Chronic Traumatic Encephalopathy (CTE) is a degenerative brain disease found in athletes, military veterans, and others with a history of repetitive brain trauma. CTE has a long history and was first described in 1928, when Dr. Harrison Martland described a group of boxers as having “punch drunk syndrome.”



In CTE, a protein called Tau forms clumps that slowly spread throughout the brain, killing brain cells. CTE has been seen in people as young as 17, but symptoms do not generally begin appearing until years after the onset of head impacts.

Early symptoms of CTE usually appear in a patients’ late 20s or 30s, and affect a patients’ mood and behavior. Some common changes seen include impulse control problems, aggression, depression, and paranoia.

As the disease progresses, some patients may experience problems with thinking and memory, including memory loss, confusion, impaired judgment, and eventually progressive dementia. Cognitive symptoms tend to appear later than mood and behavioral symptoms, and generally first appear in a patient’s 40s or 50s. Patients may exhibit one or both symptom clusters. In some cases, symptoms worsen with time (even if the patient suffers no additional head impacts). In other cases, symptoms may be stable for years before worsening.



If you are concerned that you or someone you care about has CTE, don’t lose hope. Many people live happy and productive lives despite having CTE. It is also important to know that many treatable disorders can cause symptoms of CTE, and in fact, some people who appeared to have CTE while alive have been found not to have CTE upon post-mortem examination of their brain.



CTE is a disease of the brain. To really understand the science of what’s going on, we’ll need to compare the differences between a healthy brain, and one with CTE. We’ll also look at how CTE spreads (even without additional head impacts) and how researchers are working toward solving the biggest hurdle in CTE today: How can we diagnose CTE in a living person?


The best evidence available today suggests that CTE is not caused by any single injury, but rather by years of regular, repetitive brain trauma. Importantly, the evidence does not suggest a certain number of concussions that lead to CTE. In fact, there have even been numerous people diagnosed with CTE who were never diagnosed with a concussion. Researchers believe that the repetitive brain trauma that can cause CTE can be predominantly made up of subconcussive hits.



Similar to organ donation, the pledge of one's brain is a precious gesture that helps others in a truly impactful way. Canadian Hockey icon Hayley Wickenheiser, Rugby Canada superstar and World Rugby Hall of Famer Al Charron, and CFL Linebacker Kyries Hebert are among the most recent to make the pledge. Click here to sign up to pledge your brain.



Led by Dr. Ann McKee, the VA-BU-CLF Brain Bank is a collaboration between the U.S. Department of Veterans Affairs, Boston University and the Concussion Legacy Foundation, and housed at the VA Boston Healthcare System, is the largest Chronic Traumatic Encephalopathy (CTE) brain bank in the world. The numbers are staggering – more than 500 brains donated, 300 confirmed cases of the neurodegenerative disease CTE, 110 of 111 former NFL players diagnosed with CTE. The VA-BU-CLF Brain Bank has created an undeniable body of evidence that repetitive brain trauma can lead to CTE. 


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Photo credit: Ann McKee, MD, Boston University, VA Boston Healthcare