Brave of Bradley to fess up to the concussion symptoms he's suffered as a boxer.

MRI does not tell us much:

"For a concussion, if you do an MRI scan with the normal sequences that are done clinically, you won't see any changes," Bernick said. "That's almost by definition. It's really only by doing more sophisticated analysis that you might actually pick up damage from a concussion. So, short of someone bleeding into their brain or suffering damage to that degree, an MRI scan isn't going to clinically tell you that much. It's better to be normal than not, but it doesn't give you comfort that something hasn't happened. And it's not just MRIs -- we don't have any predictors at this point."