Chronic traumatic encephalopathy can only be diagnosed after death, but a study published in April shows a first step toward a diagnostic test for people who may be living with the disease. The most well-known victims of the disease, also called CTE, are American football players. CTE has been linked to repetitive head injuries and symptoms such as mood swings, memory lapses and other mental problems.
If a person’s family suspects they had CTE, scientists can perform a brain autopsy when they die. They look for signs of brain matter deterioration and buildup of molecules like the tau protein to diagnose the disease. Unfortunately, this doesn’t help people living with its symptoms to manage the disease or understand what’s happening to them.
But in the new study, researchers performed a positron emission tomography, or PET, scan on 26 former NFL players and 31 men without a history of head injuries. The men ingested a small amount of a radioactive chemical that attaches to the tau protein. Then, the PET scan measured how the radioactivity built up in their brains, creating images in which lit-up regions meant that tau has built up.
The study found that the former NFL players had higher levels of tau than the other group.
“We found, as well, that the amount of abnormal tau detected in these PET scans was associated with the number of years playing football,” Robert Stern, first author on the study and a neuroscientist at Boston University, told The New York Times.
However, this is not a diagnostic test on its own.
Stern made it clear in a press release that “these results do not mean that we can now diagnose CTE during life or that this experimental test is ready for use in the clinic.”
The New York Times reported that experts stressed that a diagnostic test was years away and might use the PET scans in tandem with testing of blood and spinal fluid.
For now, former NFL players can be evaluated for “symptoms consistent with CTE,” which Mike Adamle, a former running back for the Chicago Bears, has done. He told The Associated Press that if a test for CTE had been available while he was playing, “I would have definitely taken note.”