MRI Evidence of Neuropathic Changes in Former College Football Players
Caleb M. Adler, Melissa P. DelBello, Wade Weber, Miranda Williams,
Luis Rodrigo Patino Duran, David Fleck, Erin Boespflug, James Eliassen, Stephen M. Strakowski, Jon Divine
Clin J Sport Med 2016;0:1-7
JACO Editorial Reviewer: Cliff Tao DC DACBR
Published: March 2017
Journal of the Academy of Chiropractic Orthopedists
March 2017, Volume 14, Issue 1
The original article copyright belongs to the original publisher. This review is available from: http//www.dcorthoacademy.com © 2017 Tao and the Academy of Chiropractic Orthopedists. This is an Open Access article which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Objective: To examine effects of participating in collegiate football on neural health several years after retirement. We hypothesized that relative cortical thinning and loss of white matter integrity would be observed in former players.
Design: Former NCAA Division I football players were compared with demographically similar track-and-field athletes with regard to cortical thickness and white matter integrity.
Setting: Participants participated in MRI scans at the Center for Imaging Research at the University of Cincinnati.
Participants: Eleven former football players and 10 demographically
similar track-and-field athletes.
Main Outcome Measures: Normalized cortical thickness was compared between groups using 2-tailed Student t test. As a secondary analysis, Spearman correlation coefficient was calculated between cortical thickness and number of concussions. Fractional anisotropy for regions-of-interest placed in frontal white matter tracts and internal capsule were compared between groups using 2-tailed Student t test.
Results: Football players showed significantly lower cortical thickness within portions of both the frontal and temporal cortex. Affected frontal regions included left frontal pole and right superior frontal gyrus. Affected temporal regions included portions of the superior temporal gyrus, left inferior temporal gyrus, and right middle and superior temporal gyri. Cortical thickness inversely correlated with number of reported concussions over most of these regions. In addition, fractional anisotropy was lower in the right internal capsule of former football players, relative to controls.
Conclusions: These findings suggest that at least some consequences of high-level collegiate football play persist even after the cessation of regular head blows. Longer-term studies are warranted to examine potential cognitive and functional implications of
sustained cortical atrophy.
JACO Editorial Summary:
- This authors are from the University of Cincinnati, Ohio. The lead author is in the department of psychiatry, and the others have varying appointments in varying other departments.
- The main purpose of this study was to see the effect of collegiate level football playing on structural changes in the brain – namely the thickness of the cortex and the integrity of white matter, using MRI.
- Chronic traumatic enchphalopathy (CTE) is a progressive neurodegenerative condition due to blunt head trauma with acceleration-deceleration forces, commonly seen in football. CTE correlates with premorbid, degenerative neurological and behavioral findings.
- There is hypothesized correlation between concussions and cognitive outcome which has spurred the motivation on preventing concussion and delaying return-to-play – however, several studies indicate possible neuropathic effects are not directly related to concussions, suggesting that repeated subconcussive impacts may have an effect, and there are some studies that suggest these neuropathic effects persist even after rest when cognitive performance deficits typically resolve. These neuropathic effects may in some individuals progress to CTE.
- 11 former Division I football players and 10 demographically similar current and former track-and-field athletes participated in this study.
- This study found persistent cortical thinning in former Division 1 football players several years after the end of their playing career, compared with demographically similar track-and-field athletes, who did not have blunt head trauma or reported history of concussion.
- Cortical thinning was found in the prefrontal and temporal brain regions involved in sustained attention, memory, and executive abilities – these are cognitive domains essential to long-term professional and social function.
- Some white matter pathology is suggested in the right internal capsule, which may be an early marker for neurocognitive change, and may be related to deficits in core cognitive domains including attention and affective regulation.
There are several limitations to this study, but there is strong suggestion that even with several years of rest and resolution of neurocognitive deficits, there are persistent cortical and white matter changes seen in former Division I collegiate level football players. These persistent changes may present a risk to developing CTE later in life.