Measuring treatment outcome in severe Wernicke’s aphasia

Abstract

ABSTRACT Background Chronic severe Wernicke’s aphasia has a poor prognosis and is challenging to treat. Furthermore, even when there is potential for improvement, formal assessments using accuracy scores only to measure changes in language abilities after treatment may not be sensitive enough to capture improvements. Less-constrained language tasks, such as discourse analysis, may be more sensitive to measuring change than more standard constrained tasks, such as confrontation naming and picture-based sentence construction. Aims In this study, we asked whether it is possible to rehabilitate language abilities in a participant with severe Wernicke’s aphasia using a verb-based sentence-level treatment (Verb Network Strengthening Treatment – VNeST) that has been successful for moderate Wernicke’s aphasia, as well as other types of moderate to severe aphasia. Furthermore, we investigated whether using less-constrained language tasks would be more, less or equally sensitive to measuring any treatment effects than more-constrained language tasks. Methods and procedures In this case study, we compared post-treatment language abilities to pre-treatment language abilities by analysing comprehension and production at the word, sentence and discourse levels, using both quantitative analyses (e.g., accuracy scores) and qualitative analyses (e.g., error analyses). Outcomes and results We found that discourse analysis was sensitive enough to identify improvements in quality of production concomitant with an overall reduction of output. Furthermore, in certain more-constrained tasks, a reduction in the production of neologistic jargon was observed, as well as stable comprehension requiring less repetition of stimuli, indicating improvement that was not captured by accuracy scores. Conclusions People with chronic severe Wernicke’s aphasia may improve after treatment but formal assessments are not always sensitive enough to identify these improvements. Speech-language therapists are encouraged to include discourse analysis in their assessments as well as the analysis of more formal assessments qualitatively as well as quantitatively.