Project 171757

Sports concussion is a major problem affecting thousands of people in North America every year. In the United States alone, close to 300,000 sports-related concussions are reported annually, though the actual number of sustained concussions is likely much higher when unreported and undiagnosed incidences are factored in (Centers for Disease Control and Prevention, 1997). There has been an increasing amount of research dedicated to investigating the effects of concussions "or mild traumatic brain injury (mTBI)- including work conducted in our laboratories. In particular, we have shown electrophysiological anomalies in asymptomatic concussed athletes up to several years post-injury, suggesting reduced attention and information processing capacities. In parallel, we have also shown long-term changes in motor cortex excitability consecutive to sports concussion and at a functional level, studies have demonstrated an association between sports concussions and balance problems that persisted at least 30 days post-injury. Moreover, we have recently found that, compared to non-concussed former athletes of the same age (60 years old), older athletes with a history of concussion displayed a lower performance on neuropsychological tests of episodic memory as well as electrophysiological and motor anomalies accompanied by bradykinesia, a profile that may suggest the emergence of dementia. These various findings stress the importance of better assessing the short and long-term effects of concussions on the brain. The general objective of the present research program will be to investigate these effects in three different sets of studies: 1) changes cognitive function and its uderlying electrophysiology; 2) changes in motor function and 3) biochemical changes. This research program should allow us to assess whether sports concussions may be considered a risk factor in the early deterioration of brain functions.