Diffuse white matter tract abnormalities in clinically normal ageing retired athletes with a history of sports-related concussions.
Tremblay S, Henry LC, Bedetti C, Larson-Dupuis C, Gagnon JF, Evans AC, Théoret H, Lassonde M, De Beaumont L. Brain. 2014 Sep 3. [Epub ahead of print]
Take Home Message: Measurable declines in neurocognitive function in older, clinically normal retired athletes may be explained by changes in white matter integrity in those with a previous history of concussion.
Concussions and aging effect cognition and motor function, however, research regarding the link between the two is limited. The purpose of this study was to evaluate white matter changes in the brain and their association with motor and cognitive function between older, former athletes who have a history of sports-related concussions and controls with no history of concussion. The authors recruited 30 former university athletes between 51 and 74 years of age who played hockey or American Football to participate in this study. Fifteen participants self-reported a history of 1 to 5 mild concussions during their collegiate playing career. These participants experienced their most recent concussion between 29 and 53 years prior to the beginning of the study. Fifteen participants similar in age, sport participation, and level of education with no history of concussion were selected as the control group. All participants were free of a number of confounding factors (for example, Alzheimer’s disease, depression, daily medications), and were otherwise considered normal healthy older adults upon examination. Participants engaged in a variety of testing protocols, including a battery of neuropsychological tests (general cognitive ability, attention, verbal and visual episodic memory function, sequential motor learning, and processing speed time trials), genotyping, and neuroimaging of the grey matter, white matter, and cerebrospinal fluid (via magnetic resonance imaging). The control group performed better on nearly all neurocognitive tests. Furthermore, the members of the concussion group showed greater white matter anomalies when compared with the control group. These anomalies were associated specifically with decreased memory function.
These findings are significant because by removing other factors such as depression, dementia, or Alzheimer’s, the results indicate that a history of sports-related concussions leaves the brain vulnerable to the onset of measurable age-related neurodegeneration. Specifically, this study shows a presence of white matter abnormalities related to neurocognitive deficits in a group of older but otherwise clinically normal participants. The authors believe the alterations seen were consistent with aging but concussions had hastened this process. This is troubling considering the injuries were identified as mild when they occurred and upon enrollment of the study they were at least 29 years removed from their most recent injury. The results of this study add to the growing literature base that highlight the impact concussions may have on the normal aging process. The findings in the present study are significant for the future health of our current athletes. We must continue to educate our athletes, parents, and coaches on the risks of concussion and the need to recognize symptoms as they present. Return-to-play protocols must be designed not only for the current season, but also with the lifelong health of our athletes in mind. With the recent focus on concussion safety and potential lasting effects of head injuries, the need for long-term research is paramount. As we improve upon tracking and reporting of head injuries, further research studies must identify the true extent of the long-term effects concussions. This will help provide the best care for our athletes for both their current and lifelong health.
Question for Discussion: Do you think the early recognition of concussions may help mitigate these abnormalities?
Written by: Adam B. Rosen, PhD, ATC and Catherine E. Lewis.
Reviewed by: Jeffrey Driban