(HealthDay News) – For college athletes, head impact exposure is associated with white matter diffusion measures and poorer cognition, even without concussion, according to a study published online Dec. 11 in Neurology.

Thomas W. McAllister, MD, from Dartmouth College in Hanover, NH, and colleagues conducted a prospective cohort study of Division I NCAA athletes including 80 non-concussed varsity football and ice hockey players (who wore instrumented helmets that recorded the acceleration-time history of the head following impact) and 79 non-contact sport athletes. Diffusion tensor imaging and neurocognitive measures were performed preseason and shortly after the season.

The researchers identifed a significant (P=0.011) difference in the athlete-groups for mean diffusivity (MD) in the corpus callosum. In the amygdala, post-season fractional anisotropy (FA) differed significantly (P=0.001). There was a correlation between measures of head impact exposure and white matter diffusivity measures in several brain regions, including the corpus callosum, amygdala, cerebellar white matter, hippocampus, and thalamus. The post-season magnitude of change to the corpus callosum MD correlated with poorer performance on a verbal learning and memory measure.

“This study suggests a relationship between head impact exposure, white matter diffusion measures, and cognition over the course of a single season, even in the absence of diagnosed concussion, in a cohort of college athletes,” the authors conclude.

Several authors disclosed financial interests in the instruments used to collect biomechanical data.

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