In the journal Radiology today, an imaging study shows that players ages 8 to 13 who have had no concussion symptoms still show changes associated with traumatic brain injury.
Christopher Whitlow, chief of neuroradiology at Wake Forest School of Medicine, wanted to see how head impact affects developing brains. His team studied male football players between ages 8 and 13 over the course of a season, recording “head impact data” using a Head Impact Telemetry System to measure force, which was correlated with video of games and practices.
Before and after the season, the players also underwent elaborate brain imaging. Diffusion tensor imaging is a type of MRI that’s used to identify tiny changes in the structure of white matter (the neurons in the brain that are coated in myelin). The image measures fractional anisotropy (FA) of the movement of water molecules along axons. In healthy white matter, the direction of water movement tends to be uniform, but FA values decrease as movement becomes less ordered, and that process has been associated with head trauma. And in this case, the images of the boys’ brains at the end of the season showed a significant relationship between head impact and decreased FA in white-matter tracts. Boys who experienced more head impact had more changes.
“These decreases in FA caught our attention,” Whitlow said in a press statement, “because similar changes in FA have been reported in the setting of mild traumatic brain injury.”
Last year researchers at Boston’s Brigham and Women’s Hospital found that NFL players who had begun playing football before age 12 had a higher risk of altered brain development, as compared to players who started later. And this August, Ann McKee, director of the Boston University Chronic Traumatic Encephalopathy Center, said that kids under 14 shouldn’t play football, reminding The Washington Post that kids’ heads are “a larger part of their body, and their necks are not as strong as adults’ necks. So kids may be at a greater risk of head and brain injuries than adults.”