Head injury: recent past, present, and future.

There is no question that substantial progress has been made over the last 30 years, since the pioneering multinational studies of Jennett and colleagues, in our understanding of the mechanisms involved in the production, progression, and amelioration of brain damage. The introduction of computed tomography and simple but elegant classifications of the severity of injury (e.g., the Glasgow Coma Scale and the Glasgow Outcome Scale) were seminal milestones in neurotraumatology. When neurosurgeons such as Langfitt, Becker, and Miller took advantage of the pioneering investigations of intracranial hypertension by Janny and Lundberg and combined them with imaging, classification of brain damage, and improvements in emergency medical services, substantial gains were soon made. However, given the perspective of the beginning of the 21 st century, one can see those gains as relatively straightforward, as they have required the consolidation of concepts and ideas that fit together relatively easily. Better attention to easily delineated abnormalities, such as shock, hypoxia, and hypercarbia, and the early evacuation of mass lesions coupled with the concurrent development of modern principles of critical care account for substantial reductions in mortality and a reduction in the number of vegetative, contracted, spastic survivors. Future improvement in the care of patients with head injuries will increasingly be dependent on advances in molecular neurobiology and psychology, our ability to successfully modulate genetic expression, and progress in the treatment of related illnesses, such as stroke, subarachnoid hemorrhage, depression, and Alzheimer's disease.