[Autoantibodies Associated with Autoimmune Basal Ganglia Disorders]

Autoimmune basal ganglia disorders (ABGDs) are presumed autoimmune encephalitides characterized by movement disorders and basal ganglia lesions on neuroimaging. The most common type of autoimmune encephalitis manifesting as movement disorders is anti-N-methyl-D-aspartate (NMDA) receptor encephalitis. Anti-phospholipid antibody syndrome and neuropsychiatric lupus may present with chorea or other involuntary movements. In childhood, Sydenham's chorea is an important differential diagnosis. Although autoantibodies directed against the surface antigens on basal ganglia neurons are assumed to cause ABGDs, few autoantibodies have been demonstrated to be relevant to certain clinical syndromes except for anti-NMDA receptor antibodies. However, recent studies have identified autoantibodies to the dopamine D2 receptor and collapsin response mediator proteins in patients with ABGDs. It remains to be elucidated, however, whether these autoantibodies to basal ganglia antigens play pathogenic roles in ABGDs.