Co-lead guideline author Dr. Christopher C. Giza of the David Geffen School of Medicine and Mattel Children's Hospital at University of California, Los Angeles, said the new guideline replaced the 1997 American Academy of Neurology guideline on concussions.
"Among the most important recommendations the academy is making is that any athlete suspected of experiencing a concussion immediately be removed from play," Giza said in a statement.
"We've moved away from the concussion grading systems we first established in 1997 and are now recommending concussion and return to play be assessed in each athlete individually. There is no set timeline for safe return to play."
Athletes of high school age and younger with a concussion should be managed more conservatively in regard to return to play, because they take longer to recover than college athletes.
The guideline was based on an evaluation of the best available research developed after reviewing all available evidence published through June 2012.
The guideline, published online in the journal Neurology, said:
-- In men, the risk of concussion was greatest in football, rugby, hockey and soccer. The risk of concussion for women was greatest in soccer and basketball.
-- An athlete who has a history of one or more concussions is at greater risk for being diagnosed with another concussion.
-- The first 10 days after a concussion appears to be the period of greatest risk.
-- There was no clear evidence that one type of football helmet could better protect against concussion over another kind of helmet.