Department of Defense: Use of Neurocognitive Assessment Tools in Post-Deployment Identification of Mild Traumatic Brain Injury

Traumatic brain injury (TBI) has emerged as a serious concern among U.S. forces serving in military operations in Afghanistan and Iraq. The widespread use of improvised explosive devices in these conflicts increases the likelihood that servicemembers will sustain a TBI, which the Department of Defense (DOD) defines as a traumatically induced structural injury and/or physiological disruption of brain function as a result of an external force. TBI cases within DOD are generally classified as mild, moderate, severe, or penetrating. From 2000 to March 2011 there were a total of 212,742 TBI cases reported by the Defense and Veterans Brain Injury Center within DOD. A majority of these cases, 163,181, were classified as mild traumatic brain injuries (mTBI)--commonly referred to as concussions. Early detection of injury is critical in TBI patient management. Diagnosis of moderate and severe TBI usually occurs in a timely manner due to the obvious and visible nature of the head injury. Identification of mTBI presents a challenge due to its less obvious nature. With mTBI, there may be no observable head injury. In addition, in the combat theater, an mTBI may not be identified if it occurs at the same time as other combat injuries that are more visible or life-threatening, such as orthopedic injuries or open wounds. Furthermore, some of the symptoms of mTBI--such as irritability and insomnia--are similar to those associated with other conditions, such as post-traumatic stress disorder. Although the majority of patients with mTBI recover quickly with minimal intervention, a subset of patients develops lingering symptoms that interfere with social and occupational functioning. Accurate and timely identification of mTBI is important as treatment can mitigate the physical, emotional, and cognitive effects of the injury. Neurocognitive deficits associated with mTBI can be identified by neurocognitive assessment tools. These tools generally consist of a series of tests that measure cognitive performance areas that may be impaired by an mTBI such as attention, judgment, and memory. Identification of mTBI in servicemembers who served in Afghanistan and Iraq has been the subject of recent media attention, with particular attention focused on the proper use of neurocognitive assessment tools to screen all servicemembers postdeployment for deficits or symptoms related to mTBI. In this context and in response to congressional request, this report describes (1) DOD's post-deployment policy on the use of neurocognitive assessment tools as a stand-alone initial screen to identify servicemembers who may have sustained an mTBI during deployment; (2) what informed DOD's decisions to establish this post-deployment policy; and (3) mTBI experts' views on the science related to DOD's policy decision.

DOD does not require that all servicemembers be screened post-deployment using a neurocognitive assessment tool but does require that all servicemembers be screened using a set of TBI screening questions. According to DOD officials, this policy was informed by findings and recommendations from several task forces and expert panel reports, and scientific studies. Additionally, mTBI experts told us that the scientific evidence supports DOD's policy. For example, these experts told us that neurocognitive assessment tools cannot determine whether low cognitive function is caused by an mTBI. These experts told us, however, that neurocognitive assessment tools can be useful as part of a full clinical evaluation for a person who has already screened positive for a possible mTBI.