CAS is a complex, multivariate speech motor disorder characterized by difficulty planning and programming movements of the speech articulators. Despite the profound impact that CAS can have on a child?s ability to communicate, there is a paucity of treatment research involving this population. The planned research is a Phase II Randomized Control Trial designed to examine the outcomes of Dynamic Temporal and Tactile Cuing (DTTC), a dynamic, multimodal approach to improving speech production, in children with childhood apraxia of speech (CAS). The long-term goal is to provide evidence based guidelines for treatment in children with CAS. The overall objectives of this application, which will be the largest randomized control trial on CAS to date, are (i) to test the efficacy of DTTC in 72 young children with CAS by examining the impact of DTTC on treated words, generalization to untreated words and post-treatment maintenance, and (ii) to examine how individual patterns of speech motor variability impact response to DTTC. The central hypothesis is that DTTC will refine speech motor control and lead to longstanding change in speech production accuracy. The rationale for this work is that research on the efficacy of DTTC will provide a strong scientific foundation for future treatment research on CAS whereby Phase III studies can be conducted. It will also enhance our theoretical understanding of speech motor learning in this underserved population. The central hypothesis will be tested by pursuing three specific aims: 1) Quantify the effects of DTTC on improved speech production (perceptual ratings) in treated words that are maintained post-treatment and generalized to untreated words in children with CAS; 2) Quantify the effects of DTTC on refined speech motor control (kinematic/acoustic measures) in treated words that are maintained post-treatment and generalized to untreated words in children with CAS; and 3) Characterize the effects of speech motor variability (within-subject) at baseline as a predictor of DTTC efficacy in children with CAS.
The first aim will be studied by documenting the accuracy and intelligibility of treated words, maintenance post-treatment and generalization to untreated words.
The second aim will be studied by measuring the duration and variability of treated words, maintenance post-treatment and generalization to untreated words.
For aim three, measures of speech motor variability at baseline will be compared to word accuracy and intelligibility post-treatment. The proposed work is innovative, as it will study the efficacy of a motor-based treatment for CAS (DTTC) in a large sample of young children, use objective measures (kinematic & acoustic) to support evidence-based decision-making and provide new evidence about participant factors that predict response to treatment. These contributions will be significant because they are expected to have a substantial impact on clinical practice by provide strong scientific justification for continued motor based treatment research for children with CAS. There is important
