Effect of anti-seizure drugs on serum S100B in patients with focal seizure: a randomized controlled trial

Purpose S100B, a cytokine produced by astrocytes, has been studied as a biomarker of glial and neuronal damage in epilepsy. The present study investigated the reliability of serum S100B as a biomarker and the effect of carbamazepine and oxcarbazepine on serum S100B in patients with focal seizure. Methods The present randomized, open-label, active-controlled, parallel design clinical trial (NCT02705768) conducted on 60 patients with focal seizure. After recruitment, clinical evaluations were performed including Chalfont-National Hospital seizure severity scale (NHS3), Quality of Life in Epilepsy Inventory (QOLIE-31) and serum S100B was estimated. Thirty healthy individuals were recruited for evaluation of serum S100B at baseline only. After randomization, the study groups received either tablet oxcarbazepine or tablet carbamazepine. At follow-up after 2 weeks, clinical status was checked and at 4 weeks, NHS3 and QOLIE-31 were scored along with serum S100B level estimation. Results Serum S100B level in patients with focal seizure increased significantly in comparison to healthy volunteers. The decrease in serum S100B was significantly higher with carbamazepine group (0.004; 95% CI 0.001-0.006; p = 0.01) over oxcarbazepine group. In logistic regression analysis, there was an increase in the log odds of 0.17 for focal seizure positivity against healthy controls if S100B level increases by 1 pg and area under curve obtained by ROC analysis was 0.96 (p < 0.001). Conclusion Serum S100B increases in the patients with focal seizure and therapy with carbamazepine can decrease serum S100B level significantly over oxcarbazepine. Serum S100B can be used as a prognostic biomarker in a focal seizure.