Casual footballers who frequently head the ball may sustain changes in the brain’s microstructure that could affect their cognitive abilities, two studies have suggested, raising concerns about the potential health risks of recreational football.
US researchers who used a new imaging technique to examine white matter close to the brain’s surface have found damage associated with repeated heading localised in fissures of the frontal lobe, a brain region just behind the forehead.
The frontal lobe supports key mental functions such as attention, memory and decision-making.
Earlier research has tied repetitive head impacts (RHI) in sports to brain dysfunction and certain neurodegenerative disorders, but the new studies are the first to show that RHI causes specific changes that directly impair cognitive functions.
“The damage we report occurs in fissures on the brain’s surface in the
frontal lobe,” Michael Lipton, professor of radiology at the Columbia University Irving Medical Centre, who led both studies, told The Telegraph via email.
“The injury at these locations has never been identified in living (sportspersons) and is greater than the injury identified previously in the brain’s deeper white matter,” Lipton said.
Lipton and his colleagues performed diffusion magnetic resonance imaging scans on 352 adult amateur football players with an average age of 26 years and 77 athletes who had no history of any head impacts. They also gave the players simple learning and memory tests.
They found that players with more frequent headers had more pronounced microstructural disruptions in the frontal lobe’s fissures and also scored fewer points on the learning and memory tests compared to those who did little or no heading.
The greater the microstructural disruptions, the worse the performance in the tests — evidence that the disruptions were likely to be the cause of cognitive deficits. The studies’ findings were published in the journal Neurology on Wednesday and in JAMA Network Openon Thursday.
The findings suggest that even non-concussive, repetitive heading may alter brain microstructure in ways that affect cognitive health, said Raffaele Cacciaglia, a neuroimaging specialist at the Barcelona Beta Brain Imaging Centre in Spain, who was not involved in the studies.
In a commentary in Neurology, Cacciaglia noted that the results, drawn from amateur players, highlight that clinically significant brain changes can occur even in recreational play.
The new studies have found that the sites of damage in the frontal lobe mirrored pathology seen earlier in autopsies of players with chronic traumatic encephalopathy (CTE).
Lipton said the results indicated that “we have been missing a large and important portion of the brain injury pathology and that this pathology affects cognitive functions”.
His team is now probing whether the microstructural changes in the frontal lobe fissures are precursors to CTE.
“Our findings add to the evidence that high amounts of heading — not necessarily any heading — can have adverse effects,” Lipton said.