Corticobasal degeneration (CBD) is now classified as a four-repeat tauopathy. The presence of neuronal and glial tau-immunoreactive lesions is critical to the pathological diagnosis. It is increasingly recognised that a variety of clinical phenotypes can occur as a consequence of this pathological state and that several other pathological conditions may be associated with the perceptuo-motor syndrome first associated with the pathological features of CBD (now referred to as the corticobasal syndrome). The high rate of diagnostic inaccuracy must be considered when interpreting previous literature dealing with cases presumed to be CBD. There is considerable clinical, pathological, and genetic overlap between CBD and progressive supranuclear palsy (PSP); however, the etiological and pathogenetic relationships between the two remain uncertain. There are reasons to believe that these diseases could be different phenotypes of a single process. Even if they are eventually found to be distinct disorders, treatments that alter the progression of one may have similar ameliorative effects on the other. Each of these issues are discussed in this selective review of CBD.
Copyright 2003 Movement Disorder Society