Seizure evolution and outcome in pediatric autoimmune encephalitis

초록

Purpose:Our study aimed to characterize seizure incidence, evolution, and outcome of pediatric autoimmune encephalitis (AE) focusing on subgroup analysis based on type and presence of antibody (Ab) to neuronal antigens. Methods: We compared seizure characteristics and outcomes in 68 patients with seizures among 110 patients, who satisfied the proposed criteria of pediatric AE. The Ab- positive group included patients with anti- MOG and anti- NMDAR antibodies. The Ab- negative group was defined according to recently proposed criteria. Univariate and multivariate analyses were performed to evaluate the risk factors for postencephalitic seizures, defined as persisting seizures six months after onset. Results:Seizure incidence in the anti- MOG group (37.8%) differed from that in the anti- NMDAR (88.9%) and Ab- negative (71.1%) groups. Median seizure frequency within 6 months was higher in the Ab- negative group (6.0, interquartile range [IQR] 3.0– 13.0) than in the anti- NMDAR group (3.0, IQR 2.0– 4.5) and anti- MOG group (2.0, IQR 1.0– 5.0). Patients in the Ab- negative group tended to develop postencephalitic seizures more frequently and have a lower seizure freedom rate than those in the anti- NMDAR and anti- MOG groups. Ab- negative status, high seizure frequency within 6 months, and the presence of status epilepticus were associated with the development of postencephalitic seizures on univariate analysis. On multivariate analysis, Ab- negative status remained the only significant variable linked with postencephalitic seizure (Odds Ratio, 4.17; 95% Confidence Interval, 1.02– 18.05). Conclusion:We delineated the seizure incidence, evolution, and outcome of Ab- positive and Ab- negative pediatric AE patients. Ab- negative status is predictive of higher seizure burden, more frequent development of postencephalitic seizures and less favorable seizure outcome than anti- NMDAR and anti- MOG Ab- positive status.