Star athlete ends career on fear of concussions

Head injuries on the sports field are getting a lot of attention these days. There's the possibility of serious long-term damage for professional athletes and National Football League rules are changing because of that risk.

But one promising young player took the unusual step of ending his career himself - long before he even reached the pros.

Steven Threet was once the ninth best high school quarterback prospect in the country. But the 21-year-old has called it quits with a year of eligibility left at Arizona State University because of fear, he says, of what another concussion could mean for his future.

Threet has suffered four concussions overall, the most recent coming on a play last November. He told "Early Show" co-anchor Jeff Glor that his symptoms lingered, and to this day, still haven't gone away.

"I still have a headache every day," he said.

"You're just not connecting the dots the way that you used to," he added. "Your thinking process isn't as sharp, your short-term memory is not quite there. It's just, you just couldn't get it together, back to feeling normal."

Glor asked if that scares him.

Threet said, "It didn't really that much because I've had it happen a few times before. I figured, it's a concussion, and I'm not gonna be able to play this game, but recover and just take my time. But as days turned into weeks, turned into months, and the symptoms were still there. ... That's when I kind of started getting a little nervous about it."

After one play in Michigan three years ago, he said he didn't remember the entire day.

"Saturday, yeah just Saturday. I woke up Sunday morning, looked at my phone, and it said Sunday," he said.

All of these experiences, Threet said, led him to his decision that comes in the middle of an ongoing national debate about concussions.

Dr. Robert Cantu, co-director of the Neurological Sports Injury Center at Brigham and Women's Hospital, told CBS News, "It's reaching epidemic proportions of recognizing, I think, the problem is out there in a way that it's never been before, and I think a lot of that is because the media has taken and run with it."

Each year, an estimated 300,000 sports-related concussions are sustained in the United States.

As for Threet, he said kids coming up in sports should be aware.

"You really gotta just listen to the information and what people are telling you," he said. "But at the same time, you gotta know your body. You just gotta be honest about the symptoms and make the best decision for yourself."

For Threet, his choice to leave the huddle was an excruciating one.

Threet said, "It was really just a combination of the information that I got from the doctors and talking to my family that I arrived at the decision."

Glor remarked, "It was something you had to come to terms with."

Threet said, "Yeah. Definitely. Football's been a big part of my life for a long time now. It still is, but it definitely plays a different role now. I obviously enjoy playing. I love the game. But I understand that, where I'm at, it's definitely the best decision for me."

Threet is currently working as an assistant coach through the fall. He'll graduate from Arizona State University in December.

For more on concussions, CBS News Medical Correspondent Dr. Jennifer Ashton discussed how to recognize a concussion, the dangers of "secondary impact" and cumulative effects of multiple hits to the head and why female athletes are especially susceptible to head injuries.