Journal article
Cortical blindness and residual vision : is the second visual system in humans capable of more than rudimentary visual perception ?
Neurology, Vol.41(6), pp.862-869
1991
DOI: 10.1212/wnl.41.6.862
PMID: 2046931
Abstract
We studied 12 patients with static cortical blindness to evaluate residual vision after destruction of area 17 and to assess the visual capacity of the subcortical "second" visual system in humans. In each case, the cause was bilateral infarction of the occipital lobes. Five patients had total blindness, and four had residual rudimentary vision (RRV), characterized by homonymous areas of light perception in the peripheral field and ability to detect moving objects. Only three patients had the ability to read; two of these had spared macular vision, and the other had spared left homonymous hemimaculae and spared temporal crescent. Neuroimaging and visual evoked potentials (VEPs) correlated with the extent of the visual dysfunction. Total destruction of area 17 bilaterally was associated with total permanent visual loss. The larger the amount of spared visual cortex, the better the vision. Positron emission tomography (PET) or single photon emission computed tomography (SPECT) demonstrated retained metabolic activity in islands of preserved area 17 in patients with some residual vision. VEPs were present in totally blind individuals. We conclude that, in humans, useful visual function is preserved only when a critical amount of area 17 is spared. The subcortical second system may participate in the generation of VEPs, but is incapable of conscious visual perception. © 1991 American Academy of Neurology.
Details
- Title: Subtitle
- Cortical blindness and residual vision : is the second visual system in humans capable of more than rudimentary visual perception ?
- Creators
- G. G Celesia - Loyola University ChicagoD Bushnell - Loyola University ChicagoS. C Toleikis - Loyola univ. Chicago Stritch school medicine, dep. neurology, Chicago IL 60153, United StatesM. G Brigell - Loyola univ. Chicago Stritch school medicine, dep. neurology, Chicago IL 60153, United States
- Resource Type
- Journal article
- Publication Details
- Neurology, Vol.41(6), pp.862-869
- Publisher
- Lippincott Williams & Wilkins
- DOI
- 10.1212/wnl.41.6.862
- PMID
- 2046931
- ISSN
- 0028-3878
- eISSN
- 1526-632X
- Language
- English
- Date published
- 1991
- Academic Unit
- Radiology
- Record Identifier
- 9984318697302771
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