The Long Term Effects of Traumatic Brain Injuries

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Audio Transcript:

Lisa Mullins: In warfare in Syria or anywhere often results in brain injuries. Among the American veterans of the wars in Iraq and Afghanistan, trauma to the brain accounts for more than one fifth of all combat related injuries. Those injuries can cause immediate health problems, such as headaches, irritability, and depression, but a new study suggest that the consequences could be far more severe and long lasting than previously though. Dr. Ann McKee is a neurologist with the VA Boston, and one of the authors of this new study. She is now in our studio. You autopsied the brains of four recent veterans who suffered head injuries. They did not die of those injuries. How did they die, and who where these men whose brains you ended up studying?

Ann McKee: Well I studied the brains of four young veterans from the recent conflict in Iraq and Afghanistan, ranging in age from 22 to 45. Three had been exposed to blasts, either one or multiple exposures. The fourth one was exposed only to concussive injuries, both in civilian life and in combat.

Mullins: So how did these men die? They were pretty young.

McKee: They were young. None of them died of their head injuries. They lived. But after they came back, they all were symptomatic. They all had trouble with headaches, irritability, a short fuse, many had sleeping problems, three were diagnosed with PTSD.

Mullins: So that's what happened when they were alive. Once they passed away you look at their brains. You autopsy them and find what?

McKee: Well we found the buildup of this protein called Tau in focal parts, or just spots, within the part of the brain called the Frontal Cortex, and that's a part of the brain that's very important for organization, planning, judgment, and our higher intellectual function. What was surprising was that the damage that we saw in the brains was exactly what we had seen in young athletes who had been exposed to concussive injuries experienced on the playing field.

Mullins: You mean all coming down to this protein called Tau?

McKee: Tau is a protein that builds up in this disorder. It becomes an abnormal protein. We normally have Tau in our brain. It serves a function both to hold up our structure of our nerve cells and also to aid in transport of important nutrients and molecules, but after trauma it becomes altered and it becomes toxic, and build up in the cell in sort of a toxic form which will eventually kill the cell and certainly destroys its function while it's there.

Mullins: OK. So here's the important part, one of the important parts, of what you're doing and that is, you are finding the similarities in brain degeneration between athletes who have suffered trauma and veterans who have suffered trauma. Do these changes that you saw affect the daily lives of these vets, and did they affect the daily lives of the athletes whose brains you studied as well?

McKee: Well, surprisingly what we see are these discreet spots on the brain, but we are definitely seeing symptomatic problems with both the veterans and the athletes. Lack of attention and concentration is common. Impulsivity is common. A tendency for a short fuse or a small trivial event makes them sort of have a violent reaction. And then of course, there's the well known problems of sleep disorders and some suicidality in both of these groups.

Mullins: One of the troubling things I would think though for you would be the fact that when there is a sports injury to an athlete you might even have the video tape that shows you the point of impact when the trauma happened, along with maybe smaller trauma along the way. With veterans, can you pinpoint exactly how many concussive events there were? How much trauma was suffered when? Over what period of time?

McKee: Yeah, great question. But no. We can't do that even in the athletes. But one question that continued after we'd seen these remarkable similarities was, the military individuals always tend to have a sort of a heterogeneous injury. I mean, they might have a blast injury but they had a history of playing football, or maybe they had an impact injury from falling out of a motor vehicle. You know, it's always a complicated history. So the real question we were trying to answer the model that we devised was can pure blast injury cause the same kind of damage to the brain that a concussive injury can cause. And that's when we turn to the mice, producing a blast model of injury, in using experimental mice. The looking at the mouse brain experiment neuropathologically and seeing very similar changes created in the mouse brain that we had seen in the human brain.

Mullins: With both the athletes and the vets.

McKee: Right.

Mullins: Uh-huh. So the question is now, what happens later and is there any way to reduce longer term effects on the brains of veterans, or any treatment that can slow down the brain degeneration that you've documented.

McKee: Well certainly this is exactly where our focus is. I mean, we've identified the process, we understand no the basic mechanisms involved, and all of our research is now at pinpointing how to interrupt this series of degeneration. How can we reverse it. How can we treat it in living veterans. That's our aim. One thing that the study did show was that if we fix the helmet to the neck or if we stabilize the head, because we stabilize some of the mouse heads, we didn't see the injury. So it suggested some improvement could be made with just changing the equipment that these military service people use.

Mullins: Which gets into the practical impact of that. The reason we're talking about the degeneration is because it is ongoing?

McKee: It can be ongoing, and I should say, this is not something that we're going to see in everybody that's ever been exposed to this. There are many, many people that have been exposed to this that will never get this.

Mullins: Really?

McKee: But we just know that some people are at risk for this, and this is something we need to look for in those people. And that's one of the things that is also a challenge for us right now, identifying this legion in living people. So one of our studies at the VA that we're embarking on now is looking at cerebral spinal fluid, or doing a spinal tap looking for the proteins, specifically the Tau protein, that develops in this disorder. We're also looking at some sophisticated imaging techniques, some of which are directed at the Tau protein, to also identify this in living veterans.

Mullins: Ann McKee is a neurologist with the VA Boston and Boston University. Her new study of brain injury among veterans appears in the journal Science Translational Medicine. Thanks for coming in.

McKee: Thanks for having me.