Neurology Central

S100B protein potential new diagnostic tool for intracranial hemorrage in mild head injury

A new study carried out at the Trauma Hospital Meidling and the Donauspital (both Vienna, Austria) has highlighted blood serum levels of S100B as a potential indicator of the likelihood of intracranial hemorrhage in patients who have experienced mild head injury (MHI). The findings, which were published recently in the Journal of Neurosurgery, may provide an alternative diagnostic tool to cranial computed tomography (CCT) which is both costly and exposes patients to potentially damaging radiation.

The research consisted of a prospective observational study of patients who had exhibited MHI at either of the two study hospitals and were either 65 years of age or older, or 18 years of age or older and receiving antiplatelet therapy. This study population, totaling 782 patients, was chosen due to their particular vulnerability to intracranial hemmorhage following MHI. As the SB100 molecule has a half-life of approximately 90 minutes, only patients in whom blood samples were drawn within 3 hours after injury were included in the study.

Results indicated that patients with blood serum S100B levels of less than 0.105µg/L were very unlikely to develop intracranial hemorrhage, highlighting a threshold level for diagnosis.

CCT studies were also performed for all study participants and instances of trauma-related intracranial hemorrhage, or lack of, were compared to blood serum SB100 levels in each patient. Overall, evidence of intracranial hemmorhage was seen in 50 of the patients and in all but one of these patients serum SB100 was 0.105µg/L or higher. In the one patient that did not adhere to the set threshold the SB100 level was very close to that expected (0.094µg/L). There was also no need for surgical intervention in this case. The negative predictive value of SB100 was 99.6% in this study.

The authors therefore concluded that: “S100B levels below 0.105 µg/L can accurately predict a normal CCT scan after MHI in older patients and those on antiplatelet medication.”

It is hoped that these findings will provide an opportunity to reduce the number of CCT studies and hospitalizations given to these two vulnerable patient groups, and provide an indicator of which MHI patients should be further evaluated and which can return home.

Heinrich Thaler, one of the lead authors on the paper concluded: “We undertook the study with the aim to reduce the workload of medical staff and costs as well as the radiation burden in the management of patients with mild head injuries. We are confident that this study will prove to be useful in achieving these aims.”

Source: Newswise press release

Thaler HW, Schmidsfeld J, Pusch M et al. Evaluation of S100B in the diagnosis of suspected intracranial hemorrhage after minor head injury in patients who are receiving platelet aggregation inhibitors and in patients 65 years and older. Journal of Neurosurgery, 1–7 DOI:10.3171/2014.12.JNS142276.