Parents typically don’t think twice when registering their children for recreational sports due to the many social and health benefits. As they get older, however, sports become more competitive and more physical. As a result, many athletes are at risk of suffering injuries, including head injuries. Concussions are a prominent issue in the world of sports as the media has increasingly focused on the sport-related head injuries of professional athletes. It is estimated that incidence of concussions is between 1.6 to 3.8 million every year in the United States alone. This number is a rough estimate due to the fact that many athletes do not seek medical assistance after suffering a head injury. Short-term effects have been studied quite extensively as athletes and coaches alike are usually focused on getting them back in the game as quickly as possible. However, research regarding the long-term effects of concussions has been neglected in comparison.
Recently, a team of researchers explored the long term effects of concussions and head-related injuries by looking at brain structure, namely the grey and white matter. White matter and grey matter are the main components of our central nervous system. The grey matter sends information about movement and senses to various parts of our body to elicit a response, while the white matter is responsible for relaying the messages. Think of it as a telephone: the grey matter would be the telephone itself – this is where you would hear the initial message. The white matter would be the cables connecting the telephones together; it relays the message. Tremblay and colleagues looked at former male varsity athletes between the ages of 51 and 75 years, 15 of which had sustained a concussion in early adulthood and 15 of which had no history of concussions. Researchers evaluated the retired athletes on various neuropsychological attributes to determine neurocognitive decline (i.e. memory, verbal fluency), and used diffusion tensor imaging (DTI) to examine the pathways of white matter in the brain.
They found that in retired athletes with a history of concussions, the white matter in various areas of the brain were more diffuse, meaning less concentrated and more spread out over the brain. They found the anomalies mainly in the fronto-parietal lobes and to a lesser extent in the temporal lobes. The researchers also found negative correlations between diffuse white matter and cognitive functions such as memory and motor learning. Loss of white matter is normal during the ageing process, but the brains of those having a history of concussions may exacerbate the effects of normal ageing.
Source: Tremblay, S., Henry, L. C., Bedetti, C., Larson-Dupuis, C., Gagnon, J-F., Evans, A. C., Théoret, H., Lassonde, M., De Beaumont, L. (2014). Diffuse white matter tract abnormalities in clinically normal ageing retired athletes with a history of sports-related concussions. Brain: A Journal of Neurology, 137, 2997-3011.
