new_n_lost
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A 55 year old woman is driving home from work one evening and makes a left hand turn. She is completely unaware of a car approaching from behind on the left and she causes a minor traffic accident. She is brought to an emergency room. Her history is unremarkable, other than a complaint of chronic headaches.
On physical exam, she is found to have a defect in her peripheral field of vision, but her central field of vision is fine. What would explain a loss of the field of vision on the periphery, but not a loss of the central vision?
a) Pituitary adenoma
b) Embolus from the internal carotid artery
c) Multiple sclerosis
d) Hysteria
e) Chronic alcoholism
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FORUM RULES-- Those who believe in telekinesis, raise my hand. I get enough exercise just by pushing my luck --P4U World.." The pure and simple truth is rarely pure and never simple."
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| tanmaynator
Forum Senior
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a pituitary adenoma..
compression of opic chiasma.. bitemporal hemianopia.. tubular vision..
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| usmle4me
Forum Elite
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A
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| rock
Forum Elite
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A..same reason as tanmaynator.
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| new_n_lost
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___________________
FORUM RULES-- Those who believe in telekinesis, raise my hand. I get enough exercise just by pushing my luck --P4U World.." The pure and simple truth is rarely pure and never simple."
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| new_n_lost
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Posts: 6,058
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Answer a) Pituitary adenoma
A pituitary adenoma pressing on the optic chiasm can result in bitemporal hemianopia; this is a loss of the visual field on both sides in the temporal region. The fibers of the nasal retina cross at the optic chiasm; the nasal retina receives images from the temporal visual field.
A transient ischemic attack of the internal carotid artery (choice b) would present with amaurosis fugax. This is transient blindness in one eye, not a bitemporal hemianopia.
Visual disturbances seen with multiple sclerosis (choice c) are a unilateral loss of vision or a central scotoma, not a bitemporal hemianopia.
Hysteria (choice d) is more likely to present with bilateral constricted visual fields or total blindness.
Chronic alcoholism (choice e) can lead to problems with visual field and central scotomas, but the peripheral field of vision usually is not affected.
Edited by new_n_lost on 03/27/07 - 09:50 AM
___________________
FORUM RULES-- Those who believe in telekinesis, raise my hand. I get enough exercise just by pushing my luck --P4U World.." The pure and simple truth is rarely pure and never simple."
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