This is pretty big news I think. Normally when you think of concussion problems you think of the NFL.
http://blackflag.jalopnik.com/dale-earnhardt-jr-sits-out-from-racing-due-to-concussi-1783706668
http://blackflag.jalopnik.com/dale-earnhardt-jr-sits-out-from-racing-due-to-concussi-1783706668