Difficulties in the clinical diagnosis of corticobasal degeneration

Abstract

The clinical diagnosis of corticobasal degeneration (CBD) is challenged by the existence of various phenotypes of CBD except corticobasal syndrome (CBS), CBD mimics, and immune–related CBS. Previously, 37% of the pathologically–verified CBD cases only had CBS, while the others presented progressive supranuclear palsy (PSP) syndrome, frontotemporal dementia (FTD), Alzheimer disease (AD)–like dementia or aphasia. Moreover, another report showed that 46% of CBS or CBD cases diagnosed by the clinical criteria were CBD mimics, which includes PSP, AD, FTD, globular glial tauopathy, prion disease, and other tauopathies. Recently, an anti–IgLON5 antibody related disease mimicking CBS was reported. The patient's symptoms were consistent for probable CBS ; however, some clinical and radiological findings were partially improved by immunotherapy. Therefore, the clinicians should be aware that such an anti–IgLON5 antibody related disease exists as a differentiated CBS, and more accurate clinical diagnostic criteria for CBD should be established.