[Clinical aspects of corticobasal syndrome]

Corticobasal degeneration (CBD) is a distinct neurodegenerative disorder characterized by neuronal and glial accumulation of abnormal tau protein. The core characteristic clinical features of the disorder include progressive asymmetric akinetic-rigid syndrome with apraxia. Pathological examinations of patients presenting such clinical presentations have indicated that several proteinopathies, including tauopathies, amyloidopathies, TDP-opathies, α-synucleinopathies, and prionopathies may underlie the same clinical phenotype. Because of this considerable clinicopathologic heterogeneity, experts use the term corticobasal syndrome (CBS) for patients with a clinical diagnosis of CBD, and reserve CBD for those whose conditions have been diagnosed on the basis of neuropathological analyses. In this review, we have focused on the clinical aspects of CBS, including its clinical presentation, diagnostic criteria, and pathological backgrounds.