You know, when I was approached by Chris Nowinski with the Sports Legacy Institute, and he had gotten the first individual player that had died to donate his brain--I think it was to Pittsburgh--for the first autopsy, and I looked at it. He said, "What do you think?" I said, "You really need a card-carrying group of people to look at these brains." "You just can't do this haphazardly." And so McKee at Boston, who I knew professionally, not personally, but I knew of her work, and people like Guy Clifton at Baylor--outstanding neuropathologists. And David Graham, who has since retired, was a great neuropathologist at Glasgow, where the Glasgow Coma Score was developed. So these are the people that need to look at these brains. What's happening is that as these individuals are dying--and they're dying from all kinds of different problems, and some of them are self-inflicted wounds-- from suicides--they're beginning to see lots of different pathology. Yes, it is a selected group of people. These aren't the people that are usually doing very, very well. These are the people that are doing very poorly, so it may be a select population. But I am very convinced with the quality of the type of histology that they're doing and the type of immunities to chemistry that they're doing, at least from the papers that I've read. I have not visited their facility, and I haven't seen how they actually section the brains or if there is any bias in how they actually do this. But I'm very convinced of the quality of their work, and I think this is a real phenomenon. We've known for many years that after head injury the brain will atrophy. Traumatic cerebral encephalopathy is real. A person that has had a head injury when they were 20, and we do a scan, a brain scan, of them when they're 45, their brain looks like they're 80 in terms of its shrinkage. So I don't need a fancy immunohistochemistry technique to tell you that there is a change going on. So I think that's real. Whether that applies to repeat mild concussions or what we were discussing earlier-- if there is such a thing as a subconcussive repeat head injury--I don't know. But I am very, very concerned about that data, not so much from the sense of its quality or whether it's real or not, but the implications that it has. I remember I was being interviewed by Alan Schwarz from the New York Times, and when we were discussing this, he says, "I hear this resistance in your voice," and I said, "I don't want this to be true." I don't want this to be true. This is horrible if this is true. If it happens to everybody, this is really a much greater cost than what I thought we had at the beginning. I think we'll have to wait to see as more specimens come in. The military now is--many of the individuals that are part of the--not part of the DOD, but the veterans that have come back have agreed to donate their brains for analysis, so maybe as things evolve we'll learn more about this. I am always impressed with--when I was younger I studied a phenomenon called cerebral hemispherectomy, which is you would remove half of the brain in children that had bad seizures. And these kids grow up, they go to school, they go to college, they run hospitals, they become lawyers, and it's always funny because you can always say, "You really only need half of a brain to do this stuff." I raise that example not so much that it's related to traumatic brain injury, but that you can perform quite a lot, probably, with losing--some atrophy. My father, who is still alive, has a lot of atrophy, but he is still very cognizant and can do quite a lot. He can't do the same things he did when he was 60, and he is now 88, but there is a lot of capacity there, and he can still enjoy life. What I'm seeing out of the Boston group, particularly some of the most recent work that--we've always known there has been sort of this relationship to dementia and to Alzheimer's disease. We now know that there is a relationship to Parkinson's disease. Head injury doesn't cause Parkinson's disease, per se, but it sets the brain up to be more susceptible to Parkinson's disease the same way it sets the brain up for post-traumatic stress. It sort of sets the brain up for that. The most recent paper that I saw that came out had it with amyotrophic lateral sclerosis. That's a motor neuron-specific problem. That was remarkable, and that's only one report, but that has me very nervous.
The implications of recent data about cumulative concussion, chronic traumatic encephalopathy, and TBI's relationship to dementia and other diseases is alarming.
Posted on BrainLine October 24, 2011.
David Hovda, PhD is the director of the UCLA Brain Injury Research Center. He is past president of the National Neurotrauma Society and past president of the International Neurotrauma Society. He has served as chair of study sections for the National Institute for Neurological Disease and Stroke.
Produced by Noel Gunther, Ashley Gilleland, and Brain King, BrainLine.