The role of brain biomarkers in distinguishing epileptic seizures from psychogenic non-epileptic attacks

Purpose: Recently there has been increasing interest in administration of different biomarkers to help distinguishing psychogenic from epileptic seizures, in patients presenting acutely with seizure-like events. In the present study, we measured postictal serum glial fibrillary astrocytic protein (GFAP), Ubiquitin C-terminal hydrolase (UCHL-1), a neuronal biomarker, and S100B, a glial biomarker, levels in patients presenting with such events. We aim to evaluate the mentioned biomarkers in differentiate epileptic from psychogenic seizures. Methods: In this analytical cross-sectional study, sixty-three patients with seizures (43 with ES and 20 with PNES), and 19 healthy subjects included in the study. Venous blood samples were obtained within the first 6 hours after seizures and serum GFAP, UCHL-1, and S100B levels were measured by protein quantification (ELIZA kit) with an electrochemical luminescence immunoassay. Results: Serum GFAP, UCHL-1 and S100-B levels were significantly higher in patients with ES compared to PNES and healthy controls. PNES patients had significantly higher serum S100-B levels compared to controls (P<0.01). There was a significant correlation between the serum UCHL-1 and S100-B levels in patients with ES (r=0.46, P=0.002). Conclusion: Our study suggested that post-seizure serum GFAP and UCHL-1 levels could be potentially used in differentiate ES from PNES. Serum S100-B level had lower value compared to GFAP and UCHL-1 (AUC 0.68 for GAFP, UCHL-1 v/s 0.59 for S100B). Post-seizure serum neuronal biomarkers could be used in future studies to better understand the underlying mechanism of seizures and may offer as an adjunctive diagnostic test in differentiate ES from PNES.

Keywords:

Epileptic seizure , psychogenic seizure , GFAP , S100B , UCHL-1