[4-Repeat Tauopathies: Progressive Supranuclear Palsy and Corticobasal Degeneration]

Progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD) are primary tauopathies that are neuropathologically characterized by deposits of 4-repeat tau proteins. Both diseases lead to a progressive impairment of motor skills, balance, speech, cognition, and everyday functioning. While PSP is often associated with axially emphasized symptoms and characteristic midbrain atrophy, CBD usually presents with asymmetric frontoparietal atrophy with cortical and subcortical deficits. Due to overlapping clinical phenotypes, it is often difficult to distinguish the two diseases from other neurodegenerative diseases in everyday clinical practice. A distinction must be made between neuropathologically defined CBD and the clinical phenotype of corticobasal syndrome (CBS), which can also be caused by other pathologies, such as Alzheimer's disease. The diagnosis of PSP or CBD is made according to current clinical criteria, based on the evaluation of multiple functional domains and the severity of presenting symptoms. Disease-modifying therapies are not yet available. Treatment currently follows symptom-oriented approaches with the aim of maintaining the quality of life and independence of patients for as long as possible. This article provides an up-to-date overview of the diagnosis, clinical presentation, management strategies, and treatment options for individuals affected by PSP and CBD.