(Science: syndrome) A disorder that is associated with nerve cell destruction and progressive lack of coordination, neck stiffness, trunk stiffness, problems with eye movement and mild dementia. Disorders that are similar include alzheimer's disease, cerebellar dysfunction, jakob-Creutzfeldt disease and parkinson's disease. The cause for progressive supranuclear palsy is unknown, but is likely a degenerative nerve disorder that is somehow triggered by a viral infection. Pathologic changes include nerve cell damage and destruction of myelin sheath. There is no known cure.