This brain disease is likely caused by repeated concussions, but this condition isn't well understood.
Update Date: 25.06.2025
Chronic traumatic encephalopathy, also known as CTE, is a brain disease likely caused by repeated head injuries. It causes the death of nerve cells in the brain, known as degeneration. CTE gets worse over time. The only way to definitively diagnosis CTE is after death during an autopsy of the brain.
CTE is rare and not well understood, but experts don't believe it's related to a single head injury. CTE appears to be related to repeated head injuries, often occurring in contact sports or military combat. CTE also has been associated with second impact syndrome, when a second head injury occurs before symptoms of a previous head injury have fully resolved.
Experts are still trying to understand how repeated head injuries and other factors might contribute to the changes in the brain that result in CTE. Researchers are looking at how the number of head injuries someone experiences and how bad the injuries are may affect risk of CTE. Experts also don't yet know how often CTE occurs in the population.
CTE has been found in the brains of people who played U.S. football and other contact sports, including boxing. It also may occur in military members who were exposed to explosive blasts. Symptoms of CTE are thought to include trouble with thinking and emotions, physical symptoms, and other behaviors. It's thought that symptoms develop years to decades after head trauma occurs.
Researchers are working on developing tests for CTE, but none has been validated yet. Healthcare professionals may diagnose traumatic encephalopathy syndrome when the symptoms associated with CTE occur together. There is no cure for CTE.
There are no specific symptoms that have been clearly linked to chronic traumatic encephalopathy, also known as CTE. Some of the possible symptoms can occur in many other conditions. In people who were confirmed to have CTE at autopsy, symptoms have included cognitive, behavioral, mood and movement changes.
CTE symptoms don't develop right after a head injury. Experts believe that they develop over years or decades after repeated head trauma.
Experts also believe that CTE symptoms appear in two forms. In early life between the late 20s and early 30s, the first form of CTE may cause mental health and behavioral issues. Symptoms of this form include depression, anxiety, impulsive behavior and aggression. The second form of CTE is thought to cause symptoms later in life, around age 60. These symptoms include trouble with memory and thinking that is likely to progress to dementia.
The full list of signs to look for in people with CTE at autopsy is still unknown. There's also little known about how CTE progresses.
CTE is thought to develop over many years after repeated brain injuries that may be mild or severe. See your healthcare professional in these situations:
Repeated head trauma is likely the cause of chronic traumatic encephalopathy, also known as CTE. Football players in the United States, ice hockey players and military members serving in war zones have been the focus of most CTE studies. However, other sports and factors such as physical abuse can lead to repeated head injuries. Research also has found that CTE can affect people who played both amateur and professional sports. This was discovered when autopsies were done of the brains of young people who had died and had repeated head injuries during their lives.
A head injury can cause a concussion, which may lead to headaches, trouble with memory and other symptoms. Not everyone who experiences repeated concussions, including athletes and military members, goes on to develop CTE. Some studies have shown no increased incidence of CTE in people exposed to repeated head injuries.
In brains with CTE, researchers have found that there is a buildup of a protein called tau around the blood vessels. Tau buildup in CTE is different from tau buildup in Alzheimer's disease and other forms of dementia. CTE is thought to cause areas of the brain to waste away, known as atrophy. This happens because injuries to nerve cells that conduct electrical impulses affect communication between cells.
It's possible that people with CTE may show signs of another neurodegenerative disease, such as Alzheimer's disease, amyotrophic lateral sclerosis (ALS), Parkinson's disease or frontotemporal dementia.
Repeated traumatic brain injuries are thought to increase the risk of chronic traumatic encephalopathy. Experts are still learning about the risk factors.
Chronic traumatic encephalopathy, also known as CTE, can be prevented by lowering the risk of getting a concussion. People who have had one concussion are more likely to have another head injury. The current recommendation to prevent CTE is to reduce mild traumatic brain injuries and to prevent additional injury after a concussion.
There is no way to definitively diagnose chronic traumatic encephalopathy, also known as CTE, during life. But experts have developed clinical criteria for traumatic encephalopathy syndrome, also known as TES. The syndrome is a group of symptoms that occur together and are associated with CTE.
Healthcare professionals may suspect you have CTE if you meet criteria for TES and have had repeated head trauma over years during sports or military experiences. A diagnosis requires evidence of degeneration of brain tissue and deposits of tau and other proteins in the brain. This can only be seen after death during an autopsy.
Some researchers are actively trying to find a test for CTE that can be used while people are alive. Others continue to study the brains of deceased individuals who may have had CTE, such as U.S. football players.
The hope is to eventually use neuropsychological tests, brain imaging such as specialized MRI and other biomarkers to diagnose CTE.
There is no treatment for chronic traumatic encephalopathy, and symptoms continue to get worse over time. More research on treatments is needed, but the current approach is to prevent head injury.
It's also important to stay informed about how to detect and manage traumatic brain injury. Therapies such as cognitive behavioral therapy and medicines may help symptoms of depression and anxiety.
You'll probably start by seeing your healthcare professional. You then may be referred to a specialist trained in nervous system conditions, known as a neurologist, or a doctor who specializes in mental health, known as a psychiatrist, for an evaluation. Or you may be referred to a specialist in neurology and psychology, known as a neuropsychologist, or other specialists for further evaluation.
You can do the following to get ready for your appointment:
Prepare a list of questions before your appointment. List your questions from most important to least important. This can help make the most of your time with the healthcare professional. Some basic questions to ask your healthcare professional include:
Other basic questions to ask include:
If you've had a concussion, some basic questions to ask your doctor include:
Don't hesitate to ask questions during your appointment at any time that you don't understand something.
Your healthcare professional may ask you a variety of questions.
Questions related to symptoms:
Other questions you may be asked related to symptoms:
Questions related to health history:
If you've had a concussion, your healthcare professional may ask questions related to events surrounding the injury:
Questions related to physical symptoms:
More questions related to physical symptoms:
Questions related to cognitive or emotional symptoms:
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