Autoimmune Encephalitis: Distinguishing Features and Specific Therapies

Autoimmune encephalitis is a rapidly progressive neurologic condition with significant morbidity and mortality, characterized by altered mental status that can often progress to autonomic instability and refractory seizures requiring care in the intensive care unit.1 While infectious, especially viral, encephalitis is generally more common,2 the last decade has seen increasing recognition of noninfectious, immune-mediated causes of encephalitis. The pathogenic mechanisms of immune-mediated encephalitis are diverse, ranging from encephalitis mediated by the innate immune system such as in febrile infection-related epilepsy syndromes (FIRES, reviewed elsewhere in this issue), to encephalitis dominated by T cell-mediated immunity triggered by onconeural antigens (typified by anti-Hu associated encephalitis), to encephalitis whose pathogenesis is dominated by autoantibody (autoAb)-mediated effects. Our discussion of "autoimmune encephalitis" (AE) will focus on autoAb-mediated encephalitis whereby