Neuropathological sequelae of traumatic brain injury: relationship to neurochemical and biomechanical mechanisms.

Brain injury is the leading cause of death among individuals under the age of 45 years in the United States and Europe. Recently, the neuropathologic classification of posttraumatic brain damage has provided insight into the specific mechanisms underlying traumatically induced neuronal damage and death. Studies regarding the biomechanics of brain trauma have also provided great insight into the pathophysiologic mechanisms underlying specific patterns of posttraumatic cellular death. Based upon recent clinical evaluations and biomechanical studies, laboratory models of human brain injury have been developed that faithfully reproduce a number of important features of clinical brain trauma. Biomechanical models have been used to study both the acute sequelae of brain injury and the role of neurochemical alterations in contributing to the development of secondary or delayed cellular death and damage. This report reviews and integrates the laboratory investigations linking experimental models of brain injury to clinical diagnosis and treatment.