Chronic Traumatic Encephalopathy (CTE)

Chronic traumatic encephalopathy (CTE) is a neurodegenerative brain disease that can develop if you have extensive repeated impacts or blows to your head. It most commonly affects former football players and boxers, and military veterans.

CTE involves permanent brain damage that can change your behavior and mental abilities. For example, you may have mood swings or struggle with problem-solving and memory loss. The brain damage and symptoms get worse with time.

You can’t get an official CTE diagnosis while you’re alive. Scientists must look at brain tissue under a microscope after death to diagnose it. Your healthcare provider might suspect this diagnosis. But symptoms of CTE are common in many other conditions that your provider will need to consider.

There’s no cure for CTE because there’s no way to reverse brain damage. And it’s a long-term condition. That’s why it’s important to do what you can to prevent CTE. Certain therapies can help manage symptoms. Your healthcare provider can develop a care plan.

Stages

Pathologists assign a stage of CTE based on the type and amount of damage in brain tissue during an autopsy. They range from stage I through IV, from mild to severe.

Symptoms of CTE

CTE shares symptoms with other brain diseases that cause neurodegeneration. It can affect your mood, thinking, memory and movement.

Symptoms can include:

• Headaches
• Mood swings, especially anger and impulsiveness
• Depression
• Personality changes
• Memory loss
• Trouble solving problems, making plans or deciding (executive dysfunction)
• Balance issues
• Loss of coordination
• Tremors, twitches or other muscle movements you can’t control
• Dementia (in late-stage cases)

It can be hard to know if these symptoms are due to CTE or another condition. In any case, it’s worth seeing your provider if you notice these changes.

CTE causes

Extensive exposure to repeated head injuries (RHI) causes chronic traumatic encephalopathy, usually over many years. In this case, a “head injury” means any impact that makes your brain shake within your skull. RHI may include:

• Mild hits that don’t cause symptoms
• Concussions
• Traumatic brain injuries (TBIs)

An impact distorts brain tissue and strains fragile structures in the grooves of your brain. These effects build up over time with repeated head impacts.

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

Experts are still studying exactly why CTE happens in some people but not others.

Risk factors

Situations that increase your risk for repeated hits to your head — and CTE — include:

• Contact sports, like American football, ice hockey or rugby
• Combat sports, like boxing, mixed martial arts (MMA) or traditional martial arts
• Military service
• Domestic violence
• Severe head-banging behavior

The more head injuries you have over time, the more likely you’ll develop CTE. Some experts think certain genes may increase CTE risk.

Avoiding head injuries is the only way to lower your risk of 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 when you’re alive. The only way healthcare providers can confirm CTE is by looking at samples of the 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 probable 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 have similar symptoms. Your provider will use various tests to help diagnose or rule out conditions.

CTE brain changes

A brain with CTE looks different from a healthy brain. Some CTE brain changes include:

• Shrinking (atrophy) of the outermost layer of your brain (cerebral cortex), especially in the front and sides
• Thinning of the tissue that connects the right and left sides of your brain (corpus callosum)
• Tau clusters (which look like brownish tangles) around tiny blood vessels deep in the brain’s grooves

How is CTE treated?

Your healthcare provider can’t directly treat CTE. There’s no way to reverse brain damage. Instead, they’ll suggest ways to manage symptoms. You might need:

• Cognitive rehabilitation therapy to improve mental functions, like memory and attention
• Talk therapy to help with mood swings and coping with CTE symptoms
• Occupational therapy to help make everyday tasks easier
• Physical therapy to help with movement issues
• Medications to address symptoms that linger despite other types of therapy

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

What is the outlook for chronic traumatic encephalopathy?

The brain damage from CTE is permanent. And the symptoms get worse over time. These changes tend to happen slowly (over years or even decades). Over time, you may develop dementia and lose the ability to feed, bathe or dress yourself.

If symptoms continue to worsen, you might want to think about future planning, like establishing an advance directive and legal and financial plans. Your healthcare team can help you plan.

Researchers are still studying whether chronic traumatic encephalopathy directly affects life expectancy.