An advanced imaging technique has revealed that some U.S. military personnel with mild blast-related traumatic brain injuries have abnormalities in the brain that have not been seen with other types of imaging. The abnormalities were found in the brain’s white matter, the wiring system that nerve cells in the brain use to communicate with each other.
Researchers evaluated 84 U.S. military personnel evacuated to Landstuhl from Iraq and Afghanistan after exposure to many types of explosive blasts. Abnormalities were found in 18 of 63 patients diagnosed with mild traumatic brain injury, but not among 21 injured in other ways.
Traumatic brain injuries are estimated to have affected as many as 320,000 military personnel in the wars in Iraq and Afghanistan. Most of these are classified as mild traumatic brain injuries, also known as concussions.
“We call these injuries ‘mild’, but in reality they sometimes can have serious consequences,” says senior author David L. Brody, MD, PhD, assistant professor of neurology at Washington University School of Medicine in St. Louis.
Mild traumatic brain injury has been a controversial topic, and the new approach may provide an additional tool to help resolve some of the debate. Much of the controversy has revolved around whether symptoms following mild traumatic brain injuries are due to structural injury to the brain, disruptions in brain chemistry, psychological factors or a combination of these.
“There is still a lot more work to be done before we fully understand whether these abnormalities truly represent significant damage to the brain white matter,” says lead author Christine L. Mac Donald, PhD, research instructor in neurology at Washington University. “And if so, how this damage affects attention, memory, emotional regulation, balance, coordination, sleep and other functions. Likewise, the relationship between mild traumatic brain injury and post-traumatic stress disorder is especially important. Our ongoing studies will hopefully start to answer some of these questions.”
Researchers have used diffusion tensor imaging to study mild civilian brain injuries previously and did not see abnormalities in the areas highlighted by the new study.
The results suggest that there may be fundamental differences between blast-related traumatic brain injuries and the sorts of mild traumatic brain injuries sustained by civilians, such as those caused by car accidents, falls, blows to the head and sports injuries.
In addition, advanced imaging also showed abnormalities in parts of the brain known to be harmed in civilian trauma.
A negative MRI scan, even with these advanced methods, does not rule out mild traumatic brain injury.
“Our hope is that these advanced MRI-based methods will one day help make more accurate diagnoses, assist with triage and allow treatment interventions to start early for people with traumatic brain injuries,” he says.
The study is reported June 2 in The New England Journal of Medicine by scientists at Washington University School of Medicine in St. Louis and the Landstuhl Regional Medical Center in Landstuhl, Germany.
Source: Washington University School of Medicine, USA