Comparison of thiol/disulfide homeostasis as an indicator of oxidative stress in children with simple, complicated and recurrent febrile convulsions

Background and Aim: Febrile convulsions are the most common cause of childhood convulsions and may recur. Information on etiopathogenesis is limited. The role of antioxidant / oxidant balance and increased free radical levels in the pathogenesis of epilepsy, as well as atherosclerosis, myocardial infarction, stroke, cancer and inflammatory diseases, in which oxidants increase or antioxidants are insufficient, as a result of oxidative stress that the organism experiences, cellular metabolism and tissue damage occur. There are several studies showing that As non-enzymatic antioxidants, thiols are important molecules that trigger redox reactions and remove oxidant substances. With a method that Erel and Neşelioğlu developed recently; antioxidant status and oxidative stress are evaluated by measuring the plasma concentrations of low molecular weight thiols and disulfides (total thiol, native thiol, disulfide, disulfide / total thiol, disulfide / native thiol, total thiol / native thiol). The advantage of studies involving children is that oxidative stress can be monitored from the blood and is an easy test with a small amount of serum samples. In this study, we aimed to determine the relationship between oxidative stress and febrile convulsion development and complicated or recurrent seizures by evaluating the changes in thiol / disulfide homeostasis. Materials and Methods: Forty five patients between the ages of 6 months and 5 years who were admitted to the pediatric emergency department of Zonguldak Bülent Ecevit University Medical Faculty Hospital with febrile convulsion and 45 patients between the ages of 6 months and 5 years, who were admitted due to fever, as a control group between October 2018 and October 2019 were included to the study. As thiol / disulfide homeostasis parameters; Serum native thiol, total thiol and disulfide levels, disulfide/total thiol, disulfit disulfide/native thiol and thiol/total thiol ratios were studied with the newly developed automatic measurement method by Erel & Neselioglu. Results: There was no significant difference between the two groups in terms of age and gender. There was a history of simple febrile convulsion in 20 (40.4%) of the patients with febrile convulsion, and complicated in 25 (55.6%) of them. The average of native thiole levels of patients with febrile convulsions was 370.10 ± 58.5µmol / L (211.80-484.70µmol / L), the control group's average was 404.72 ± 47.16µmol / L (284.20-493.70µmol / L ) and the mean value of the native thiol levels of febrile convulsion group was significantly lower. The average of total thiol levels of patients with febrile convulsions 411,71 ± 60,47µmol / L (262,60-544,25µmol / L), the average of the control group is 448,57 ± 52,68µmol / L (326,20-544,96µmol / L ) and significantly lower in the febrile convulsion group again. While the average of disulfide levels of patients with febrile convulsions was 20.83 ± 5.76 (6.10-29.78µmol / L), the average of the control group was 21.92 ± 5.73 µmol / L (8.07-37.83 µmol / L ), although there was no statistically significant difference, it was higher in the febrile convulsion group. The average of disulfide / native thiol ratios of patients with febrile convulsions was 5.78 ± 1.92µmol / L (21.52-11.99), the average of the control group was 5.43 ± 1.33µmol / L (2.0-8.13µmol / L). It was observed that the average of disulfide / total thiol ratios and the average of native thiol / total thiol ratios in patients with febrile convulsions did not differ significantly from the control group. Although it was not significant, it was observed that the average antioxidant levels of the patients who had more than one seizure were low and the average oxidant levels were high. When we group our patients as simple FK (n = 20), complicated FK (n = 25) and compare thiol / disulfide parameters, we did not find a statistically significant difference; however, we found that the average of antioxidant parameters was low and the average of oxidant parameters was high in patients who had complicated FK. We grouped our patients with febrile convulsion as those with a history of recurrent febrile convulsion and those who had febrile convulsion for the first time, and when we compared native thiol, total thiol, disulfide level and disulfide / native thiol, disulfide / total thiol, native thiol / total thiol ratio, there was no statistically significant difference. Discussion-Conclusion: Since the antioxidant levels of our patients who had febrile convulsions were found to be significantly lower than the control group, it was thought that one of the factors that triggered the seizures in these patients might be the insufficient antioxidant capacity in the face of oxidative stress during febrile disease. It was observed that the oxidative stress during the seizure, due to the inadequacy of antioxidant systems in the patient group with febrile convulsions, was not affected by the number of seizures on the same day, the history of previous febrile seizures, the duration of the seizures, and the type of febril seizures. More comprehensive studies with more patients are needed to determine the role of oxidant/antioxidant balance in simple, complicated and recurrent febrile seizures.