Autoimmune Corticobasal Syndrome and Progressive Supranuclear Palsy Mimics

Abstract

Progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS) are classically

associated with 4-repeat tauopathies, but emerging evidence indicates that a subset of patients

with PSP-like or CBS-like phenotypes have autoimmune or paraneoplastic etiologies. These

immune-mediated mimics can present with subacute onset, atypical features (such as

prominent sleep disturbances, seizures, or rapid early progression), and the presence of

specific neural autoantibodies. Recognizing these cases is critical, as they are potentially

reversible with immunotherapy, unlike the relentlessly progressive course of neurodegenerative

PSP/CBD. Here we review the mechanistic overlap between autoimmunity and

neurodegeneration, highlight reported cases of autoimmune CBS and PSP mimics (and their

characteristic clinical clues), and discuss immunotherapy strategies. While many patients

improve with timely immunosuppressive treatment, outcomes vary by antibody type – reflecting

direct pathogenic roles for cell-surface antibodies versus bystander phenomena in some

intracellular (paraneoplastic) antibody cases. Ongoing research and accumulation of case

reports will clarify the true frequency of autoimmune PSP/CBS and optimize their management