United States National Institutes of Health (NIH) Concludes CTE Is Caused by Repetitive Traumatic Brain Injuries

Nov 18, 2022

The National Institute Neurological Disorders and Stroke (NINDS), part of the United States National Institutes of Health (NIH), has formally acknowledged publicly, for the first time, that the brain disease chronic traumatic encephalopathy (CTE) is caused by repetitive traumatic brain injuries.
The nation’s top medical research agency agreed to update its official statement on causation.

The Concussion Legacy Foundation (CLF), the long-time organization that raises awareness about the risk of concussion, sent a letter, cosigned by 41 of the world’s top experts on CTE and related areas of science, urging the NINDS to review the current evidence outlined in the 2022 article Applying the Bradford Hill Criteria for Causation to Repetitive Head Impacts and CTE, published in Frontiers in Neurology.
On October 5, Dr. Nsini Umoh, Program Director for Traumatic Brain Injury, responded that the NINDS official statement on CTE causation has been updated to now say “CTE is a delayed neurodegenerative disorder that was initially identified in postmortem brains and, research-to-date suggests, is caused in part by repeated traumatic brain injuries.”

“The National Institutes of Neurological Disorders and Stroke new statement on CTE causation is a landmark moment in the fight to end CTE,” said Dr. Chris Nowinski, study lead author and CLF founding CEO. “We thank all the scientists who built the evidence and advocated for this change as well as the families of the brain donors who died with CTE for their important role. The impact of this change will save lives.”
The announcement came just as the Concussion in Sport Group’s (CISG) 6th International Consensus Conference on Concussion in Sport in Amsterdam, where a meeting of doctors, organized by FIFA, the International Olympic Committee, World Rugby, and others, debated their own position on CTE causation. Their most recent statement claimed, “a cause and effect relationship between CTE and concussions or exposure to contact sports has not been established.”
The NINDS joins the US Centers for Disease Control and Prevention in recognizing CTE is caused by repeated traumatic brain injuries.” The CDC fact sheet defines repeated traumatic brain injuries as “concussions, and repeated hits to the head, called subconcussive head impacts.”

The NIH and CDC each independently concluded that CTE is caused by repeated traumatic brain injuries, like those suffered by contact sport athletes, military veterans, and victims of abuse, is expected to have significant public policy and medico-legal consequences.
Many international professional sports organizations that are part of the CISG are facing lawsuits from the families of former players diagnosed with CTE and former players exhibiting cognitive and behavioral symptoms that may be caused by CTE. Some sports organizations have defended those lawsuits by citing the CISG statement on CTE causation.

Dr. Robert Cantu, medical director of the Concussion Legacy Foundation, has served as a coauthor of CISG statement to promote improved concussion care but has been on record disagreeing with their CTE statements. Dr. Cantu served as senior author on the paper that helped inspire NIH to change their statement on CTE causation. After Dr. Paul McCrory resigned as chair of the CISG in March due to allegations, now proven, of serial plagiarism, Dr. Cantu was invited to co-chair the scientific committee of the Amsterdam meeting.

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