You want to know more…?

There is now enough evidence that doctors have created or I suppose – defined – a new condition called CTE: Chronic Traumatic Encephalopathy. ‘Chronic’ means it comes on over time, not just from a one-off head injury, ‘Traumatic’ – well we know that’s related to trauma or damage, ‘Encephalopathy’ – brain damage due to swelling. So CTE is a condition caused by repeated blows to the head, leading to eventual brain damage.

How did they decide this? The docs looked at pieces of brain, not knowing whose they were. (I’ll quickly point out this is after the people have died!) They found specific, obvious changes in the brains of some people. Once they had seen these changes they  were told which people the brains had belonged to. It was obvious that they were people who had chronic trauma. These changes could not be explained by any other disease or process. (They weren’t just normal changes from getting old.) They were only found in people who had head traumas.

So yes, they can be quite certain that repeated head injury (whether there are symptoms at the time or not) can lead to permanent brain damage.

How bad does the concussion need to be?

They don’t know yet. They did say CTE “has only been found in individuals who were exposed to brain trauma, typically multiple episodes” and that they don’t have to have had symptoms of concussion at the time. The CTE can start “months, years or even decades” after the last blow to the head.

What are the signs and symptoms of CTE?

  • memory loss, 
  • confusion, 
  • impaired judgment, 
  • impulse control problems, 
  • aggression, 
  • depression, 
  • eventually, progressive dementia

The head injuries seem to cause damage both to the outer layers of the brain as well as the deeper areas.


No, not yet. Although it’s a question often asked in class, they’ve only just figured out for sure that this happens. The best thing we can do is prevent head injuries from happening as far as possible; and know what to do if someone does get a head injury by taking training.


The easier read (but not as easy as the notes above):

The technical read: