DTTC: Evidence Based Practice in Childhood Apraxia of Speech. An interview with Dr. Ruth Stoeckel
Today I am honored to introduce Ruth Stoeckel, nationally recognized expert and published researcher on Childhood Apraxia of Speech. I first saw Ruth Stoeckel speak back in 2005 when she presented in Colorado. The packet she handed out during that talk helped me greatly in those early years when I was first learning about how therapy for apraxia is very different than therapy I had been doing for other speech sound disorders; and helped me treat the kids I did see with apraxia after that time.
Since then, I was honored to be selected as part of CASANA’s intensive apraxia training institute in 2014, where Ruth was my mentor for four days. I can say that during that time I was able to get to know Ruth better and I can tell you that she is absolutely passionate about CAS.
Hi Ruth! Thank you so much for guest blogging today. To start, can you please talk a little about your background, where you work, and how you found yourself specializing in CAS.
Thanks for opportunity, Laura. I’ve met a lot of great SLPs and parents through CASANA and I’m glad you are out there spreading the word to increase awareness.
How did I find my way to special interest in apraxia? Lots of things seemed to push me in this direction. I did undergraduate work at University of Iowa at a time when Penelope Meyers was there and talking with students about apraxia several years before she and Donald Robin co- wrote the book Developmental Apraxia of Speech: Theory and Clinical Practice. When I moved to Minnesota, my clinical supervisor in the local school system was none other than Kathe Yoss, who together with Fred Darley had published an early study (1974) of a cohort of children who had a unique set of characteristics that they described as similar to adults with apraxia. Kathe was a wonderful mentor and encouraged me to develop expertise in low incidence disorders like childhood apraxia. A number of years later, I left the school system to work at Mayo Clinic. I have had the opportunity to work with and learn from two exceptional leaders in the field of motor speech disorders, Joe Duffy and Edythe Strand. Finally, I happened upon the Apraxia-Kids listserv one night early in the evolution of what would become CASANA and was drawn in by the passion of the parents and SLPs who contributed there. The combination of my work experiences and relationship with CASANA has allowed me to have great opportunities to develop my expertise and learn from both parents and colleagues!
Almost weekly I get asked, “What is the BEST approach for CAS.” I know that you are a proponent of DTTC. Can you explain what this is, and do you feel this is the BEST approach? Why or Why not?
There is so much we still need to learn about how to treat CAS. I have to say that, based on what we know right now, there is NO single “best” approach for treatment. The greatest amount of empirical evidence is for Integral Stimulation/DTTC, but positive results are being seen in studies using other techniques, including PROMPT, ReST, and ultrasound in treatment.
I do use Dynamic Temporal and Tactile Cuing (DTTC) to guide my treatment. DTTC is a flexible framework for dynamic decision-making in treatment – changing what you do moment to moment based on the child’s responses. It was developed by Edythe Strand based on the adult 8-step continuum proposed for adults by Rosenbeck and colleagues. This framework emphasizes the shaping of movement gestures for speech production using a systematic hierarchy of cues, with continued practice of those gestures in the context of speech. The focus of treatment is not on sounds – but on the movement gestures, or movement transitions for sound combinations.
DTTC is primarily an integral stimulation method that can incorporate whatever types of cues facilitate a child’s production, including visual, tactile and gestural. Prosody is incorporated early on as well. There is a temporal hierarchy (i.e. simultaneous production, immediate repetition, repetition after delay) in addition to the different types of cues. The dynamic adjustments in temporal characteristics and level of cuing allow opportunities for the child to take increasing responsibility for assembling, retrieving and habituating motor plans. This approach is individualized to the child by using a functional core vocabulary of words meaningful to them. The principles of motor learning are integrated into this framework as well. These principles are thought to be an important element for any treatment of motor speech disorder.
What does the research say about DTTC?
Based on recent review studies, DTTC has the largest base of empirical research to suggest effectiveness for treatment of children with CAS. However, the studies have been done with a small number of children, and further studies are needed to identify which elements of the framework may be key ingredients, and which may be less important. As I said above, there is emerging evidence to support other approaches as well.
Since you mentioned principles of motor learning, can you provide a *brief* overview? What do SLP’s really need to be doing differently from traditional articulation or phonological based therapy?
Edwin Maas and colleagues wrote a great tutorial in 2008 that I recommend to anyone interested in motor speech disorders. There have been a few small studies since then that have looked at these principles on a more individual basis, but there is still much to learn about how they apply to speech therapy.
Key aspects of treatment that are different for apraxia versus phonological disorder are that apraxia therapy focuses on movementsequences rather than sound sequences and that it emphasizes working on movement sequences (coarticulation) within and between syllables. Repetition is another key difference. Based on just a couple of studies, there is evidence that we need a large number of repetitions per sessions to help a child establish the needed level of skill for producing a target. It may take some time to build up to, but I try to get 100-200 repetitions of targets within a 20-30 minute session. How those repetitions are organized is decided using the principles of motor learning. As they are laid out in the Maas article, we consider these principles as a way to influence how a child acquires a skill and then transfers or generalizes the skill. They include the following:
*Massed versus Distributed practice, which is many trials in a short period of time compared to practice of a given number of trials or sessions over a longer period of time.
*Variable versus Constant practice, which is working on the same target in the same context as compared to practice on different targets in different contexts
*Blocked versus Random practice, which is working on different targets in predictable blocks or treatment phases compared to mixing practice on various targets in less predictable ways.
*Simple versus Complex task, which is a focus on “easier” sounds and sequences (what the child can say, or what is presumed easier or earlier developing) compared to more complex sounds and sound sequences.
*Feedback on performance versus feedback on results, which is telling the child what behavior was produced accurately (e.g., you got your lips closed before you started”) need to do differently as compared to telling them “you got 3 out of 5 right.”
Many SLP’s want to know how to pick therapy targets. Where do you start when picking targets?
I start by: 1) identifying the child’s phonetic repertoire; 2) their phonotactic (syllable) repertoire; and 3) finding out from the child and their caregivers what words are important and potentially motivating for that child. In my motor speech exam, I probe the words that I might consider including as therapy targets by exploring what sequences the child can produce with different levels of help. I want to try to expand their sound repertoire and their ability to sequence syllables, looking for how I can do that using a core functional vocabulary.
What if the child has a later developing sound in their repertoire? Would you include this in a potential target word?
This comes up a lot. Many SLPs are trained in their graduate programs to think of a “sequence” of sound development and to focus efforts on sounds thought to be earlier developing. It seems that among the folks who have been doing this a while (it’s not validated in a study as of yet), the kids with apraxia “didn’t read the book” on speech sound development. It’s possible they will have an “sh” or /r/ in several words before they have a consistent /b/or /m/. That is why I think it is so important in assessment to survey the child’s phonetic and phonemic repertoire and to build the targets used in intervention on sounds that the child can produce either on their own or with help, regardless of where it is on a chart. So, for example, the /s/ sound is very important in English for intelligibility and as a linguistic marker. If a child is stimulable for it at all, I go for it in vocabulary targets, even though it’s considered later-developing.
Do you ever use oral motor exercises in the treatment of CAS? Why or why not?
I want to be very clear in my response to this question. Because speech is accomplished by moving the mouth, pretty much everything we do in speech therapy can be considered “oral motor” work. The key distinction seems to be doing “exercises” vs “speech work.” I do use some physical materials to assist with placement, like suckers or tongue depressors, and I do sometimes have a child practice a speech movement a number of times without speaking as a way to simplify the task at first. But I always move the child as quickly as possible from that type of practice to using the movement in the context of a spoken target. I don’t presume that practicing nonspeech tasks (e.g., chewing, blowing, etc. ) will result in improved speech movements and never ask a child to practice repetitions of isolated nonspeech movements or exercises to “strengthen” or “increase awareness of movement.” Based on what we know of speech physiology, muscle movements are task-specific rather than muscle-specific. That is, the activation pattern for a given muscle is different depending on the task that it is doing. So we need to teach a movement in the context in which it will be used.
What advice would you give for a beginning clinician who has minimal background on apraxia and apraxia therapy? Do you have any webinars available for viewing, or good articles they could use as a start guide?
I’d advise a clinician with minimal knowledge of background to do 2 things:
1) to find a colleague who has expertise and can provide mentoring; and 2) take advantage of the wealth of information available at the Apraxia-Kids website. Next, they could attend workshops or webinars sponsored by CASANA. I think it’s usually more meaningful when seeking information to be pursuing it for a particular student – as it was for you, when deciding you needed to learn about apraxia because of Ashlynn. I think the information will be more relevant and perhaps “stick” better when it is being sought for an immediate purpose. Then that learning can be transferred to how one thinks about additional students who come along later with apraxia or severe speech sound disorder.
Thank you SO much Ruth for being here today! I am honored and thrilled that you agreed to guest blog. I continue to admire your work in the field, your dedication to the children and their families affected by CAS, as well as your contribution to the field with your research.
Thanks so much for having me!
Ruth Stoeckel, Ph.D., CCC-SLP is a speech-language pathologist at the Mayo Clinic in Rochester, Minnesota. She has experience working as a clinician and independent consultant in schools, private practice, private rehabilitation agency and clinical settings. She specializes in assessment and treatment of children with severe speech sound disorders and developmental challenges. Dr. Stoeckel has participated in research studies on apraxia treatment and on the relationship of speech sound disorders to later learning disorders. She has presented workshops and advanced trainings nationally and is known for presenting practical, evidence-based information that participants can put to immediate use in their day-to-day practice. Dr. Stoeckel is on the Professional Advisory Board of CASANA and has been a faculty member of the Intensive Training Institute sponsored by CASANA.