The Pathology of CTE Versus That of Other Neurodegenerative Diseases
The question about whether we see the pathology associated with CTE in individuals who have not had a trauma history, the evidence for that is really none. The pathology is very characteristic. I think at this point a lot of this work has been done by my colleague, Dr. Ann McKee, at Boston University School of Medicine and at the Boston VA Healthcare System. And to our knowledge collectively as a field, the types of pathology we see are really unique to this disorder and are unique to individuals who have had repetitive trauma in most cases, and now we're starting to see some evidence of blast-related trauma. But as we may discuss in a short while, there are some connections there. But we do not see this type of pathology in individuals without any trauma history. I'm going to put a slight caveat on that. It's rare amongst people alive and walking around that no one has been bumped on the head. I certainly have, and I think most people have. So we don't really know what that relationship is to neurodegenerative diseases. One thing that's becoming clear is that this type of trauma does not require concussion per se or loss of consciousness. So some of these injuries may occur in people who are stunned maybe or they're not exactly right--their bells have been rung, for example-- but they're not knocked out, they don't black out. So it may not be that you require a loss of consciousness for these injuries. In fact, the data seem to be pointing in that direction rather strongly-- that it's more the nature of repetitive brain injury, or in the case of some injuries like blast, for example, which turn out to be multiple injuries very closely spaced together, the intensity of the inciting trauma. So we don't know the answer to that yet, and we actually don't know what the contribution of CTE might be in relationship to other neurodegenerative disorders.
So far, research shows that chronic traumatic encephalopathy does not occur in people who have not sustained repetitive hits to the head either in sports or in combat.
Posted on BrainLine February 28, 2013
Produced by Brian King, Vicky Youcha, and Erica Queen, BrainLine.