Orphanet rare-disease nomenclature id Orphanet_240085 (Progressive supranuclear palsy - parkinsonism) can be described as follows. PSP-parkinsonism (PSP-P) is an atypical variant of progressive supranuclear palsy (PSP; see this term), a rare late-onset neurodegenerative disease. Also known as: PSP-p, PSP-parkinsonism.