Vascular Injury and Cortical Deformation in a Model of Brain Contusion

Traumatic brain injury (TBI) is a leading cause of death and disability, affecting 1.7 million Americans annually, 50,000 of whom die [1]. Victims who survive the initial injury often suffer debilitating neurologic deficits. The total annual cost of TBI in the United States has been estimated at $60 billion [2]. While damage to brain tissue is of primary concern in TBI, nearly all head trauma includes some element of vascular injury or dysfunction [3], putting neural tissue uninjured in the primary event at subsequent risk. Contusion, which includes injury to both brain and vessel tissue in the cortex, is considered the hallmark of head injury, but little is known about the specific mechanisms of vascular injury in contusion. Previous efforts to elucidate mechanisms and thresholds for contusion, including inanimate gel, animal, and computational models [e.g. 4–7], have defined bulk tissue deformations that are associated with contusion, but the relationship to vascular injury is not clear. In order to address this question, our laboratory is studying acute disruption of the blood-brain barrier using a controlled cortical impact (CCI) mouse model. The objective of this study was to compare acute vascular injury in CCI with cortical mechanics predicted by a computational model of the experiment. This comparison is then discussed in the context of results from isolated vessels testing in our laboratory.