- Positive for autoantibody (serum and or CSF) : NMDAR, anti-leucine-rich glioma inactivated-1(LGI-1), contactin-associated protein-like 2 (CASPR2), α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPA) 1, AMPA2, GABAB-R, anti-Hu, -Yo, -Ri, -Ma2, -CV2/collapsing response mediator protein 5 (CRMP5), -amphiphysin, or glutamic acid decarboxylase (GAD)