Chronic traumatic encephalopathy (CTE) is a type of dementia associated with repeated blows to the head and recurrent episodes of concussion.
Chronic traumatic encephalopathy is particularly associated with contact sports, such as boxing or American football. Most of the available studies are based on ex-athletes.
It was previously known as "punch drunk" syndrome and dementia pugilistica. However, these terms are no longer used as it's now known that the condition isn't confined to ex-boxers.
There's still some debate about how widespread chronic traumatic encephalopathy is and how it should be diagnosed.
Currently, there are only supportive treatments available and research is focused on finding a reliable technique to diagnose the condition.
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The symptoms of chronic traumatic encephalopathy may be similar to those seen in other types of dementia , particularly Alzheimer's disease .
Symptoms typically begin gradually several years after receiving repetitive blows to the head or repeated concussions.
They may include:
As the condition progresses, further symptoms may include:
Read more about the symptoms of dementia .
Any prolonged activity that involves repeated blows to the head or recurrent episodes of concussion is thought to increase the risk of chronic traumatic encephalopathy.
However, chronic traumatic encephalopathy and concussion are separate conditions.
Many people who are concussed don't go on to develop the condition, but evidence suggests a pattern of recurrent minor head injuries increases the risk.
Although the exact causes aren't fully understood, certain groups of people are believed to be most at risk, including:
If you're worried about your memory or think you may have dementia, it's a good idea to see your doctor.
If you're worried about someone else, you should encourage them to make an appointment and perhaps suggest that you go along with them.
Memory problems aren't just caused by dementia – they can also be caused by:
Your doctor can carry out some simple checks to try to find out what the cause may be, and they can refer you to a specialist memory clinic for more tests, if necessary.
Read about when to seek medical advice for:
As chronic traumatic encephalopathy shares many features with other neurodegenerative conditions, there's currently no test available to diagnose the condition.
A diagnosis is usually based on a history of participating in contact sports, symptoms and clinical features.
Your doctor will talk to you about the problems you're experiencing and may ask you to perform some simple mental or physical tasks, such as moving or walking around, to help with the diagnosis.
Your doctor may refer you to a specialist memory assessment service, staffed by experts in diagnosing, caring for and advising people with dementia, and their families.
Memory clinic staff can listen to your concerns, assess your skills and, if necessary, arrange further tests to rule out other conditions.
Currently, the most reliable way of confirming a diagnosis of chronic traumatic encephalopathy is to examine a person's brain during an autopsy (an examination of the body after death) for certain changes.
These changes may not show up on routine brain scans or may occur in other conditions, which is why it can be difficult to confirm a diagnosis in life.
Research has found that the changes in the brain associated with chronic traumatic encephalopathy are different from those seen in Alzheimer's disease.
However, both conditions are associated with shrinking of the brain (atrophy) and the presence of neurofibrillary tangles that contain a protein called tau.
Research is ongoing to determine whether other brain imaging techniques will be able to help diagnose chronic traumatic encephalopathy in the future.
Read more about:
tests for diagnosing dementia
what to do if you've just been diagnosed with dementia
As with many other types of dementia, treatment for chronic traumatic encephalopathy is based around supportive treatments.
If you've been diagnosed with the condition, healthcare professionals, such as your doctor or specialist, and social care services will usually both be involved in helping draw up and carry out a long-term care plan.
You may also see a speech and language therapist or occupational therapist .
Dementia Choices provides detailed information for people with dementia and their families, including:
help and support for people with dementia
staying independent with dementia
looking after someone with dementia
It may also be helpful to get in touch with a local or national Alzheimer's or dementia support group, such as the Alzheimer's Society, for more information and advice.
The only known way to prevent chronic traumatic encephalopathy is to avoid repetitive head injuries. Although many head injuries are difficult to predict or avoid, there are ways to reduce your risk.
Important: Our website provides useful information but is not a substitute for medical advice. You should always seek the advice of your doctor when making decisions about your health.