Since you're saying that said person WILL be braindead (or briandead, heh) for the rest of their life, I'm going to have to pull le plug. If there was some hope, maybe I'd wait but...you can almost attribute comatosing to inhuman suffering. If it was a lover, I'd be twice as mindful of this. Give her a final kiss and switch the machine off...because I know what happens to the brain after enough time in that state. It turns to jelly. If someone you love is irretrievably comotose, you have to set them free.