Chronic Traumatic Encephalopathy – Symptoms and Causes

Overview

Chronic traumatic encephalopathy (CTE) is a degenerative brain disorder linked to repeated head injuries. The condition progressively worsens over time as nerve cells in the brain die. Currently, definitive diagnosis can only be made after death through brain autopsy.

CTE remains relatively rare and poorly understood by medical science. It doesn’t typically result from a single head injury but develops from repeated trauma. It is particularly common in contact sports and military service.

Second impact syndrome—when a new head injury occurs before a previous one has healed—appears to increase the risk.

Scientists continue researching several key factors:

• How many head injuries increase risk
• The severity of injuries needed to trigger CTE
• The time between injuries

The condition has been identified in the brains of:

• Football players
• Boxers
• Other contact sport athletes
• Military personnel exposed to blast injuries

Symptoms typically don’t appear immediately after injuries but develop years or even decades later. These may include:

Cognitive Issues

• Memory problems
• Confusion

Emotional Changes

• Depression
• Mood swings

Physical Problems

• Coordination difficulties
• Balance issues

While CTE cannot be conclusively diagnosed in living people, healthcare providers may diagnose “traumatic encephalopathy syndrome” when symptoms match typical CTE patterns in people with high-risk exposure histories.

Researchers are working to develop reliable biomarkers for diagnosis, but none have been validated for clinical use yet.

The prevalence of CTE in the general population remains unknown, though current evidence suggests it’s uncommon. Unfortunately, there is currently no cure for this condition.

Signs and Symptoms

Changes in Thinking

Brain injuries can lead to troubles with thinking over time. You may notice memory problems, especially with recent events. Simple tasks might become harder to plan and finish.

These changes don’t happen right after an injury but develop slowly, sometimes taking years or decades to appear.

Some people notice these problems in their 60s. The thinking problems might get worse over time and could lead to more serious memory conditions.

Changes in Behavior

After repeated head injuries, some people become more impulsive. This means they might act without thinking about consequences first.

Common behavioral changes include:

• Acting without thinking
• Becoming more aggressive
• Taking unnecessary risks
• Having trouble controlling emotions

These changes often appear in early adulthood, around the late 20s or early 30s.

Changes in Mood

Brain injuries can affect how you feel emotionally. Depression is common, where you might feel sad most of the time or lose interest in activities you once enjoyed.

Watch for these mood changes:

• Feeling depressed or showing less emotion
• Mood swings
• Problems with alcohol or drugs
• Thoughts about suicide

These emotional problems may be some of the first signs to appear, often showing up in younger adults.

Changes in Movement

Physical symptoms can also develop after repeated brain injuries:

1. Walking problems and poor balance
2. Shaking hands and slow movements
3. Slurred speech
4. Difficulty with basic movements

These physical changes can make daily activities harder and may get worse over time.

When to Talk to a Doctor

See a healthcare provider if you notice any of these signs, especially if you’ve had head injuries in the past:

Seek help immediately for:

• Thoughts of harming yourself (call 988 for the Suicide & Crisis Lifeline)
• Any head injury, even if it seemed minor at the time

See a doctor soon for:

• Memory problems or confusion
• Trouble completing familiar tasks
• Changes in personality
• Feeling depressed, anxious, or more aggressive
• Movement problems or tremors

Don’t wait for symptoms to go away on their own. Early medical attention is important, especially if you’ve had multiple head injuries throughout your life.

Causes

Repeated head trauma is likely the main factor in the development of CTE. Most research has centered on American football players, ice hockey players, and military personnel in combat zones.

But other activities with risk of head injuries, including other sports and physical abuse, may also lead to this condition.

Head injuries can cause concussions with symptoms like headaches and memory problems. Not everyone who experiences multiple concussions develops CTE. Some research has found no higher rates of CTE in people who have had repeated head injuries.

In CTE, a protein called tau builds up around blood vessels in the brain. This tau buildup differs from what happens in Alzheimer’s and other types of dementia.

The condition is thought to cause brain atrophy (wasting away of brain tissue) because:

• Injuries damage nerve cells that carry electrical signals
• This damage disrupts communication between brain cells

People with CTE may also show signs of other brain diseases, including:

• Alzheimer’s disease
• ALS (amyotrophic lateral sclerosis)
• Parkinson’s disease
• Frontotemporal dementia

Brain tissue changes from repeated injuries may contribute to these overlapping conditions.

Risk Factors

People who suffer multiple traumatic brain injuries may have a higher chance of developing CTE. Scientists are still studying what other factors might increase this risk.

Prevention

There is currently no cure for CTE. Prevention focuses on reducing the risk of repeated concussions, which are linked to this condition.

People who have suffered one concussion face a higher risk of subsequent head injuries.

Experts recommend these prevention strategies:

• Avoid mild traumatic brain injuries when possible
• Allow complete recovery after any concussion before returning to activities
• Follow safety protocols in contact sports
• Wear proper protective equipment during high-risk activities

Proper management of concussions is essential to prevent more serious damage.