cortical blindness

blindness, with normal pupillary responses, that is due to complete destruction of the optic radiations or the striate cortex. Because the subcortical structures (white matter) of the visual system are involved, it is also called cerebral blindness. Typically caused by a stroke affecting the occipital lobe of the brain, cortical blindness can also result from traumatic injury or hypoxia. In children, it is often a consequence of hydrocephalus, meningitis, toxic or hypertensive encephalopathy, trauma, or diffuse demyelinating degenerative disease. Complete loss of vision in a portion of the visual field is called partial cortical blindness.

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Psychology term of the day

May 10th 2024

ether

n. a drug introduced into medicine as a general anesthetic in the mid-1800s. The effects of ether include a progressive series of physical and psychological reactions, beginning with a feeling of suffocation, bodily warmth, visual and auditory aberrations, and a feeling of stiffness and inability to move the limbs. A second stage may be marked by some resistance to the sense of suffocation of the anesthetic, but the muscles relax, blood pressure and pulse increase, and pupils dilate. In the third stage, pulse and blood pressure return to normal, pupils contract, and reflexes are absent. If additional ether is administered beyond the third stage, there is danger of paralysis of the medullary centers, followed by shock and death. In clinical practice, ether has been replaced by safer anesthetics.