The authors point out that there is growing evidence of persistent changes in the brain that last well beyond clinical recovery and clearance to return to play. This study confirmed those findings showing clear brain changes in both structure and function that persisted six-months after injury. They also showed that these persistent brain changes related to concussion history, even in healthy athletes. "We were able to show evidence of prior concussion history through this method," said Menon who is also a scientist at Robarts Research Institute and the director of the Western Centre for Functional and Metabolic Mapping. "This component correlates directly with the number of previous concussions that an athlete has had. This hasn't been shown before." - www.sciencedaily.com