LAUSR

BACKGROUND We identified seizure characteristics, long-term outcome, and predictors of persistent seizures in children with anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis. METHOD Data from patients with anti-NMDAR encephalitis who presented with seizures at our center between August 2012 and June 2018 were analyzed. RESULTS Sixty-two of 86 patients with anti-NMDAR encephalitis experienced seizures. Seizures occurred within two weeks of disease onset in 58 of 62 (93.6%) patients; 36 of 62 (58.1%) had seizures as the initial symptom. Males were more likely to exhibit seizures as the initial symptom (P = 0.039). More than a quarter of patients (17 of 62, 27.4%) manifested two or more seizure types. Focal seizures were the most common (46 of 62, 74.2%). Status epilepticus occurred in 27 of 62 (43.5%) patients, and nonconvulsive status epilepticus, in two of 62 (3.2%) patients. No patient developed refractory status epilepticus. No systemic tumors were found. Electroencephalographic abnormalities included background slowing (77.4%), absence of a posterior dominant rhythm (62.9%), interictal epileptic discharges (50.0%), and extreme delta brush (6.5%). In the acute phase, 45 patients (45 of 62, 72.6%) received antiepileptic drugs. Persistent seizures occurred in only five of 62 (8%) patients. On univariate analysis, status epilepticus and combination antiepileptic drug treatment were associated with persistent seizures, but neither independently predicted persistent seizures. CONCLUSIONS Multiple seizure types may develop at any stage of anti-N-methyl-d-aspartate receptor encephalitis. Refractory status epilepticus, systemic tumors, and extreme delta brush in electroencephalography are rare in pediatric patients. Anti-NMDAR encephalitis-associated seizures appear to have good prognosis, without the need for long-term antiepileptic drug treatment.