Hmmm...I'm actually around halfway through a fic that takes place a few months post Matt getting a severe TBI, and there are language issues and motor control issues, and the damage is permanent, and he does have problems controlling his anger along with a slew of other things...however, the story is Matt & Foggy (and Karen) and not Matt/Foggy, I'm not sure if the TBI is more severe than you were thinking (major cognitive issues, motor issues, memory issues, problems controlling emotions and aggression, anomic aphasia and other speech issues) and it's honestly not even as angsty as it sounds. Would you be interested in me posting this as a sort-of-fill when I'm finished?