Serum S-100B is a type of protein that is related to glial cells (a type of cell that helps regulate and support neurons). Past studies have shown that an increase in S-100B is a sensitive indicator of brain injury in adults.
Evaluating mild traumatic brain injury is difficult in any situation, but it is especially so with children. There are increased complications with obtaining a CT scan, and it is challenging to obtain an accurate history or reliable measures of cognition.
A recent study in Sweden has shown that testing for S-100B is an accurate and reliable tool for determining mild traumatic brain injury in not only adults, but also children. Levels of S-100B can be easily obtained using urine or serum samples. Although the study used a cutoff time of six hours after injury to obtain a sample, the researchers suggested that by testing both urine and serum samples for S-100B, a reliable measurement might be obtained up to 24 hours after the trauma.
Although larger clinical studies would verify cutoff levels and times, it is useful to know that a sensitive marker could predict traumatic brain injury in an otherwise challenging population.
Hallen M, Karlsson M, Carlhed R, et al. S-100B in serum and urine after traumatic head injury in children. The Journal of Trauma: Injury, Infection, and Critical Care. (April 2010).