(CBS News) RIDGEWOOD, N.J. - For the first time since 1978, no one named Earnhardt raced Saturday night at Charlotte Motor Speedway. Dale Earnhardt Jr., one of NASCAR's most popular drivers, is sidelined by concussion. Brain injuries in sports are under increasing scrutiny --even among athletes in high school.
No matter what the sport at Ridgewood High School in New Jersey, Nick Nicholaides is the certified trainer athletes count on to prevent injury. He's also the guy that puts them to the test after every hit, looking for any sign of brain injury.
"My second year here at Ridgewood, I saw an alarming trend of a lot of concussions," he said. "Concussions are one of those injuries that you don't necessarily always see the signs of when you look at someone."
So Nicholaides created his own concussion awareness campaign, using a video to educate students on the dangers of concussions and recognizing the symptoms early.
Dr. Rosemarie Moser has studied the impact of concussions on student athletes for the last 25 years.
"They are more vulnerable than adults, because their brains are still young," she said. "They are still growing, still changing."
According to the CDC, those injuries caused by a bump, blow or jolt to the head, take longer to heal in minors. Symptoms range from headaches and fatigue to dizziness and nausea.
"I started feeling the symptoms immediately," said hockey player Megan Donnelly. "But for some reason I kept playing anyway."
She fell on the ice last year, a jolt that put her out of commission for six months. It was her fourth concussion.
"If I get another one, there is the potential I would be out for even longer," she said. "I am not really eager to go back to sports." Now a junior, Donnelly is spending her time this semester focusing on academics.Asked if he is hesitant about playing sports now, another student, Colin Keating, said: "Not really. I'm someone who goes out there and gives it all."
Keating has recovered from the concussion he suffered while playing basketball as an 8th grader two years ago.
"Whenever I get hit in the head, i always take a step back to make sure I'm fine," he said, and added, "I actually do some of the tests that Nick does."
And that's the effect Nicholaides had hoped for. "That's very encouraging to me. You're educating kids to let you know when they're hurt."
And to get help from a healthcare professional sooner rather than later.