In a pair of studies published in Neurology, the medical journal of the American Academy of Neurology, researchers have discovered that even mild blows to the head can cause measurable damage to the brain, even when there are no signs of concussion from the blow.
In the first study, published in December 2013, a group of 80 football and ice hockey players were compared to a group of 79 skiers and track runners. The football and hockey players were equipped with helmets that measured acceleration of blows to the head. Both groups were given brain scans and a series of cognitive and memory tests before and after the season.
Although none of the athletes suffered blows serious enough to cause concussion, 20% of contact athletes and 11% of non-contact athletes showed a significant decline in test scores, of a degree that would be expected in less than 7% of a typical population. The athletes that had the greatest declines in test scores showed the most significant changes in the corpus callosum and in the white matter. The surprising result of this study was the number of athletes who showed declines and signs of damage despite not engaging in contact sports.
In the second study, published in July 2014, a group of 33 people who had suffered mild brain trauma and a group of 9 people who had experienced moderate brain trauma were compared with 44 people who had not suffered any recent brain trauma. All of the participants were given diffusion tensor imaging scans. These scans are a type of MRI that is specially designed to identify damage to brain cells. The brain injured participants were given the scans and tests an average of six days after the trauma.
The participants who had experienced trauma scored 25% lower on tests of cognition, memory, learning and verbal fluency than the participants without trauma. The the scores correlated strongly with the amount of damage observed on the scan images, with lower scores associated with greater damage. A year after the first scans, 23 of the participants with brain trauma repeated the scans and the tests. Their scans still showed signs of damage, though their test scores were similar those of the uninjured participants.
These studies are the first of their kind to examine what happens to the brain in the wake of mild to moderate brain trauma and blows to the head that do not cause noticeable symptoms of concussion. This is significant because 90% of all brain injuries are mild to moderate, and because many people suffer blows to the head without necessarily suffering concussion. Further research is needed to find out whether there are factors other than force of impact that influence the degree of damage cause by a blow to the head. They also illustrate the importance of protecting the brain from the effects of impact to the head. To get help with concussion and concussion effects call 03 9034 7735 or click here to book a consultation online.