A matched assessment/rehabilitation resource to assess functional gains after naming therapy

Background and aims
Word-retrieval difficulty is a common and serious symptom of aphasia. Although improvements after speech and language therapy (“SLT”) are possible, determining their value for both patient and community has proven controversial (Carragher et al., 2012). Studies which show success often assess improvement with materials which are similar to those used in therapy, with little evidence for generalisation (Raymer et al., 2007). Conversely, studies which claim that SLT programmes are unsuccessful often measure gains in terms of general parameters of functional communication with little direct reference to what has been practiced in training (Bowen et al., 2012). To determine the value of SLT we need matched training and assessment resources which strike a balance between: 1. narrow gains linked to the trained context which are of little use for the patient; and 2.overarching gains improving communication across all domains which may be unrealistic. Our study aimed to design and validate such a resource.
Method
Training materials: three sets of functionally useful words (A, B, C), matched for various linguistic variables; N=60 per group: 30 nouns and 30 verbs (180 in total) were used. Each word was coupled with a picture so that it could be practiced in a picture-naming context. Three matched sets of stimuli allowed comparison between different types of therapies.
Matched Assessment material: In addition to picture naming, for each set of words, three pictured scenarios were provided, with each scenario prompting the production of 20 trained words. The scenarios depicted everyday scenes (e.g., a home with different rooms; a garden; a street, a fair etc.) Care was taken to make the target representation in the scenarios as different as possible from that in the pictures used in therapy (e.g., flying a kite vs. an airplane; different types of chairs). Patients were asked to describe they saw in the scenario. Therapy efficiency was measured in terms of target words produced, but also in terms of other functional parameters: mean sentence length, % or meaningful words, rate of speech errors and speech rate.
Materials were validated by administering them to a group of six aphasic participants with moderate-severe naming difficulties who undertook a group-games-based rehabilitation programme, as well as to groups of younger and older controls. Results are presented in Table1.
Results
Control results show the pictured scenarios are successful in eliciting the production of target words. Aphasic results show that therapy gains are evident both when using picture naming and scenario descriptions as assessments. Percentage of meaningful words produced beside the targets also showed a marginal improvement, but not other speech parameters, consistent with gains being specific for word retrieval.
Conclusions
Our results show that therapy for word retrieval difficulties can produce naming improvements beyond the narrow context used in therapy. Gains were seen with different pictorial stimuli but also, more importantly, both in naming individual pictures and a narrative context when production was triggered by appropriate materials. Our study highlights the importance of using carefully designed materials to assess therapy gains.