Paraneoplastic syndrome mimicking progressive supranuclear palsy

Paraneoplastic syndrome presenting with progressive supranuclear palsy (PSP) phenotype is extremely rare. We report a patient who presented with features of rapidly progressive parkinsonism similar to PSP and was found to have small cell carcinoma of the lung along with seropositivity for onconeural antigen. The patient was treated with immunomodulation and was given chemotherapy for the malignancy and subsequently improved.