CTE has been part of the national lexicon in the US since the 2015 film concussion dramatizes the discovery of this degenerative brain disease in football players.
Chronic traumatic encephalopathy is found in people who have suffered head injuries. Although not everyone with head trauma develops CTE, the group that has become most involved are football players whose brains can routinely be shaken by hard blows. The disease has been linked to depression, dementia and even suicide among those who play the game.
But that Journal of Alzheimer's Disease published a study on Tuesday that helps to extend understanding of who might be affected by CTE to military personnel. And, perhaps more importantly, the study represents a step forward to develop a test for the disease in the living.
Right now, the precise diagnosis of CTE requires the careful study of brain tissue during autopsy to identify the tell-tale abnormal proteins that kill brain cells. And this is an important reason why knowledge about CTE – who gets it, how widespread it is and the development of treatments – lags behind.
"You really have to have a vivid diagnostic scan to make progress in understanding the disease," Dr. Julian Bailes, neurosurgeon in the Chicago NorthShore University Health System and one of the authors of the study.
With this diagnostic scan, the researchers have come closer in this case.
A comparison of the brains
The small study involved seven military personnel – five veterans and two active employees – who had suffered brain injuries and had CTE-typical symptoms, such as memory loss and mood swings. They were injected with a so-called molecular tracer – in this case the short name is FDDNP. The FDDNP tracer, which is radioactive, binds to the abnormal proteins in the brain and then appears in neural PET scans.
"The PET scanner works a bit like a Geiger counter that measures radioactivity," says study lead investigator Dr. Gary Small, Professor of Geriatric Psychiatry and Biobehavioral Science at the David Geffen School of Medicine, UCLA.
Small's team compared the scans to those of a number of other people: fifteen retired footballers who had suffered brain injuries and CTE symptoms; two dozen people with Alzheimer's disease and 28 healthy controls who were cognitively intact.
The results: The military personnel scans showed patterns similar to those of retired footballers, and differed from Alzheimer's patients and controls.
And it should be noted that the former players – all professionals who had played in the NFL – had brain scans that matched those of people who had died and had autopsies Approved CTE.
Not just a problem for athletes and soldiers
Small says the study paves the way for a deeper investigation of CTE brain changes.
"It could not only help us with people who have suffered head trauma through sports," he says, "but also from other forms of injuries, such as military injuries." Domestic violence survivors are another group susceptible to CTE.
Small is very careful that the study is not definitive.
"There are some limitations," he says. "One is [the small] Sample size Another is that we do not have a control group of individuals who were exposed to the same degree of head trauma but are asymptomatic. … And what does that tell us? It may be something else that we do not know is driving the disease. "
A reliable test for CTE in living people is still at least a few years away, he estimates. But there are already plans for more scanning and more research.
"We're still in the scientific process of figuring out where this test will end up at the level of final destination," says Bailes. Researchers still need to figure out "how it correlates with the changes in the brain when people die," he explains. "It's not final yet, but this paper in a military environment is another piece of the puzzle, we think."
A possibly central part of the puzzle.
"If you can not diagnose a disease, if someone lives," says Bailes, "you really can not help them, and you really do not know it, in a new and emerging and incompletely understood situation like CTE. who has it and why, you do not know how it will evolve or change over time and if there is any treatment potential at all. "
As another football season approaches, CTE will be a continuing problem again. And in some cases it is portrayed by some as in recent years – as an "epidemic" that threatens the future of the game.
What Bailes says is wrong.
"I do not think it's an epidemic," he says, "but whatever the number is, it's important, and you have to have a living diagnosis to say that."