The CAS Hypothesis Karen Chenausky investigates whether childhood apraxia of speech limits speech acquisition in some children with autism. Foundational Questions
Foundational Questions  |   March 01, 2018
The CAS Hypothesis
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Development / Speech, Voice & Prosodic Disorders / Apraxia of Speech & Childhood Apraxia of Speech / Special Populations / Autism Spectrum / Speech, Voice & Prosody / Foundational Questions
Foundational Questions   |   March 01, 2018
The CAS Hypothesis
The ASHA Leader, March 2018, Vol. 23, online only. doi:10.1044/
The ASHA Leader, March 2018, Vol. 23, online only. doi:10.1044/
Name: Karen Chenausky, PhD, CCC-SLP, research fellow in neurology, Beth Israel Deaconess Medical Center
ASHFoundation funding: 2016 Clinical Research Grant
What is the focus of your research?
In general, I am fascinated by how speech develops, almost magically, in most young children—and why it doesn’t in others. Recently, I discovered that I love working with minimally verbal children with autism. I want to know how we can decide whether it is feasible for them to learn spoken language—and, if so, how best to teach them. I’m focusing on the “CAS hypothesis”—the idea that childhood apraxia of speech (CAS), the motor-planning disorder, could be one factor limiting speech acquisition in many minimally verbal children with autism. CAS is a disorder of speech, not of language, but I wonder if severe CAS may also affect these children’s ability to acquire language.
How did your award from the ASHFoundation lead to your current work?
My 2016 Clinical Research Grant enabled me to investigate the question: How prevalent is CAS in minimally verbal children with autism? That’s a first step to investigating all the other questions above. If you’re wondering whether CAS limits speech acquisition in a group of kids, you first have to determine whether they show signs of it. But looking for signs of a motor speech disorder in children who don’t vocalize much is extremely difficult.
My ASHFoundation grant allowed me to partner with a clinician with expertise in diagnosing CAS, and with two senior autism researchers who have video databases of minimally verbal children with autism participating in an experimental speech treatment or receiving a speech production test.
These collaborations will yield the first estimate of how many minimally verbal children with autism also meet criteria for CAS, what CAS looks like in these severely affected children, and maybe even whether they also experience other speech disorders such as stuttering or dysarthria. The data that come from this project will, I hope, help me get a larger independent grant from the National Institutes of Health.
What do you hope to demonstrate through your research—or what has it already demonstrated?
Our preliminary results suggest that CAS is indeed over-represented in minimally verbal children with autism. CAS is estimated to affect one to two children per thousand in the general population, but all but one of the 38 children in our first group (the children receiving experimental speech treatment) met criteria for CAS. We think this may be a high estimate, because the inclusion criteria for the study they participated in appear to have selected for children with CAS. For that reason, we will perform the same study in the children who received a test of speech production to see whether the results hold up. Then, we can test whether CAS diagnosis or severity might correlate with expressive or receptive language scores or how much improvement there is in speech after treatment.
Ultimately, I’d like to use the results from these initial investigations to do two things: First, to come up with some reliable clinical measures that can help us understand which minimally verbal children might respond to speech treatment and which children are unlikely to. This information will help us make clinical decisions about treatment much earlier than we can now, saving children and parents time. Second, I’d like to create and refine treatments that can help the kids who can achieve useful speech. My dream goal would be to help these children move from the single-word stage to word combinations, or even sentences—at no matter what age.
Why did you choose this particular research focus?
There are lots of reasons. When I was finishing my dissertation, a couple of other SLPs who knew I was studying speech development in autism asked me what I thought about the “CAS hypothesis.” I realized I was in a unique position to investigate whether it could be one of the things limiting speech development in some minimally verbal kids with autism. I never thought that my research experience in speech production and my clinical experience in autism spectrum disorders would actually unite into such a high-impact area.
I also deeply respect the minimally verbal children I work with. Producing speech is so hard for them—harder than anything in my life—and they are so much less motivated by adult praise than other children are. But they still work incredibly hard in treatment. Their experience has so much to teach us about what speech is and how it develops, almost independently, in most other children.
And, last, I love the idea of trying to make sense of this complex and understudied area. Even if all I accomplish is to carefully lay out what questions we need to ask about minimally verbal children with autism, I will feel like I’ve made a contribution to the field. Coming up with answers will be icing on the cake.
How has ASHFoundation funding affected your professional life?
ASHFoundation funding helped launch my research career. Just the process of writing the grant forced me to carefully think through what I wanted to investigate and how I was going to do it. The grant itself is paying for half of my time for two years so that I can investigate an independent line of research, and I’m not tied just to my mentor’s research. The award has given me the credibility to approach potential collaborators with some hope of success. And perhaps most of all, it showed me that there is a great deal of support and interest in my work from my professional peers. That gives me the confidence to take on these hard questions and to compete for NIH funding.
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March 2018
Volume 23, Issue 3