Teen pop sensation Justin Bieber reportedly suffered a concussion Thursday afternoon when he went head-first into a glass wall during a performance in Paris.  The accident reportedly occurred when Bieber went backstage between songs, delaying the show for a few minutes before returned to finish his set.  Following the show, TMZ reported, Bieber passed out for a short time in his dressing room.  Doctors confirmed the singer had suffered a concussion, but reassured him he would not have any ill-effects moving forward.