School-aged football players are at an increased risk of long-term effects in the brain after just one season of play, according to new research.
Two new studies conducted on children aged nine to 17 found changes in the area of the brain known as the default mode network (DMN), which is active while a person’s mind is wandering and responsible for processing emotions.
The effects were seen in both players with and without a history of concussion, but were even greater in those who had suffered at least one in the past.
This study adds to the mounting evidence that concussions due to football lead to serious changes in the brain including multiple sclerosis, impaired emotions, depression and most popularly CTE, which was found in former professional football player Aaron Hernandez.
Two studies conducted on young football players found changed in the brain caused by blows to the head while more players were impacted if they had a history of concussion
The studies conducted at UT Southwestern Medical Center in Dallas, Texas, and Wake Forest University in Winston-Salem, North Carolina, used Head Impact Telemetry System (HITS) helmets on players with and without a history of concussion for an entire season.
The results found that both types of players had changes in the DMN area, though those who had experienced concussions in the past showed greater brain disconnection than those who had not.
Previous research has shown that the more connected the default mode network regions are at rest, the more efficiently the brain works when it is actively engaged.
Changes in this part of the brain have been linked to patients with Alzheimer’s and on the autism spectrum. But decreased connectivity in the area can be caused by traumatic brain injury.
‘The DMN exists in the deep gray matter areas of the brain,’ explained Elizabeth M. Davenport, Ph.D., study researcher at UT Southwestern’s O’Donnell Brain Institute. ‘It includes structures that activate when we are awake and engaging in introspection or processing emotions, which are activities that are important for brain health.’
In the first study, researchers observed 26 football players aged nine to 13 without a history of concussion to identify the effects that head trauma, not classified as concussions, had on the DMN.
The players wore the HITS helmets lined with sensors that measure the magnitude, location and direction of impacts to the head for an entire season.
Impact data from the helmets were used to calculate a risk of concussion for each player.
Pre- and post-season MRI scans were conducted and machine learning was used to analyze the data. Machine learning is a type of artificial intelligence that allows computers to perform analyses based on existing relationships of data.
The results found a growing change in the brain with increasing exposure to head impact.
‘Over a season of football, players are exposed to numerous head impacts. The vast majority of these do not result in concussion,’ said Gowtham Krishnan Murugesan, a PhD student. ‘This work adds to a growing body of literature indicating that subconcussive head impacts can have an effect on the brain. This is a highly understudied area at the youth and high school level.’
In the second study, 20 high school football players with an average age of 16.9 wore the HITS helmets for a season. Five of the players had experienced at least one concussion in the past and 15 had no history of concussion.
Before and following the season, the players underwent a brain scan.
The five players with a history of concussion had significantly lower connectivity between DMN regions. Players with no history of concussion had, on average, an increase in DMN connectivity.
The results demonstrate that concussions from previous years can influence the changes occurring in the brain during the current season, suggesting that there are long-term effects from concussions that affect brain function.
‘The brains of these youth and adolescent athletes are undergoing rapid maturation in this age range. This study demonstrates that playing a season of contact sports at the youth level can produce neuroimaging brain changes, particularly for the DMN,’ Murugesan said.
Most professional football players begin the sport at six-years-old.
Previous research has shown that football players who start tackle football from at least age 12 have impaired emotions and behaviors later in life, and the younger the players started, the worse their clinical function was.
Dozens of other studies have been published this year specifically highlighting the effects football-related concussions have on the brain long-term.