Effect of Immunotherapy on Seizure Outcome in Patients with Autoimmune Encephalitis: A Prospective Observational Registry Study

Abstract

ObjectiveTo evaluate the seizure characteristics and outcome after immunotherapy in adult patients with autoimmune encephalitis (AE) and new-onset seizure.MethodsAdult (age ≥18 years) patients with AE and new-onset seizure who underwent immunotherapy and were followed-up for at least 6 months were included. Seizure frequency was evaluated at 2–4 weeks and 6 months after the onset of the initial immunotherapy and was categorized as “seizure remission”, “> 50% seizure reduction”, or “no change” based on the degree of its decrease.ResultsForty-one AE patients who presented with new-onset seizure were analysed. At 2–4 weeks after the initial immunotherapy, 51.2% of the patients were seizure free, and 24.4% had significant seizure reduction. At 6 months, seizure remission was observed in 73.2% of the patients, although four patients died during hospitalization. Rituximab was used as a second-line immunotherapy in 12 patients who continued to have seizures despite the initial immunotherapy, and additional seizure remission was achieved in 66.6% of them. In particular, those who exhibited partial response to the initial immunotherapy had a better seizure outcome after rituximab, with low adverse events.ConclusionAE frequently presented as seizure, but only 18.9% of the living patients suffered from seizure at 6 months after immunotherapy. Aggressive immunotherapy can improve seizure outcome in patients with AE.

Seizures and risk of epilepsy in autoimmune and other inflammatory encephalitis

“…[29,49,73,74] A study on AE associated with antibodies against neuronal cell-surface or intracellular antigens reported good seizure response to rituximab in cases refractory to corticosteroids, intravenous immunoglobulins and plasma exchange. [74] Overall, the risk of developing chronic epilepsy after AE appears low (10–15%) and varies according to the target autoantigen. [38**,49,52*] For example, in two cohorts of patients with anti-AMPAR and anti-GABA B R encephalitis none of the survivors had persistent seizures.…”

FDG-PET and MRI in the Evolution of New-Onset Refractory Status Epilepticus

“…[2][3][4][5] Typical findings include the following: hippocampal or neocortical T2-hyperintense MR imaging lesions, mild pleocytosis and/or elevated protein in the CSF, and periodic and epileptiform discharges on electroencephalography (EEG). 1,6 An underlying inflammatory mechanism has been suggested by the following findings: 1) Up to two-thirds of patients are found to have an associated neuronal cell surface or intracellular antibody, 1 2) a proportion of patients may respond to early immunosuppressive therapy, [7][8][9][10][11] and 3) elevated levels of cytokines interleukin-6 and interleukin-8 return to normal after treatment, corresponding to clinical improvement. 12 Given the substantial morbidity (neurologic disability, subsequent epilepsy) and mortality associated with the diagnosis of NORSE, this hypothesis is of interest.…”

Increased adverse events associated with antiepileptic drugs in anti–leucine‐rich glioma‐inactivated protein 1 encephalitis

“…[1][2][3] Faciobrachial dystonic seizure (FBDS) is very specific to the disease, and antiepileptic drugs (AEDs) have limited efficacy in controlling FBDS and other seizures. 2,4 Rationale for the use of AEDs in treating anti-LGI1 encephalitis include a certain degree of seizure-suppressing effects until immunotherapy effectively ameliorates seizure activity 2,4,5 and the risk of withdrawal seizures occurring before complete remission of disease activity. However, a previous study raised the possibility that patients with FBDS are more vulnerable to adverse cutaneous drug reaction (ACDR) than the general population.…”