Corticobasal Degeneration (CBD) is clinically and pathologically similar to PSP. Age at onset is typically in the 7th decade, and the predominant symptoms are motor dysfunctions, including rigidity, ataxia, dysarthria, Parkinson’s-like signs, and in some cases, supranuclear gaze palsy. These symptoms and the underlying pathology frequently are asymmetric. CBD also exhibits clinical signs of cortical involvement: constructional apraxia (inability to perform complex movements), “alien hand” sign, and frontal dementia. Neuropathology involves the basal ganglia, corticospinal tracts, and parietal and frontal cortices. In the cortex white matter is as much involved as gray.  Two types of neuronal pathology are observed: ballooned achromatic neurons that lack tau inclusions, and neurons with tau inclusions that resemble Pick bodies. As with PSP, glial involvement is massive, and includes coiled bodies and glial threads in the white matter. The astrocytic pathology consists of astrocytic plaques, rather than the tufted astrocytes of PSP.

Reference: Rebeiz, et al., 1968