The many faces of corticobasal degeneration.

Corticobasal degeneration (CBD) has characteristic neuropathological features, but is a clinically heterogeneous disorder. It can present with various clinical syndromes. The corticobasal syndrome (CBS) is the best recognized and over the course of the illness may be the most common manifestation. Dementia, progressive non-fluent aphasia, speech apraxia, progressive supranuclear palsy (PSP)-like syndrome and posterior cortical atrophy syndrome are other presentations of CBD. The CBS is not specific for the pathology of CBD. Patients presenting as CBS have CBD as the underlying pathology in about 55% of the cases, PSP pathology in 20%, Pick's disease in 7%, and non tau pathology in the remaining. CBS is a sensitive clinical phenotype for tau pathology. Patients with CBS could potentially be candidates for therapies aiming to modify tau biochemistry.