“Blast-related traumatic brain injury research gaps”

Abstract

The DoD Blast Injury Research Program was established at the direction of Congress in the FY 2006 National Defense Authorization Act to coordinate and manage the medical research efforts and programs of the DoD relating to the prevention, mitigation, and treatment of blast injuries. The Secretary of Defense has designated the Secretary of the Army as the Executive Agent (EA) for this Program. A Program Coordinating Office at the U.S. Army Medical Research and Materiel Command carries out the coordinating functions on behalf of the EA. The scope of this Program is very broad because the term ldquoblast injuriesrdquo encompasses the entire spectrum of injuries that can result from exposure to an explosive device. Most injuries, such as penetrating and blunt impact injuries, are not unique to blast. Others, such as blast lung injury, are unique to blast exposure. For example, blast overpressure can cause primary blast injuries to internal organs such as the lungs and gastrointestinal tract. The strong winds behind a blast can propel fragments that can cause penetrating and blunt impact injuries (secondary blast injuries). The strong winds behind the blast front can also accelerate the body and cause blunt impact injuries similar to those seen in car crashes and falls (tertiary blast injuries). Blast exposure can also cause a host of other types of injuries such as burns and toxic gas inhalation injuries. The Blast Injury Research Program addresses critical medical research gaps for blast-related injuries and fully addresses traumatic brain injury (TBI). The Program focuses on filling gaps in the blast injury knowledge base in three key research topic areas: Prevention, Acute Treatment, and Reset. (The term ldquoResetrdquo is used to describe a concept that extends beyond rehabilitation to include all activities necessary to return injured warfighters to duty or to productive civilian life). A major research knowledge gap is whether blast exposure causes non-impact (primary) mTBI (concussion). It is not known whether non-impact, blast-induced mTBI exists as a unique injury. If it does exist, the mechanism of injury is unknown. Despite this lack of knowledge, many people mistakenly expound or assume that exposure to blast overpressure alone can cause mTBI. Several proposed mechanisms by which a blast could produce non-impact mTBI are the subject of ongoing animal and human research. Vascular surge, air emboli, electromagnetic pulse, biochemical, micro-flexure of the skull, and toxic gas mechanisms have received the most attention. The DoD blast injury research portfolio consists of over 45 ongoing research projects totaling more than $57 M that are studying aspects of non-impact, blast-induced TBI. Researchers are conducting these studies at military, federal, academic, and industry sites throughout the United States. To date, data have neither confirmed that non-impact mTBI exists as a unique injury, nor identified the mechanism by which it occurs. The Program Coordinating Office closely monitors ongoing research in this area to learn research results, synthesize this body of knowledge, rapidly disseminate new conclusive findings, and recommend research proposals for funding.