Guest posting: Dr Thérèse Boyle, Immunology Advanced Trainee Registrar, Health Pathology NSW. 

Anti-NMDARE (003) Boyle 2018

Take home messages-

• Autoimmune encephalitis is divided into 2 main categories; classic onco-neuronal encephalitis that is generally paraneoplastic, and limbic encephalitis of which anti-NMDA receptor encephalitis is one of the most common forms.
• Autoantibodies within these categories can causes syndromes other than encephalitis.
• NMDA receptor encephalitis has a multiphasic presentation, usually with a prodrome, psychiatric followed by neurological symptoms and subsequent slow resolution (with treatment).
• Up to 50% females and <5% males with anti-NMDA receptor encephalitis have an underlying malignancy (ovarian teratomas being most common).
• EBV and Mycoplasma infections have also been associated with development of these antibodies.
• Anti-NMDA receptor antibody detection is most sensitive and specific in CSF (~30% cases missed, and antibodies detectable in other conditions in serum).
• Early recognition and treatment with immunosuppression (and surgery when appropriate) leads to better outcomes.
• ~80% of patients with anti-NMDAR encephalitis recover within 2 years, leaving ~20% with persistent morbidity or mortality. This severe form of encephalitis is a particularly important area of ongoing research.