Niki Popyer was in seventh grade when she hit her head on the gym floor and had her first concussion. Her freshman year of high school, she got fouled during a basketball game and endured concussion No. 5. That time, she couldn't see for a while afterward.
By age 16, the New Jersey girl had had 11 concussions, some just days apart. The repeated trauma to her brain took its toll on her once-normal life.
"Taking notes [in class is] impossible," Popyer told "Good Morning America." "I can't finish...Full Story