A Comparison of Outcome Measures Following Electropalatography (EPG) Therapy in Children with Down's Syndrome

Abstract

Background Electropalatography (EPG) therapy has shown to remediate speech sound errors that have been intractable through traditional speech therapy. In more recent years, EPG therapy has been explored as an intervention technique for children with Down's syndrome. There are a variety of ways to measure progress following EPG therapy. However, at present, too much reliance is placed on subjective measures to analyse EPG patterns and this does not promote consistency within research addressing the clinical effectiveness of EPG therapy. Aims The principle aim of this project is to compare outcome measures post EPG therapy and identify if a change seen in one outcome measure is also reflected in other outcome measures, and if not then why not? A secondary aim of this project is to explore the possibility of quantifying EPG patterns by developing a classification scheme that provides a set of criteria associated with a target phoneme's idealized articulatory pattern. Methodology Three children with DS were selected from a larger study. Each child received EPG therapy from the school learning assistant with the aim for therapy to be carried out daily in schools over the course of twelve weeks. Each child had an individualized word list which contained phonemes considered most problematic at pre-therapy recordings. The word lists presented target phonemes in word initial and word final position. Four analyses were carried out; a percent consonant correct analysis, an EPG pattern analysis, a property analysis and analysis of intelligibility measures. A classification scheme designed by the author was implemented to enable quantitative results from the EPG pattern analysis. Results from these outcome measures were compared. Results Participants showed variability between different outcome measures and within the results from the same outcome measure, suggesting that the clinical effectiveness of EPG therapy was reflected differently depending on the outcome measure that was used. Intelligibility measures did not provide enough evidence to capture progress about therapy goals and inform intervention. Conclusions This project highlighted questions surrounding the ability of EPG patterns to be quantified and demonstrated how sensitive these patterns can be when analysed in a quantitative manner. The devised classification scheme was binary (tongue palate contact patterns were measured as acceptable or unacceptable) and was therefore unable to measure and recognize incremental change within EPG patterns from pre to post-therapy. Speech and language therapists should give closer consideration to well written therapy goals with carefully designed outcome measures that reflect those therapy goals.