Platform Presentation: Neuro-Ophthalmic Findings that May Reliably Differentiate Progressive Supranuclear Palsy and Parkinson's Disease

Progressive supranuclear palsy (PSP1) causes progressive parkinsonism with prominent early postural instability. The characteristic cardinal feature of PSP, supranuclear vertical gaze palsy, may not appear until later in the course of the disease making an accurate early diagnosis difficult