Soccer heading -- not collisions -- cognitively impairs players
April 24, 2018–(BRONX, NY)–Worse cognitive function in soccer players stems mainly from frequent ball heading rather than unintentional head impacts due to collisions, researchers at Albert Einstein College of Medicine have found. The findings suggest that efforts to reduce long-term brain injuries may be focusing too narrowly on preventing accidental head collisions. The study published online today in the Frontiers in Neurology.
"Unintentional head impacts are generally considered the most common cause of diagnosed concussions in soccer, so it's understandable that current prevention efforts aim at minimizing those collisions," said study leader, Michael Lipton, M.D., Ph.D., F.A.C.R., professor of radiology and of psychiatry and behavioral sciences at Einstein and medical director of MRI Services at Montefiore. "But intentional head impacts–that is, soccer ball heading–are not benign. We showed in a previous study that frequent heading is an underappreciated cause of concussion symptoms. And now we've found that heading appears to alter cognitive function as well, at least temporarily."
While heading has previously been associated with transient cognitive problems, the Einstein study is the first to compare the cognitive effects of heading to unintentional head impacts such as collisions. Three hundred and eight amateur soccer players in New York City filled out questionnaires detailing their recent (previous two weeks) soccer activity, including heading and unintentional head impacts. Participants also completed neuropsychological tests of verbal learning, verbal memory, psychomotor speed, attention and working memory. The players ranged in age from 18 to 55, and 78 percent were male.
Players headed soccer balls an average of 45 times during the two weeks covered by the questionnaire. During that time, about one-third of the players suffered at least one unintentional head impact (e.g., kicks to the head or head-to head, head-to-ground, or head-to-goalpost collisions).
Players who reported the most headings had the poorest performance on psychomotor speed and attention tasks, which are areas of functioning known to be affected by brain injury. Heading frequency also correlated with poorer performance on the working memory task, although the association was of borderline significance. In contrast, unintentional head impacts were not related to any aspect of cognitive performance.
The changes in cognitive function did not cause overt clinical impairment, the Einstein team reported. "However, we're concerned that subtle, even transient reductions in neuropsychological function from heading could translate to microstructural changes in the brain that then lead to persistently impaired function. We need a much longer-term follow-up study of more soccer players to fully address this question," said Dr. Lipton.
In the meantime, soccer players should consider reducing heading during practice and soccer games, Dr. Lipton advises. "Heading is a potential cause of brain injury," he says, "and since it's under control of the player, its consequences can be prevented."
The paper is titled, "Heading Frequency is More Strongly Related to Cognitive Performance than Unintentional Head Impacts in Amateur Soccer Players." Other Einstein authors are Richard B. Lipton, M.D., Mimi Kim, Sc.D., Namhee Kim, Ph.D. (now at Rush University in Chicago), Chloe Ifrah (now at Yeshiva University's Ferkauf Graduate School of Psychology in New York City), and Molly E. Zimmerman, Ph.D., also at Fordham University, Bronx, NY. Additional contributors are: Walter F. Stewart, Ph.D., M.P.H., Sutter Health Research, Walnut Creek CA, and Martin J. Sliwinski, Ph.D., Pennsylvania State University, University Park, PA.
The study was funded by grants from the National Institutes of Health (R01 NS082432) and the Dana Foundation David Mahoney Neuroimaging Program. The authors report no financial conflicts of interest.
About Albert Einstein College of Medicine
Albert Einstein College of Medicine is one of the nation's premier centers for research, medical education and clinical investigation. During the 2016-2017 academic year, Einstein is home to 731 M.D. students, 193 Ph.D. students, 106 students in the combined M.D./Ph.D. program, and 278 postdoctoral research fellows. The College of Medicine has more than 1,900 full-time faculty members located on the main campus and at its clinical affiliates. In 2015, Einstein received $148 million in awards from the National Institutes of Health (NIH). This includes the funding of major research centers at Einstein in aging, intellectual development disorders, diabetes, cancer, clinical and translational research, liver disease, and AIDS. Other areas where the College of Medicine is concentrating its efforts include developmental brain research, neuroscience, cardiac disease, and initiatives to reduce and eliminate ethnic and racial health disparities. Its partnership with Montefiore Medical Center, the University Hospital and academic medical center for Einstein, advances clinical and translational research to accelerate the pace at which new discoveries become the treatments and therapies that benefit patients. Through its extensive affiliation network involving Montefiore, Jacobi Medical Center–Einstein's founding hospital, and three other hospital systems in the Bronx, Brooklyn and on Long Island, Einstein runs one of the largest residency and fellowship training programs in the medical and dental professions in the United States. For more information, please visit www.einstein.yu.edu, read our blog, follow us on Twitter, like us on Facebook, and view us on YouTube.