Head trauma doesn’t predict memory problems in NFL retirees, UT Southwestern study shows: Newsroom
A study by researchers at UT Southwestern examined the cognitive abilities of retired professional football players who suffered concussions during their careers. (Photo credit: Getty Images)
DALLAS – February 02, 2023 – A study of retired professional football players by researchers at UT Southwestern Medical Center found that their cognitive abilities did not differ significantly from a control group of similarly aged men who did not play football, nor did these abilities show significant change over one to five years. The findings, published in Brain Injury, suggest that exposure to concussions and head injuries among National Football League (NFL) players is not a predictor of neurocognitive decline later in life.
Dr. Munro Cullum is Professor of Psychiatry, Neurology and Neurological Surgery and Chief of Psychology at UTSW. He specializes in the assessment of cognitive impairment and is the lead author of the study.
“This is the first study, to our knowledge, that has measured cognitive functioning over time in older NFL retirees, and it provides evidence that the degree of exposure to head injuries n ‘is not related to neurocognitive changes over time compared to carefully matched peers,’ said the study’s lead author, Munro Cullum, Ph.D., professor of psychiatry, neurology and neurological surgery and head of psychology at UTSW. “It’s significant given the media portrayal of cognitive impairment regularly associated with a professional American football story.”
The effect of concussions and repeated blows to the head on NFL players has been of increased concern in recent years, as a number of deceased former NFL players have been found to suffer from chronic traumatic encephalopathy (CTE). CTE, a neuropathological condition linked to repetitive head trauma, has been identified in some former football players and boxers as well as in military veterans exposed to explosions. But its real cause is unknown and it can only be diagnosed by autopsy.
Medical experts have been challenged to better understand how repeated head trauma and other factors might contribute to degenerative brain changes. Previous studies have reported mixed results on the relationship between head injury exposure and neuropsychological functioning later in life. While some surveys have suggested that former NFL players may have lower verbal memory and executive function scores, others have found no differences from control groups, according to a review of the literature.
The latest survey, conducted by faculty and interns from UTSW’s departments of Psychiatry, Neurology, Neurological Surgery, and Physical Medicine and Rehabilitation, included 53 former NFL players aged 50 or older, as well as 26 healthy controls and 83 people with mild cognitive impairment or dementia who did not play collegiate or professional contact sports and matched NFL retirees as closely as possible in age and education. Participants underwent clinical interviews that included concussion history, neuropsychological testing, neuroimaging, and neurological examinations. Twenty-nine players had follow-up evaluations ranging from one to five years.
The retired players in the study had an average of 5.63 concussions, 8.89 years in the NFL and 115.12 games played.
Researchers report that retired soccer players had slightly lower memory scores than healthy controls, but did not find this to be significantly associated with head injury exposure. The results held true whether the athletes had played non-speed positions (quarterback, lineman, linebacker) or positions involving speed (back, defensive back, receiver) during their playing careers. And the results did not change significantly in follow-up assessments.
Dr. Jeff Schaffert is assistant professor of psychiatry at UTSW and lead author of the study.
“These findings underscore that not all NFL retirees will experience cognitive problems later in life, and they add to the complex and mixed literature on whether there is a clear dose-response relationship between exposure to head injuries and subsequent cognitive impairment,” said Jeff Schaffert. , Ph.D., assistant professor of psychiatry at UTSW and lead author of the study. “Our finding that some NFL retirees may have slightly lower memory scores is not clinically significant and, importantly, is not related to any measure of head injury exposure that we could assess.”
Dr. Schaffert, who is a neuropsychologist, added that these latest findings are not the end of the story. “Future research will be essential to determine if there is a subset of former athletes who may be most at risk,” he said.
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UT Southwestern researchers are currently working on a study of aging athletes at the college level, known as CLEAATS, which is designed to advance knowledge about collegiate athletic participation and sports-related concussions as they relate to current brain well-being nationwide.
Dr. Cullum is a clinical neuropsychologist specializing in the assessment of cognitive disorders. “This survey was the first to assess cognitive functioning over time in these gamers,” he said. “It also builds on our concussion aging research exploring this and other risk factors for cognitive decline later in life.”
Ongoing fieldwork at UTSW includes the Concussion-Texas (ConTex) studies, which collect data on sports-related concussions in middle and high school athletes, and the Care4Kids multisite study of biomarkers and Persistent symptoms after concussion in adolescents.
Dr Nyaz Didehbani is Associate Professor of Psychiatry and Physical Medicine and Rehabilitation at UTSW and co-investigator of the study.
“With our rich multidisciplinary research teams, UT Southwestern has been a natural environment to pursue research in brain injury and brain aging,” Dr. Cullum said. “Graduate students as well as postdoctoral fellows have contributed significantly to this line of work, and I’m proud to say that several of our faculty doing this latest research were former UTSW interns.”
Nyaz Didehbani, Ph.D., associate professor of psychiatry and physical medicine and rehabilitation at UTSW and co-investigator of the study, said research efforts on brain aging continue with a new funded study by the Darrell K Royal Research Fund called the Aging Collegiate Athlete Study. Researchers are investigating female and male athletes, now 50 and older, who were part of the National Collegiate Athletic Association and the National Association of Intercollegiate Athletics.
“Our concussion research teams are unique in that our projects encompass the lifespan of young and aging retired athletes,” said Dr. Didehbani. “This project focuses on athletes’ brain health over time to broaden the scope to greater athlete representation.”
Other researchers who contributed to the study include Christian LoBue, John Hart Jr., Heidi Rossetti, Kristin Wilmoth, Will Goette and Laura Lacritz from UTSW and Michael Motes from the University of Texas at Dallas.
This work was supported by Texas Alzheimer’s Research and Care Consortium, the Texas Institute for Brain Injury and Repair, part of UTSW’s Peter O’Donnell Jr. Brain Institute, and UTSW.
Dr. Cullum holds the Pam Blumenthal Professor Emeritus Chair in Clinical Psychology and is Scientific Director of Texas Alzheimer’s Research and Care Consortium (TARCC).
About UT Southwestern Medical Center
UT Southwestern, one of the nation’s leading academic medical centers, integrates pioneering biomedical research with exceptional clinical care and education. The institution’s faculty has received six Nobel Prizes and includes 24 members of the National Academy of Sciences, 18 members of the National Academy of Medicine, and 14 researchers from the Howard Hughes Medical Institute. Full-time faculty of more than 2,900 are responsible for groundbreaking medical advances and committed to rapidly translating scientific research into new clinical treatments. UT Southwestern physicians provide care in more than 80 specialties to more than 100,000 inpatients, more than 360,000 emergency room cases, and oversee nearly 4 million outpatient visits annually.
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