A recent study published last month presents the strongest case yet that repetitive hits to the head, which don’t lead to actual concussions, can cause chronic traumatic encephalopathy (CTE).
“We’ve had an inkling that sub-concussive hits — the ones that don’t show neurological signs and symptoms — may be associated with CTE,” says Dr. Lee E. Goldstein, an associate professor of psychiatry at the Boston University School of Medicine and the lead investigator on the study, told the media. “We now have solid scientific evidence” to support it.
Dr. Goldstein added that while he and other researchers in the field are obviously concerned about those who suffer concussions, “we’re really worried about the many more people who are getting hit and getting hurt, … but are not getting help because we can’t see the evidence (that they suffered a concussion). It’s a silent injury.”
Dr. Goldstein pointed out that in about 20 percent of known cases of CTE, there is no record or report of concussion.
“Our experimental results showed no correlation between concussive signs at the time of injury and CTE brain pathology,” he said. “These findings provide strong evidence — the best evidence we have so far — that sub-concussive impacts are not only dangerous but also causally linked to CTE,” Goldstein said.
The unexpected findings led to the third part of the study, which utilized computer simulations performed at Lawrence Livermore National Laboratory, along with mechanical models implemented at Boston University. “The simulations showed that the mechanisms that trigger concussion may be distinct from those that lead to CTE,” said William C. Moss, PhD, physicist at Lawrence Livermore National Laboratory and co-author of the study. “Our results also provide fundamental insight into the origin of concussion.”
“In order to reduce CTE risk in contact sport athletes and military veterans, there must be a reduction in the number of head impacts. The continued focus on concussion and symptomatic recovery does not address the fundamental danger these activities pose to human health,” said Ann McKee, MD, chief of Neuropathology at Boston VA Healthcare System, Director of BU’s CTE Center and a co-author on this study.
The study involved researchers from Boston University, Cleveland Clinic, Harvard Medical School, Lawrence Livermore National Laboratory in California, Ben-Gurion University of the Negev in Israel and Oxford University in the U.K.
The NFL Players Association issued the following statement about the study:
“We stood firm against an [expanded] 18-game schedule and insisted on changes to the work rules in 2011 to limit contact of all types to protect players, and this study reinforces we made the right decision. We have been in close touch with the researchers at Boston University, who are also members of our Mackey-White Health and Safety committee, and we will review this study carefully to consider future changes to improve the health and safety of our players.”
Meanwhile, Dr. Allen Sills, the NFL’s Chief Medical Officer (CMO), as well as a neurosurgeon and sports physician, issued a statement to USA TODAY Sports in which he said the NFL “has made real strides to try to better protect our players.
“As the research community continues to explore these critical questions, the NFL has made real strides to try to better protect our players and reduce contact to the head, including implementing data-driven rules changes intended to eliminate potentially dangerous tactics and reduce the risk of injuries, especially to the head and neck; enforcing limits on contact practice; and mandating ongoing health and safety education for players and training for club and non-affiliated medical personnel.”
