Neurobiology of Neuroimmune Encephalitic Disorders

The impact of encephalitis in neuropsychiatric disorders is just beginning to be understood despite the known impact the immune system has on the brain. This chapter describes the basic features of neuroimmunology, especially those related to autoimmune disorders. The following section addresses autoimmune encephalitides, including those mediated by antibodies against intracellular antigens (GAD, Ma2, Hu), those mediated by antibodies against synaptic receptors (NMDAR, AMPAR, GABA A, GABA B, mGluR5, D2R), and those mediated by antibodies against ion channels and other surface proteins. There is a section focused on pediatric acute-onset neuropsychiatric syndrome (PANS) and pediatric neuropsychiatric disorder associated with streptococcal infections (PANDAS). Finally, it discusses the neuropsychiatric symptoms related to the direct effects of SARS-CoV-2 infection of the central nervous system and the indirect effects mediated by immune response, also including post-acute COVID-19 (long COVID).