Chronic Traumatic Encephalopathy (CTE)

Chronic traumatic encephalopathy (CTE) is a brain condition that can develop if you experience repeated impacts or blows to your head.

CTE permanently destroys nerve cells in your brain. This is called neurodegeneration. Over time, this damage can cause changes in your behavior and mental abilities.

Visit a healthcare provider if you think you’ve experienced a head injury, especially if you know this isn’t your first one. They’ll help you understand how you can protect your brain from more damage.

Symptoms of CTE

CTE shares symptoms with other brain conditions that cause neurodegeneration. It can affect:

• Your ability to think and remember (cognitive function)
• Your mood and personality
• How you physically move and use your body (motor function)

Cognitive function

CTE can affect certain mental abilities. You might notice:

• Memory loss
• Trouble solving problems or making plans
• Trouble making a choice or judging what you should do next
• Mild cognitive impairment

Mood and personality

Neurodegeneration can affect the parts of your brain that control your personality and emotions. You might experience:

• Anxiety
• Depression
• Mood swings, especially acting or feeling more aggressive or impulsive
• Personality changes
• Thoughts of self-harm or suicide

It might be hard to notice some of these changes in yourself. Loved ones might tell you you’re acting differently or “not like yourself.” Try to remember that people care about you and are sharing these concerns because they want to make sure you’re feeling safe and healthy.

Motor function

CTE can affect your brain’s ability to control your body. Some symptoms can include:

• Balance issues
• Loss of coordination
• Tremors, twitches or other muscle movements you can’t control

CTE causes

Experiencing repeated head injuries causes CTE. Experts are still studying exactly why it happens in some people but not others. But they know having multiple head injuries is one of the most common causes. People with chronic traumatic encephalopathy almost always have a history of repeated head injuries over many years.

You don’t have to pass out (get “knocked out”) for a hit to your head to damage your brain. The effects of repeated head impacts build up over time.

Researchers think a buildup of abnormal tau proteins in your brain may also cause CTE. Tau proteins help your cells keep their shape. But if repeated head hits damage your cells, the tau proteins may lose their normal structure.

Risk factors

Having multiple head injuries is the biggest risk factor for CTE. Some activities that increase your risk include:

• Playing contact sports like ice hockey, American football or rugby
• Practicing combat sports like boxing, mixed martial arts (MMA) or traditional martial arts like taekwondo, aikido, judo or jiu-jitsu
• Serving in the military

Some experts think having certain genes may increase your CTE risk. Researchers are still studying these potential genetic factors.

How to lower your risk for CTE

Avoiding head injuries is the only way to lower your risk of developing CTE. Wear the right protective equipment for all activities and sports, especially helmets or protective headwear.

How doctors diagnose CTE

There’s no way to diagnose chronic traumatic encephalopathy in a living person. The only way healthcare providers can confirm CTE is by examining samples of a person’s brain with a microscope. But they can only do this during an autopsy after someone dies.

Even though your provider can’t definitively diagnose CTE while you’re alive, they can still make an educated assumption. They’ll build a diagnosis using a few factors:

• A physical exam
• A neurological exam
• The symptoms or changes you’re experiencing
• Your medical history (especially if you know you’ve had head injuries)

Experiencing CTE symptoms doesn’t automatically mean you have it. Lots of other conditions can cause similar symptoms. Your provider will use tests to help diagnose or rule out these other issues. You might need:

• Blood tests
• CT scan
• Lumbar puncture (spinal tap)
• MRI
• PET scan

How is CTE treated?

Your healthcare provider can’t directly treat CTE, and there’s no way to reverse the brain damage. Instead, they’ll suggest ways to manage any symptoms you’re experiencing. You might need:

• Cognitive behavioral therapy
• Occupational therapy
• Physical therapy
• Speech therapy

Experts are still researching CTE. Ask your provider about any clinical trials that you might be eligible for. These may let you try new or experimental treatments.

When should I see my healthcare provider?

Visit a healthcare provider if you think you have a head injury. Tell them how many head injuries you’ve had (if you can remember them all or know they happened).

It might help to ask your provider a few questions, including:

• How likely do you think it is that I have CTE?
• Is it safe for me to keep playing sports or doing physical activities?
• Which kinds of therapy will I need in the future?
• Which symptoms or changes should I watch out for?

In the U.S., you can call the 988 Suicide & Crisis Lifeline if you’re thinking about hurting yourself or have suicidal thoughts. Call or text 988 anytime for 24/7 help from specially trained providers and counselors.

What can I expect if I have chronic traumatic encephalopathy?

CTE is a permanent, lifelong condition. It’s also progressive, which means the symptoms will get worse over time. These changes can happen slowly (over years or even decades).

Chronic traumatic encephalopathy isn’t fatal. It won’t affect your life expectancy. But as it progresses, it can cause complications that affect your health and well-being. At the end stage of CTE, you might lose the ability to feed, bathe or dress yourself.

You can start planning for the future before you experience more severe symptoms. You might want to think about things like advance directives and legal and financial plans.

Your healthcare provider will help you understand what you and your loved ones can expect.