Clinical features of the seizures in the neuronal surface antibody-associated autoimmune encephalitis - Report of 18 Cases

Abstract

To investigate clinical features of seizures in different types of neuronal surface antibody-related autoimmune encephalitis (AE). The clinical data of seizures in 18 cases of neuronal surface antibody-related AEs diagnosed in our hospital were retrospectively analyzed. Among 18 cases, 9 was LGI1 antibody-related encephalitis, 1 anti-GABABR encephalitis, 6 anti-NMDAR encephalitis, and 2 AE with undefinable antibodies. Epileptic seizures in 9 cases of LGI1 antibody-associated AE manifested in 3 forms: faciobranchial dystonia seizure (FBDS) in 4, mesial temporal lobe epilepsy (MTLE) in 6, and GTCS in 7 patients. The brain MRI of 4 patients showed high T2 flair signal on one hippocampus, 2 showed high T1/T2 signal on one side basal ganglia. For EEG, 6 revealed interictal epileptic discharges; ictal EEG were recorded in 5 patients, 2 FBDS, 3 MTLE. Epileptic seizures in patient with anti-GABABR encephalitis manifested in 2 forms: GTCS and MTLE. Epileptic seizures in 6 cases of anti-NMDAR encephalitis manifested in 2 forms: partial seizures in 3, GTCS in 5 cases. For EEG, 2 cases showed interictal epileptic discharges, 3 showed δ activity or rhythm in frontal area. Most neuronal surface antibody-associated AE have seizures. LGI1 antibody-associated AE usually affected limbic system or basal ganglia, seizure type accordingly were MTLE or FBDS. Anti-GABABR encephalitis showed severe and refractory seizures, GTCS or MTLE, which rapidly progress to status epilepticus and AEDs were ineffective. Anti-NMDAR encephalitis showed more generalized than partial seizures. The δ activity or rhythm in frontal area in EEG was helpful for diagnosis.