Revision of Alexia series of articles

Main Alexia (condition) article

edit
WikiProject Dyslexia/Alexia reorganization

Alexia (from the Greek , privative, expressing negation, and λέξις = "word") is a type of aphasia[1] where damage to the brain causes a patient to lose the ability to read.[2] It is also called word blindness, text blindness or visual aphasia.[3]

Those who suffer from "alexia" and "dyslexia" can have similar difficulties, however, "alexia" refers to an acquired reading disability, where reading ability had previously been developed, usually occurring in adulthood conditions, while "dyslexia" refers to developmental reading disability.[4][5]

Classification

edit

There are two groups of alexia.

  • The first or main group is "the central dyslexia" group which includes surface dyslexia, phonological dyslexia, and deep dyslexia.[6][7]
  • The second group, "the peripheral dyslexia" group, includes neglect dyslexia, attentional dyslexia, and pure alexia which is also known as alexia without agraphia.[7]

Causes

edit

Alexia typically occurs following damage to the left hemisphere of the brain or to the areas of the occipital and parietal lobes, which are responsible for processing auditory, phonological and visual aspects of language. The region at the junction of occipital and temporal lobes (sometimes called the occipito-temporal junction) coordinates information that is gathered from visual and auditory processing and assigns meaning to the stimulus. Alexia can also occur following damage to the inferior frontal. Damage to these different areas of the cortex result in somewhat different patterns of difficulty in affected individuals.[citation needed] In some cases, a stroke can cause alexia.[2][8]

Presentation

edit

Alexia may be accompanied by expressive and/or receptive aphasia (the inability to produce or comprehend spoken language). Alexia can also co-occur with agraphia, the specific loss of the ability to produce written language even when other manual motor abilities are intact. In other cases, damage is restricted to areas responsible for input processing. The result is known as pure alexia. In this scenario, an individual's ability to produce written language is spared even though they are unable to understand written text.

Alexia without agraphia results from a left occipital splenium of the corpus callosum lesion.

See also

edit

References

edit
  1. ^ "alexia" at Dorland's Medical Dictionary
  2. ^ a b Damasio, Antonio R. (1977). "Varieties and Significance of the Alexias". Archieves of Neurology. 34 (6): 325–326. Retrieved 2010-07-08.
  3. ^ http://medical-dictionary.thefreedictionary.com/visual+aphasia American Heritage® Medical Dictionary
  4. ^ Elisabeth Ahlsén (2006). Introduction to neurolinguistics. John Benjamins Publishing Company. pp. 115–. ISBN 9789027232335. Retrieved 28 June 2010.
  5. ^ Leff AP, Crewes H, Plant GT, Scott SK, Kennard C, Wise RJ (March 2001). "The functional anatomy of single-word reading in patients with hemianopic and pure alexia". Brain. 124 (Pt 3): 510–21. doi:10.1093/brain/124.3.510. PMID 11222451.
  6. ^ Harley, Trevor A. (2001). The psychology of language: from data to theory. Taylor & Francis. ISBN 978-0863778674.
  7. ^ a b Coslett HB (2000). "Acquired dyslexia". Semin Neurol. 20 (4): 419–26. doi:10.1055/s-2000-13174. PMID 11149697.
  8. ^ Sacks, Oliver (June 28, 2010). "A Man of Letters". The New Yorker. 86 (18). New York, New York: Condé Nast Publications: 22–28. ISSN 0028-792X.


Alexia article series of sub-pages

edit
Existing Articles
Articles to be Created
  • Neuroanatomical Alexias
    • Alexia with Agraphia (Central Alexia)
    • Frontal Alexia
    • Spatial Alexia
  • Psycholinguistic models of reading
  • Psycholinguistic - Central Alexias (with an aphasia)
    • Phonological dyslexia (alexia)
    • Surface dyslexia (alexia)
  • Psycholinguistic - Peripheral Alexias
    • Neglect Alexia
    • Attentional Alexia (this category may be using a different label)