The Impact of Individual-Level Factors on Progress in Speech Therapy for Children with Childhood Apraxia of Speech (CAS)

Abstract

Childhood apraxia of speech (CAS) is a motor-based disorder that often results in long-term communication challenges, as well as adverse academic and psychosocial consequences. Response to CAS treatment is variable, with some children achieving slow or limited progress. A better understanding of factors associated with treatment response is needed to generate accurate prognoses and guide future development of efficient, targeted treatments. This dissertation research includes two studies. Study 1 examined speech perception skills among children with CAS using a discrimination (AX) task and a mispronunciation detection (MPD) task. Study 2 examined the association between four individual-level characteristics—age, speech accuracy, inconsistency, and perception—and CAS treatment response. Participants included 27 children (Study 2; subset of 12 children for Study 1) involved in an ongoing clinical trial for CAS (i.e., the “parent trial;” ClinicalTrials.gov ID = NCT03903120). Research questions were addressed using nonparametric correlation and t-tests, as well as multivariable linear regression. Results from Study 1 indicated that speech perception ability (1) did not differ by task, (2) did not differ by consonant and vowel conditions, (3) was positively correlated with age and speech accuracy, and negatively associated with speech inconsistency and nonverbal cognition, and (4) did not change after integral stimulation treatment. Results from Study 2 indicated that speech perception ability was the sole significant predictor of CAS treatment response, such that children with better perceptual skills at baseline made greater treatment gains. Further research is needed to replicate and extend these findings.