MRI Study Reveals Significant Brain Changes in Adolescent Football Players

In contrast to high-school athletes from non-contact sports, adolescent football players had a variety of brain changes, including numerous areas of cortical thinning, increased sulcal depth and decreased coherence of neural signals in the frontal and medial regions, according to newly published magnetic resonance imaging (MRI) research.

 By Jeff Hall

 Emerging magnetic resonance imaging (MRI) research suggests that adolescent football players are susceptible to a variety of brain changes due to head impact exposure from the sport.

 For the study, recently published in JAMA Network Open, researchers reviewed findings from structural MRI for 205 high-school football players and 70 high-school athletes who participated in non-contact sports such as swimming and tennis. The study authors also assessed resting state functional MRI scans for 149 football players and 59 participants from non-contact sports.

 In comparison to athletes in non-contact sports, the study authors noted the MRI findings for football players revealed deeper sulcal depth in “widespread brain regions,” including the frontotemporal regions, precentral gyrus, and the cingulate cortex. Noting a “water hammer effect” from traumatic insult with a rapid clustering of cerebral spinal fluid at the base of the sulci, the researchers noted the resulting potential for accelerated tissue atrophy.

“These findings shed light on the potential impact of mechanical stressors on brain structure and provide valuable insights into the dynamics of cortical changes in individuals engaged in football,” wrote lead study author Taylor Zuidema, a Ph.D candidate who is affiliated with the Department of Kinesiology and the Program in Neuroscience at Indiana University in Bloomington, Ind., and colleagues.

Football players also had cortical thickening in the anterior and posterior cingulate cortex as well as cortical thinning in multiple brain regions, according to the researchers.

 “ … Our data showed significant cortical thinning in the fronto-occipital regions of adolescent football players’ brains, accompanied by cortical thickening in the cingulate cortex. (Traumatic brain injury) and repetitive exposure to head impacts can emerge as potential accelerators of age-related cortical thinning in these identified regions,” explained Zuidema and colleagues.

Physiological characteristics from functional MRI findings of football players revealed elevated amplitude of low-frequency fluctuation (ALFF) in occipital brain regions and lower ALFF in frontal brain regions, findings that respectively suggest impacts on visual memory and attention as well as lower density of neuronal signaling, according to the study authors.

While cautioning that variations in regional homogeneity (ReHo) require further study to help determine clinical implications, the researchers also found that football players had higher ReHo in numerous cortical areas within occipitotemporal regions.

 “This aligns with previous observations of increased ReHo in patients with acute concussions and those with persistent symptoms beyond 3 months after concussion,” noted Zuidema and colleagues.

(Editor’s note: For related content, see “What MRI-Derived Data and Other Factors Reveal About White Matter Hyperintensity in Former Football Players,” “Could Structural MRI Findings Help Detect CTE During Life?” and “MRI Reveals Impact of Repetitive Head Impacts in Young Players.”)

In regard to study limitations, the researchers acknowledged a lack of racial and ethnic diversity with over 90 percent of the cohort being comprised of White study participants. The study authors also conceded a lack of objective assessment for head impact severity and history of head impact exposure. Future research should attempt to integrate psychometric assessment and functional assessment and explore correlations between physiological and morphological changes from head impact exposure, according to the researchers.