Speech apraxia is one of the labels applied to a disorder of communication characterized by slow speech tempo ("groping for words"), impaired articulation, and dysprosody, with relatively intact language function and no dysgraphia. More errors occur with increasing articulatory complexity (consonant clusters vs. single consonants). Automatic or reactive speech (e.g., expletives, clichés) is without error. This, or a very similar, constellation of features has also been known as cortical dysarthria, aphemia, or phonetic disintegration. There may be associated orofacial apraxia.
Speech apraxia has been associated with inferior frontal dominant (left) hemisphere damage in the region of the lower motor cortex or frontal operculum; it has been claimed that involvement of the anterior insula is specific for speech apraxia.
The exact nosological status of this entity remains in some doubt. The syndrome is thought to reflect disturbances of planning articulatory and phonatory functions, but is most often encountered as part of a nonfluent aphasia.
Dronkers NF. A new brain region for coordinating speech articulation.
Nature 1996; 384: 159-161