Last night on an episode of HOUSE doctors removed the entire right hemisphere (HALF) of a man's brain because they believed by so doing his overall brain function would vastly improve. He was neither in a coma or vegetative state before or after the surgery. And the entire program is based on real medicine.
Terri who was not brain dead, or in a comatose or vegetative state, was brain damaged. After Michael left her languishing for over ten years with no therapy what so ever, some recovery for Terri was less promising, but not hopeless. And as cases like the one in this article prove, doctors are frequently wrong.
In my psychology class at university last semester, we studied a boy who had half his brain removed and he's doing great. I have the video tape of his story that we studied. His only real impairment is that he can't count back change very well.