Brain pathology can develop from head blows that cause no obvious symptoms.
Concussions per se do not cause chronic traumatic encephalopathy (CTE), a prominent brain researcher said here.
Rather, the condition stems from the accumulation of subacute blows to the head, none of which necessarily has to be severe enough to be diagnosed as a concussion.
So said Lee Goldstein, MD, PhD, of Boston University's CTE Center and School of Medicine, speaking at the eighth annual Traumatic Brain Injury Conference on Thursday. He reviewed some of the center's latest research, including a mouse study published in February in Brain showing that "closed-head impact injuries, independent of concussive signs, can induce traumatic brain injury as well as early pathologies and functional sequelae associated with chronic traumatic encephalopathy."
"We can completely dissociate concussion" from CTE, Goldstein said. Along with a few case studies of human brains, the studies have revealed about CTE "no correlation on the concussion score with anything we have measured," he said.
Goldstein said his group thinks they have seen profiles of dementia in the brains of deceased former contact-sport athletes in their 20s and 30s. This "has nothing to do with concussions," he said, but instead is directly related to hits to the head. The bottom line: Athletes never diagnosed with concussion may still suffer serious brain injury.
The team has also seen early signs of CTE in the brains of teenagers, Goldstein said, citing a 17-year-old male in particular whose brain revealed signs of chronic neurotrauma.
CTE has been a controversial topic in brain injury and sports medicine. While researchers such as Goldstein and colleague Robert Cantu, MD, have argued CTE's connection with contact sports, others have questioned the condition's very existence. Athletic organizations in particular have been slow to accept CTE as a legitimate concern.