A study published online in Brain, a journal of neurology, finds that repetitive hits to the head that don’t lead to concussions – meaning no loss of consciousness or other symptoms that can include headaches, dizziness, vision problems or confusion – cause CTE.
The study examined the brains of four athletes, ages 17 and 18 years old, after receiving a sports-related head injury. The individuals had shown signs of CTE, including leaky blood vessels and abnormal buildups of the protein tau, as soon as 24 hours after injury.
“Collectively, these results raise concern that repetitive neurotrauma, independent of concussion, may induce early CTE brain pathologies, even in teenagers and young adults,” reseachers wrote in the study. “Cumulative exposure to such injuries may also increase risk for other tau protein neurodegenerative diseases, including Alzheimer’s disease. These considerations are important not only for understanding and differentiating concussion, TBI, and CTE, but also to inform clinical practice, return-to-play protocols and public health policy.”
“We’ve had an inkling that subconcussive hits — the ones that don’t [show] neurological signs and symptoms — may be associated with CTE,” Dr. Lee Goldstein, an associate professor of psychiatry at the Boston University School of Medicine and the lead investigator on the study, told NPR. “We now have solid scientific evidence to say that is so.”
