Traumatic brain injury research opportunities: Results of Department of Veterans Affairs Consensus Conference

Abstract

Traumatic brain injury (TBI) is one of the foremost medical problems resulting from the wars in Afghanistan and Iraq. In 2006, 13,969 active-duty servicemen and servicewomen with incident TBI were treated in the military medical system; of those, 7.6 percent were hospitalized [1]. While the consequences of moderate to severe TBI capture public and media attention, the majority of brain injuries are mild. Mild TBI (mTBI) represents 85 to 90 percent of civilians with TBI and a large majority with war-related TBI [2-5]. Our current ability to accurately diagnose war-related mTBI is greatly challenged because much of our knowledge of this injury is based on experience accrued from civilian patients, even though the conditions under which war-related injuries occur differ vastly from those of civilian injuries. TBIs of civilian patients typically result from falls or motor-vehicle or sports-related incidents, whereas war-related TBIs are more often sustained under emotionally traumatic circumstances. Furthermore, since a major portion of current war-related injuries result from blast exposure, inherently different mechanical processes are involved. Although the definition of mTBI varies, it typically refers to injuries that are associated with loss or alteration of consciousness for Postconcussive syndrome (PCS) is diagnosed when patients with mTBI present with ongoing symptomatic complaints. Those who experience multiple TBIs are more likely to have long-lasting symptoms [7]. PCS can occur with any level of head injury severity. According to recent reports, U.S. soldiers returning from Iraq have a high rate of coexistence of mTBI-related complaints and posttraumatic stress disorder (PTSD) [8]. PTSD is an anxiety disorder that may develop after exposure to a traumatic event in which grave harm occurred or was threatened [9]. PCS and PTSD have many symptoms in common, but a hallmark of PTSD is reexperiencing the traumatic event. As expected, PTSD is more prevalent than TBI in combat veterans. An important issue that complicates differentiating traumatic stress and TBI is the retrospective diagnosis of war-related mTBI. The diagnosis is difficult because it requires documenting the history of an injury that would typically have involved alteration of consciousness or amnesia for events before, during, or after injury in the midst of a battle. Despite their overlapping symptoms, PTSD and mTBI may be two distinct disease entities with differential responses to various treatment approaches. Patients who survive severe TBI commonly suffer cognitive impairments (e.g., memory, executive functions, and processing speed), language difficulties, emotional problems, sensory-motor losses, posttraumatic epilepsy, and a variety of other impairments and disabilities. Unlike the symptoms of a majority of patients with mTBI, these problems, in spite of some initial improvement, may persist and become chronic. These chronic cognitive, physical, and emotional impairments often interfere with individuals' abilities to function independently and resume their prior family, workplace, and social roles and responsibilities. Currently, no well-validated therapies exist to treat war-related TBI other than existing TBI rehabilitation programs and careful supportive care. …