Suffering multiple concussions may be linked to poorer brain function later in life, according to a study of nearly 16,000 people.
Among 15,764 people aged 50 to 90, those who reported three or more concussions had worse planning and complex attention scores on a range of cognitive tests.
People with four or more concussions showed poorer attention, processing speed and working memory.
“What we found was that…you really only need three concussions in a lifetime to have some kind of long-term cognitive deficits,” said lead author Dr Matthew Lennon. study and PhD candidate at the Center of the University of New South Wales. for healthy brain aging.
“If you have multiple concussions as a teenager, between your 20s, 30s and 40s, you’ll still feel the effects when you’re 70 or 80.”
The findings come a day after the first hearings of a Senate inquiry into concussions and repetitive head injuries in contact sports. The investigation was established following growing public concern and ongoing reporting by Guardian Australia into sports organizations’ handling of player concussions and the effects of long-term exposure to heavy blows which may not result in a clinical diagnosis of concussion but still cause harm. to the brain.
A large and growing body of scientific evidence has shown links between repeated exposure to head injuries and subconcussive blows in contact sports and the neurodegenerative disease chronic traumatic encephalopathy (CTE), which has been found in the brains of many Australian athletes, from amateurs to professionals.
Lennon’s research found that although people who had repeated concussions had significantly lower cognitive performance, the differences were not drastic. “We’re not talking about 20 or 30 IQ points — we’re talking maybe a few IQ points difference,” said Lennon, who is also a doctor.
The physical and cognitive health benefits of sport were significant, Lennon pointed out. “When we looked at the subgroup analysis [in data yet to be published] …if you had suffered a concussion while playing sports, you actually had better working memory and processing speed than those who had never suffered a concussion.
“What this tells us is that even if you have had a concussion, the benefits of playing sports, especially as a youngster, outweigh the risks to your long-term cognition,” said Lennon. “It makes sense when we look at the aggregate data, because we know blood pressure, high cholesterol, diabetes…these are all really big risks to our cognitive health.”
Lennon’s research did not study CTE or the cumulative effect of exposure to subconcussive blows.
The article, however, argued that given the “highly controversial” question of when people should stop participating in high-risk activities, such as contact sports, the finding that three or more concussions caused long-term cognitive impairment offered a baseline.
“This is an extremely important result. This provides a clear threshold at which cognitive deficits can reasonably be expected in mid to late life,” the paper states. “When you make recommendations to those who have suffered from [traumatic brain injury] clinicians should be aware that some long-term cognitive deficits may be expected after 3 or more.
The research, published in the Journal of Neurotrauma, is part of a larger project known as the Protect Study, which follows UK participants for up to 25 years to understand factors affecting brain health later in life. life.
Lennon said one of the advantages of his study was his cohort of nonathletes, since most previous studies of the link between concussions and cognitive outcomes had focused on professional or college athletes. “They didn’t really include the average person.”
On average, participants reported their last head injury 30 years before the study. The study authors admitted that the long time that had elapsed since the concussion experiences was a potential limitation.
“The retrospective design of the study, with older participants often recalling details of events more than three decades in the past, may have caused underreporting of head injuries and therefore underestimation of the magnitude of the injury. their effect,” they wrote.