Dynamic Temporal and Tactile Cueing in Young Children With Childhood Apraxia of Speech: A Multiple Single-Case Design.

PURPOSE: Childhood apraxia of speech (CAS) is a multivariate motor speech disorder that requires a motor-based intervention approach. There is limited treatment research on young children with CAS, reflecting a critical gap in the literature given that features of CAS are often in full expression early in development. Dynamic Temporal and Tactile Cueing (DTTC) is a treatment approach designed for children with severe CAS, yet the use of DTTC with children younger than 3 years of age has not been examined. METHOD: A multiple single-case design was employed to examine the use of DTTC in seven children with CAS (aged 2.5-5 years) over the course of 6 weeks of intervention. Changes in word accuracy were measured in treated words from baseline to posttreatment and from baseline to maintenance (6 weeks posttreatment). Generalization of word accuracy changes to matched untreated words was also examined. A linear mixed-effects model was used to estimate the change in word accuracy for treated and untreated words across all children from baseline to posttreatment and to maintenance. A quasi-Poisson regression model was used to estimate mean change and calculate effect sizes for treated and untreated words. RESULTS: Group-level analyses revealed significant changes in word accuracy for treated and untreated words at posttreatment and maintenance. At the child level, six of seven children displayed medium-to-large effect sizes where word accuracy increased in an average of 3.4/5 words across all children. Each child displayed some degree of generalization to untreated targets, specifically for words with the same syllable shape as the treated words. CONCLUSIONS: These results demonstrate that DTTC can yield positive change in some young children with CAS. Key differences in each child's performance are highlighted.

Dynamic Temporal and Tactile Cueing: Quantifying Speech Motor Changes and Individual Factors That Contribute to Treatment Gains in Childhood Apraxia of Speech.

PURPOSE: Speech motor skill is refined over the course of practice, which is commonly reflected by increased accuracy and consistency. This research examined the relationship between auditory-perceptual ratings of word accuracy and measures of speech motor timing and variability at pre- and posttreatment in children with childhood apraxia of speech (CAS). Furthermore, the degree to which individual patterns of baseline probe word accuracy, receptive language, and cognition predicted response to treatment was explored. METHOD: Probe data were collected from seven children with CAS (aged 2;5-5;0 [years;months]) who received 6 weeks of Dynamic Temporal and Tactile Cueing (DTTC) treatment. Using a multidimensional approach to measuring speech performance, auditory-perceptual (whole-word accuracy), acoustic (whole-word duration), and kinematic (jaw movement variability) analyses were conducted on probe words produced pre- and posttreatment. Standardized tests of receptive language and cognition were administered pretreatment. RESULTS: There was a negative relationship between auditory-perceptual measures of word accuracy and movement variability. Higher word accuracy was associated with lower jaw movement variability following intervention. There was a strong relationship between word accuracy and word duration at baseline, which became less robust posttreatment. Furthermore, baseline word accuracy was the only child-specific factor to predict response to DTTC treatment. CONCLUSIONS: Following a period of motor-based intervention, children with CAS appeared to refine speech motor control in conjunction with improvements in word accuracy. Those who demonstrated the poorest performance at treatment onset displayed the greatest degree of gains. Taken together, these results reflect a system-wide change following motor-based intervention.