The Georgia Concussion Coalition offered this guide to the warning signs of a concussion, prepared by the Centers for Disease Control and Prevention. Coaches, teachers and parents should watch to see if the student:

• Appears dazed or stunned

• Is confused about assignment or position

• Forgets an instruction

• Is unsure of game, score, or opponent

• Moves clumsily

• Answers questions slowly

• Loses consciousness (even briefly)

• Shows mood, behavior, or personality changes

• Can’t recall events prior to hit or fall

• Can’t recall events after hit or fall

Student athletes should monitor their own symptoms as well, added the CDC, and watch for these symptoms:

• Headache or “pressure” in head

• Nausea or vomiting

• Balance problems or dizziness

• Double or blurry vision

• Sensitivity to light

• Sensitivity to noise

• Feeling sluggish, hazy, foggy or groggy

• Concentration or memory problems

• Confusion

For more information, see the CDC's page on concussions.

Girls may suffer fewer concussion than boys, but the effects can last longer.

Those findings, by kinesiologist Tracey Covassin of Michigan State University, were among the surprising conclusions reported at a recent Atlanta summit on sports concussions that drew neurologists, epidemiologists and trainers from around the country to a Buckhead conference room.

Weeks earlier Gov. Nathan Deal had signed "return to play" legislation requiring Georgia's youth athletes who suffer concussions to be cleared by a health professional before returning to the field of play. The proposed law received vocal support from the families of Georgia's injured athletes, including Paige Havens of Lawrenceville, whose daughter Rachel, 15, is still feeling the effects of a concussion from the fall of 2011. Read her story here.

Also advocating for the law was Cassie Bruce, of Lawrenceville, whose 16-year-old son, Caleb, sustained a concussion at a football game last fall.

While football still causes the most concussions, girl’s soccer has also emerged as a dangerous place for head injuries, even ahead of boys soccer.

Speaking at the Buckhead J.W. Marriott hotel before a group of about a hundred sports and medical professionals, Covassin said that in a survey of concussed Michigan athletes, girls’ symptoms, including headache, fatigue, reduced visual memory and reduced verbal memory, were higher than boys’ symptoms eight days after an injury.

Covassin said that male athletes had greater neck strength and a higher body mass index, which might help explain their resilience. But neither boys nor girls understood the symptoms of concussions well, she said: 13 percent thought “chest pain” was among the warning signs.

The task of recognizing concussions and treating them correctly was a focal point for the conference.

Dr. Julie Gilchrist, an epidemiologist with the Atlanta-based Centers for Disease Control and Prevention, spoke about the CDC’s “Heads-Up” initiative, an educational program begun in 2005 to teach coaches, athletes and parents about the signs and treatment of traumatic brain injury.

More than 800,000 coaches have completed the online training developed by the CDC, said Gilchrist.

That increased awareness has probably contributed to the 57 percent rise in emergency room visits for concussions from 2001 to 2009, Gilchrist said. Greater attention to traumatic brain injury among professional athletes and soldiers has also pushed that trend.

Now thousands of football players are suing the National Football League to be compensated for brain injuries they received on the field in an era when players were expected to take a hit and shake it off.

Youth football organizations are aware of the risk. The Pop Warner league, one of the largest youth football organizations in the country, co-sponsored last week’s summit and last summer established stringent rules requiring training of coaches and careful evaluation of players with suspected concussions.

Yet the league came under criticism last September when a lopsided game between two Massachusetts teams left five players on the losing side with concussions.

Will the lawsuits begin cropping up in youth sports?

“It’s not a question of ‘if.’ It’s a question of ‘when,’” said Dr. Tony Strickland, director of the Sports Concussion Institute, a chain of treatment centers (including an Atlanta office) and a sponsor of the summit.

Dr. David Reiss, a San Diego psychiatrist who is in Atlanta this week for the Sports Lawyers Association annual conference, said “I expect there are lawyers waiting with bated breath” for youth sports lawsuits. Reiss deals with the effects of trauma on emotion and personality and said he worries about cognitive loss in the marginal student.

Many of the drugs used to treat depression and attention deficit are a “crap-shoot” in the case of brain injury and can make things worse, Reiss said.

While clinics using computerized testing and blood tests to detect and measure concussion have sprung up in Atlanta and elsewhere, participants in the summit make it clear that it’s a developing science.

“No single tool can make the assessment,” said speaker Dr. Christopher Giza, a neurologist at UCLA Medical Center who gently criticized the broad use of CT scans as unnecessary “radiation therapy.”

Most agreed that having an athletic trainer on staff improves detection, though only 40 percent of high schools have trainers on retainer and many of those trainers don’t attend practices, according to Gilchrist.

Nor can such volunteer-led groups as the Metro Atlanta Youth Football League, one of the area’s largest youth football organization, afford trainers.

“If we had paid staff, we wouldn’t exist,” commissioner Ross Mosley said.

But Mosley and others said that better safety equipment and trained coaches of organized sports give them a great advantage.

Said Strickland, “The reality is that playing sports across the board has never been safer.”