Publisher Summary The chapter offers information on progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD). Although PSP and CBD are considered distinct nosologic entities, it is reasonable to consider them together because both are associated with the accumulation of pathologically hyperphosphorylated four repeat tau protein isoforms in the brain. They also share an over-representation of the extended H1 microtubule associated protein tau gene haplotype, raising the possibility that they may share a common genetic background. Recently a specific variant of H1, designated the H1c haplotype, has been found to be over-represented in PSP, whereas the other common H1 derived haplotypes showed no association. Although both PSP and CBD are sporadic disorders, some younger patients with frontotemporal dementia with Parkinsonism linked to chromosome 17 (FTDP-17) present with a remarkably similar clinical picture. These FTDP-17 cases most often have mutations that affect the splicing of exon 10 of the tau gene. Most cases of PSP are eventually referred to movement disorder specialists. CBD is a much rarer disorder than PSP. Its frequency may be greater than currently acknowledged because a number of patients are referred to cognitive disorder clinics, where alternative diagnoses of primary progressive aphasia, frontotemporal dementia, or Pick's disease are often given. In the absence of a disease-modifying therapy or consistently effective symptomatic treatment, good management of PSP centers on expert palliative care, which must be introduced in the early stages for best results. Botulinum toxin may be effective in the relief of eyelid spasms, neck extension, and drooling.