WASHINGTON, DC—The risk for dementia may not be a condition that many worry about until their senior years, but military researchers are taking steps now to better understand and prevent young warfighters from the potential of developing it in their old age.

According to the National Institute of Neurological Disorders and Stroke (NINDS), research suggests an association between head injury in early adulthood and the development of Alzheimer’s disease (AD) later in life. The more severe the head injury, the greater the risk of developing AD, according to NINDS.

In the military, where servicemembers are sustaining head injuries on the battlefield, this is of concern. “We are aware of evidence that certainly suggests that those individuals who suffer from moderate to severe traumatic brain injuries have been shown to be at an increased risk and, as they age, of having more cognitive decline, putting them at higher risk for dementia and potential changes similar to those seen in Alzheimer’s,” said Air Force Col Michael Jaffee, MD, national director for the Defense and Veterans Brain Injury Center.

Researching Head Injuries and Dementia

One study that is examining the association between head injuries and cognitive decline is the Vietnam Head Injury Study (VHIS), a long-term, prospective followup study of head-injured Vietnam veterans. The study’s goal is to evaluate patients with penetrating head injuries to learn about the role of head injury in the etiology of dementia and other conditions. In 2008, the study produced reports that found that Vietnam veterans with head injuries had a higher risk of cognitive decline than Vietnam veterans who had not sustained head injuries.

In response to concerns from VA regarding whether TBI has long-term health effects on servicemembers, the Institute of Medicine (IoM) examined the issue in its December 2008 report, Gulf War and Health: Long-term Consequences of TBI. The report found that there is sufficient evidence of an association between moderate and severe TBI and dementia of the Alzheimer’s type and that there is limited evidence of an association between mild TBI (with loss of consciousness) and dementia of the Alzheimer’s type. In addition, the report found that there is insufficient evidence to determine whether an association exists between mild TBI (without loss of consciousness) and dementia of the Alzheimer’s type.

The report called for more prospective longitudinal research on nonpenetrating traumatic head injuries that result from blasts. Jaffee pointed out that one reason why more research is necessary is that head injury veterans that were studied from the Vietnam era typically had penetrating head injuries. In contrast, head injuries sustained by servicemembers from the current conflicts in Iraq and Afghanistan are mostly closed head injuries caused by blasts. “One of the things that has been identified and recognized is that we don’t have as much of the long-term knowledge of what can happen from injuries from blasts compared to the other types of injuries that we study.”

Understanding the Association Between Dementia and TBI

Jaffee said that the military is taking several steps to better understand the long-term outcomes for TBI patients and to ensure that these patients are currently getting the best care as possible.

Among the IoM’s recommendations from its 2008 report was the initiation of a longitudinal study on combat TBI and the effects of blasts, which Congress mandated be conducted by DoD. In response, the Defense and Veterans Brain Injury Center is launching such a study in collaboration with the Uniformed Services University of the Health Sciences. “We are hoping to get evidence that can give us similar evidence to what has been evaluated with regard to long-term outcomes of TBI that we know of from more conventional types of acceleration-deceleration or impact injuries. We recognize we have that knowledge gap in the long-term sequelae of combat injuries, specifically blasts.”

While TBI research will hopefully benefit TBI patients in the future, DoD is also taking steps to protect servicemembers who are now on the battleground and at risk for sustaining a TBI. In order to ensure that servicemembers on the battlefield get early care for a head injury that may not be obvious to them or others, DoD is issuing new proposed in-theater guidelines to help catch head injuries as early as possible.

Educating servicemembers and their families on TBI through curriculum, multimedia websites and other means, is also a major priority for DoD, according to Jaffee. “One of the things that we are looking to roll out is a whole educational program and guide for family members of those who sustain moderate to severe brain injuries.”

Jaffee said that it has also been important to engage with DoD and VA providers to make sure that they are aware of the most current guidance in evaluating and caring for those who have brain injuries. In addition, DoD has also been taking steps to make sure that civilian providers who care for servicemembers have TBI training. “We work with the CDC, for example, to provide TBI training to civilian providers. We are aware that a lot of our reservists and guardsman will be getting their medical evaluation and care from civilian providers in their community.”

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