Autoimmune encephalitis is emerging as an important and relatively common cause of encephalitis in the developed world. Crucially, early recognition and prompt initiation of a range of immunotherapies is likely to improve the outcomes of patients with autoimmune encephalitis, particularly for those with identifiable antibodies against neuronal cell surface proteins. There are a rapidly growing number of specific autoantibodies and associated syndromes, but many of these remain very rare. The majority of cases comprise anti-N-methyl-D-aspartate (NMDA) receptor encephalitis or anti-leucine-rich glioma-inactivated protein 1 (LGI1) encephalitis with the remaining cases a mixture of over 10 other specific antibodies or being seronegative. The core anti-NMDA encephalitis phenotype is a distinct symptom complex involving psychiatric and neurological features and anti-LGI1 encephalitis presents with cognitive changes and distinct seizure types. Diagnosis can be delayed owing to limited access to specialised laboratory testing or in cases with atypical or limited features.
Keywords: NMDA receptor; antibody; autoimmune; encephalitis; psychosis; seizure.