Intravascular coagulation: a major secondary insult in nonfatal traumatic brain injury

Object. The goal of this study was to determine the frequency with which cerebral intravascular coagulation (IC) complicates traumatic brain injury (TBI). The authors also investigated the incidence of IC in relation to varying mechanisms, time courses, and severities of TBI and in different species. Methods. Tissue was sampled from surgical specimens of human cerebral contusions, from rats with lateral fluid-percussion injuries, and from pigs with head rotational acceleration injuries. Immunohistochemical fluorescent staining for antithrombin III was performed to detect cerebral intravascular microthrombi. Abundant IC was found in all specimens, and microthrombi had formed in arterioles and venules of all sizes, ranging from 10 to 600 mum. Although it was more pronounced in focal lesions and more severe injuries, considerable IC was also observed in mild and diffuse injuries. The authors found a strong association between the severity of coagulopathy and the density of IC. Conclusions. These results strongly support the contention that IC is a universal response to TBI and an important secondary cerebral insult.