Improved status following behavioural intervention in a case of severe dysarthria with stroke aetiology

There is little published intervention outcome literature concerning dysarthria acquired from stroke. Single case studies have the potential to provide more detailed specification and interpretation than is generally possible with larger participant numbers and are thus informative for clinicians who may deal with similar cases. Such research also contributes to the future planning of larger scale investigations. Behavioural intervention is described which was carried out with a man with severe dysarthria following stroke, beginning at seven and ending at nine months after stroke. Pre-intervention stability between five and seven months contrasted with significant improvements post-intervention on listener-rated measures of word and reading intelligibility and communication effectiveness in conversation. A range of speech analyses were undertaken (comprising of rate, pause and intonation characteristics in connected speech and phonetic transcription of single word production), with the aim of identifying components of speech which might explain the listeners’ perceptions of improvement. Pre- and post intervention changes could be detected mainly in parameters related to utterance segmentation and intonation. The basis of improvement in dysarthria following intervention is complex, both in terms of the active therapeutic dimensions and also the specific speech alterations which account for changes to intelligibility and effectiveness. Single case results are not necessarily generalisable to other cases and outcomes may be affected by participant factors and therapeutic variables, which are not readily controllable.