Speech and language disorders associated with corticobasal degeneration

Corticobasal degeneration (CBD) is a neurodegenerative disease characterized by asymmetric cortical and extrapyramidal signs including progressive asymmetric limb rigidity and apraxia. Other commonly occurring signs include alien limb phenomena, frontal release signs, postural instability, cognitive and/or memory deficits, aphasia, apraxia of speech, and dysarthria. An extensive literature review revealed that although speech and language deficits are common, they rarely are described in detail. The current study examined the speech and language characteristics of 13 cases of autopsy-confirmed CBD. Findings indicate that speech and language disorders were common signs of the disorder and often were among the first signs of CBD. Aphasia was present in over half of the patients and was most often characterized as nonfluent, or anomic. Dysarthria and apraxia of speech were present in approximately 30% and 40% of patients, respectively. Dysarthria type was typically mixed, with either spastic or hypokinetic features present in all affected cases. Although the presentation of speech and language disorders was heterogeneous across patients, the findings highlight the importance of these disorders in the detection and diagnosis of CBD.