Proteomic Analysis of patients with Epileptic Seizure and Psychogenic Non-epileptic Seizure; a Cross-Sectional Study

Introduction: there is an increasing interest in the use of different biomarkers to help distinguish psychogenic non-epileptic seizure (pnes) from epileptic seizures (es). this study aimed to evaluate the patterns of differentially expressed serum proteins in es and pnes cases. methods: in this cross-sectional study, 4 patients with mesial temporal lobe epilepsy and 4 patients with pnes were selected from patients with history of recurrent seizures. venous blood samples were obtained within 1 hour after seizure and serum proteomes as well as the extent of protein expression were analyzed. results: 361 proteins were identified; of these, expression of 197 proteins had altered. 110 (55.9%) proteins were down-regulated and 87 (44.1%) were up-regulated in the pnes samples compared to es samples. the mean pi for deregulated proteins with 1.5 to 3 fold changes were 6.69 ± 1.68 in proteins with increasing expression in es group and 5.88 ± 1.39 in proteins with increasing expression in pnes group (p = 0.008). the median and interquartile range (iqr) of molecular weight changes in proteins with 1.5 to 3 fold changes were 64 (22.0-86.0) in proteins whose expression had increased in es group and 39.5 (26.0-61.5) in proteins whose expression had increased in pnes cases (p = 0.05). conclusion: several spots with differential expression were observed by comparing patients with es against the pnes groups, which could be potential biomarkers of the disease. damage to the blood-brain barrier is the most important difference between the two groups, thus identifying total protein changes offers a key to the future of differentiating es and pnes patients.