Contact sports: what are the long-term effects of multiple impacts to the head?
Chronic traumatic encephalopathy (CTE) has been in the news recently, with a landmark lawsuit brought against the Australian Football League (AFL) by players who claim that they've been permanently damaged by concussions or other head knocks. In the latest episode of the RCPA’s podcast series, Associate Professor Buckland, Senior Staff Specialist and Head of the Department of Neuropathology at the Royal Prince Alfred Hospital, explains why he is concerned about the long-term effects of multiple impacts to the head. His work with the Australian Sports Brain Bank (ASBB) aims to better understand its effects.
What is chronic traumatic encephalopathy?
“CTE is a progressive degenerative brain disease, not that dissimilar to Alzheimer's disease. It cannot be reliably diagnosed during life; therefore, an accurate diagnosis relies on an autopsy. To date, almost everyone that has been diagnosed with CTE at autopsy has had a history of repetitive head impacts. It doesn't necessarily have to be a direct impact to the head, it could be force transmitted from a blow to the body or a whiplash type injury where the head moves around violently, and the brain is moving and twisting about inside the skull.
“CTE is something we've known about for almost 100 years, but for most of that time it has been associated with ex-boxers. It wasn’t until 2005 when the first case of CTE was described in an ex-player of professional American football, that awareness started to grow, and it was recognised that CTE can also be connected to a variety of different contact sports. To date, CTE has now been described in American football players, Australian rules football players, rugby union and rugby league players, boxers, and people exposed to repetitive head impacts outside of sport, such as people who have large numbers of tonic-clonic seizures. It has also been reported in women exposed to quite severe intimate partner violence,” said A/Prof Buckland.
Symptoms and age of onset
CTE can occur at any age, and in most cases the first symptoms occur years or decades after brain injury. As CTE can only be diagnosed after death, and the brains must be donated, it is difficult to get a clear idea of how widespread CTE is in the Australian population or internationally.
“We have seen CTE in people in their 20s and 30s, but sometimes it only seems to declare itself in people in their 60s or 70s. What we know about the clinical symptoms has predominantly been derived from retrospective interviews with family and friends of people that have been diagnosed with CTE after death.
“In people under the age of 60, CTE often manifests initially with symptoms that would overlap with mental health or post-traumatic stress disorder. Often, these people will present with anxiety or depression, impulsivity, aggression, suicidality, drug and alcohol abuse – symptoms that are relatively non-specific. In the older population, it can look a lot like Alzheimer's disease in that people start to experience problems with memory, thinking and planning. Symptoms are almost always progressive and get worse over time,” said A/Prof Buckland.
The Australian Sports Brain Bank
Headed by A/Prof Buckland, the ASBB is an international collaboration aiming to better understand the effects of regular concussions in Australian sportspeople. People can sign up during life to donate their brain after death, or family members can reach out when a loved one dies. The ASBB accepts brains from people aged 18 years and older with any history of sports participation.
“Through the ASBB, we're collecting brains from people with exposure to repetitive head impacts to understand CTE. What’s slightly disturbing is how easy it is to find this distinctive pathology in those who have been exposed to large numbers of head impacts. Half of our brains will end up showing definitive signs of CTE under the microscope. In the rest of my day job as Head of Department at Neuropathology at RPA Hospital, I perform a large number of cranial brain examinations and hospital autopsies, and we almost never see it,” said A/Prof Buckland.
In 2022, a study[1] by the ASBB reported preliminary findings based on the first 21 completed brain donations. Of the 21 brains, 12 had CTE. In addition, eight of the 11 ex-professional players that donated their brains had CTE.
“Perhaps more disturbing is that half the cases of CTE, both amateurs and professionals, had died from suicide. Many people will say that there's no good evidence to link CTE and suicidal behaviour. Regardless, the observation and the fact it is consistently strong is highly disturbing. I don't think the public understands that if you or your loved one commits suicide, you are referred to the state coroner for investigation, but in almost all cases, the brain is not examined. It does worry me what are we missing by not looking at the brains of suicide cases.
“I think Australia has been a bit slow to the party internationally when it comes to recognising CTE. I have worried in the past that our international reputation on the science of CTE is worse than our reputation on climate science because we have been known to be the bastion of denialism. However, I think that's changing and I'm optimistic that although we might have been slow to start, we are quickly catching up. I'm still hopeful that we could turn it around and be a world leader in addressing the issue of CTE, particularly in contact sports,” said A/Prof Buckland.
