To continue our celebration of Better Hearing and Speech month at HomeCEU, we have invited several prominent Speech-Language pathology authors and practitioners to share their thoughts and experiences with us. Last week we heard about Arlene Romoff's journey back to hearing through the technology of Cochlear Implants. Today we are honored to welcome Dr.Peter Flipsen Jr, Ph.D., S-LP(C), CCC-SLP as he addresses some of the difficulties SLPs can face when diagnosing Childhood Apraxia of Speech.
Childhood Apraxia of Speech
Childhood Apraxia of Speech (CAS) has a long history in the field of speech-language pathology. It has gone by several names including developmental apraxia of speech, suspected developmental apraxia of speech, developmental verbal dyspraxia, and developmental dyspraxia.
It has also been a controversial label. Many argued that it didn't exist. They contended that it was merely a severe form of delayed speech. In 2007, following considerable deliberations by an expert panel, ASHA adopted a position statement and a technical report which (1) stated that there is sufficient evidence that CAS exists, (2) provided a working definition, and (3) suggested at least three features that may be unique to CAS. Readers are strongly encouraged to read these ASHA documents.
In brief, the expert panel concluded that CAS is a neurological disorder, it is a problem of "precision and consistency" of speech production, does not require problems with tone or reflexes, and may arise in different ways. It might be the result of obvious damage to the nervous system (e.g., a head injury or severe infection), or it might be associated with some developmental disorder like Rhett's syndrome, Fragile X syndrome, or even autism. In many cases, however, it may have no obvious cause.
The core problem in CAS is with planning the movements for speech. In other words, it's about difficulty with translating the intended message into the instructions for the articulators. It's not about the message itself (i.e., it's not phonological), and it's not about producing the words (i.e., it's not articulatory).
CAS is about speech; It is possible to have oral apraxia (difficulty with non-speech motor movements) and yet have normal speech. On the other hand, it is possible to have CAS and have no oral apraxia. The same is true for adult apraxia, where it is also possible to have both oral apraxia and CAS at the same time.
There are three features that seem to be key to CAS. First, there is a specific kind of inconsistency. When children with CAS attempt the same word on different occasions their output may change from one time to the next. A second feature is difficulty with transitions. Children with CAS can reproduce simple movements (e.g., puh, puh, puh) but changes in place of articulation (e.g., puh, tuh, kuh) cause great difficulty because they involve more complex motor plans. Finally, children with CAS often with difficulty with prosody (intonation, use of stress, etc). Prosody complicates the motor plan even further.
Children with CAS are often slow to progress in therapy. However, by itself, slow progress doesn't mean the child has CAS. Thats because slow progress could also mean that we have either misdiagnosed the problem or that we have not yet found the appropriate intervention. Slow progress could just as easily be our fault.
Prevalence?
We still don't have solid numbers to go on. But it's probably a lot less common than some clinicians believe. The best available estimates are that CAS occurs roughly 1-2 times per 1000 in the population. That's a pretty small number. But how often will we see CAS on our caseloads? If we assume that up to 10% of preschoolers have some sort of speech sound disorder, that's 10 out of 100 children in the population. It's also 100 per 1000 in the population. If we combine that number with the CAS estimates, the average clinician should be seeing 1-2 cases of CAS for every 100 children on our caseloads.
Assessment
Some published tests claim to allow you to diagnose CAS. Although well-intentioned, none of them was developed based on the current ASHA documents. For the moment assessment needs to be informal and based on the three features mentioned above.
Consistency can be assessed by recording the child saying 20-25 words, doing another activity, recording the same words a second time, doing a different activity, and recording the words a third time. Then we can transcribe the productions and see how consistent the productions are. We want the productions separated by other activities to force the child to create new motor programs each time. Transitions can be assessed using our old standby diadochokinetic task (DDK) tasks. The child with CAS will have less trouble when the place of articulation is constant and more trouble when the place of articulation changes. Prosody can be informally evaluated from a conversational speech sample.
Treatment
Treatment for CAS is still not well developed. We don't yet have a good sense of what the best treatments might be for these children.
About The Author
Peter Flipsen Jr, Ph.D., S-LP(C), CCC-SLP obtained his doctorate from the University of Wisconsin-Madison and is currently an Associate Professor of Speech Pathology at Idaho State University. He has also served on the faculty at the University of Tennessee, Knoxville, and Minnesota State University, Mankato. He holds the Certificate of Clinical Competence in Speech-Language Pathology from the American Speech-Language-Hearing Association and is certified as a Speech-Language Pathologist by the Canadian Association of Speech Pathologists and Audiologists. He currently serves as an Associate Editor for the journal Language, Speech, and Hearing Services in Schools. His primary research interest is in the area of speech sound disorders in children.
Continuing Education For SLPs from HomeCEU
HomeCEU, an ASHA approved continuing education provider, has added several new live interactive courses created by well-known Speech-Language Pathology speakers like Denise Dougherty, MA, CCC-SLP and Patricia Ourand, MS, CCC-SLP. If you're looking for a high quality continuing education experience, please visit our online catalog or reserve a seat today!