more than 2,000 injury descriptors, each of which can be localized to a small section of the body, if desired, by using precise methods incorporated into the scale (Gennarelli and Wodzin, 2006). Moreover, AIS 2005 includes new sections that cover blast and other nonmechanical injuries (Gennarelli and Wodzin, 2006).
The Red Cross Wound Classification (RCWC) was developed as a grading system for use under adverse conditions on the battlefield, scoring such wound features as degree of tissue damage, presence or absence of metallic fragments, and presence or absence of a cavity. Once scored, the wound can be further graded according to severity and typed according to structures injured; thus, wounds can be identified by their clinical significance (Coupland, 1992). However, there has been some discrepancy between the RCWC, routinely performed on the battlefield during combat operations in the former Yugoslavia, and clinical signs and outcomes of patients with blast injuries (Savic et al., 1993, 1995).
With regard to blast injuries, there is not an easily applicable and reliable scoring system. Experimental studies have often used the Walter Reed Army Institute of Research Blast Injury Subjective Score, which establishes blast-injury severity on the basis of the extent of lung damage (Jaffin et al., 1987; Mayorga, 1997) but does not take into account injuries in other organs or organ systems due to blast exposure. A pathology scoring system (PSS) for blast injuries (Yelverton, 1996) uses an alphanumeric measure of the severity of various lesions caused in animals by a blast wave, including those induced by secondary or tertiary effects, to arrive at a severity-of-injury index (SII) for each subject. That complex system correlates external lesion, injury grade, severity type, and severity depth or disruption of the injury with the presence or absence of some complications (such as pneumothorax, hemothorax, hemoperitoneum, coronary air, and cerebral air) and with the trauma outcome (nonfatal or fatal). A modified Yelverton scoring system has been helpful in some clinical studies (Cernak et al., 1999b).
Assessment of injury severity is of fundamental importance in the clinical management of patients with TBI and for developing novel diagnostic and therapeutic approaches. The Glasgow Coma Scale (GCS) has been the gold standard of neurologic assessment of trauma patients since its development by Teasdale and Jennett in 1974 (Teasdale and Jennett, 1974). Other TBI severity-classification systems grade single indicators, such as loss of consciousness (LOC) and duration of posttraumatic amnesia (PTA). The predictive value of those measures has been demonstrated (Dikmen et al., 1990; Levin, 1990, 1995; Levin et al., 1990; Sherer et al., 2008), but each may be influenced by factors unrelated or indirectly related to the severity of TBI, such as intoxication, sedation, and other treatments.
The GCS is used to determine the depth and duration of impaired consciousness and for continued assessment. It includes three independently measured components of behavior: eye opening, motor responsiveness, and verbal performance (Teasdale and Jennett, 1974).
Eye Opening. Spontaneous eye opening is most highly scored (4) and indicates active arousal mechanisms in the brainstem. Eye opening in response to speech, which is scored a 3, is a response to any verbal approach and indicates functional cerebral cortex in