Transcranial direct current stimulation with multiple oral re-reading therapy for pure alexia without agraphia: a case report.

Pure alexia without agraphia is characterized by impaired reading due to damage to the occipitotemporal cortex with preserved writing skills. In this case report, we investigate the effect of multiple oral re-reading (MOR) therapy adjunct with transcranial direct current stimulation (tDCS) in improving reading recovery of a 64-year-old patient with pure alexia without agraphia following a stroke. His MRI revealed an area of infarct with microhemorrhages at the left occipitotemporal region. The patient was blinded to each therapy and underwent seven consecutive sessions of sham tDCS followed by seven consecutive sessions of real tDCS, coupled with 1-hour MOR therapy during each session. Western Aphasia Battery (WAB) was performed at baseline, before sham and real-tDCS, and 6 weeks after completing tDCS therapy. The patient showed improvement using both sham and real-tDCS with better reading comprehension, average reading time, and word per minute after real-tDCS. This study suggests that MOR, coupled with tDCS therapy may accelerate the reading recovery in patients with pure alexia.

On compensatory strategies and computational models: the case of pure alexia.

The article is concerned with inferences from the behaviour of neurological patients to models of normal function. It takes the letter-by-letter reading strategy common in pure alexic patients as an example of the methodological problems involved in making such inferences that compensatory strategies produce. The evidence is discussed on the possible use of three ways the letter-by-letter reading process might operate: "reversed spelling"; the use of the phonological input buffer as a temporary holding store during word building; and the use of serial input to the visual word-form system entirely within the visual-orthographic domain such as in the model of Plaut [1999. A connectionist approach to word reading and acquired dyslexia: Extension to sequential processing. Cognitive Science, 23, 543-568]. The compensatory strategy used by, at least, one pure alexic patient does not fit with the third of these possibilities. On the more general question, it is argued that even if compensatory strategies are being used, the behaviour of neurological patients can be useful for the development and assessment of first-generation information-processing models of normal function, but they are not likely to be useful for the development and assessment of second-generation computational models.

Reading therapy strengthens top-down connectivity in patients with pure alexia.

This study tested the efficacy of audio-visual reading training in nine patients with pure alexia, an acquired reading disorder caused by damage to the left ventral occipitotemporal cortex. As well as testing the therapy's impact on reading speed, we investigated the functional reorganization underlying therapy-induced behavioural changes using magnetoencephalography. Reading ability was tested twice before training (t1 and t2) and twice after completion of the 6-week training period (t3 and t4). At t3 there was a significant improvement in word reading speed and reduction of the word length effect for trained words only. Magnetoencephalography at t3 demonstrated significant differences in reading network connectivity for trained and untrained words. The training effects were supported by increased bidirectional connectivity between the left occipital and ventral occipitotemporal perilesional cortex, and increased feedback connectivity from the left inferior frontal gyrus. Conversely, connection strengths between right hemisphere regions became weaker after training.

Treatment for Alexia With Agraphia Following Left Ventral Occipito-Temporal Damage: Strengthening Orthographic Representations Common to Reading and Spelling.

PURPOSE: Damage to left ventral occipito-temporal cortex can give rise to written language impairment characterized by pure alexia/letter-by-letter (LBL) reading, as well as surface alexia and agraphia. The purpose of this study was to examine the therapeutic effects of a combined treatment approach to address concurrent LBL reading with surface alexia/agraphia. METHOD: Simultaneous treatment to address slow reading and errorful spelling was administered to 3 individuals with reading and spelling impairments after left ventral occipito-temporal damage due to posterior cerebral artery stroke. Single-word reading/spelling accuracy, reading latencies, and text reading were monitored as outcome measures for the combined effects of multiple oral re-reading treatment and interactive spelling treatment. RESULTS: After treatment, participants demonstrated faster and more accurate single-word reading and improved text-reading rates. Spelling accuracy also improved, particularly for untrained irregular words, demonstrating generalization of the trained interactive spelling strategy. CONCLUSION: This case series characterizes concomitant LBL with surface alexia/agraphia and demonstrates a successful treatment approach to address both the reading and spelling impairment.