Diagnosing residual aphasia using spontaneous speech analysis

Abstract

Background: It is well known that about 20% of patients with anomic aphasia still show residual aphasic symptoms 1 year post onset. As we do not have any tests to reliably diagnose residual aphasia it is difficult to decide whether these persisting problems are signs of residual aphasia that have to be treated, or are indications of a normal variability in language use, which also may occur in elderly people. Aims: The main aim of this research is to find out whether there are variables in spontaneous communication of persons with residual aphasia (P-RA) that enable us to distinguish them from persons without aphasia (P-NA). Methods & Procedures: Following a detailed linguistic analysis of spontaneous speech we employed binary logistic regression analysis to find the most relevant variables for differentiation between P-RA (N = 41) and P-NA (N = 25). Outcomes & Results: Significant group differences at different processing levels could be observed. Lexically varied, informative, and cohesively tied phrases in particular pose the main problem for P-RA. Regression analysis including variables of spontaneous communication explains 82.5% (R2) of the variation and correctly identifies 39 of 41 (95.1%) cases of P-RA and 21 of 25 (84.0%) cases of P-NA. Conclusions: Analysing spontaneous communication seems to be a promising possibility for diagnosing residual aphasia. The importance of spontaneous communication in everyday interaction, and its sensitivity to even slight deficits in language processing, promote the described analysis as a very useful screening instrument to distinguish P-RA from P-NA.