What We Know and Don't Know About Multiple Concussions

When has a person had too many concussions? There is no definitive answer but with each additional concussion comes more danger. Learn more about the effects of cumulative concussions.

See more videos with Dr. Jeffrey Barth.

Posted on BrainLine July 29, 2010. Reviewed December 20, 2017.

Produced by Vicky Youcha and Brian King.