A case of inflammatory peripheral nerve destruction antedating anti-NMDA receptor encephalitis

NMDA receptor (NMDAR) antibody encephalitis is the second most common autoimmune encephalitis after acute disseminated encephalomyelitis, presenting with a multistage clinical progression with prodromal signs, psychiatric abnormalities, reduced levels of consciousness, epileptic seizures, dyskinesias, and autonomic dysfunction. PathogenicNMDAR autoantibodies downregulate NMDARs in cultured hippocampal neurons and after injection into the rat brain. Teratomas are common in adult women and are believed to trigger the antibody response against NMDARs by ectopically expressing neuronal antigens. Causal factors in tumor-negative patients are largely unknown. Recent studies showed that infectious encephalitides with herpes simplex virus (HSE) are associated with the generation of NMDAR antibodies and that antibodies cause immunotherapy-responsive relapsing symptoms post-HSE. It is unknown, however, whether further types of neuronal damage can trigger a secondary immune response leading to NMDAR encephalitis.