Researchers at the Medical College of Wisconsin in Milwaukee have just concluded a study on student athletes that sheds new light on how long the effects of a brain injury may actually last. Under current protocols, when an athlete suffers a concussion they are monitored for symptoms such as headaches, balance difficulties, and issues with memory and thinking. In many cases those symptoms clear up after a few weeks and the athlete is cleared to return to normal activity. However, these researchers found that changes in the brain can still be detected six months after the initial brain injury.
The study followed 18 football players at both the high school and college levels. All of the participants were cleared to return to normal activities with 10 days of their injuries under current protocols. The researchers later performed advanced MRI scans known as diffusion tensor imaging and diffusion kurtosis tensor imaging. These scans can detect various changes in the brain’s white matter, which is often described as the connective tissue of the brain. This tissue is comprised of nerve fiber bundles which transport messages from one area of the brain to another. The scans were compared to the scans of peers who had not suffered a concussion. The scan comparison showed that the previously injured athletes had less measurable water movement throughout their brain leading researchers to conclude that the white matter tissue was still torn or leaking.
The senior author of the study, Michael McCrea, who is the Director of Brain Injury Research at the Medical College of Wisconsin, says that “the findings generally add to the growing body of science to suggest that the tail of physiological recovery after concussion extends beyond the time point of clinical recovery.” McCrea wants to determine not only when athletes are ready to return to activity functionally but also when their brains are ready to return on a physiological level.
One question raised by these findings is whether the effects of even a single relatively minor concussion could be permanent. James Couch, a neurology professor at the University of Oklahoma Health Science Center, says that it is still too soon to answer that question because “there is not a direct one-to-one correlation between the anatomical appearance of the brain and the way a person performs.” This means that even when microstructural changes are still present in the brain, the in some cases the person may still function exactly as they did prior to injury. In order to properly evaluate the issue of permanence, these studies will need to extend until 20 years or more after an injury, but in the interim studies like this may slowly begin to transform the return to activities protocols currently accepted throughout the world of sports.