Introduction: Elevated serum levels of S100beta, an astrocyte-derived protein, correlate with unfavourable neurological outcomes following cardiac surgery, neurotrauma, and resuscitation. This study evaluated whether pre-/postoperative serum S100beta levels correlate with unfavourable clinical and radiological findings in patients undergoing elective meningioma resection.
Methods: In 52 consecutive patients admitted for meningioma surgery, serum S100beta levels were determined upon admission and immediately, 24 hours, and 48 hours after surgery. All patients underwent complete pre- and postoperative neurological examination and mini-mental state examination. Radiological evaluation included preoperative magnetic resonance imaging (MRI) and postoperative computed tomography. Tumour volume, brain edema, and bleeding volume were calculated using BrainSCAN software.
Results: Preoperative S100beta levels did not correlate with the tumour characteristics demonstrated by preoperative MRI (for example, tumour volume, edema volume, ventricular asymmetry, and/or midline shift). Preoperative serum S100beta levels (0.065 +/- 0.040 microg/l) were significantly lower than the levels measured immediately (0.138 +/- 0.081 microg/l), 24 hours (0.142 +/- 0.084 microg/l), and 48 hours (0.155 +/- 0.119 microg/l) postoperatively (p < 0.0001). Significantly greater postcraniotomy S100beta levels were observed with prolonged surgery (p = 0.039), deterioration in the mini-mental state examination (p = 0.005, 0.011, and 0.036 for pre versus immediate, 24 hours, and 48 hours postsurgery, respectively), and with postoperative brain computed tomography evidence of brain injury; bleeding was associated with higher serum S100beta levels at 24 and 48 hours after surgery (p = 0.046, 95% confidence interval [CI] -0.095 to -0.001 and p = 0.034, 95% CI -0.142 to -0.006, respectively) as was the presence of midline shift (p = 0.005, 95% CI -0.136 to -0.025 and p = 0.006, 95% CI -0.186 to -0.032, respectively). Edema was associated with higher serum S100beta levels immediately (p = 0.022, 95% CI -0.092 to -0.007) and at 48 hours after surgery (p = 0.017, 95% CI -0.142 to -0.026). The degree of elevation in S100beta levels at 24 and 48 hours after surgery also correlated with the severity of midline shift and edema.
Conclusion: In patients with meningioma, serum S100beta levels perform poorly as an indicator of tumour characteristics but may suggest ongoing postcraniotomy injury. Serum S100beta levels may serve as a potentially useful early marker of postcraniotomy brain damage in patients undergoing elective meningioma resection.