Walsh & Hoyt: Corticobasal Degeneration

Corticobasal degeneration (CBD), one of the parkinsonism-plus syndromes, is a neurodegenerative condition characterized by the deposition of tau in the brain: a tauopathy. Following its original description in 1967 by Rebeiz et al. as ""corticodentatonigral degeneration with neuronal achromasia,"" it was 20 years before the first of several papers on the disease appeared, suggesting that either the condition is rare or under-recognized. In our opinion, the latter explanation is correct, and we agree with Watts et al. that the diagnosis of CBD should be considered in all levodopa-unresponsive parkinsonian patients.