title: Alexia with and without agraphia: an assessment of two classical syndromes.
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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Medicine (Neurology), University of British Columbia, Vancouver, BC, Canada.
authors.forename: Claire A
authors.initials: CA
authors.lastname: Sheldon
authors.forename: George L
authors.initials: GL
authors.lastname: Malcolm
authors.forename: Jason J S
authors.initials: JJ
authors.lastname: Barton
mesh_terms: D000368:Aged; D000381:Agraphia / Q000209:etiology / Q000473:pathology* / Q000503:physiopathology; D020237:Alexia, Pure / Q000209:etiology / Q000473:pathology* / Q000503:physiopathology; D020520:Brain Infarction / Q000150:complications / Q000473:pathology* / Q000503:physiopathology; D002540:Cerebral Cortex / Q000098:blood supply / Q000473:pathology* / Q000503:physiopathology; D003937:Diagnosis, Differential; D004185:Disability Evaluation; D006801:Humans; D007807:Language Tests; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010296:Parietal Lobe / Q000098:blood supply / Q000473:pathology / Q000503:physiopathology; D010364:Pattern Recognition, Visual / Q000502:physiology; D010700:Phonetics; D011932:Reading; D012660:Semantics; D012720:Severity of Illness Index; D013060:Speech / Q000502:physiology; D014057:Tomography, X-Ray Computed