Abstracts

Rationale: Autoimmune Epilepsy (AE) is an immunologically mediated disorder in which recurrent seizures are the primary clinical feature. Immunotherapy remains the cornerstone for treatment; however, some remain refractory. The RNS System may offer a new treatment option for this population. Methods: Description of the epilepsy characteristics, clinical outcomes and RNS System data in patients at 2 centers with refractory AE receiving bilateral mesial temporal (MTL) treatment. Results: Demographics, seizure information and outcomes are presented in Table 1. All 5 patients were female and localized to bilateral MTLs. There were no surgical complications or stimulation related side-effects in this group.Patient 1 has trialed 9 anti-seizure drugs (ASDs) and immunotherapy (IVIG+IVMP). Eighteen months after receiving the RNS System, she had a 75% reduction of right-sided electrographic seizures (ECoG Szs) and 25% in left-sided ECoG Szs; the latter became shorter and less intense. Neuropsychiatric evaluation disclosed improved memory. The data established nocturnal seizures which allowed us to modify her ASD timing. Given that 85% of ECoG Szs arise from the left, a left temporal lobectomy is being considered with continued treatment on the right. Patient 2 had a history of 11 ASDs and immunotherapy (IVIG, IMP, Rituximab, AZT) with persistent seizures. RNS System data helped identify catamenial seizures, following which ASDs were adjusted accordingly. It also helped establish her sensitivity to immunotherapy (AZT) which she continues to receive. Patient 3 failed 3 ASDs and steroid treatment. She had an initial response to the RNS System, however seizures returned. ECoG Szs lateralized to the left (>90%). This guided a temporal lobectomy decision. She continues to have right ECoG Szs which are treated with the RNS System and has had no clinical seizures > 2 years. Patient 4 failed 7 ASDs, steroid, IVIG, Plasma exchange and Rituximab treatment. ECoG Szs lateralized to the left (90%) and the patient has had a significant clinical response to treatment. Patient 5 responded well to the RNS System prior to developing Myasthenia Gravis with Anti-GAD 65 Ab. She was treated with immunotherapy (steroid, IVIG and Cellcept) as well as Mestinon and thymomectomy. Seizures improved but then returned to baseline. ECoG Szs were lateralized to the left (>75%) which may open surgical treatment options. Conclusions: Treatment with the RNS System was safe and lead to excellent results in these 5 cases of medically refractory AE. The data provided insights on seizure lateralization, seizure timing/patterns and response to immunotherapy treatment which would have otherwise not been possible. Funding: No funding