Moreover, these symptoms appeared worse in children who had lost consciousness or had abnormalities seen on brain scans, the investigators added.
It's not just football and hockey that pose a risk for student athletes. Soccer is the leading cause of sports-related concussions among high-school-age girls, the study pointed out.
Dr. Frederick Rivara, a professor and division chief of general pediatrics at the University of Washington in Seattle and author of an accompanying journal editorial, said concussions are taken more seriously by physicians, parents and coaches nowadays.
Sports are important for health, but care must be taken to protect youngsters from head injuries, Rivara said.
"If kids have symptoms of concussion they should be taken out of the game and shouldn't return to play without seeing a physician," he said.
Rivara said children should see a doctor after a concussion whether or not they lose consciousness.
"We have ignored these injuries, and we don't know enough about these injuries," he said. More research is needed about the consequences of concussions, he added.
For more information on concussions, visit the U.S. Centers for Disease Control and Prevention.
SOURCES: Keith Owen Yeates, Ph.D., director, Behavioral Health Services, Nationwide Children's Hospital, Columbus, Ohio; Frederick P. Rivara, M.D., M.P.H., professor, division chief, general pediatrics, University of Washington, Seattle; March 5, 2012, Archives of Pediatrics & Adolescent Medicine, online
All rights reserved