Brain Changes Seen in Youth Football Players without Concussion

An increase in subconcussive head impact exposure may have an effect on white matter (WM) integrity in youth athletes, even in the absence of a clinically diagnosed concussion, according to new Radiology research.

Naeim Bahrami, PhD, from the Advanced Neuroscience Imaging Research (ANSIR) Laboratory in Winston-Salem, N.C., and colleagues found a statistically significant relationship between combined-probability risk-weighted cumulative exposure (RWECP) and change of fractional anisotropy (FA) in the left inferior fronto-occipital fasciculus (IFOF).

In a study of 25 male participants (age range 8 to 13 years) from a local youth football league, researchers used the Head Impact Telemetry system to record head impact data and quantify the RWECP There were statistically significant linear relationships between RWECP and decreased FA in the whole, core and terminals of left IFOF. A trend toward statistical significance in right superior longitudinal fasciculus (SLF) was observed. A statistically significant correlation between decrease in FA of the right SLF terminal and RWECP was also observed.

“The results of this study suggest that subconcussive impacts can result in changes in the WM microstructure of the IFOF and SLF fiber bundles,” the authors write.

Linear regression plot depicts the relationship between percent change of fractional anisotropy of the left inferior fronto-occipital fasciculus and cumulative exposure.
Figure 1: Linear regression plot depicts the relationship between percent change of fractional anisotropy of the left inferior fronto-occipital fasciculus and cumulative exposure. The blue shaded area indicates the estimated confidence interval region around the true regression line. The inferior fronto-occipital fasciculus is a fiber bundle connecting the occipital cortex, which is the visual processing center in the back of the head, to the frontal brain. RWECP= risk-weighted cumulative exposure combined-probability.
MR images of left inferior fronto-occipital fasciculus
Figure 2: MR images of left inferior fronto-occipital fasciculus (top) before and (middle) after the playing season, and (bottom) the overlay. In the overlay (bottom), the red region is after the season and the blue region is before the season.
HITS System and Riddell Helmet
Figure 3: HITS System and Riddell Helmet