Admission serum S100B concentrations were significantly higher in patients who subsequently developed delayed cerebral ischemia and showed good discriminative ability for DCI (AUC 0.79) and unfavorable 3-month outcome (AUC 0.86), with longitudinal analyses showing persistently elevated serum S100B in patients who developed DCI.
Key Findings
Results
Admission serum S100B concentrations were significantly higher in patients who subsequently developed delayed cerebral ischemia compared to those who did not.
Median admission serum S100B was 152.6 ng/L in DCI patients versus 21.0 ng/L in non-DCI patients.
The difference was statistically significant (p = 0.012).
The study enrolled 26 consecutive patients with aneurysmal subarachnoid hemorrhage.
This was a prospective observational study with serial measurements throughout hospitalization.
Results
Admission serum S100B showed good discriminative ability for predicting delayed cerebral ischemia.
Area under the receiver operating characteristic curve (AUC) for DCI was 0.79.
AUC for unfavorable 3-month neurological outcome was 0.86.
These values indicate good discriminative ability for both endpoints.
Analyses were performed in 26 consecutive aSAH patients.
Results
Longitudinal serum S100B concentrations remained persistently elevated in patients who developed delayed cerebral ischemia throughout the observation period.
Serial measurements were conducted throughout hospitalization in all 26 patients.
Patients who developed DCI showed persistently elevated serum S100B compared to those who did not.
The temporal profile of serum S100B reflected the evolution of secondary brain injury after aSAH.
This pattern distinguished DCI patients from non-DCI patients across multiple time points, not only at admission.
Results
Serum and cerebrospinal fluid S100B exhibited similar temporal profiles throughout the observation period.
Both serum and CSF S100B were measured serially throughout hospitalization.
The two compartments showed comparable kinetic patterns over time.
This parallel behavior suggests that serum S100B may serve as an accessible surrogate for CSF S100B measurements.
Serial measurements were obtained in 26 consecutive aSAH patients.
Results
Admission serum S100B correlated with disease severity and inflammatory biomarkers in aSAH patients.
Associations were found between S100B concentrations, disease severity measures, and inflammatory biomarkers.
This suggests S100B reflects both neurological injury severity and inflammatory activation following aSAH.
The study analyzed associations between S100B concentrations, DCI, disease severity, inflammatory biomarkers, and 3-month neurological outcome.
The study population consisted of 26 consecutive aSAH patients in a prospective observational design.
Conclusions
Serial serum S100B measurements may provide complementary biological information alongside established clinical assessment after aSAH.
The authors conclude that serial serum S100B measurements 'appear to reflect the temporal evolution of secondary brain injury after aSAH.'
S100B was described as potentially providing 'complementary biological information alongside established clinical assessment.'
The clinical utility of serial measurements had previously remained uncertain prior to this study.
The study used a prospective observational design in 26 patients with 3-month follow-up for neurological outcome.
What This Means
This research suggests that a protein called S100B, measured in the blood at the time of hospital admission, may help predict which patients with a type of brain bleed called aneurysmal subarachnoid hemorrhage (aSAH) will go on to develop a serious complication called delayed cerebral ischemia (DCI) — a secondary reduction in blood flow to the brain that can worsen outcomes. In 26 patients studied, those who later developed DCI had blood S100B levels about seven times higher at admission than those who did not (152.6 vs. 21.0 ng/L). The test showed reasonably good accuracy for predicting both DCI and poor neurological recovery at three months.
The study also tracked S100B levels repeatedly over the course of hospitalization, finding that levels stayed persistently high in patients who developed DCI, while levels in blood and cerebrospinal fluid (the fluid surrounding the brain and spinal cord) followed similar patterns over time. This is notable because drawing blood is far less invasive than obtaining cerebrospinal fluid, suggesting that blood tests might serve as a practical stand-in for spinal fluid analysis.
This research suggests that monitoring S100B levels serially — not just once at admission — could give doctors ongoing biological information about how a patient's brain injury is evolving after a brain hemorrhage. However, the study was small (26 patients) and observational, meaning larger studies are needed before S100B monitoring could be routinely incorporated into clinical care.
Burzyńska M, Lebiedzińska A, Kędziora J, Smarzewska K, Lemańska-Perek A, Miś M, et al.. (2026). Longitudinal Kinetics of Cerebrospinal Fluid and Serum S100B in Patients with Delayed Cerebral Ischemia After Aneurysmal Subarachnoid Hemorrhage.. International journal of molecular sciences. https://doi.org/10.3390/ijms27167274