We evaluated a 60-year-old woman with a 7-year history of a progressive dystonia-ataxia syndrome with supranuclear gaze palsy, suspected to represent Niemann-Pick disease Type C. Postmortem evaluation unexpectedly demonstrated neurodegeneration with 4-repeat tau deposition in a distribution diagnostic of progressive supranuclear palsy (PSP). Here, MAPT is linked to cerebellar ataxia.