Childhood Apraxia of Speech (CAS) has become a bit of a buzzword within the last several years and if we're being honest, it sounds a little scary. So what is it?
Simply put, CAS is a motor speech disorder. The term "Childhood Apraxia of Speech", is a diagnostic label given to a child's speech sound difficulties-if the disorder is motor based.
Here is a more formal definition: "Childhood apraxia of speech is a neurological childhood speech sound disorder in which the precision and consistency of movements underlying speech are impaired in the absence of neuromuscular deficits (e.g. abnormal reflexes, abnormal tone), (ASHA, 2007a, Definitions of CAS section, para. 1).
This is to say that CAS is not the same as dysarthria, which is muscular weakness of the oral structures such as the tongue, lips, cheeks, or jaw. The defining characteristic of CAS is impaired precision and consistency of speech sound movements.
What does this look like?
In order to receive a proper diagnosis, a skilled speech-language pathologist should complete a thorough motor speech evaluation. If your child is not speaking at all and has been diagnosed with CAS, I would strongly question that diagnosis if not refute it. I don't mean to sound snarky-let me explain.
In order to diagnose CAS, a clinician should obtain a thorough medical and developmental history, a language sample to assess phonemic and vocabulary inventory, a receptive and expressive language assessment, and lastly a dynamic motor-speech exam. Hence, if your child is not vocalizing at all, it would be very difficult to obtain the information needed to confidently say that Billy's speech sound difficulty is due to motor planning (aka CAS).
In terms of signs and symptoms of CAS, Dr. Edythe Strand CCC-SLP, states that the following are considered to be "descriptive diagnostic characteristics", meaning that they are very common in children with CAS (March 2017, ASHA Leader):
1. Vowel distortions (e.g. "muh" for "my")
2. Prosody errors (intonation and rhythm of speech may sound awkward/unnatural)
3. Groping of oral structures (child may start and stop again or try several times to say a word)
4. Difficulty with articulatory transitions (e.g. child may be able to produce "my" but when trying to say "my bike", may struggle)
5. Inconsistent voicing errors (may produce /g/ correctly sometimes such as "go" but then in other instances may say "do", where the /d/ sounds less voiced).
Other signs, which although present, may not necessarily indicate CAS include poor speech intelligibility, a high number of speech sound errors, limited vowel and consonant sound inventory, difficulty with more complex syllable shapes, and frequent sound omissions (e.g. "uh" for "apple").
A child who makes consistent speech sound errors or substitution patterns ( e.g. /t/ for /k/, "tat" for "cat", "tan" for "can", "tolor" for "color") but does not demonstrate vowel errors, awkward transitions between words and/or syllables, groping, or prosody errors, is much more likely to have a phonological disorder than CAS. Often times a child with CAS may also have phonological difficulties; however, not all children with phonological disorders have CAS.
It's a lot to unpack! I know. That is why a proper evaluation is so crucial.
If you suspect your child may have CAS, here are some steps you can take:
1. Don't panic. It is not your fault. Often times, we do not know the cause of CAS; however, research has shown that with evidence based therapy programs, speech-language therapy can significantly help improve your child's motor planning.
2. Schedule an evaluation with a speech-language pathologist who is familiar with CAS. Don't be afraid to ask what to expect from the evaluation.
3. Do your research. The internet can be a scary place. Let me help by suggesting a few pages as a starting point.
In my own practice, I implement Dynamic Tactile Temporal Cueing (DTTC), which is an evidence-based motor speech based treatment approach. DTTC was developed by Dr. Edythe Strand. Her approach is based upon the principles of motor learning, where the key focus of therapy is to improve the child's accuracy of movement needed to consistently produce speech targets. If you recall, the main impairment with CAS is the ability to precisely and consistently motor plan. DTTC was designed to target this impairment in a systematic way.
I highly recommend visiting this page to learn more. Below are more great resources to learn more about CAS and the DTTC treatment method:
ASHA Leader Article by Dr. Edythe Strand
ASHA's CAS Informational Page
Apraxia Kids DTTC Information
As always, feel free to contact me at firstname.lastname@example.org if you have concerns regarding your child's speech or language skills. Thanks for reading!