Still, "they are very important findings," said TBI researcher Dr. Amy Wagner of the University of Pittsburgh School of Medicine.
For abnormalities to begin so soon after injury triggers questions about how resilient different people are, she said: Who's more likely to recover? How many blows are too many? What other factors could make this slow-moving disease eventually worsen?
A key next step will be for brain banks, which store donated brain tissue for research, to look more closely for CTE so scientists can learn how often it occurs and in whom, said neuroscientist Dr. Sam Gandy of New York's Mount Sinai School of Medicine. He predicts that people who carry genes linked to Alzheimer's disease would be more prone to lasting damage from TBI. In an editorial in the same journal on Wednesday, he suggested studying if gene testing of would-be high school athletes or military recruits might one day help persuade the most vulnerable to avoid those occupations.
McKee said her lab so far has found evidence of CTE in more than 65 athletes and veterans, ranging from the early abnormalities to profound degeneration. She now is researching how to diagnose CTE before death, perhaps with brain scans or by measuring tau in spinal fluid.
"This work raises a number of questions for researchers to explore in further studies. In particular, the animal model developed by the researchers will enable a better understanding of the brain pathology involved in blast injuries and ideally lead to new therapies to help service members and veterans with TBIs," Dr. Joel Kupersmith, research chief at the Department of Veterans Affairs, said in a statement.
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