Video transcript

MAN: And The story is that, back in April of 2010, she's a soccer player and a softball player. She headed the ball. And as soon as she headed the ball, she got a headache, felt nauseated, was unsteady on her feet.

SYDNEY URZENDOWSKI: I used to play sports, soccer and softball, at my high school. I'm going to be a senior. To be honest, I don't really remember much anymore.

My freshman year I played soccer and softball. And I don't really remember either of those seasons. So from what my coach said, there is just a hard ball that just came darting at me. I guess I headed it and I scored so that's good. But I don't really remember-- I don't remember anything, actually.

MAN: She came back to the sideline. They decided that they would hold her out and repeat the baseline test that she had. She actually had a concussion baseline test.

They repeated that and found that she didn't do as well. And she did significantly worse, in fact, than she did at her baseline. So that, plus her symptoms, they held her out.

SYDNEY URZENDOWSKI: Red flags just popped up everywhere. So they knew I had a concussion.