronic PCS (>1 yr), it is the field's belief that symptoms likely involve a number of complicating factors, including anxiety, depression, anger, etc... Essentially, the more these are alleviated, the greater the chance of a full recovery. The role of the original TBI at this stage is not clear, and their is very little that can be done, other than perhaps DTI, to suggest that the TBI may be a, or even the only, significant factor.

In the end, the group I'm working with believes that if you push your sensitivities, they will improve. Again, not endorsing as they're currently making my days miserable, but I'm giving it a try.