The objective of this study was to determine whether the type of intracranial traumatic lesions, the number of simultaneous traumatic lesions, and the occurrence of skull and facial bone fractures have an influence on S100 calcium binding protein B (S100B) serum levels. Patients with blunt traumatic brain injury were prospectively enrolled into this cohort study over a period of 13 months. Venous blood samples were obtained prior to emergency cranial CT scan in all patients within 3 h after injury. The patients were then assigned into six groups: 1) concussion, 2) epidural hematoma, 3) subdural hematoma, 4) subarachnoid hemorrhage, 5) brain contusions, and 6) brain edema. The study included 1696 head trauma patients with a mean age of 57.7 ± 25.3 years, and 126 patients (8%) had 182 traumatic lesions on CT. Significant differences in S100B serum levels were found between cerebral edema and the other four bleeding groups: epidural p = 0.0002, subdural p < 0.0001, subarachnoid p = 0.0001, brain contusions p = 0.0003, and concussion p < 0.0001. Significant differences in S100B values between patients with one or two intracranial lesions (p = 0.014) or with three (p < 0.0001) simultaneous intracranial lesions were found. In patients with intracranial traumatic lesions, skull fractures, as well as skull and facial bone fractures occurring together, were identified as significant additional factors for the increase in serum S100B levels (p < 0.0001). Older age was also associated with elevated S100B serum levels (p < 0.0001). Our data show that peak S100B serum levels were found in patients with cerebral edema and brain contusions.
Keywords: biomarkers; brain edema; traumatic brain injury.