GRIN1 and encephalitis: NMDAR1 autoantibodies (NMDAR1-AB) of the immunoglobulin G (IgG) class in serum and CSF have originally been described as pathognomonic for “anti-NMDAR encephalitis”, characterized by psychosis, cognitive decline, dyskinesia, epileptic seizures, loss of consciousness, and autonomic instability [7–10].