| Abstract: |
BACKGROUND: Acquired apraxia of a speech (AOS) is a commonly encountered word production deficit following stroke. The efficacy of treatments for AOS is the subject of several recent studies. Evidence is mounting that verbal-based treatment methods result in improved production of treated phonemes in trained contexts (Schneider and Frens, 2005; Wambaugh et al., 1998; Wambaugh and Martinez, 2000; Wambaugh et al., 1999; Wambaugh and Nessler, 2004). Alternatively, arm and hand gestures have previously been suggested as a possible useful treatment method/modality for AOS (Rao, 2001; Skelly et al., 1974; Wertz et al., 1984), and multi-modality treatments are often considered more efficacious than single-modality treatments, but there is minimal empirical evidence to support these suggestions. Speech-language pathologists have little evidence on which to base their choice of gesture or verbal treatment methods. Such evidence is vital for ensuring treatment efficiency in clinical environments where total treatment times are reducing. AIMS: This study aimed to investigate the relative efficacy of gesture, verbal, and combined verbal plus gesture treatments for a patient with chronic moderate acquired apraxia of speech. METHODS AND PROCEDURES: AS, a 52-year-old male, participated in the study. AS sustained a single left fronto-temporal stroke 60 months prior to the study, which resulted in Broca's aphasia and a moderate apraxia of speech. AS participated in a controlled multiple-baseline single-case experiment comparing the efficacy of the three treatments for the production of multi-syllable words and words containing double and triple consonant clusters. OUTCOMES AND RESULTS: Large, statistically significant, and clinically relevant treatment effects were found for all three treatment conditions and there were no significant differences between conditions. Improvements made in word production were maintained at both the 1-month and 3-month follow-up assessments. Generalisation of enhanced word production was found for trained sounds and clusters to untreated words and to conversation. CONCLUSIONS: The results caution clinicians to question the superiority of multi-modal treatments for acquired apraxia of speech. Consistent with our previous work (Rose and Douglas, 2001, in press; Rose et al., 2002), it is suggested that the underlying treatment strategy in this case, knowledge about phoneme place and manner of production, is a more potent factor in treatment outcome than the modality (gesture versus verbal) in which the strategy is presented. The suggestions recently made in the AOS literature to incorporate multiple sound targets in a session, blocked versus random order of practice, and complex stimuli all gained support from results of the current study. |
