Overview

Chronic traumatic encephalopathy (CTE) is the term used to describe brain degeneration likely caused by repeated head traumas. CTE is a diagnosis only made at autopsy by studying sections of the brain.

CTE is a very rare condition. It has been found in the brains of people who played contact sports, such as football, as well as others. Some symptoms of CTE are thought to include difficulties with thinking (cognition), physical problems, emotions and other behaviors.

CTE is a very controversial condition that is still not well-understood. Researchers do not yet know the frequency of CTE in the population and do not understand the causes. There is no cure for CTE.

Source: http://www.mayoclinic.com

Symptoms

Some of the possible signs and symptoms of CTE may include:

• Difficulty thinking (cognitive impairment)
• Impulsive behavior
• Depression or apathy
• Short-term memory loss
• Difficulty planning and carrying out tasks (executive function)
• Emotional instability
• Substance abuse
• Suicidal thoughts or behavior

Other suspected symptoms may include:

• Irritability
• Aggression
• Speech and language difficulties
• Motor impairment, such as difficulty walking, tremor, loss of muscle movement, weakness or rigidity
• Trouble swallowing (dysphagia)
• Vision and focusing problems
• Trouble with sense of smell (olfactory abnormalities)
• Dementia

The full list of symptoms of people with CTE at autopsy is still unknown. It is unclear what kind of symptoms, if any, it may cause. Little is known right now about how CTE progresses.

When to see a doctor

CTE is thought to develop over many years after repeated brain injuries (mild or severe). However, see your doctor in case of the following:

• Suicidal thoughts. Research shows that people with CTE may be at increased risk of suicide. If you have thoughts of hurting yourself, call 911, your local emergency number or the National Suicide Prevention Lifeline at 800-273-TALK (800-273-8255).
• Head injury. See your doctor if you have had a head injury, even if you didn't need emergency care. If your child has received a head injury that concerns you, call your child's doctor immediately. Depending on the signs and symptoms, your doctor may recommend seeking immediate medical care.
• Memory problems. See your doctor if you have concerns about your memory or other thinking (cognitive) or behavior problems.
• Personality or mood changes. See your doctor if depression, anxiety, aggression or impulsivity occur.

Source: http://www.mayoclinic.com

Causes

Initial injury

Repetitive head trauma is likely the cause of CTE. Football players have been the focus of most CTE studies.

However, athletes participating in other sports, including soccer, ice hockey, rugby, boxing, wrestling, basketball, field hockey, cheerleading, volleyball and lacrosse, may experience repeated head impacts and also have high rates of concussion.

CTE has also been found in people who repeatedly bang their heads, people who have been physically abused, and those with epilepsy that has not been well-controlled. Blast injuries to military personnel also can result in CTE.

However, not all athletes and not everyone who experiences repeated concussions, including military personnel, go on to develop CTE. Some studies have shown no increased incidence of CTE in people exposed to repeated head injuries.

Effect of injury

CTE is thought to cause areas of the brain to waste away (atrophy). Injuries to the section of nerve cells that conduct electrical impulses affect communication between cells.

It's possible that people with CTE may show signs of another neurodegenerative disease, including Alzheimer's disease, amyotrophic lateral sclerosis (ALS) — also known as Lou Gehrig's disease — Parkinson's disease or frontotemporal lobar degeneration — also known as frontotemporal dementia.

Source: http://www.mayoclinic.com

Diagnosis

There is currently no reliable way to diagnose CTE. A diagnosis requires evidence of degeneration of brain tissue and deposits of tau and other proteins in the brain that can be seen only upon inspection after death (autopsy). Some researchers are actively trying to find a test for CTE that can be used while people are alive. Others continue to study the brains of deceased individuals who may have had CTE, such as football players.

Eventually, the hope is to use a range of neuropsychological tests, brain imaging and biomarkers to diagnose CTE. In particular, imaging of amyloid and tau proteins will aid in diagnosis.

Neurological tests

Your doctor will check your neurological health by testing your:

• Speech, language and cognition — including short- and long-term memory
• Reflexes
• Muscle tone and strength
• Ability to get up from a chair and walk across the room
• Sense of sight and hearing
• Coordination
• Balance

Brain-imaging tests

Brain-imaging technology is currently used to diagnose mild traumatic brain injury. Some of the following technologies might be used for CTE diagnosis in the future.

Magnetic resonance imaging (MRI). An MRI uses a strong magnetic field to detail brain images. Researchers believe that as the following specialized MRI tests improve, they may be able to help diagnose CTE.

• Susceptibility-weighted imaging (SWI) is a type of MRI that shows tiny bleeds (hemorrhages) that result from injury to the central nervous system.
• Diffusion tensor imaging (DTI) is a type of MRI that reveals the movement of water and the path of white matter in the brain, which can show brain abnormalities. It shows promise for detecting CTE, but needs to become more accurate and precise.
• Magnetic resonance spectroscopy (MRS) is similar to MRI but may be able to provide greater details about neurological damage.

Positron emission tomography (PET). A PET scan uses a low-level radioactive tracer that is injected in a vein. Then, a scanner tracks the tracer's flow through the brain. Researchers are actively working to develop PET markers to detect tau abnormalities associated with neurodegenerative disease.

The goal is to develop a marker to identify the tau pathology of CTE in people who are living.

Researchers are using various substances that bind to tau and other proteins on PET scans. These PET scans are in the research phase and not available for clinical testing.

Event-related potentials (ERPs) and quantitative EEG. These noninvasive tests use electroencephalography (EEG), in which a mesh cap covered with electrodes is placed on a person's head. It allows doctors to detect, record and analyze brain waves, which may find brain changes that result from multiple traumatic brain injuries.

Single-photon emission computerized tomography (SPECT). SPECT is an imaging test used to diagnose types of dementia. Studies are needed to show whether SPECT can tell CTE from Alzheimer's disease or other neurodegenerative diseases.

Other tests

There's been little research on plasma or cerebral spinal fluid to diagnose the long-term disease processes of CTE. Some biomarkers that are used in Alzheimer's disease research may be useful for CTE because the conditions are similar. These biomarkers would need to identify brain degeneration from CTE separately from the original brain trauma.

Source: http://www.mayoclinic.com

Prevention

There is no treatment for CTE. But CTE may be prevented because it is associated with recurrent concussions. Individuals who have had one concussion are more likely to have another head injury. The current recommendation to prevent CTE is to reduce mild traumatic brain injuries and prevent additional injury after a concussion.

The following equipment can help reduce head injury:

• Sports-specific helmets. Helmets have reduced injury for baseball, ice hockey, rugby, alpine skiing and snowboarding. It's possible that people choosing to wear a helmet also take fewer risks. Helmets have not reduced injury for soccer players. Helmets also cannot eliminate the occurrence of concussions.
• Bicycle and motorcycle helmets. These reduce head injury in case of accident.

Coaches and players need to understand current guidelines for sports-related injuries. It's difficult to evaluate concussion during play, and coaches and players should be cautious and keep injured athletes out of the game.

The following signs and symptoms of concussion may be visible to coaches or to the athlete.

Danger signals:

• Loss of consciousness, even briefly
• One pupil larger than the other
• Drowsy or cannot be awakened
• A headache that gets worse
• Weakness, numbness or decreased coordination
• Repeated vomiting or nausea
• Slurred speech
• Convulsions or seizures
• Unable to recognize people or places
• Increasingly confused, restless or agitated or has other unusual behavior

Signs of concussion someone might observe in another person:

• Appears dazed or stunned
• Is confused about assignment or position
• Forgets an instruction
• Is unsure of game, score or opponent
• Moves clumsily
• Answers questions slowly
• Loses consciousness, even briefly
• Shows mood, behavior or personality changes
• Can't recall events prior to or after hit or fall

Symptoms of concussion someone might notice themselves:

• Headache or pressure in head
• Nausea or vomiting
• Balance problems or dizziness
• Double or blurry vision
• Sensitivity to light
• Sensitivity to noise
• Feeling sluggish, hazy, foggy or groggy
• Concentration or memory problems
• Confusion

If you suspect a concussion in yourself or someone else, follow the four-step action plan:

• Remove the athlete from play for the day.
• Have a health care professional evaluate the athlete.
• Inform the athlete's parent, guardian or significant other.
• Keep the athlete out of play until health care professional OKs a return.

Follow the gradual five-step plan to return to play:

1. Light aerobic exercise, no weightlifting
2. Moderate exercise, weightlifting OK
3. Heavy, noncontact exercise
4. Practice and controlled full contact
5. Competition

Risk factors

Repeated exposure to traumatic brain injury is thought to increase the risk of CTE, but experts are still learning about the risk factors.

Source: http://www.mayoclinic.com