Biomarkers of focal and diffuse traumatic brain injury

Traumatic brain injury (TBI) is a pathologically heterogeneous disease affecting people of all ages. The highest incidence of TBI occurs in young people and the average age is 30 to 40 years. Injury grading may range from mild with a low frequency (1 per 100) of life-threatening intracranial hematoma that needs immediate neurosurgical operation and very low mortality (1 per 1,000) to severe with a high likelihood of life-threatening intracranial hematoma (up to 1 per 3), a 40% case fatality rate and a high disability rate (2 per 3) in survivors. Estimation of the prognosis in severe TBI is currently based on demographic and clinical predictors, including age, Glasgow Coma Scale, pupillary reactions, extracranial injury (hypotension and hypoxia) and computed tomography indices (brain swelling, focal mass lesions, subarachnoid hemorrhage). Biomarkers reflecting damage to neurons and astrocytes may add important complementary information to clinical predictors of outcome and provide insight into the pathophysiology of TBI.