According to a new study presented today at the annual meeting of the Radiological Society of North America (RSNA), a single season of football can interfere with cognitive development among young players.
Study co-author Gowtham Krishnan Murugesan is a research assistant in the Department of Radiology at the UT Southwestern Medical Center in Dallas, Texas.
“This research demonstrates that playing a season of contact sports may affect normal gray matter pruning in high school and youth football players,” said Murugesan.
During the process of pruning, new brain connections are formed and unused connections are lost. This highly dynamic process is needed for healthy brain development.
“Pruning is an essential part of brain development,” said Murugesan. “By getting rid of the synapses that are no longer used, the brain becomes more efficient with aging.”
The researchers set out to investigate whether repetitive head impacts may affect normal pruning of the brain in young football players. The study was focused on 60 youth players with no history of concussion and no history of developmental, neurological, or psychiatric abnormalities prior to the season.
The subjects were fitted with the Head Impact Telemetry System (HITS), which are helmets lined with sensors that measure the magnitude, location, and direction of impacts to the head. The experts used the impact data from the helmets to estimate the risk of concussion exposure for each player, and then divided them into two groups: high-impact players and low-impact players.
Functional (fMRI) scans were performed on all players before and after the season. The experts analyzed changes within five components of the default mode network (DMN), a network of regions deep in the gray matter areas of the brain. The DMN includes structures that activate when a person is processing emotions, which is important for brain health.
Among players in the high-impact group, the post-season results showed significant increases in power and gray matter volume.
“Disruption in normal pruning has been shown to be related to weaker connections between different parts of the brain,” said Murugesan. “Our study has found a significant decrease in gray matter pruning in the frontal default mode network, which is involved in higher cognitive functions, such as the planning and controlling of social behaviors.”
Further analysis of the biomechanical data that was conducted at Wake Forest University revealed that most of the head impacts occurred during practice.
“By replacing high-impact practice drills with low- or no-impact drills, the overall head-impact exposure for players can be reduced,” said Murugesan.
The researchers explained that minor modifications to the game could also be implemented to reduce the extent and the force behind full-speed contact.
The findings were presented at the 104th Scientific Assembly and Annual Meeting of the Radiological Society of North America (RSNA).