Wednesday, September 23, 2020
US flag

Some young NFL players have brain injuries

In a small study of young or recently retired NFL players, researchers at Johns Hopkins report finding evidence of brain injury and repair that is visible on imaging from the players compared to a control group of men without a history of concussion.


Example of a PET scan on a healthy brain (source: NIH)

In a report on the study that used positron emission tomography (PET) and MRI, published yesterday in JAMA Neurology, the researchers highlighted the value of PET imaging to monitor a marker of injury and repair in the brains of NFL players and athletes in other contact sports.

The new research builds on a rising tide of anecdotal evidence and a few scientific studies suggesting that people with repeated concussive head injuries incurred while playing football, hockey or boxing are at higher-than-normal risk of developing the neurodegenerative disease called chronic traumatic encephalopathy (CTE). CTE is associated with memory deficits, confusion, poor decision-making and later onset of dementia.

However, because CTE is often only diagnosed at autopsy, and because similar symptoms may occur in people without repeated head injuries, researchers, including those at Johns Hopkins Medicine, have been developing methods to better visualize tissue damage in the living brain to demonstrate better cause and effect. “The exciting part of our new findings is that we now believe we have a useful tool to monitor the brains of NFL players and athletes in other contact sports,” says Jennifer Coughlin, M.D., assistant professor of psychiatry and behavioral sciences at Johns Hopkins. “We can measure TSPO, a PET biomarker of brain injury, in these younger players, and we can now begin to follow it over time to see if the brain is repairing itself or not.”

In early 2015, the Johns Hopkins research team published PET imaging results showing higher levels of this same biomarker in the brains of nine elderly former NFL players compared to control participants. However, since they initially studied elderly players who were many years from play, the researchers were unable to tell if the findings were also linked to aging and vascular disease, independent of past NFL play.

For the new study, the researchers collected PET imaging data from 11 men without a history of concussion and compared the scans to those of 12 young NFL players, all of whom were still active or had retired within the past 12 years. All players had a self-reported history of at least one concussion. These players were an average age of 31 years old. About 80 percent were Caucasian and 20 percent were African-American. The control participants were matched to the players by body mass index, age and education level.

The PET imaging was acquired using a radioactive chemical that binds to translocator protein 18 kDa (TSPO), which is normally found at low levels in healthy brain tissue. Since TSPO is increased during cellular response to brain injury, high levels of the TSPO signal on each PET scan can indicate where injury and reparative processes occur. The researchers found higher radiotracer binding to TSPO in players compared to control participants in eight of the 12 brain regions studied. These regions included the hippocampus, a region functionally involved in memory.

Separately, the researchers examined data from MRI scans to look for structural changes in the brains of the study participants. They found no evidence of brain tissue loss in players compared to control participants in any of the brain regions examined, yet they did find some evidence of white matter changes in the players’ brains. “We suspect that when the brain moves during a hard hit, it causes a shearing injury of the white matter fibers that travel across the brain,” says Coughlin.

Coughlin cautioned that there are some limitations to the imaging technique. For example, the radiotracer used in the PET scans doesn’t work well in people with a specific variation in the gene that codes for TSPO protein, which occurs in about one in 10 people of European descent. Also, the researchers observed that use of creatine supplements—taken by athletes to improve performance—may interfere with the imaging results, necessitating further study of this effect before including participants taking creatine.

“With further research using this technology, we may better understand the relationship between concussion and brain damage,” says Coughlin. “Further understanding may help inform players of associated risk, and will allow us to test preventive and therapeutic interventions that may improve the lives of players.”

According to Centers for Disease Control and Prevention estimates, anywhere from 1.6 to 3.8 million concussions happen each year in the US because of sports or recreational activities.

Paul Katula is the executive editor of the Voxitatis Research Foundation, which publishes this blog. For more information, see the About page.

Recent posts

How citizens prefer to fund environmental action

Growing demand for countries to combat climate change, less consensus on how to fund it. New study offers insight from the US, UK, Germany, France.

Student news roundup, Illinois, Sept. 21

The death of The Notorious RBG, foreign exchange student from France, live streaming plays, BLM, and (of course) remote learning.

Fewer kindergartners, more college drop-outs

The nation has experienced an increase in college drop-outs, esp. among low-income families, and an explainable decrease in kindergarten enrollment.

Tim Kaine talks to Fairfax Co. seniors

In Virginia, protesters intimidated citizens at an early voting center in Fairfax Co. Sen. Tim Kaine talks about voting to students.

Obituary: Justice Ruth Bader Ginsburg

The death of Supreme Court Justice Ruth Bader Ginsburg is certain to bring a political battle between the president, the Senate, and Democrats.

Students help in wake of Gulf Coast storms

Hurricane victims in the South got some much needed help from students at one Louisiana school. Laura and Sally have been very destructive.

Scientific American endorses a candidate

It's rare that a science journal would endorse a presidential candidate, but it has happened, due mainly to Pres. Trump's rejection of science.

Student news roundup, Maryland, Sept. 16

The pandemic reveals much more about us than our unpreparedness for virtual learning; Md. students look at healthcare and choices about schooling.

Smoke from Calif. paints the East Coast sun

The sunrise this morning in Baltimore and Chicago was cooled by smoke from the Calif. wildfires, which created a thick haze aloft.

Student news roundup, Illinois, Sept. 14

Special ed advocate in Evanston dies; Remembering 9/11; Business, fine arts, and cultural life during the pandemic.

No, the president can’t run for a 3rd term

The 22nd Amendment limits the number of times a president can be elected to two. But maybe Constitutions mean little to the current administration.