Up–to–date on autoimmune encephalitis and its related disorders

Abstract

It has been demonstrated that neuronal surface (NS) antibodies play an important role in the pathophysiology of various neurological and neuropsychiatric disorders, including non–infectious/post–infectious encephalitis, first–episode psychosis, epileptic and non–epileptic seizures, atypical demyelinating syndrome, post–partum psychosis, progressive dementia, involuntary movements (orofacial–limb dyskinesias, faciobrachial dystonic seizures, catatonia, rigidity, stiffness, tremors, myoclonus, chorea, stereotypies, oculomotor abnormalities), and non–REM/REM sleep disorder. IgG NS antibodies are considered more likely to be pathogenic, accordingly the presence of NS antibodies supports early initiation of immunotherapy. In 2016, a practical diagnostic approach to autoimmune encephalitis (AE) was proposed to achieve prompt immunotherapy at 3 levels of evidence for AE (possible, probable, and definite) with diagnostic criteria for possible AE, probable AE, probable and definite anti–NMDAR encephalitis, autoimmune limbic encephalitis, ADEM, and Hashimoto encephalopathy. Identification of autoantibodies against NS or intracellular antigens is crucial in making a diagnosis ; however, the antibody testing results should be carefully assessed especially when measured with commercial assay alone.

In this lecture, I focus on recent progress in AE, and its related disorder including cryptogenic new–onset refractory status epilepticus.