"They...it wasn't cause of them. I was sick before then..." He sighed some, hating to have to tell Derek about this stuff, but if he was going to be camping out here he knew he'd have to tell the werewolf. Eventually he would figure out it was a lot worse than he was making it sound.
"my brain is...shutting down, and with it so will the rest of me probably. I'm...I've got Frontotemporal Dementia? It's what we thought was going on when I...with the Nogitsune, but then things happened and we figured that it had to be because of him." He shrugged his shoulders some, "I never went back for more tests to make sure it was gone but...I'm pretty sure my brain is gonna light up like a christmas tree if I went back now."
Closing his eyes for a moment he pinched the space between his eyes for a moment. "It attacks the part of the brain that makes a person who they are. Their personality, behavior, and even their ability to speak." He could barely see straight and it was starting to make him regret eating anything at all. "There's....nothing that can be done about it. There's no cure..." Stiles was trying to come to peace with that. It was all he could do.