Chronic traumatic encephalopathy (CTE) results from blows to the head over a period of time that cause concussion (mild traumatic brain injury). These injuries lead to difficulties with thinking (cognition), emotions and behaviors that do not become noticeable until many years later. CTE can lead to physical problems as well. Not everyone who has one or more concussions develops CTE.
CTE involves progressive damage to nerve cells (neurodegenerative disease). The damage results in visible changes to the brain. Some of these changes can be seen with brain imaging, but a diagnosis at this time can be made only on inspection after death (autopsy). Researchers are working to find a way to diagnose CTE in those who have the disease while the individuals are still alive.
Originally called punch drunk syndrome (dementia pugilistica), CTE was first demonstrated in boxers. Doctors now know that other individuals who play a wide variety of sports that involve repeated blows to the head, such as football players, can develop CTE. Military personnel who have had blast injuries also are at risk.
Researchers do not yet fully understand CTE's prevalence and causes. There is no cure for CTE.