Biomarkers may help us understand recovery time after concussion

Press Release:

MINNEAPOLIS – A blood test may help researchers understand which people may take years to recover from concussion, according to a study published in the May 27, 2020 online issue of Neurology┬«, the medical journal of the American Academy of Neurology. The study looked at a biomarker called neurofilament light chain, a nerve protein that can be detected in the blood when nerve cells are injured or die.

Researchers found that, years later, people with a history of three or more concussions were more likely to have high levels of the biomarker than people who had not had a concussion. High levels of the biomarker were also associated with more severe symptoms such as post-traumatic stress disorder and depression years after the concussions occurred.

“While most people with mild concussions recover completely, some never get their lives back fully because of chronic disability,” said study author Kimbra L. Kenney, M.D., of the National Intrepid Center of Excellence, Walter Reed National Military Medical Center, Bethesda, Md., and a Fellow of the American Academy of Neurology. “These people may benefit greatly from a test that could predict those disabilities years ahead of time. Our study found there’s great potential for this protein to predict the problems people with concussions may experience years after their injuries.”

The study involved 195 military veterans with an average age of 38; 85 percent were male. Participants were divided into three groups: 45 people with no history of concussions, 94 people with one or two concussions, and 56 people with three or more concussions. It had been at least seven years since the last concussion for the participants. They were also tested to confirm whether they had symptoms of post-traumatic stress disorder, depression or post-concussive syndrome, which refers to lingering symptoms like mood changes, memory problems and headaches after a concussion.

Blood samples were taken to determine levels of the protein in participants. Then they measured levels of protein in the blood overall as well as in the exosomes found in the blood. Exosomes are like tiny bubbles that carry protein and other information between cells. The average blood levels of neurofilament light were 33% higher in those with three or more concussions than those who had never had a concussion. Exosomal levels were similarly 34% higher in those with multiple concussions. Two other proteins associated with inflammation were also increased in those with multiple concussions.

“The main finding in the study is that people with multiple concussions have more of these proteins in their blood, even years after the last injury,” said Kenney. “Additionally, these proteins may help predict who will experience more severe symptoms such as PTSD and depression. That’s exciting because we may be able to intervene earlier to help lessen the overall effects of concussions over time.”

Kenney said a limitation of the study was the relatively small number of people involved and the need to verify these results in a much larger, separate group of people.

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The study was supported by the Department of Defense, Department of Veterans Affairs and National Institutes of Health.

Learn more about concussion at BrainandLife.org, home of the American Academy of Neurology’s free patient and caregiver magazine focused on the intersection of neurologic disease and brain health. Follow Brain & Life┬« on Facebook, Twitter and Instagram.

The American Academy of Neurology is the world’s largest association of neurologists and neuroscience professionals, with over 36,000 members. The AAN is dedicated to promoting the highest quality patient-centered neurologic care. A neurologist is a doctor with specialized training in diagnosing, treating and managing disorders of the brain and nervous system such as Alzheimer’s disease, stroke, migraine, multiple sclerosis, concussion, Parkinson’s disease and epilepsy.

Football-loving states slow to enact youth concussion laws

Press Release:

PULLMAN, Wash. – States with college teams in strong conferences, in particular the Southeastern Conference (SEC), were among the last to take up regulations on youth concussions, according to a recent study. The study, which investigated the association between youth sport participation and passage of concussion legislation, uncovered the importance of SEC affiliation, and found a similar connection in states with high rates of high school football participation.

In contrast, states with higher gender equality, measured by the number of women in the labor force, were early adopters.

Washington State University sociologists Thomas Rotolo and Michael Lengefeld, a recent WSU Ph.D. now at Goucher College, analyzed the wave of youth concussion laws from 2007 to 2014, specifically looking at return-to-play guidelines: a mandated 24-hour wait period before sending a player with a possible concussion back on to the field.

“We explored a lot of different ways of measuring college football presence, and the thing that just kept standing out was SEC membership,” said Rotolo, the lead author on the study published in the journal Social Science & Medicine. “Every college town thinks they have a strong college football presence, but the SEC is a very unique conference.”

Co-author Lengefeld, a former high school football player from Texas, knows first-hand how important the sport is throughout the South, but the data showed a specific correlation between resistance to youth concussion regulations among SEC states in particular.

“This SEC variable was similar to the South effect, but not all southern states have an SEC school–and in SEC states the resistance to concussion laws was a bit stronger,” he said.

Lengefeld added that the SEC also stands out since it has the largest number of viewers and brings in more profits than any other conference.

Scientists have known for more than a century that youth concussions were a serious health issue, but the movement to create concussion health policies for youth sports did not gain any ground until a Washington state middle school player was badly injured. In 2006, Zackery Lystedt was permanently disabled after being sent back onto the field following a concussion. The Seattle Seahawks took up the cause in the state, followed by the NFL which took the issue nationwide.

Even though the NFL advocated for youth concussion policy changes, the states responded differently. Washington state, Oregon and New Mexico were among the first to adopt the new return-to-play guidelines, while states like Georgia and Mississippi were among the last.

“There’s clearly something culturally going on that was different in those states,” said Lengefeld.

The researchers also investigated the role of gender equity in concussion adoption since football is often viewed as hyper-masculine. They used women’s participation in the labor market as a rough indicator of a state’s gender egalitarian views and found a statistically significant difference showing that states with higher levels of women’s labor market participation enacted the concussion legislation more quickly.

Lengefeld said the methodology they used in this study can also be applied to analyze how many other health policies are enacted across different states.

“As we were submitting this research for publication, COVID-19 was just starting, and we noticed all the differences in the way states are behaving,” Lengefeld said. “It’s not new for sociologists to study the diffusion of laws at the state level, but this is another way of doing that that incorporates a set of ideas about culture.”