It is also helpful to distinguish between traumatic injuries involving penetration of the brain substance (“penetrating” injuries) and injuries that do not penetrate

the brain (often referred to as “closed” head injuries). The main reasons for drawing this distinction is that the injury profiles can be quite different, and thus the associated neurobehavioral sequelae can be quite different. Broadly speaking, the profile of injury involving Inhibitors,research,lifescience,medical penetration of the brain substance will depend on the location and trajectory of the object that is involved, for example the entrance location, trajectory, and size of a bullet that enters the head will largely predict the neurobehavioral sequelae. In these injuries damage typically

results from displacement or destruction of brain tissue by the projectile; fragmentation and deposition of bone or a www.selleckchem.com/products/BIBW2992.html projectile Inhibitors,research,lifescience,medical within brain tissue; or introduction of potential infectious material on the projectile. Nonpenetrating or closed injuries are better understood based on how the typical Pazopanib 444731-52-6 biomechanical forces involved in causing injury interact with the material properties of the brain substance and its relationship to the bony structure (skull) in which it sits. The following discussion focuses primarily on the latter category of injury (closed or nonpenetrating). However, it Inhibitors,research,lifescience,medical Inhibitors,research,lifescience,medical is important to note that many injuries, particularly in the modern combat context, can be a combination of these different forces and injury types. Mechanisms of injury Contact forces The biomechanical effects of nonpenetrating injuries may be divided broadly into two types, both of which are applicable across

the spectrum of injury severity: contact and inertial. Contact injuries result when the brain, moving inside the skull, strikes the inner surface of skull. Movement Inhibitors,research,lifescience,medical of brain against the various ridges and bony protuberances of the anterior (frontal) and middle (temporal) fossae is particularly injurious to the temporal and frontal poles and the ventral anterior, medial, and lateral temporal cortices, and the frontal cortices.11-14 Inertial forces Linear translation and rotational forces, which in combination produce Dacomitinib angular acceleration or deceleration, can result in straining, shearing, and compression of brain tissue.15-22 When these forces exceed the tolerances of brain tissue, injury results. These forces tend to be maximal in brain areas that experience the highest angular acceleration or deceleration forces (superficial > deep and anterior > posterior), at the planes between tissues of different densities and elasticities (eg, the junction between gray and white matter), and at the rotational center of mass in the intracranial space (rostral brain stem).