Abstracts

Rationale: Recent studies have suggested a relationship of the immuno-modulatory and anti-inflammatory effects of corticosteroids with improvement of refractory epileptic seizures, although the mechanisms of the antiepileptic effect of corticosteroids remain unclear. In this study, we investigated the efficacy and indications of methylprednisolone pulse therapy (MP) for refractory epilepsy, focusing on the immune-mediated mechanism. Methods: Thirty-one consecutive patients treated with MP at our center between 2004 and 2015 were studied. In a course of MP, methylprednisolone (30 mg/kg/day) was injected intravenously on three consecutive days every 4 weeks. Several courses of MP were given. Responder to MP was defined as seizure reduction rate ≥50% maintained for three months after the first MP. Clinical data of responder and non-responder groups were compared to identify the characteristics of patients showing response to MP, focusing on immune-mediated mechanism suspected to be related to refractory epilepsy. Results: Etiologies comprised encephalitis/encephalopathy (EE, n=15), bacterial meningitis (n=2), cortical dysplasia (n=2), perinatal hypoxia (n=1), gene mutation (n=1), traumatic brain injury (n=1) and unknown (n=9). Seizure types were focal onset impaired awareness seizure alone (FIAS, n=23), FIAS with epileptic spasms (ES) (n=7) and ES alone (n=1). Ten patients were responders (32% of all patients; 40% of EE patients; 43% of patients with FIAS alone and 0% of patients with ES). Three patients (9%) became seizure-free, and 6 patients also showed behavioral and cognitive improvement. Biochemical markers suggesting epilepsy-related immune-mediated mechanism (Qalb ≥4.0, IgG index ≥0.7, serum and CSF anti-GluN2B antibody positive) were not related to seizure outcome, while a medical history of seizure aggravation after administration of inactivated vaccination was related to seizure outcome (p=0.01). Conclusions: MP given at intervals of four weeks is safe and has the potential to improve not only epileptic seizures but also cognitive and behavioral comorbidities. It is worthy to try MP in patients having refractory focal epilepsy without ES, and patients with seizure aggravation after administration of inactivated vaccination. Funding: No funding