J. Zihl, U. Schiefer and J. Schiller
The fifth Marquis of Salisbury - briefly a prime minister of Great Britain - noticed at a court ceremony a young man who gave him a friendly smile. "Who is this young man?" he whispered to his neighbor. "Your eldest son!" answered the latter . . . Lord David Cecil: Description of a Prosopagnosia; Damasio et al., in: Oliver Sacks: The Man Who Mistook His Wife for a Hat
A central disturbance of vision should be suspected when an ophthalmic examination finds normal visual acuity and normal appearing anterior and posterior segments in both eyes, in the setting of a plausible complaint of difficulty with recognition of visual images. The human visual system does not terminate at the primary visual cortex. On the contrary, central processing of images begins at the striate cortex. Given the well-vascularized tissue of the poststriate visual cortex, damage to vision in these regions is compar atively uncommon (found in approximately 2% of cases of posterior brain disease) and is often transient, managing to recover within a few weeks following onset. It is all the more important to recognize the significance of transient loss of central visual function, as it often occurs as an ischemic prodrome of subsequent permanent infarction with irreversible loss of visual perception. In contradistinction to most disturbances of the posterior visual pathways, in which there is a deficit of vision, central disturbances are
j \ Occipital I lobe
Temporal lobe j \ Occipital I lobe
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