Ultrasound biofeedback therapy is another tool in the toolbox for treatment of children with persistent speech errors related to CAS

PUBLISHED DECEMBER 2018 | BY JONATHAN PRESTON

Most speech sounds require moving the tongue.  The sounds that are often the hardest for children with CAS to master, such as r, l, s, sh, require complex movements of the tongue. Figuring out how to position the tongue can be a challenge for both a child with CAS, and figuring out how to explain the movements can be difficult for clinicians.A study funded by Apraxia Kids was the first to investigate the use visual feedback of the tongue as a way to teach production of speech sounds for school-age children with CAS. This study involved using ultrasound (the same device used to obtain images of a fetus or heart) to provide a real-time visual display of the tongue while children talk (Preston, Brick & Landi, 2013). In this approach, the ultrasound transducer is held under the chin, and the ultrasound images are then used to teach children how to move their tongue into different positions to produce certain speech movements. Speech-language pathologists can use this information to provide the child with cues about the tongue.

The primary advantage of using ultrasound biofeedback for children with persisting speech errors is that both the clinician and the child have more information about what the child is doing with the tongue when he or she speaks. Additionally, clinicians can provide more direct and explicit cues to the child, such as “move this front part of your tongue up here,” and the child can readily see if the movement was produced properly. The approach is safe, and the visual display can be motivating for some children.

Among the disadvantages of this approach are the cost of the equipment (an ultrasound probe costs about $5,000) and the need for clinicians to be trained in the approach. Presently, only about a dozen clinics in the world are using ultrasound biofeedback therapy. In general, children younger than 7-8 years are probably not good candidates for this type of therapy because it requires a great deal of focus and is not as “play-based” as some other therapy approaches.The Apraxia Kids-funded study included children who had speech errors that had not resolved by the age of 9 years (Preston et al., 2013). Six children, ages 9-15, participated in the study for 18 therapy sessions. All children had been resistant to traditional treatment methods and were showing limited progress in their school-based speech therapy programs. All of the participants in the study showed improvement in their speech sound accuracy on treated sounds. Specifically, each child achieved 80% accuracy or higher on at least two treatment targets, and some children showed substantial generalization to sound patterns that were untreated.This Apraxia Kids-funded project led to several follow-up studies funded by the National Institutes of Health on the use of ultrasound biofeedback for school-age children with CAS.  Subsequent studies have shown that many children with speech errors associated with CAS can successfully acquire treated speech sounds using ultrasound biofeedback, and many show evidence of generalization to untreated words (Preston, Maas et al., 2016; Preston et al 2017). Because ultrasound biofeedback is currently available in only a few clinics and research facilities, intensive treatment models may be one clinical option (Preston, Leece & Maas, 2016; Preston & Leece, 2017).As with all treatment approaches, not all children necessarily respond equally well to ultrasound visual feedback. Factors such as attention, motivation, and perseverance can affect progress. Further research is needed, and there is presently an ongoing clinical trial testing this approach at Syracuse University (through 2020).

The Bottom Line

The results of studies to date on ultrasound biofeedback are promising, particularly for school-age children who have been in treatment for many years and still have unresolved speech errors due to CAS. The use of ultrasound biofeedback therapy should be considered another tool in the toolbox for treatment of children with persisting speech errors related to CAS.

References:

Preston, J. L., Brick, N., & Landi, N. (2013). Ultrasound biofeedback treatment for persisting childhood apraxia of speech. Am J Speech Lang Pathol, 22(4), 627–643. https://doi.org/10.1044/1058-0360(2013/12-0139)

Preston, J. L., & Leece, M. C. (2017). Intensive treatment for persisting rhotic distortions: A case series. Am J Speech Lang Pathol, 26(4), 1066–1079. [link to full text]

Preston, J. L., Leece, M. C., McNamara, K., & Maas, E. (2017). Variable practice to enhance speech learning in ultrasound biofeedback treatment for childhood apraxia of speech: A single case experimental study. Am J Speech Lang Pathol, 26(3), 840–852. [link to full text]

Preston, J. L., Leece, M. C., & Maas, E. (2016). Intensive treatment with ultrasound visual feedback for speech sound errors in Childhood Apraxia. Frontiers in Human Neuroscience, 10(AUG2016).  [link to full text]

Preston, J. L., Maas, E., Whittle, J., Leece, M. C., & McCabe, P. (2016). Limited acquisition and generalisation of rhotics with ultrasound visual feedback in childhood apraxia. Clin Lin Phon, 30(3–5). [link to full text]

Updated 11-5-19