Justin Bieber has reportedly sustained a mild concussion after running into a glass wall. The 18-year-old heartthrob hurt himself while performing a concert in Paris. TMZ reports that after Justin sang onstage, the pop star walked backstage and slammed into the glass. Although disoriented, the star went back onstage to complete his show. When Justin ambled backstage following the conclusion of his performance, the star \"passed out cold for around 15 seconds.\" Doctors have diagnosed Justin with a minor concussion. Justin doesn\'t feel that he has much luck with glass blockades. \"I guess me and glass windows just don\'t work,\" he told the website. This has been an eventful week for the young superstar, as 14 teenage girls had to be taken away for \"emergency care\" after hysteria over the singer broke out at the Norwegian show Wednesday. It is understood 49 fans were injured. Justin was in Norway to perform four new songs outside Oslo\'s famed opera house as part of his Around the World TV special, attracting crazed fans from all over Europe.