The neural basis of ataxic dysarthria.

Lesions to the cerebellum often give rise to ataxic dysarthria which is characterized by a primary disruption to articulation and prosody. Converging evidence supports the likelihood of speech motor programming abnormalities in addition to speech execution deficits. The understanding of ataxic dysarthria has been further refined by the development of neural network models and neuroimaging studies. A critical role of feedforward processing by the cerebellum has been established and linked to speech motor control and to aspects of ataxic dysarthria. Moreover, this research has helped to define models of the cerebellar contributions to speech processing and production, and to posit possible regions of speech localization within the cerebellum. Bilateral, superior areas of the cerebellum appear to mediate speech motor control while a putative role of the right cerebellar hemispheres in the planning and processing of speech has been suggested.