Coagulopathy in the Setting of Mild Traumatic Brain Injury: Truths and Consequences

Mild traumatic brain injury (mTBI) is a common, although poorly-defined clinical entity. Despite its initially mild presentation, patients with mTBI can rapidly deteriorate, often due to significant expansion of intracranial hemorrhage. TBI-associated coagulopathy is the topic of significant clinical and basic science research. Unlike trauma-induced coagulopathy (TIC), TBI-associated coagulopathy does not generally follow widespread injury or global hypoperfusion, suggesting a distinct pathogenesis. Although the fundamental mechanisms of TBI-associated coagulopathy are far from clearly elucidated, several candidate molecules (tissue plasminogen activator (tPA), urokinase plasminogen activator (uPA), tissue factor (TF), and brain-derived microparticles (BDMP)) have been proposed which might explain how even minor brain injury can induce local and systemic coagulopathy. Here, we review the incidence, proposed mechanisms, and common clinical tests relevant to mTBI-associated coagulopathy and briefly summarize our own institutional experience in addition to identifying areas for further research.