Here is a startling case from the UK. A severely brain-damaged 43-year-old father of two, Richard Rudd, became a quadriplegic, unable to move or communicate after a motorcycle accident last October. He had left no advance directives, but his family clearly recalled remarks about a friend who had become a paraplegic. "If ever this happens to me, I don't wanna go on. I don't wanna be like him," he told them.

So after his situation stabilised, his family felt that doctors should withdraw his life support system.

However, Mr Rudd’s doctor noticed that he could move his eyes. This meant that even though he was “locked in”, it was possible to communicate with him. After six months, the doctor asked him if he wanted to continue living. The answer was an unequivocal Yes. “I asked him again and on three occasions he made it clear, just with yes/no answers, that this was a consistent response," said Professor David Menon of the Neuro Critical Care Unit (NCCU) in Addenbrooke's Hospital in Cambridge..

Since them Mr Rudd has made steady improvement. He can smile and his long-term memory is intact.  

His father, also named Richard Rudd, told the BBC: "We all sit round and talk in the pub or at work and say 'if this happened to me, turn the machine off'. It's all hypothetical and you don't know until it happens to yourself. As a family and friends, if that person can't decide for themselves, sometimes you feel that you can decide for them…

"But now Richard's in the situation where that's actually happened. It's real life - it's not pretend. He is in that situation. The will to live takes over… For my part, I'm glad he's alive and didn't make a living will." ~ BBC, July 13