Did Justin suffer a concussion?

Rumors that Justin had a concussion are totally true- but thankfully he's OK. During a concert in Paris, JB ran into a glass wall backstage. Always a trooper, he came back out to finish his set before collapsing. "It was a mild concussion but he's fine," manager Scooter told Twist. Justin tweeted afterwards, "I will see you again glass. I will have my revenge." LOL!