My Child Has CAS Part II: What Makes CAS Different from Other...

My Child Has CAS Part II: What Makes CAS Different from Other Speech Problems?

In Part I, we discussed the difference between CAS (childhood apraxia of speech) and childhood dysarthria. CAS (often referred to as verbal dyspraxia outside of the USA) must also be distinguished from a childhood phonological disorder and acquired apraxia of speech (AAS) which are frequently confused with CAS. Additionally, some children can have a phonological disorder along with CAS.

What Characterizes a Language-Based Childhood Phonological Disorder?
A language-based childhood phonological disorder is different from CAS. Children with phonological disorders have difficulty internalizing speech sound production rules as part of the language system.

Children with phonological disorders (Strand, 2010; Velleman, 2005) tend to:

  • Have a history of middle ear problems (e.g., ear infections).
  • Babble and say many speech sounds, but don’t use those speech sounds properly (e.g., saying “gog” instead of “dog” or “kak” instead of “cat” where both consonants are made at the back of the mouth). They also tend to make consonant errors instead of vowel errors.
  • Have trouble saying speech sounds in spontaneous speech that they can imitate.
  • Have generally typical speech rate, rhythm, stress, and inflection.
  • Have difficulty identifying and remembering speech sounds (e.g., What sounds do you hear in the word “dog?” or Tell me a word that begins with the “d” sound).
  • Have difficulty with reading and spelling because they have not made adequate brain-level connections between speech and language.
  • Have other specific language problems such as word-finding difficulties.
  • Have no soft neurological signs (e.g., problems with gross or fine motor coordination used in activities such as tricycle riding or coloring).

What is Acquired Apraxia of Speech (AAS), and How Is AAS Different from CAS?
AAS is usually found in adults who have had a stroke resulting in something called Broca’s aphasia. While a similar area of the brain may be involved (i.e., the premotor cortex), children with CAS do not have specific brain damage or injury.

However, many people confuse the characteristics of AAS with CAS. While some characteristics of AAS may seem similar to CAS, the two disorders are qualitatively unique (Bahr, 2001, pp. 153, 211-213). For example, children with CAS often leave sounds out of (particularly the beginning) of words, while adults with AAS most frequently substitute one speech sound for another. Children with CAS tend to turn voice on when they should turn voice off, while adults with AAS do the opposite (voicing explained in next section). Children with CAS may say an occasional word “out of the blue,” while adults with AAS may say clear and complete phrases and sentences under certain circumstances.

So, What Characteristics Specifically Distinguish CAS from Other Speech Disorders?
CAS affects the sequencing, coordination, and timing of speech. Children with CAS (Bahr, 2001, p. 153, Lindsay, 2012, pp. 7-8) tend to:

  • Have far greater understanding of language than they can express or say.
  • Have limited babbling and speech play as infants. They are often relatively quiet babies or only make a few speech sounds. They may gesture or grunt instead of using speech.
  • Say a limited number of vowel and consonant sounds instead of a full range of speech sounds (Bahr, 2010, pp. 218-224).
  • Mispronounce vowel sounds (e.g., saying “cot” instead of “cat”) which significantly affects “understandability.”
  • Make many speech errors and frequently leave sounds out of (particularly the beginning) of words (e.g., saying “_at” instead of “cat”).
  • Make consistent speech errors in spontaneous speech (e.g., saying “_at” instead of “cat” consistently when commenting or responding ).
  • Make inconsistent speech errors when attempting to imitate speech (e.g., saying “gad,” “got,” “cad,” “cot,” “_at,” etc. instead of “cat” when given a speech model by another person).
  • Turn their voices on (sometimes only partially) when they should turn their voices off during speech (e.g., saying something closer to “gad” instead of “cat”). The “g” and “d” sounds use voice; the “k” and “t” sounds do not. Children with phonological problems can also have voicing errors, but the sound of their errors is somewhat different from those of children with CAS.
  • Grope, struggle, and use trial and error (with the mouth moving all over the place or getting stuck in place) during speech attempts.
  • Speak in short, telegraph-like words and phrases (e.g., saying “_ant _oodie” instead of “I wanna cookie.” or “I want a cookie.”).
  • Have difficulty with speech rate, rhythm, stress, and intonation. Speech often sounds “out-of sync” making it very difficult to understand.
  • Say words “out of the blue” without being able to say them again (e.g., saying brother’s name “Alexander” perfectly without being able to repeat it).
  • Have problems learning movement sequences throughout the body (e.g., movements for bubble or horn blowing, gesturing, coloring, tricycle riding, etc.). However, children may have CAS without these additional issues (called oral and limb dyspraxia).

Now, you know many characteristics that can distinguish CAS from other speech disorders. Next month we will discuss what you might look for in the treatment of your child’s CAS. Until then, don’t forget to look at these two parent websites on the topic:

Bahr, D. (2010). Nobody Ever Told Me (or my Mother) That!: Everything from Bottles and Breathing to Healthy Speech Development. Arlington, TX: Sensory World.

Bahr, D. C. (2001). Oral Motor Assessment and Treatment: Ages and Stages. Boston, MA: Allyn & Bacon.

Lindsay, L. A. (2012). Speaking of Apraxia: A Parents’ Guide to Childhood Apraxia of Speech. Bethesda, MD: Woodbine House.

Strand, E. A. (2010). Differential diagnosis and treatment of childhood apraxia of speech. Workshop presented in Las Vegas, NV: The Childhood Apraxia of Speech Association.

Velleman, S. (2005). Perspectives on assessment. In A. G. Kamhi and K. E. Pollock (Eds.). Phonological Disorders In Children: Clinical Decision Making In Assessment and Intervention. Baltimore: Paul H. Brooks Publishing Company, 23-33.