Chronic Traumatic Encephalopathy (CTE): Causes and More

Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease caused by repeated traumatic brain injuries. About 17% of people with recurrent concussions or traumatic brain injuries will get CTE, but around 90% of people who develop CTE are athletes—particularly football players and boxers.

CTE typically causes changes in your cognition (thinking), mood, behavior, and movement ability. Symptoms often start mild and worsen over time.

There is no definitive way to test someone for CTE before death, making the condition challenging to treat. That’s why CTE prevention is so important.

CTE can cause changes to your mood, behavior, cognition, and ability to move. Mood and behavior symptoms are more common if you develop CTE at a younger age. Older people who get CTE are more likely to experience changes in cognition.

Psychological Symptoms

CTE can greatly affect your emotions. Research suggests that those living with CTE may experience a variety of mood-related symptoms, such as:

• Frequent mood swings
• Irritability
• Delusions
• Manic episodes
• Paranoia
• Depression
• Anxiety
• Loss of motivation
• Withdrawing from social situations

Cognitive Symptoms

Cognitive (brain-related) changes can severely affect people living with CTE. You may notice symptoms such as:

• Short-term memory loss
• Difficulty remembering important details
• Lack of focus or concentration
• Trouble understanding information and language
• Lowered ability to complete tasks or accomplish goals
• Higher risk of developing dementia

Behavioral Symptoms

As their cognition and mood change, people with CTE may start to behave differently. The condition can cause the following behavioral symptoms:

• Impulsive actions or decision-making
• Aggression toward others
• Emotional outbursts
• Inappropriate comments

Motor Symptoms

Motor (movement-related) symptoms are more common among older adults with CTE and may include:

• Frequent falls
• Tremors
• Shuffling gait
• Difficulty speaking
• Being more clumsy than usual
• Muscle pain or stiffness

Research has shown a link between CTE and a movement disorder called Parkinsonism, which can cause symptoms like tremors, rigidity, and slow movement.

When you experience a traumatic brain injury, the high-speed force of impact stretches the cells and blood vessels in your brain. This injures your nerve fibers and compromises your blood-brain barrier by introducing small hemorrhages (bleeding). The trauma or force also causes inflammation and stores a protein called tau in different parts of the brain, which can damage your brain tissues.

Traumatic brain injuries, like concussions, are the most common cause of CTE. These events typically occur over several years. Concussions are usually triggered by a strong blow to the head or body that moves the brain inside the skull. A strong whiplash, such as during a car accident, can also cause a concussion.

Risk Factors

Several risk factors have been linked to CTE. You are more likely to develop the condition if you:

• Play (or played) contact sports like football, boxing, and hockey
• Were in the military
• Use performance-enhancing drugs
• Experienced concussions at a young age

At this time, there is no surefire way to diagnose CTE while you are still alive. A definitive diagnosis can only occur after you have passed through closely examining changes in your brain tissue. To do this, a healthcare team may order tests like:

• Magnetic resonance imaging (MRI): Uses imaging to determine if certain areas have become thicker or thinner
• Functional magnetic resonance imaging (fMRI): Checks to see if there is reduced blood flow to any areas of the brain
• Diffusion tensor imaging (DTI): Assesses the white matter in your brain to see if it has broken down
• Fluid biomarkers: Utilizes blood tests that can check the presence of biomarkers (like the tau protein) in your brain

It’s worth noting that if you have symptoms of CTE, it’s still important to see your healthcare provider or a neurologist (a doctor who specializes in the brain and spinal cord) for support.

While they can’t offer a definitive diagnosis, they can presume that you have CTE or another neurological condition that is causing your symptoms. Your healthcare team can also help you find treatments that may better manage your symptoms.

There are currently no treatments that cure CTE. Instead, treatment focuses on managing symptoms and supporting your overall well-being. This may occur through medications or supportive treatments.

Prescription Medications

The United States Food and Drug Administration (FDA) has not approved any medications that specifically treat CTE, but some healthcare providers prescribe medications off-label (not for their intended use) to help manage symptoms. These include:

• Aricept (donepezil): Helps improve memory
• Ritalin (methylphenidate): Can boost attention
• Zoloft (sertraline): Manages depression
• Lexapro (escitalopram): May help lower anxiety
• Eskalith (lithium): Aids in decreasing impulsivity

The research landscape for CTE is bright. Clinical trials are currently underway to study more treatment options for managing symptoms, and experts hope to find improved treatments soon.

Supportive Treatment

There are several supportive therapies you can use to manage symptoms of CTE. These therapies focus on improving a specific symptom but may not eliminate it entirely. Your healthcare team may suggest these supportive therapies:

• Motor therapy
• Behavioral therapy
• Psychotherapy
• Aerobic exercise
• Mindfulness 
• Cognitive rehabilitation

While there is no cure for CTE, the condition is highly preventable. You can prevent CTE by reducing traumatic brain injuries and concussions. If you do experience a head injury on accident, treating the injury quickly and effectively can also help prevent CTE.

Experts also believe implementing more safety policies within sports can lower the risk of CTE, especially in athletes. Recommendations include:

• Use helmets
• Teach safe tackling techniques
• Penalize reckless hits
• Encourage athletes to report any symptoms of CTE they may have
• Have increased access to trained team physicians
• Return to play only when cleared to do so

Some athletes are also more likely to develop CTE than others. One study found that goalkeepers had the lowest rate of CTE among soccer players, potentially because they use their heads to hit the ball less than other players.

That said, you can help prevent CTE by being selective with the sports you engage in, the positions you play, and how aggressively you compete.

People who have a history of head injuries and a high risk of developing CTE may also have an increased chance of developing several other brain-related disorders. These may include:

CTE is a neurodegenerative disease caused by repetitive trauma to the head, which can cause inflammation, changes to your blood-brain barrier, and an increase in tau protein deposits in your brain.

While the condition is not currently diagnosable during life, experts warn of several symptoms that CTE can cause, such as changes in mood, behavior, thinking, and movement.

No cure for CTE is available at this time, but practicing head safety in contact sports can significantly lower your risk of the condition. If you’ve received a traumatic brain injury, proper treatment and management of symptoms can promote maximum recovery and lessen your risk of developing CTE.