Chronic Traumatic Encephalopathy (CTE): How It Affects the Brain and the Damage It Can Cause

Protecting the brain from trauma seems like an obvious task that most people would eagerly accept. But many don’t realize that common activities can cause a brain injury. Repeated blows to the head during contact sports can cause chronic traumatic encephalopathy (CTE). This can occur more often in sports like football and boxing. Military veterans are also more likely to experience it.

But having a concussion or serious head injury does not mean you’ll develop CTE right away or at all. In some people, CTE symptoms can occur long after the actual impact. While the diagnosis can only be made by autopsy, there are some classic warning signs.

What are the symptoms of CTE?

Changes in behavior, thinking, and movement can be symptoms of CTE. Although these symptoms can mimic conditions like Alzheimer’s, there is one major difference. People who are at most risk for CTE also have experienced repetitive hits to the head. 

There are four stages of CTE as it advances. With each stage, the symptoms become more severe, pronounced, and debilitating. Here’s what to look for in each stage:

• Stage 1:

  • Headaches 

  • Short-term memory loss

  • Mild depression

• Stage 2:

  • Severe depression

  • Mood swings

  • Thoughts of self-harm

• Stage 3:

  • Difficulty organizing materials, setting schedules, and sticking with tasks

  • Aggressive and impulsive behavior

  • Decreased coordination 

• Stage 4: 

  • Slow movement (similar to Parkinson’s disease)

  • Slurred speech

  • Dementia

What causes CTE?

CTE is caused by recurring episodes of head trauma. Researchers believe this leads to tau protein buildup in the brain. 

Tau protein helps to keep the structure of nerve cells in the brain. But, in excess, it can play a role in cell death and cause a decline in healthy brain function. The result is the classic neurological changes in CTE.

Who is most at risk for CTE?

CTE is a rare disorder among the general population. But there are groups who are at greater riskfor developing it. These include:

• Athletes who play contact reports (like boxers and American football players)

• Military veterans exposed to blast injuries

• Survivors of domestic violence

• People with developmental disorders who engage in head-banging behavior

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Other factors that may influence someone’s risk of CTE are:

• The age of first exposure to head impacts

• The number of years of head trauma exposure

• Genetics

How do you diagnose CTE?

CTE is a diagnosis largely based on a thorough medical history and physical exam. So a healthcare provider must have a strong reason to suspect CTE. It can only be definitively diagnosed by evaluating brain tissue after death. 

That said, there is hope for the living. Researchers are doing studies to see how effective imaging is in identifying CTE. Imaging tests that may help with CTE diagnosis are:

• A PET scan (positron emission tomography) may prove useful to detect deposits of tau proteins that are specific to CTE.

• MRI (magnetic resonance imaging) may be able to show findings in the brain that can be associated with CTE. 

There is much more work that needs to be done in this area to increase confidence in these imaging tests for CTE.

What is the treatment for CTE?

Unfortunately, there is no cure for CTE. To manage the disease, researchers are looking at medications that target inflammatory pathways. But there are treatments for the symptoms of CTE.

Medications can be helpful in treating the symptoms of CTE, including:

• Depression: SSRIs (selective serotonin reuptake inhibitors), like Lexapro (escitalopram), Celexa (citalopram), and Zoloft (sertraline), are helpful in improving mood.

• Movement disorders and tremors: Medications that have shown some success are Sinemet (carbidopa/levodopa), Mysoline (primidone), and Tegretol (carbamazepine).

• Dementia: Aricept (donepezil) may help with memory loss and attention deficit in CTE. Namenda (memantine) may help to improve thinking in those with CTE. 

There are also supportive therapies that have shown promise in easing the burden of living with CTE. Therapies include:

• Mindfulness  

• Acupuncture

• Motor therapy

• Cognitive rehabilitation therapy

• Mood and behavior therapy

• A Mediterranean diet 

• Aerobic exercise 

Why trust our experts?

Written by:

Bernadette Anderson, MD, MPH

A native of Saginaw, Michigan, Dr. Bernadette earned an undergraduate degree in psychology from the University of Michigan, Ann Arbor. She completed a master's degree in public health at the University of California, Berkeley, and a doctorate of medicine from the Medical College of Ohio.

Edited by:

Karla Robinson, MD

Karla Robinson, MD, is a medical editor for GoodRx. She is a licensed, board-certified family physician with almost 20 years of experience in health through varied clinical, administrative, and educational roles.

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