Traumatic brain injury (TBI) is one of the leading causes of morbidity and mortality in children and young adults throughout the world. Substantial progress has been made in reducing death and improving outcome for this little recognized epidemic since the 1980s. Nonetheless, over 50000 US citizens die annually as a consequence of TBI and 80000–90000 survivors experience substantial long-term disability. In this chapter, we will discuss recent epidemiologic studies, diagnosis and management of TBI and describe ongoing efforts in bench and translational research.

Trends in TBI(Thurman et al., 1999)

The Centers for Disease Control and Prevention (CDC) began the development of a multi-state surveillance system for TBI in 1989 in response to a Federal Interagency Head Injury Task Force report that identified a need for better information on TBI. Prior to this, data was derived from hospital-based clinical case series in geographically restricted epidemiological studies. Consequently, the ability to broadly generalize findings from these early efforts was limited. Prior to 1990, estimates of hospital admissions for TBI in the US were about 500000 per year, with an incidence ranging from 132 to 367 per 100000, depending on the region studied. With the onset of the CDC study, a much broader and more representative analysis began which now includes 15 states (Thurman et al., 1999). These include states with rural populations (Alaska, Arkansas, Minnesota and Nebraska), major cities (New York, California) and broad racial representation. Guidelines were established to define TBI: craniocerebral trauma due to blunt or penetrating trauma to the head resulting in decreased level of consciousness, amnesia, other neurologic or neuropsychologic abnormalities, skull fracture, diagnosed intracranial lesions or death. As a result of these efforts, a more accurate representation of TBI in the US may now be described (see Figs. 11.1, 11.2).

Recent data show that 230000 people are hospitalized and survive TBI with over 80000 of these individuals sustaining long-term disability. The hospital admission number is substantially reduced from prior decades when over 500000 patients per year were hospitalized. This is probably a consequence of improved and readily available technology (CT scan) which can screen for intracranial pathology as well as changing criteria for hospital admission. About 50000 die from TBI, which is 30% of all traumatic deaths. Adolescents, young adults and the elderly are most at risk, with a male:female rate of 2:1.