This article reports data regarding the efficacy of treatment for four young children with severe childhood apraxia of speech (CAS). A single subject, multiple baseline design across behaviors was used for experimental control and replicated over the four children. Baseline, probe and maintenance data were continuously collected. A treatment approach based on integral stimulation, dynamic temporal and tactile cueing (DTTC), was used. The article includes a rationale for the treatment approach based on several principles of motor learning, a description of how treatment was implemented, and a summary of the data showing responses to treatment. Three of the four children exhibited rapid change following the implementation of treatment. The degree of performance change was greater than that for control probes, and improvement was maintained for all utterances, although performance was variable. This study shows that frequent treatment, incorporating the principles of motor learning, may facilitate the treatment of severe developmental speech disorders that are accompanied by motor impairment.
Researchers and clinicians face innumerable challenges in the management of children with severe speech disorders, including demonstrating the efficacy of treatment provided. Pressure from third-party payers to establish the efficacy and effectiveness of treatments, as well as a need to engage in ethical clinical practice necessitates being accountable for treatment effects (Robey & Shultz, 1998). The important recent attention to evidence-based practice (Dollaghan, 2004; Robey, 2004; Ylvisaker et al., 2002) also calls for more treatment efficacy research. Such reports are rare, especially in the area of motor speech disorders in children and particularly in the area of childhood apraxia of speech (CAS).
CAS is a motor speech disorder caused by difficulty with planning and programming movement gestures for speech production (Caruso & Strand, 1999; Davis, Jakielski, & Marquardt, 1998). Although there are controversies regarding specific behavioral markers (Davis et al., 1998; Forrest, 2003; McCabe, Rosenthal, & McLeod, 1998), several characteristics are generally agreed to be discriminative for the disorder including difficulty with reaching and maintaining articulatory configurations, difficulty with smooth transitions from one configuration to another, vowel distortions, prosodic errors, and inconsistency of error patterns upon nonspeeded word repetition (Davis et al., 1998; Maassen, 2002; McNeil, 2002; Shriberg, Aram, & Kwiatkowski, 1997; Strand, 2002). There are numerous reports that children with CAS require intensive treatment (Davis & Velleman, 2000; Strand, 1995; Strand & Skinder, 1999), yet there is little empirical data regarding its outcome.
Parents of children who are essentially nonverbal due to severe apraxia of speech often ask about the prognosis for verbal communication. Currently there are no data to show whether intensive treatment, focused on improving motor skill for speech, may facilitate early speech acquisition in children who have not benefited from other more traditional forms of articulation treatment. This article reports data regarding the efficacy of intensive treatment for four young children with severe apraxia of speech, using dynamic temporal and tactile cueing (DTTC) for Speech Motor Learning. This treatment approach has been developed by the first author over a number of years. It has been described (Strand &...