A report by a non-profit US medical organization suggests that military personnel who suffer severe or moderate traumatic brain injury (TBI) are at greater risk of long term health problems including Alzheimer’s-like dementia, aggression, symptoms similar to Parkinson’s disease, depression, and memory loss.

Titled “Gulf War and Health: Volume 7: Long-Term Consequences of Traumatic Brain Injury”, the report is published by the National Academies press and compiled by a committee of experts working under the auspices of the Institute of Medicine. The study was funded by the US Department of Veteran Affairs.

The researchers reviewed evidence of the long term consequences of TBI and concluded that even mild TBI is linked to some of the severe health consequences. They also noted that brain injuries from explosions that don’t directly impact the head may be under-diagnosed because there is not enough research on blast injury: one of the most common hazards of serving in Iraq and Afghanistan.

The report said the US Defense and Veteran Affairs Departments should set up more clinical and animal studies into brain injuries caused by blasts, also known as blast-induced neurotrauma (BINT).

Chair of the committee that wrote the report, George W. Rutherford, who is professor of epidemiology and preventive medicine and also vice chair of the department of epidemiology and biostatistics at the University of California School of Medicine in San Francisco, said patterns of war-related brain injury have changed recently:

“Explosive devices and other weaponry have become more powerful and devastating throughout the wars in Iraq and Afghanistan, and we are seeing much higher rates of nonpenetrating traumatic brain injury and blast-induced injury among military personnel who have served in these countries than in earlier wars.”

“It is important to identify and understand any long-term health effects of these injuries so that wounded service members do not lose valuable time for therapy and rehabilitation,” he added.

According to the Department of Defense, up to January this year, over 5,500 troops have suffered TBI in the fighting in Iraq and Afghanistan. Explosives have become the hallmark of these conflicts, with more and more personnel suffering blast-related injuries, often as a result of experiencing more than one explosion.

There has been a prevailing tendency among neurologists to assume that the human skull protects most people from blast-related injury where no blow to the head occurs, and that neurological damage, both short and long term, is relatively unlikely. However, there is an increasing body of clinical research and military experience that says otherwise, according to the authors.

The authors said there are no adequate animal models of BINT and that the Departments of Veteran Affairs (VA) and Defense should sponsor research to establish some. Without these, it is not possible to conduct reliable experiments and accurately assess, diagnose and treat the changes in brain function and behaviour that veterans exposed to bomb blasts may develop.

There are mild and severe forms of TBI, and there is sufficient evidence to show that the seizures that can occur from skull piercing TBI wounds can also occur in non-penetrating TBI and less severe brain injury. Studies show that moderate and severe TBI is linked to other long term consequences too, including increased risk of a dementia that is like Alzheimer’s, a disorder that is like Parkinson’s, and reduced ability to form and maintain social relationships. Other studies shows that mild TBI is linked to increased risk of post-traumatic stress disorder or PTSD.

The evidence does not show that the TBI causes these problems, only that it is linked to increased risk of developing them. It also shows that even mild TBI is linked to increased incidence of aggressive behaviour, depression, and problems with concentration and memory.

The authors said there is limited evidence that TBI is also linked to increased risk of diabetes and psychosis.

Because the evidence is not strong, it is not possible to say whether mild TBI is also linked to many of the risks associated with moderate and severe TBI.

The authors also recommended that troops be more carefully screened before they are deployed so as to establish a baseline for diagnosing post-injury consequences. The VA should also include uninjured personnel in the health registry it is compiling on TBI veterans, so that better comparisons can be made, they said.

“Gulf War and Health: Volume 7: Long-Term Consequences of Traumatic Brain Injury.”
Committee on Gulf War and Health: Brain Injury in Veterans and Long-Term Health Outcomes
Board on Population Health and Public Health Practice (BPH), Institute of Medicine (IOM)
Published by the National Academies Press, 2008.

Click here for details of how to order a copy and to read the report online.

Sources: IOM.

Written by: Catharine Paddock, PhD