From what I understand it's a portion of the brain where the seizures activity is. As long as all the seizures come from the same section of the brain, that is. If they are scattered from various portions they can't do a thing. Now the problem is he's had this before and he's had the surgery where they removed the portion of his brain that supposedly was causing the seizures. After that surgery his seizures got much worse and he's lost a portion of his memory. Now I'm scared that if they do this again and take even more brain tissue / cells and it doesn't work again what else will he lose? I just want this to work and then it is worth the risks. He has to be awake during any brain surgery so they can ask him questions, he was last time too, they need to ask him to speak, they quiz him about things, ask him to move an arm a leg, etc. That way they know they aren't messing with a portion of the brain he can not do without.