There has been some question about the difference in the brain injuries that occur from blast trauma compared to physical impacts. But, a new study suggests the injuries suffered by U.S. military personnel in Iraq and Afghanistan have similar outcomes regardless of the cause.
According to the findings published in the June 16 issue of the journal JAMA Neurology, nearly 80 percent of all active military personnel who have suffered a concussion developed moderate to severe disability within a year after the injury, no matter how the brain injury was caused.
The researchers also say an estimated 20 percent of U.S. forces in Iraq and Afghanistan suffered a head injury, with concussions occurring in about 83 percent of those cases.
For the study, the researchers evaluated 178 military personnel six to 12 months after they suffered a concussion while serving in either Iraq or Afghanistan, of which 53 were injured in a blast, and 29 were injured by other causes.
The study compared these participants against two “control” groups of 27 military personnel who were exposed to blasts but suffered no brain injuries and 69 who had no blast exposure but required medical treatment for injuries other than brain trauma.
The investigators found that rates of overall disability were nearly the same for patients with both blast- and nonblast-related concussion, 77 percent and 79 percent, respectively. The two groups also showed no differences in headache severity, depression, post-traumatic stress disorder (PTSD), and scores on mental skills tests.
Both groups of concussion patients also had worse overall disability compared to those in both control groups. Rates of moderate-to-severe disability were 59 percent in the blast-without-head-injury group and 41 percent in the group who had not experienced a blast or head injury.
“For our patients with blast-related concussions, I want to emphasize that the explosion was always in combination with another event, such as a motor vehicle crash, a fall or an object striking the head,” study senior author Dr. David Brody, an associate professor of neurology at Washington University School of Medicine in St. Louis, said in a university news release.
“It’s important that we’re mostly studying the combination of blast plus impact, compared to impact alone. Blast injury alone — without a secondary impact — appears to be extraordinarily rare,” he explained.
“This study and others make us a bit skeptical of the notion that the long-term effects of blast injury to the brain are somehow unique,” Brody said. “We still think the physics of how a blast interacts with the brain is quite different from other kinds of brain trauma. But we have yet to find the consequences of that — if there are any — for patients.”