Corticobasal degeneration

History Rebeiz and colleagues first reported clinical and pathological findings in three patients with “corticodentatonigral degeneration with neuronal achromasia” in 1967 and 1968 [1, 2]. The name derived partly from the finding of numerous large neurons with pale-staining cytoplasm, especially in deep cortical layers, due to loss of Nissl substance, termed “neuronal achromasia.” No additional reports of this disease were added until a single clinicopathologic case in 1985 [3]. In 1990, Riley and colleagues published the first clinically diagnosed cases, a total of 15 patients, some with detailed clinical descriptions, including two autopsy-verified cases [4]. This report outlined a seemingly characteristic, predominantly motor syndrome that quickly gained widespread recognition. Over time, however, corticobasal degeneration was found to have considerable heterogeneity [5]. Some patients with clinically diagnosed corticobasal degeneration were proven pathologically to have other diseases, e.g., progressive supranuclear palsy (PSP), Alzheimer disease, Creutzfeldt–Jakob disease (CJD), Pick disease, and other disorders. In addition, patients with pathologically proven corticobasal degeneration showed variant clinical features. The high number of false-positive diagnoses associated with alternate pathologies, and of false-negative diagnoses associated with other clinical presentations, prompted Boeve and colleagues to suggest the term corticobasal syndrome (CBS) for clinical diagnosis and reserve the term corticobasal degeneration (CBD) for pathological diagnosis [6].