Research conducted on the brains of 111 former NFL players found evidence of chronic traumatic encephalopathy in 110 samples, Boston University researchers reported Tuesday.
The research, led by neuroscientist Dr. Ann McKee of university's CTE Center, is the largest update on the debilitating brain disease, which can cause a range of symptoms, including memory loss. The report doesn't confirm that the condition is common in all football players; it reflects high occurrence in samples at the Boston brain bank that studies CTE. Many donors or their families contributed (to the brain bank) because of the players' repeated concussions and troubling symptoms before they died.
"There are many questions that remain unanswered," McKee said, per The Associated Press. "How common is this" in the general population and all football players?
The NFL released a statement Wednesday in regard to the report:
"We appreciate the work done by Dr. McKee and her colleagues for the value it adds in the ongoing quest for a better understanding of CTE. Case studies such as those compiled in this updated paper are important to further advancing the science and progress related to head trauma. The medical and scientific communities will benefit from this publication and the NFL will continue to work with a wide range of experts to improve the health of current and former NFL athletes. As noted by the authors, there are still many unanswered questions relating to the cause, incidence and prevalence of long-term effects of head trauma such as CTE. The NFL is committed to supporting scientific research into CTE and advancing progress in the prevention and treatment of head injuries.
"In 2016, the NFL pledged $100 million in support for independent medical research and engineering advancements in neuroscience related topics. This is in addition to the $100 million that the NFL and its partners are already spending on medical and neuroscience research."
The NFL has made 47 rule changes since 2002 to protect players, improve practice methods, better educate players and personnel on concussions and strengthen the league's medical protocols. The NFL deploys 29 medical professionals on the sidelines for each game. Working with the NFL Players Association, the league enforces a concussion protocol for players that has been instrumental in immediately identifying and diagnosing concussions and other head-related injuries.
The Associated Press contributed to this report.