HMN 2025: How CTE and regular getting older are troublesome to tell apart

In latest years, some scientists and advocates have warned that enjoying contact sports activities like soccer and hockey could improve the chance of mind ailments like Alzheimer’s illness or continual traumatic encephalopathy (CTE) resulting from a buildup of a particular protein within the mind.

But a brand new Northwestern Medicine study of 174 donated brains, together with some from former highschool and faculty soccer gamers, pumps the brakes on that principle.

“The lengthy and in need of it’s no, this protein on this particular mind area isn’t elevated in individuals who performed soccer on the newbie degree. It throws a bit little bit of chilly water on the present CTE narrative,” stated corresponding creator Dr. Rudolph Castellani, professor of pathology at Northwestern University Feinberg School of Medicine and a Northwestern Medicine neuropathologist.

The study was recently published in the Journal of Alzheimer’s Disease. It raises vital questions on how scientists interpret delicate mind modifications related to getting older, Alzheimer’s illness and repetitive head impacts.

How the research labored

The study analyzed mind tissue from the Lieber Institute for Brain Development, which collects mind donations from individuals who had psychiatric situations (e.g. schizophrenia, main despair, basic nervousness, substance use dysfunction, and so forth.) all through their life. Of the 174 samples collected from older grownup males (with a median age of 65 at demise), 48 males participated in soccer in highschool or faculty whereas 126 had no historical past of enjoying a contact or collision sport.

The study didn’t embrace brains from skilled athletes.

The scientists centered on a small memory-related mind area referred to as CA2, a part of the hippocampus. This area has been proven to build up phosphorylated tau (p-tau) protein—which is usually current in neurodegenerative illness—in a wide range of contexts, together with regular getting older, Alzheimer’s illness and in people with a historical past of repetitive head impacts.

But the findings recommend p-tau buildup in CA2 is not particular to contact sports activities. The scientists discovered no over-representation of CA2 p-tau in people with a historical past of youth soccer participation. Instead, the presence of p-tau on this area was statistically related to age.

“What’s novel here’s a return to the null speculation—that there could also be no hyperlink between repeated head accidents and p-tau buildup on this location,” stated Castellani, who is also the neuropathology core director of the Northwestern University Alzheimer’s Disease Research Center. “Rather than assuming p-tau in CA2 is inherently pathological, we’re asking whether or not it is perhaps a part of regular getting older or a non-specific response to environmental components.”

The study additionally highlights broader challenges within the subject of neurodegeneration analysis. In explicit, the authors mark to the problem of assigning scientific which means to delicate pathological findings. The paper’s part, “Knowledge gaps and implications for future analysis,” underscores how even knowledgeable consensus teams battle to outline CTE in clinically significant phrases.

“Modern research on CTE could also be increasing the boundaries of what is thought-about regular variability within the human mind,” Castellani stated. “This work reminds us to be cautious in deciphering pathology with out clear scientific correlation.”

The authors name for bigger research to raised perceive how p-tau pertains to getting older and head accidents, whereas urging the scientific neighborhood to critically consider assumptions about what constitutes neurodegenerative illness.

The study is titled “Postmortem tau within the CA2 area of the hippocampus in older grownup males who participated in youth newbie American-style soccer.”