Approaches to the treatment of alexia in chronic aphasia

Background: Reading problems are a common consequence of brain damage, whether as an isolated symptom or part of an aphasic syndrome. Despite the prevalence of acquired alexia, accurate and reliable assessment and treatment strategies have not yet been definitively identified. Furthermore, a growing volume of research has documented generalised cognitive deficits (separate from language-specific deficits) in individuals with acquired disorders of spoken or written language. Little to no data exist regarding whether addressing those deficits (e.g., attention and working memory) might facilitate reading abilities. Aims: The purposes of the current study were to determine the following: (1) Whether a variation of a text-level reading treatment, modified to address comprehension, would have a specific rehabilitative effect with a mildly aphasic and alexic patient. (2) Whether a working memory treatment would generalise to improve the cognitive processes (working memory and attention) necessary for decoding and comprehending high-level text. (3) Which treatment, the specific reading programme or generalised cognitive protocol, would yield a greater positive effect on reading speed and comprehension accuracy. Methods & Procedures: A cognitive neuropsychological analysis of deficit patterns in a subject with acquired alexia was utilised to identify two possible sources of reading difficulty: (1) diminished lexical-semantic abilities for decoding and analysing complex orthographic stimuli, and (2) deficits in attention and working memory. Based on this pre-treatment analysis, two treatment protocols were implemented and compared via a single subject, alternating treatment design. The first was a variation of Multiple Oral Reading (MOR; Beeson, 1998), a text-level reading treatment, and the second was an experimental cognitive treatment, Sequenced Exercises for Working Memory (SEW), created to address cognitive components relevant to reading disorders. Outcomes & Results: Both approaches yielded within-treatment positive effects. Probes indicated improved reading rates with little to no improvement in comprehension. Neither treatment effected greater or more rapid change than the other. Post-treatment testing revealed modest improvements in reading comprehension, processing efficiency, and working memory abilities. Conclusions: Results are discussed in terms of cognitive neuropsychological theories of reading, possible treatment alternatives, and the need for a multi-factorial model of reading, to extend the single-word models postulated by current theories. Without an adequate model, current reading assessments inadequately depict the nature of high-level reading impairments. This allows clinicians limited resources from which to document and treat such deficits.