Biomechanical Basis of Traumatic Brain Injury

The complex pathophysiologic phenomena encountered in patients with traumatic brain injuries can be viewed, ultimately, as the brain ’ s response to an external mechanical force. Preventing and treating the consequences of these injuries require an understanding of the mechanical factors that induce the injuries. In this chapter, we focus on the acute consequences of traumatic loading, referred to as the primary injury, including an overview of the principal mechanical forces that contribute to these brain injuries, how these mechanical forces cause movement and damage within the brain, and the predominant clinical consequences of the primary injury mechanism or mechanisms. Damage from the primary injury is often compounded over time by evolving and multifaceted pathophysiologic sequelae collectively referred to as secondary injuries, but that topic is beyond the scope of this chapter (see Chapter 346 and Loane and Faden 1 for a review). This chapter, which addresses the unique biomechanical causes and consequences of traumatic brain injury, is introductory; more detailed investigations of these principles can be found in other publications. 2,3