By Dr. Brian McDonough, Medical Editor

PHILADELPHIA (CBS) - There is a great deal of controversy surrounding the University of Michigan allowing quarterback Shane Morris to return to play in a college football game despite clear indications he had suffered a concussion.

This is just the latest controversy in a sport where some measures have been taken to try and deal with concussions and protect athletes - but inconsistency still exists.

On the heels of this comes a very disturbing report from the nation's largest brain bank focused on traumatic brain injury, which has found evidence of a degenerative brain disease in 76 of the 79 former players it's examined. This is a twofold increase over an older study which looked at chronic traumatic encephalopathy in football players.

It is crucial to note that concussions occur at all levels of play - not just professional and college and in children the injury can have greater long term effects.