The most common autoimmune encephalitis in children, primarily affecting females (>80%). Etiology includes ovarian teratomas, and herpes simplex infections. Affected patients develop serum antibodies targeting extracellular epitopes of the NRI subunits of the NMDA receptor
On imaging MRI is normal in 50% of cases. In the other half of patients they have increased T2 hyperintensities in the with matter, hippocampi, cerebellum, cortex, basal ganglia, brain stem, and insula