Doctors are closer to a test in live brains that could help diagnose chronic traumatic encephalopathy, a disease that's been linked to concussions and other repeated brain assaults.
The Zika virus may have infected more than 1 million people in Puerto Rico, including thousands of pregnant women. Doctors are watching babies born to infected moms who don't show birth defects.
At least 19 young football players have died so far in 2015. Pediatricians are calling for changes in the way the game is played, including a move to non-tackle games.