Childhood Apraxia of Speech

Is there a speech disorder that is less well understood than childhood apraxia of speech (CAS) (also known as Verbal Dyspraxia)?  If so, we’d like to know what it is.

CAS is a speech motor programming impairment that manifests as a difficulty in producing the sounds (articulation) and melody (prosody) of speech.  As one author puts it in plain English: the brain tries to tell the speech muscles what to do and the message gets scrambled somehow (Lindsay, 2012).

CAS is NOT a disorder of the speech muscles themselves.  Nor is it a cognitive disorder or a speech/developmental delay.

For years, experts have debated the definition of the disorder and the criteria used to diagnose it.  In contrast to voice disorders in children, CAS may be over-diagnosed, and there are lots of terrible websites – many spruiking books, flashcards and services to desperate parents – filled with half-truths or blatant falsehoods about what CAS is (and isn’t).

Compared to speech sound disorders, CAS is quite rare.  It is also very serious, with symptoms typically persisting for life.

In 2007, the American Speech-Language-Hearing Association (the US counterpart to our Speech Pathology Australia) published a position statement to serve as a guide for research on children with CAS.  They identified three diagnostic characteristics of CAS:

• inconsistent errors on consonants and vowels in repeated productions of syllables or words;
• lengthened and disrupted coarticulatory transitions between words and sounds and syllables; and
• inappropriate prosody, especially in producing the correct stress patterns on words and phrases.

When assessing a child for possible CAS, speech-language pathologists pay special attention to these three criteria, and the common perception that children with CAS segment their speech, almost as if talking syllable by syllable.

Treatment for CAS should be be based on the latest research about the principles of motor learning.  Sydney University is currently doing some great (and much needed) work comparing the efficacy of two evidence-based programs:

• the Nuffield Dyspraxia Programme; and
• the Rapid Syllable Transition Treatment (developed by researchers at Sydney University), including a randomised controlled trial testing for the long-term treatment effects of both programs.

We employ both programs in our practice and are watching these and other research developments closely to ensure we provide the most effective evidence-based treatments to clients with CAS.

Related articles:

• Childhood Apraxia of Speech: FAQs and treatment update