The analysis of sera autoantibodies levels in refractory epilepsy patients with normal MRI

Purpose: Over recent years, it has been detected that neuronal autoantibodies were associated with many neurological disorders despite of the pathogenesis is unclear. In this context, the concept of autoimmune epilepsy draws attention in patients with epilepsy resistant to antiepileptic drugs (AEDs). In this study, our aim was to investigate the presence of neuronal antibodies in epilepsy patients with refractory seizures with normal brain magnetic resonance imaging (MRI). Material and Method: Patients with drug-resistant epilepsy who had normal MRI, who followed in our epilepsy clinic between January 2015 and October 2016 were included in the study. Anti-GAD, anti-VGKC and VGKC complex antigens (LGI1 and Caspr2), anti-NMDAR, AMPAR and GABAR antibodies were analyzed in all serum samples. Immunofluorescence, RIA or ELISA methods were used for measurement of antibodies. Clinical, laboratory findings and EEG of the patients were recorded. The characteristics of the autoantibody positive and negative groups were compared. Results: Out of 50 patients, 27 (54%) were female and 23 (46%) were male (46%), and 50 healty volunteers were included in this study. The mean age of the patients was 30,54±9,41 years. Thirty seven of the patients (74%) were diagnosed focal and 7 of them (14%) were diagnosed generalized epilepsy. Other 6 patients (12%) could not be classified as having either generalized or focal epilepsy. Neuronal antibodies were positive in eight (%16) patients. One patient had anti-GAD antibody positivity and 7 patients had anti-VGKC antibody positivity. Although the percentage was higher in the antibody-positive group, there was no significant difference between the groups in terms of the results such as psychiatric disease, febrile convulsion, status epilepticus. However, the presence of depression and hypothyroidism were statistically significantly higher in anti-VGKC antibody-positive patients. Conclusion: Recent studies have shown that epileptic patients with autoimmune etiology are more resistant to treatment. However, in our study, there was no significant increase in neuronal autoantibody levels in patients with epilepsy resistant to drugs who had normal MRI, and the results that can support this knowledge have not been reached.