Autoantibody-Associated Central Nervous System Neurologic Disorders

Autoimmune neurology is a rapidly evolving new subspecialty driven by the discovery of novel neural- (neuronal- or glial-) specific autoantibodies and their target antigens. The neurologic manifestations affecting the central nervous system include encephalitis, dementia, epilepsy, and movement and sleep disorders. Laboratory testing is now available for most of these neural-specific autoantibodies, which serve as diagnostic markers, in some instances directing the physician toward specific cancer types (e.g., N-methyl-D-aspartic acid receptor antibodies for teratoma, collapsin response mediator protein 5 for small-cell lung cancer) and assisting in therapeutic decision making. Antibodies targeting intracellular proteins serve as markers of cytotoxic effector T-cell-mediated injury, which is generally poorly responsive to immunotherapy. By contrast, antibodies targeting extracellular plasma membrane proteins may act as pathogenic effectors and often infer good responses to immunotherapy. Diagnosing these conditions and implementing treatment as early into the clinical course as possible ensures the best possible clinical outcomes. An adequate immunotherapy trial to assess maximum reversibility of symptoms, as assessed through objective functional measures, is crucial and can help to determine whether maintenance therapy is needed.