Advanced MRI in Blast-Related TBI

PUBLIC ABSTRACT

Traumatic brain injury can be fatal, or in survivors it can cause permanent problems with thinking, memory, control of emotions, organization, and planning. Thousands of soldiers, marines, and other military personnel have had injuries to the brain due the wars in Iraq and Afghanistan. Traumatic brain injury has been called the "signature injury" of these wars. Very large numbers of civilians, up to perhaps 1.5 million people per year, in the United States have traumatic brain injuries caused by car accidents, falls, sports-related injuries, or assaults. We don't know very much about traumatic brain injuries right now, but there are some important new advances in technology that may help us learn a lot more about these injuries. One such advance involves new types of magnetic resonance imaging (MRI) scans that we think will be able to show what has happened to the brain after trauma more clearly that regular scans can. The first new scan is called diffusion tensor imaging, which shows injury to the axons (the wiring of the brain). The second new scan is called resting-state functional MRI correlation analysis, which shows how well various parts of the brain are connected to each other. Importantly, the new types of scans can be done using regular scanners that we already have in every major hospital. The innovation is entirely in how the scanners are used and how the resulting pictures are analyzed on a computer after they have been taken.

What are the goals of the proposed study? Our overall goal is to see whether these new MRI scans will be useful for people who have had traumatic brain injuries. We have already tested them on some civilian brain injury patients and found them to be very helpful. For this study, we will test them on military personnel who have had traumatic brain injuries caused by explosions. The specific goal will be to see if the amount of injury we see can be used to predict how well the patients will do overall over the next 6-12 months. We think that with the new scans we will be able to predict overall outcomes better than with regular scans and other information. A related goal will be to see whether injuries to specific parts of the brain seen by these new scans can be used to predict whether patients will be likely to have specific problems like memory loss, attention deficit, depression, or post-traumatic stress disorder. A final goal will be to repeat the scans 6-12 months later to see whether the new MRI scans can show whether the injuries to the brain have healed, gotten worse, or stayed the same.

What are the likely contributions of this study? If the study is successful, it will show that these new MRI techniques can to be used to make earlier and more accurate diagnoses of traumatic brain injury, predictions of the sorts of problems that are likely to occur after brain injury, and assessments of how severe the injuries are.

What types of patients will it help? This study will help traumatic brain injury patients. It will be most useful for military personnel who have had brain injuries due to explosions. It is highly likely that it will also be useful for younger adults who have had brain injuries due to other causes like car accidents, sports-related concussions, falls, or assaults. It is possible, but not known for sure, that it will help young children or older adults with traumatic brain injuries. It is also possible that it may help people with other brain injuries or diseases.

How will it help them, and how long will it likely take? These new scans could help with decisions about whether military personnel can return to duty, what sort of rehabilitation and treatment would benefit them most, and what family members should watch for and expect. This could become used in some hospitals within 2 years, and could become standard in every major hospital within 5 years. The new scans could also be helpful in developing new treatments. For example, if a new drug works by blocking injury to the axons, it would be a good idea to test on people who have injury to their axons. Right now we have no good way to tell who these people are, and so a new drug like this would get tested on lots of people who don't have injured axons, along with those who do. This would make it harder to tell if the new drug is working. With the new scans, we should be able to tell who has injured axons, tell how severe the injury is, and figure out whom to test the drugs on. It will likely take 10 years or more to develop new drugs like this. Further in the future, the new scans could be used to help guide surgery to implant computer chips to help rewire the brain. We don't know how long this will take, but estimate 15-20 years or more.

What are the risks of the proposed study, and what will we do about them? Overall, MRI scanning is very safe and has no known major risks. Because the scanner uses strong magnets, anyone with metal objects in their bodies can't be scanned, as this could be dangerous. We will make sure that no one with metal objects in their bodies is included in the study. There can be some psychological risks involved in taking tests and answering questions, but these are usually mild and can be managed. There is always a risk that important confidential information will be made public and that this could have consequences. We will do everything possible to maintain confidentiality. Nearly all of the information will only be identified using a code number and not by the name of the person, and all of it will be kept securely.