Autoimmune encephalitis in children.

Autoimmune encephalitis is a heterogeneous group of disorders characterized by cognitive and behavioral decline due to an immune reaction against neuronal antigens. There is increasing evidence that autoimmune encephalitis represents a significant subgroup of encephalitis in children, which are defined by the presence of antibodies against important proteins involved in neurotransmission. The distinction between the different causes of autoimmune encephalitis is important for the patient, as there is a marked difference in therapeutic response; specifically, autoimmune encephalitis associated with the classical onconeuronal antibody is unresponsive to treatment, while autoimmune encephalitis in association with antibodies against surface proteins may respond to immunomodulation. Autoimmune encephalitis may be classified into forms with prevalent involvement of the grey matter (polioencephalitis), white matter (leucoencephalitis), or endothelial cells (vasculitis). The subject of this review includes polioencephalitis, which encompasses syndromes in which there is a loss and/or alteration of neuronal function and in which autoantibodies can be detected in the serum or CSF.