A Randomized Control Trial of Motor-based Intervention for Childhood Apraxia of Speech
Childhood apraxia of speech (CAS) is a complex, multivariate speech motor disorder characterized by difficulty planning and programming movements of the speech articulators (ASHA, 2007; Ayres, 1985; Campbell et al., 2007; Davis et al., 1998; Forrest, 2003; Shriberg et al., 1997). Despite the profound impact that CAS can have on a child's ability to communicate, little data are available to direct treatment in this challenging population. Historically, children with CAS have been treated with articulation and phonologically based approaches with limited effectiveness in improving speech, as shown by very slow treatment progress and poor generalization of skills to new contexts. With the emerging data regarding speech motor deficits in CAS, there is a critical need to test treatments that directly refine speech movements using methods that quantify speech motor control. This research is a Randomized Control Trial designed to examine the outcomes of a non-traditional, motor-based approach, Dynamic Temporal and Tactile Cuing (DTTC), to improve speech production in children with CAS. The overall objectives of this research are (i) to test the efficacy of DTTC in young children with CAS (N=72) 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.
• Diagnosis of childhood apraxia of speech (CAS). Diagnostic classification for CAS will be determined according to the presence of the three core features identified in the ASHA position statement on CAS: 1) inconsistent consonant and vowel errors over productions of repeated trials; 2) difficulties forming accurate movement between sounds and syllables; and 3) prosodic errors (ASHA, 2007). These three characteristics must be present in more than one speaking context (i.e. single words, connected speech, sequencing tasks). In addition to the three core features, children with CAS must demonstrate at least four of the following characteristics: vowel errors, timing errors, phoneme distortions, articulatory groping, impaired volitional oral movement, reduced phonetic inventory and poorer expressive than receptive language skills, which is consistent with the Strand 10-point checklist (Shriberg et al., 2012). We will identify the presence of these factors from the Dynamic Evaluation of Motor Speech Skills (DEMSS, Strand et al., 2013), Verbal Motor Production Assessment for Children (VMPAC, Hayden \& Square, 1999), Goldman Fristoe Test of Articulation (GFTA-3, Goldman \& Fristoe, 2016), and a connected speech sample. We have used these stringent criteria for diagnosing CAS in our past research (Please see the Diagnostic Framework and Criteria for CAS in Grigos and Case (2017)). The diagnosis will be made independently by two speech language pathologists (one being the PI) with expertise in assessing and treating children with CAS.
• Age between 2.5 and 7.11 years of age.
• Normal structure of the oral-peripheral mechanism.
• Participants must pass a hearing screening conducted at 20 dB SPL at 500, 1000, 2000 and 4000 Hz.
• No prior DTTC treatment.