Blast‐related mild traumatic brain injury: mechanisms of injury and impact on clinical care

Abstract

Mild traumatic brain injury has been called the signature injury of the wars in Iraq and Afghanistan. In both theaters of operation, traumatic brain injury has been a significant cause of mortality and morbidity, with blast-related injury the most common cause. Improvised explosive devices have been the major cause of blast injuries. It is estimated that 10% to 20% of veterans returning from these operations have suffered a traumatic brain injury, and there is concern that blast-related injury may produce adverse long-term health affects and affect the resilience and in-theater performance of troops. Blast-related injury occurs through several mechanisms related to the nature of the blast overpressure wave itself as well as secondary and tertiary injuries. Animal studies clearly show that blast overpressure waves are transmitted to the brain and can cause changes that neuropathologically are most similar to diffuse axonal injury. One striking feature of the mild traumatic brain injury cases being seen in veterans of the wars in Iraq and Afghanistan is the high association of mild traumatic brain injury with posttraumatic stress disorder. The overlap in symptoms between the disorders has made distinguishing them clinically challenging. The high rates of mild traumatic brain injury and posttraumatic stress disorder in the current operations are of significant concern for the long-term health of US veterans with associated economic implications.

Down-Regulation of Olfactory Receptors in Response to Traumatic Brain Injury Promotes Risk for Alzheimer's Disease

“…In the civilian population, TBI is typically associated with direct, closed impact mechanical trauma to the brain due to falls, motor vehicle accidents, sports, etc. [2]. In contrast, TBI among military personnel, particularly among veterans returning from the Persian Gulf region, is primarily due to exposure to blast pressure waves stemming from blast-producing weaponry, leading to prototypical cognitive deficits including impairments in attention, memory, processing speed, and executive functioning [2][3][4].…”

“…[2]. In contrast, TBI among military personnel, particularly among veterans returning from the Persian Gulf region, is primarily due to exposure to blast pressure waves stemming from blast-producing weaponry, leading to prototypical cognitive deficits including impairments in attention, memory, processing speed, and executive functioning [2][3][4]. Both civilians and veterans who suffer from TBI exhibit symptoms that range in severity from mild to very severe, with a minimal to profound impact on daily functioning.…”

“…Similarities between the pathophysiologies of mechanical and blast-related TBI [2] suggested that information gathered from TBI cases in the civilian population may also be relevant to combatrelated TBI. Based on this, we tested the ability of OR11H1, OR4M1, and OR52N5 to distinguish TBI cases from non-TBI controls from a study cohort of OEF/OIF veterans.…”

Evaluation of trauma patterns in blast injuries using multiple correspondence analysis

“…In the last ten years, research on blast injuries has primarily targeted the pathogenesis and etiology of traumatic brain injury along with the medical management of musculoskeletal injuries and limb salvage [1][2][3][4][5]. In the anthropological analysis of trauma, examination of blast injury features little in published literature, with most information associated with case studies [6,7] and some experimental research [8].…”

Clinical relevance of blast-related traumatic brain injury

“…Diffuse axonal injury (DAI) is widely hypothesized to be a principle mechanism of damage and the cause of persistent cognitive defects after traumatic brain injury (TBI). Angular forces can cause shearing or stretching of axons, leading to impaired axonal transport and swelling [9]. However, further elucidation of the pathological mechanism behind blast injury and determining the ideal diagnostic method to identify this condition may help lead to greater protection for military personnel and treatments for those already suffering from this disease.…”