Apraxia of speech

Donald A. Robin, Sabina Flagmeier

Research output: Chapter in Book/Report/Conference proceedingChapter

1 Scopus citations


Apraxia of speech: definition and features Apraxia of speech (AOS), which is one of a family of motor speech disorders (Duffy 2005), affects the programming of speech movements. Pioneering work in AOS emerged from an extensive study of motor speech disorders by Darley, Aronson and Brown in 1975, which resulted in the publication of their now classic textbook (Darley et al. 1975). However, the nature of AOS, its diagnosis and treatment have been topics of great controversy, and it is only recently that consensus has been reached on some of these issues. For example, because AOS and Broca’s aphasia are often comorbid symptoms, AOS has been associated with other co-occurring pathologies such as aphasia. The term ‘apraxia’ was first coined by Steinthal (1871) and was subsequently elaborated upon by Liepmann as a ‘disorder of voluntary movements not attributable to the loss of strength, coordination, or mental faculty and restricted to certain body parts and functional activities’ (Liepmann 1913: section XI, part II; Ballard et al. 2000: 970). In 1969, Darley presented the concept of apraxia as it applies to speech (Darley 1968, 1969). Darley suggested that the term would only be applicable when assurance could be given that the patient had the intent, the underlying linguistic representation and the fundamental motor abilities to produce speech, but could not do so volitionally (Darley et al. 1975). However, the precise characterization of AOS has been debated for a number of years. The controversy that surrounds apraxia of speech focuses in part on the unique features that are used to define AOS. For example, Martin (1974) challenged the use of the term ‘apraxia of speech’ as it was applied to select subject populations for study. He argued that the specific features used to differentiate AOS from other speech disorders were in fact not able to do so. Investigators are also divided on whether the pathogenesis of AOS is phonological or phonemic in nature.

Original languageEnglish (US)
Title of host publicationThe Cambridge Handbook of Communication Disorders
PublisherCambridge University Press
Number of pages13
ISBN (Electronic)9781139108683
ISBN (Print)9781107021235
StatePublished - Jan 1 2015
Externally publishedYes

ASJC Scopus subject areas

  • Arts and Humanities(all)
  • Social Sciences(all)


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