There are injuries to the brain that can cause symptoms such as you describe that won't show up on MRIs or other standard imaging tools; diffuse axonal injury is a common example.

Regarding your wife's observation, those that are near us are in a better position to notice improvements before we are. When I was just home from the hospital I didn't recognize a lot of my deficits. My wife was able to observe them and was also able to tell when they were improving long before I was.

As I recall your injury was sustained about five months ago? While this probably seems to you like an eternity, in the TBI/PCS world this is relatively recent. The fact that your wife is seeing the difference shows that healing is taking place.

I don’t remember from your prior posts; have you have had a neuropsychological assessment from a clinical neuropsychologist? This can give you an objective measure of where you are in your recovery and can help design specific therapies.