Frequency, nature, and predictors of alexia in a convenience sample of individuals with chronic aphasia

Background: It is broadly known that persons with chronic aphasia experience difficulty reading. However, the frequency of acquired reading disorders (alexia), and the most common subtype of alexia, as well as predictors of reading in this population are yet to be determined. Aims: This study aims to provide initial evidence regarding the frequency, nature, and predictors of alexia in a large convenience sample of persons with chronic aphasia. Methods & Procedures: Single-word oral reading abilities for lexical items (regular and irregular words) and sublexical items (pseudohomophones and nonwords) from 99 persons with aphasia (PWA) and 29 normal controls (NC) were assessed and retrospectively analysed. Outcomes & Results: Of the 99 PWA, 68% met our alexia criteria. These PWA and coexisting alexia performed worse than the NC on all reading stimuli and tended to perform worse with stimuli requiring sublexical processing (i.e., pseudohomophones and nonwords) than on stimuli requiring lexical processing (i.e., real words). The group of PWA and alexia had a wide range of aphasia types and severities. Less severe aphasia was found to predict higher oral reading performance. Education was not found to be a significant predictor of reading. Conclusions: Our retrospectively analysed results from a convenience sample suggest that reading problems occur frequently among PWA and severity of aphasia influences reading performance. Moreover, our results suggest that acquired reading difficulties after stroke are likely to be characterised by difficulty with sublexical processing. A priori work is needed to provide greater control over participant and stimuli selection to further systematically explore the presence and nature of alexia within chronic aphasia.