Alexia With and Without Agraphia: An Assessment of Two Classical Syndromes

Abstract

Alexia is traditionally classified according to the site of anatomic damage and to the presence or absence of deficits in writing and oral language.1 Alexia without agraphia ('pure alexia') is associated with left occipital damage 1-3 while alexia with agraphia is associated with lesions of the left angular gyrus, and often accompanied by other left parietal signs, such as apraxia, anomia, and Gerstmann's syndrome. 4 More recent studies have used linguistic and cognitive approaches to categorize alexia within a hierarchy of processing steps. 1,5,6 Peripheral alexias refer to 'sub-lexical' impairments in perceptual processing of letters and word-forms: reduced ABSTRACT: Background: Current cognitive models propose that multiple processes are involved in reading and writing. Objective: Our goal was to use linguistic analyses to clarify the cognitive dysfunction behind two classic alexic syndromes. Methods: We report four experiments on two patients, one with alexia without agraphia following occipitotemporal lesions, and one with alexia with agraphia from a left angular gyral lesion. Results: The patient with occipital lesions had trouble discriminating real letters from foils and his reading varied with word-length but not with linguistic variables such as part of speech, word frequency or imageability. He read pseudo-words and words with regular spelling better, indicating preserved use of grapheme-to-phoneme pronunciation rules. His writing showed errors that reflected reliance on 'phoneme-to-grapheme' spelling rules. In contrast, the patient with a left angular gyral lesion showed better recognition of letters, words and their meanings. His reading was better for words with high imageability but displayed semantic errors and an inability to use 'grapheme-to-phoneme' rules, features consistent with deep dyslexia. His agraphia showed impaired access to both an internal lexicon and 'phoneme-to-grapheme' rules. Conclusion: Some cases of pure alexia may be a perceptual word-form agnosia, with loss of internal representations of letters and words, while the angular gyral syndrome of alexia with agraphia is a linguistic deep dyslexia. The presence or absence of agraphia does not always distinguish between the two; rather, writing can mirror the reading deficits, being more obvious and profound in the case of an angular gyral syndrome.RÉSUMÉ: Alexie avec et sans agraphie : revue de deux syndromes classiques. Contexte : Selon les modèles cognitifs actuels, plusieurs processus sont impliqués dans la lecture et l'écriture. Objectif : Notre but était d'utiliser l'analyse linguistique pour clarifier la dysfonction cognitive sous-jacente à deux syndromes alexiques classiques. Méthodes : Nous rapportons quatre expériences effectuées chez deux patients, dont l'un présentait une alexie sans agraphie suite à des lésions occipitotemporales et l'autre une alexie avec agraphie suite à une lésion gyrale angulaire gauche. Résultats : Le patient porteur de lésions occipitales avait de la difficulté à distinguer de vraies lettres de s...

Association of dorsal inferior frontooccipital fasciculus fibers in the deep parietal lobe with both reading and writing processes: a brain mapping study

“…1,2,9,10,33,40 These findings imply that lesions resulting in alexia with agraphia may be related to damage in common subcortical pathways necessary for reading and writing, including cerebral white matter tracts.…”

Case report: An approach to the patient with reading difficulties in the primary care setting

“…A disconnection optic ataxia has also been documented, where the patient was unable to visually control the right arm in the left visual field (Damasio & Damasio, 1983). Difficulty spelling, either orally (Newcombe, Marshall, Carrivick, & Hiorns, 1974) or written (Beeson, Magloire, & Robey, 2005;Sheldon, Malcolm, & Barton, 2008), has been observed with errors evolving with time from phonologically implausible misspellings to more plausible phoneme-grapheme conversion errors akin to the spelling patterns of children learning to read and write.…”

The Aspect of Neurocognitive and Rehabilitation on Alexia Without Agraphia Case

“…An examination for the capability of writing is possibly done through the reading test as well as by giving the patient to write down words that are read aloud. There is no time restriction for the patient; furthermore, there will be an evaluation of the results in the area of addition, transposition, substitution, and phonology [13].…”