Most documented cases of CTE have occurred in athletes involved in contact sports such as boxing, American football, professional wrestling, ice hockey, rugby and soccer. It may also occur in military personnel after exposure to explosive blasts.
It's an ugly condition with no specific treatment. The Mayo Clinic website says diagnosis is made only at autopsy by examining sections of the brain and early symptoms may include difficulty thinking; impulsive behaviour; depression or apathy; short-term memory loss; substance misuse and suicidal thoughts or behaviour. Experts believe symptoms might develop over years or decades of repeated head trauma.
Neither of my children play rugby or American football on a regular basis, but they do play football. Some researchers believe heading the ball in soccer could lead to CTE. The man who discovered the disease, Dr Bennett Omalu, told the BBC last year heading a football should be restricted in the professional game and banned for those under the age of 18.
Former England striker Jeff Astle died in 2002 of a degenerative brain disease at the age of 59. The coroner attributed his death to repeatedly heading heavy leather footballs. In 2014, Scottish neuropathologist Willie Stewart re-examined Astle's brain and found CTE.
A study released two years ago found four more former footballers who died of dementia had been suffering from CTE.
While I was proud women from my native land (USA) won the soccer World Cup earlier this month, I fear for the future health of those players. Researchers at Boston University have already established CTE can be caused by even minor head injuries. Late last month, BU announced a new study that'll include American soccer stars Brandi Chastain and Michelle Akers. Researchers want to see how headers affect cognitive function and overall health.
Chastain and Akers told CBS News last month they "aggressively and very proudly" did a lot of heading the ball, sometimes more than 50 times during a game. Akers even said she would not do it again.
The NRL in Australia now has strict protocols regarding concussions. Club doctors and concussion spotters take players from the field for a head injury assessment if they are suspected to have sustained a concussion. FIFA (the world governing body for football) has strengthened concussion protocols regarding players returning to action after head collisions. New Zealand Football adopted the Consensus Statement on Concussion in Sport in 2016. But they're guidelines - not hard and fast rules. And the protocol doesn't mention repetitive head trauma not resulting in concussion.
Research by a team of doctors in Canada after the 2014 World Cup revealed two-thirds of head collisions during the tournament were not followed by players being assessed by medical professionals on the sidelines. The study also noted the few assessments that were carried out were too brief, with the longest stoppage of play being 180 seconds.
A neurosurgeon who co-authored the research said, "It doesn't matter whether they had a concussion – my point is that they should be assessed. It is almost impossible to do an assessment in that short a time."
Remember when tobacco companies told us the jury was still out on the dangers of cigarettes? Executives said things like "There's not enough evidence" and "The studies were flawed". Even doctors used to promote tobacco. Published documents show tobacco company executives decided to call for more science, not less. The idea was keep demanding studies to stall change. The strategy worked for decades.
Author Malcolm Gladwell in a talk at the University of Pennsylvania in 2013 suggested students boycott football at a school known for its strength in the sport. He argued the request for "proof" can become an excuse for inaction, leaving people suffering unnecessarily.
Gladwell compared CTE to black lung disease in coal miners. He recounted the story of an insurance statistician who published research in 1918 using government death statistics to connect black lung to coal mining. Gladwell says people read the report and said, "You've got no proof." It wasn't until 1975 work conditions finally improved. By then, tens of thousands of miners had died horrible deaths.
If you watch or play sport you know there are rules - and sometimes, there's the way the game actually unfolds. The two aren't always aligned. Trusting my teenaged footballers' coaches is key. So is trusting my gut and my children. I've heard the kids say how other players tried to hide or minimise head knocks so they could stay in the game.
We're informed enough in 2019 about the dangers of head trauma to err on the side of caution rather than take the stance of "she'll be right". Those of us who put more stock in science than tradition know we must listen to mounting evidence showing the need to protect our noggins and those of our children. Imagining a world of angry, forgetful, depressed former athletes decades from now is too gut wrenching to bear.
It's time to change how we use our head in sport - especially for young people. Maybe, as a colleague suggested, we restrict headers in soccer players under age 18 to shots on goal. It would reduce myriad subconcussive blows that happen when the ball is bounced from head to head and when two players' heads clash. It won't make the game less exciting. It will make it safer for generations of developing brains.
