Rapidly progressive neurological deterioration in anti-AMPA receptor encephalitis with additional CRMP5 antibodies.

Anti-α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) encephalitis positive for additional onconeural antibodies is rarely reported. Here we report the clinical features of a patient who developed limbic encephalitis with both glutamate receptor 2 (GluR2) and collapsin response mediator protein 5 (CRMP5) antibodies. Brain magnetic resonance imaging revealed multifocal encephalopathy. Chest computed tomography showed a highly suspicious malignant thymoma. He experienced rapid neurological deterioration during hospitalization. This report indicates that the clinical diversity of anti-AMPAR encephalitis and the presence of onconeural antibodies may lead to poor prognosis.