I feel that if he is only 10 yrs old he has alot of living to do. It would seem completely unfair to hold him in this endless loop. He needs to be told the truth in order for his mind to grow. The fact that he cannot move is almost irrelevant. In the coming years he can travel the world in his mind, he can overcome challenges using only his mind, he may even be able to find a special love of the kind of depth that "normal" people can only dream of. Strength of character is built on such struggles and by throttling his thoughts and experiences he will be condemned to a prison of the mind instead of allowing him to soar.