Introduction to Vision and Brain Injury
Vision Problems
In general, 20-40 percent of people with traumatic brain injury experience related vision disorders. Some vision-related issues can be permanent; others resolve quickly. This depends, of course, on the individual and his unique brain injury.
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Eye Tracking Technology to Test TBI Symptoms
If you wanted to measure performance variability, you could do it with reaction tests. I would say that a lot of the reaction tests are static interactions. So it's, "When you see the yellow triangle, press the button as soon as possible." They're not dynamic interactions. Most of what we do on a daily basis are dynamic interactions. Hearing somebody speaking is a dynamic cadent interaction. We have to keep up with the words. It's not just one word sitting there and you say, "Okay, what's that word?" We don't do static interactions; we do very dynamic interactions. You've got to predict in those interactions. So that's one thing. The eye tracking is really a continuous dynamic test of attention. The other thing is you do collect-- because of this camera and the eye position, you can collect many, many data points within a second-- hundreds, maybe thousands of data points within a second of eye tracking depending upon how fast the camera is. In the reaction time test you only collect a few data points, and so you have to go to 20, 30 minutes. The other problem is that reaction times are effort-related. So if I don't feel like performing well on a neurocognitive test, I just delay my reaction times, whereas the eye tracking you're either eye tracking or you're not. There's no effort issues. You're either following the red ball going around or you're not. So when we do test-retest reliability, we look at-- for instance, we've done this in soldiers; we test them and then we bring them back 2 weeks later and test them again-- there's a very high test-retest reliability. So it says basically that you can take the test and if there's any real change, it's really because of the neurology and not so much because of the testing itself. So I think the test-retest reliability, I think it's a very quick test. The actual test itself is 30 seconds. Because you get a lot of data points within a short period of time, you're looking at continuous performance tasks for attention, I think that makes it-- Now, you could say that there are other parts of attention. People have a problem knowing what a yellow triangle is. People may have trouble with memory. They may be blind, they may have motor problems. All those things have to be assessed as well. And I would say that these are just measuring certain parameters. We're measuring a continuous visual attention test. If you want to measure something else, then you use some other test. I think the idea that there's going to be one test that's going to be used solely for coming up with a diagnosis of concussion or mTBI is ludicrous. We don't do that in medicine. If you look at diagnoses, they're based upon the history, they're based upon imaging, they're based upon symptoms, quantitative testing, and so on. You bring all that together and you come up with a diagnosis. So I think we're looking at--and the military, the Defense Department, is certainly looking at--from this perspective is that there's not going to be just one test we're going to be using. We're going to be looking at multiple different parameters and looking at a basket of tests and from that, over time, see how they relate to each other in terms of producing diagnostic criteria that both have immediate clinical utility but also in terms of prognosis as well.
The Most Costly, Least Effective Treatment for Brain Injury
The issue of traumatic brain injury and incarceration is a really tragic one. We know that for behavioral problems the least effective, most costly place to deal with behavioral problems of that type, whether they be related to challenging behaviors associated with brain injuries or serious mental disorders or substance use disorders, the most costly, least effective place to deal with those challenging behaviors is in our jails. And we know when it comes to, for example, substance use disorders and serious mental disorders, the largest single institutional provider for treatment in those populations is our jails. Los Angeles County jail, Cook County jail, and Rikers Island are 1, 2, 3 with respect to that. Booker T. Washington said--or Du Bois, one of those individuals-- said a long time ago, "Better to build a child than to fix a broken adult." It's better to do preventative stuff than restorative stuff. f So to the extent we have wounded warriors who lack facilities, have barriers, perceived or real, for access to care, we need to figure out a way to address those barriers as a preventative strategy.
Vocational Rehab: What Works and Doesn't Work with TBI
I think larger and traditional vocational services are not designed to help people with brain injury very effectively. The dismal outcomes that state vocational rehab agencies show for people with brain injuries kind of attest to that. In many ways, traditional voc-rehab is oriented towards tuning the person up, and then getting them back to work. After a brain injury, it almost has to be the other way around. In fact, some of the seminal people in this field-- like Paul Wehman and the group at Stout, Dale Thomas-- really recommend a place-then-train model. In other words, get the person back to a job that it looks like they can do, and then help them learn how to do that job, on the job. Because people with brain injury have difficulty generalizing training from one setting to another, they really need to learn the job on the job. They also may need ongoing support almost indefinitely. Now, that doesn't have to be a lot of support, but they may need somebody to call if things start to fall apart. In our program at Mayo we found, not infrequently, that people would get on a job, be quite successful for a period of time, and then there'd be some change in procedures, and they would just fall apart. If we knew about that--if somebody called us back--that was not a hard fix. We could help them learn the new procedures and get things back on track and save the job. But if there's nobody to intervene, the employer just concludes that they're not able to do the job anymore, and they have to let them go. I think vocational services like that-- that involve support and employment, and developing a network of support for the person--both professional and non-professional-- we've engaged people from their church group, from their social clubs. If they need a ride to work, who are you going to call? If your car breaks down, you know--really working on the environment as much as the person is probably more successful in getting people back to work and helping them sustain those jobs than the more traditional intervention of tune-up and placement.
