ATLANTA - Sixteen-year old Devan Johnson of Buckhead remembers the moment last year her cheerleading stunt went very wrong, and a falling teammate stuck her hard on the head.
"I just remember throwing her, and then a big hit, and I was on the floor," Johnson says.
This was actually Johnson's second concussion.
But a neurocognitive test known as the ImPACT test made a big difference in how her concussions were treated.
Six years ago, when Johnson was hit in the head the first time, she had not had a baseline screening doctors can use to assess the level of her brain injury.
So, her mom Judy Johnson says they were sent from doctor to doctor.
"It was a trip to the emergency room," Judy Johnson says. "And then waiting for an appointment, getting in. Being sent from pediatrician to a specialist, a then specialist checking you out."
That's because concussions are common in contact sports, but they can be hard to diagnose.
A concussion happens when a blow to the head or a sudden jarring, shakes the brain inside the skull, stretching and damaging brain cells and triggering chemical changes in the way the brain works..
But Emory Sports Medicine physician Kenneth Mautner, a concussion specialist, says you can't see that damage.
"There is no scan we can use," says Dr. Mautner. "There is no one test we can do that tells of it's a concussion or not. So, we base it a lot on what the athlete is telling us of their symptoms. But the only real objective piece of information we have is this baseline test, this ImPACT test."
That test came in handy, when Devan was hit the second time by a falling cheerleader on her competitive cheerleading team.
"My head just started throbbing as time went on," she says.
But this time, her school, PACE Academy in Atlanta, had given Devan a baseline concussion test as a varsity cheerleader, before she was injured.
So, this time, instead going from doctor to doctor, a school athletic trainer sent her straight to Dr. Mautner, to be screened for a concussion.
"It's not a black or white, you pass or your fail," says Dr. Mautner. "We also look at balance and we look a lot at the eyes."
"I just wasn't myself," Johnson remembers. "I was just kind of quiet and not paying attention to anything, really. I was not hungry, I was just there."
About 5 days after her concussion, Devan took the ImPACT test again, allowing Dr. Mautner to compare her brain function before and after the concussion. She says she failed the first test.
"My head felt fine about a week later, but I was still failing the test, so the trainer would not let me go back to sports," she says.
Devan's mother says the school's concussion protocol was pretty strict, designed to give her injured brain a chance to recover.
"She had to sit out (cheerleading)," Judy Johnson says. "Limit her classroom time, her screen time. No TV. Not a lot of heavy homework or exams."
"I took the ImPACT test 3 times before I passed it," says Devan Johnson.
But, a year later after that concussion, Devan Johnson is back to cheerleading at PACE Academy, and back to feeling like herself again.
Most experts recommend a baseline concussion screening for young athletes in high-contact sports beginning at about age 10.
After that, the test should be re-administered every couple of years, Dr. Mautner says.
The screening takes about 30 minutes and typically costs between $30 and $55, depending on insurance coverage.
A new test can be used to screen children as young as 8 for concussion.