Symptoms of concussions often disappear within 7-10 days of an injury–prompting medical release back to sports play. However, preliminary results of a new imaging study presented at a recent American Academy of Neurology conference showed that brain changes caused by “temporary” concussions may last six months or more after the injury. The study, which is ongoing, used diffusion tensor imaging (DTI) to exam connective brain tissue or “white matter” in eighteen students with concussions. White matter brain changes are also associated with stroke and Alzheimer’s.

The concussed study participants exhibited decreased water movement in the white matter of their brains after their injuries. Despite documentation that symptoms were resolved within 10 days, the DTI scans showed that these white matter microstructural brain changes were still evident six months later. Whether or not this is indicative of permanent damage is unknown because the brain has a unique ability to self-heal and rewire itself to restore function. According to Michael McCrea, the senior researcher on the project and Director of Brain Injury Research at the Medical College of Wisconsin in Milwaukee, a study of twenty or more years would be necessary to speculate on the long term effects of concussion. McCrea’s study is expected to last two years with a goal of determining “not only when the athlete is ready to return to an activity functionally but when their brain is ready to return physiologically.”

The use of the DTI scanner to detect brain function has recently been found to be effective for identifying brain repair activities in Mild Traumatic Brain Injuries (MTBI), and in a recent study of retired NFL players, the scans showed that 40% of the participants had marked deviations in fluid movement. Here participants also demonstrated “abnormalities in attention and concentration, executive function, learning/memory and spatial/perceptual function” suggesting that long term and repeated concussive episodes could cause permanent damage to the brain.