Evaluation & Diagnosis: The Best List of CAS Characteristics

By Pam Marshalla

toddler by cereza_juana on flickrQ: Do you have a list of diagnostic indicators for young children with CAS?

The best I have found has been from a seminar I attended by Dr. Barbara Davis in 2010. This is what I put together from her handout:

Characteristics of Apraxia

Barbara Davis does research in the area of childhood apraxia of speech and she presented a summary of research in this area at a recent seminar (Davis, 2010). She reported that the incidence of apraxia is higher in males than in females, that children with apraxia have normal intelligence, and that these children score higher on non-verbal than on verbal tests. Children with apraxia have normal comprehension of language, their receptive language skills are far superior to their expressive abilities, and their hearing is normal. These children always have a positive history of delayed language development, restricted use of syntax and pragmatic functions. These children have poor discourse strategies (eye contact, turn taking, imitation/response), but non-verbal communication may be well developed and compensatory.


According to Davis, the following characteristics of expressive speech generally are agreed upon in the apraxia literature––

  • Inconsistent errors on consonants, vowels, and syllables in connected speech
  • Limited phonetic repertoire
  • Predominant use of simple syllable shapes–CV and V predominant
  • Frequent omission errors
  • Vowel errors even though entire vowel inventory may be intact
  • Increased errors on longer units of speech
  • Significant difficulty imitating words and or phrases

Controversial Characteristics

According to Davis, the following characteristics are controversial in the apraxia literature. In other words, some children with apraxia display these characteristics while other do not––

  • Poor auditory memory
  • Sequencing difficulties
  • Cross modality difficulties
  • Discrimination abilities may be normal
  • Decreased performance on oral sensory tests
  • General motor clumsiness
  • Feeding or swallowing problems
  • Inappropriate stress and intonation
  • Variable rate
  • Monotone
  • Poor loudness dynamics
  • Fluctuating nasality

Clinical Signs

Davis also reported on the following clinical signs of apraxia. These are characteristics of apraxia that she notes regularly in the clinic but for which there is no definitive research to substantiate these claims––

  • Uncoordinated feeding patterns.
  • Lack of CV babble.
  • Incomplete syllables used for words: Client uses a single consonant or a single vowel for a syllable.
  • Limited variety of syllables. Often uses the same CV used for a variety of words.
  • Cannot combine different syllables.
  • Home sign development (Idiosyncratic signs).
  • Uses one stereotyped intonation pattern.
  • Uses only one movement pattern (e.g., uses only labial sounds).
  • Oral motor incoordination.
  • Groping for phonemes.
  • Words seem to be learned and then disappear more than normal.
  • Basic Subject-Verb-Object word order may be in error.
  • Lack of general motor flexibility.
  • Difference between automatic and functional gestures versus elicited gestures. (Automatic gestures versus gestural imitation on demand). 


  • Davis, B. L. (2010). Assessment and Intervention Issues in CAS. Seminar handbook. CESA 5 School-based SLP Institute, March 8-9, 2010, Wisconsin Dells, WI.



2 thoughts on “Evaluation & Diagnosis: The Best List of CAS Characteristics”

  1. Thank you for this information. I was just looking for a list like this yesterday. Thinking about you and hopefully you are on a speedy recovery.

  2. Have you noticed possible subsets of children with CAS, such as a group that is more likely to have dyslexia but normal oral sensation, versus a group that oral sensory issues but not dyslexia, or a group that has mildly decreased oral muscle strength, etc? Thank you.

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