ESSENTIALS OF DIAGNOSIS
History or clinical evidence of trauma
Headache, altered mental status, seizure, focal neurologic deficit
Signs of transtentorial herniation with progressive mass effect
Computed tomography (CT) or magnetic resonance imaging (MRI) showing skull fractures; epidural, subdural, subarachnoid, or intraparenchymal hemorrhage; or cerebral edema
Traumatic brain injury is a major cause of death and disability. The incidence is rising due to increasing motor vehicle accidents in low- and middle-income countries and falls of members of the aging population in high-income countries. Violence is reported to cause closed-head injury in about 7–10% of cases. Penetrating injuries are more common with the more frequent use of firearms, and a greater amount of blast injuries became the result of improved explosive devices used in terrorist and other attacks. More than 1.7 million patients with head injuries are treated annually in US emergency departments, and 21% of these patients are hospitalized. Almost 10% of all deaths in the United States are caused by injury, and about half of traumatic deaths involve the brain. The annual financial burden accounts to US $60 billion.
Brain injuries occur at all ages, but the peak is in young adults between the ages of 15 and 25 years. Head injury is the leading cause of death among people younger than 25 years. Men are affected three to four times as often as women.
Traumatic brain injury can be classified according to the mechanism of injury, clinical severity, structural damage on imaging, and prognosis (Table 14–1).
Table 14–1.Classification of traumatic brain injury. |Favorite Table|Download (.pdf) Table 14–1. Classification of traumatic brain injury.
Mechanism of injury
Closed, penetrating, crash, blast
Clinical severity: level of consciousness
(Glasgow Coma Scale, see Table 14–2)
Clinical severity: Injury Severity Score
Abbreviated injury score is obtained for six body regions:
The score (range 0–75) is the sum of the quadratic scores for each of the six body regions.
Radiographic damage on CT or MRI
Diffuse injury I: no visible pathology
Diffuse injury II: cisterns present, midline shift 0–5 mm and/or lesion densities present and no mass lesion >25 mL
Diffuse injury III: swelling, cisterns compressed or absent with midline shift 0.5 mm and no mass lesion >25 mL
Diffuse injury VI: shift, midline shift >5 mm, no mass lesion >25 mL
Evacuated mass lesion: any lesion surgically evacuated
Nonevacuated mass lesion: high or mixed-density lesion >25 mL, not surgically evacuated
Prognosis according to the CRASH or IMPACT studies
Classification of the patient by expected outcome. Two examples can be found on the following websites: