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56 Cards in this Set
- Front
- Back
Optic nerve lesion causes what kind of defect and why?
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arcuate due to horizontal raphe
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What types of lesion does not respect horizontal or vertical
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Retinal lesions
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Top part of visual field ends up where in the calcrine cortex
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bottom half
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What types of lesions cause incongruity
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optic tracts
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Temporal lobe causes what type of visual field defects
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pie in the sky
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What is the center of visual field defects in the brain?
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fovea, not the optic nerve
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Where in the visual field is the blindspot?
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temporal visual field
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Goldmann visual fields are based on what units
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isopters
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What vf testing is kinetic?
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Goldmann
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What units are used in static perimetry
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decibles, foveal threshold is in 30's
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What is the mean deviation on the visual field? What disease is it used for?
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a weighted average, good for monitoring for pseudotumor cerebri
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Altitudinal vf defect see in what disease?
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Ischemic optic neuropathy
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Mitochondrial optic neuropathy causes what type of vf defect
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Centrosecal
central scotoma central think B12 and toxic optic neuropathies too |
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Wilbrands knee carries what fibers
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Inf nasal fibers from contralateral eye visiting the optic nerve and then back to the optic tract. Left eye fibers go to right occipital lobe. Junction of optic nerve and chiasm.
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T/F Vertical projecting vf defect can come from the orbit or eyeball.
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False
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Where do nasal and temp fibers begin to segregate?
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In the ON just prior to the chiasm.
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How far is the ON above pituitary
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1mm above
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Postfixed chiasm a sellar lesion can cause what defect?
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Affect both optic nerves
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Chiasmal defect at junction with ON causes what defect?
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Junctional scotoma - optic neuropathy on same side as lesion and a vf defect sup temp in the other eye.
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Pressing on the chiasm from below causes what vf defect?
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bitemp hemianopia
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Bottom of chiasm corresponds to what part of the visual field
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top part
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craniopharyngiomas cause visual field dects by what mechanism and what does the defect look like.
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Craniopharyngioma pushes down on the chiasm and cause inf bitemp defects.
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Where do macular fibers cross?
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posterior chiasm
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Temp VF defect -> must rule out what?
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Chiasmal lesion, unilateral or bilateral temp defects
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Kids and young adults get chiasmal syndrome due to what?
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craniopharyngioma
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Middle aged people get chiasmal syndromes due to what?
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meningioma
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Younger adults get chiasmal defects due to what?
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Pituitary adenoma - most common cause of all chiasmal defects
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Old people get chiasmal defects due to what?
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Aneurysms
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Young children get chiasmal defects due to what 2 things?
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Gliomas
Disgerminomas |
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Chiasmal lesions can cause what strange entity?
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post fixation blindness - must have complete temp hemianopia
can't see what they focus on at near |
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Visual field defects in both eyes must be caused by lesions where?
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Postchiasmal.
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Sectorenopias caused by lesion where
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LGB
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Optic tract syndrome features 3
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Triad of:
incongruent hemianopia bow-tie atrophy contralateral APD |
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What are the two vascular patterns of the LGB?
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Hilum=post choroidal artery=pie cut out
medial and lateral horn=ant choroidal artery=spare a pie |
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Meyers service what part of the visual field
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sup-temp
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Parietal lobe lesion causes what type of movement problem
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optokinetic nystagmus b/c pursuit movements start in the parietal lobe
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Occipital lobe most anterior part corresponds to what part of the visual field
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most peripheral field
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Macula uses up what % of the occipital lobe?
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60% of the lobe
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Macular sparing is caused by supply from what
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Middle cerebral artery
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Hemianopic scotoma is caused by a lesion where
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occipital lobe
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Monocular temp crecent is where in the occipital lobe
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contralateral occipital lobe
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Quadrantanopia implies lesion where
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occipital lobe only b/c calcrine fissure separates upper and lower field
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What test is used to assess for temporal crecent
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Goldmann
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Meridional sparing or involvement is caused by lesions where
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occipital lobe lesion along the calcrine cortex base vs. lips
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B/L occipital infarcts can be confused with
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Ischemic optic neuropathy
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What is the most commonly encountered higher cortical dysfunction?
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simultagnosia, b/l parietal lobe lesions
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Who gets simultagnosia
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parkinson's
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Gertsmann's Syndrome
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Simultagnosia
posagnosia |
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Balant syndrome
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Bilateral parieto-occipital lobe lesions
optic apraxia (can't initiate eye movements) optic ataxia |
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Cerebral achromatopsia has what features
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Blind quadrant superiorly
inf visual field does not percieve color lingual or fusiform gyrus |
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Alexia without agraphia, lesion where?
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Lesion in the left occipital lobe but not angular gyrus and involves splenium of corpus collosum which brings info from right occipital lobe.
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Alexia with agraphia lesion where?
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Left angular gyrus (left occipital lobe)
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Where in the brain is the reading center?
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Left anglular gyrus
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Movement or sound induced phosphenes are caused by what?
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optic neuritis
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Charles-Bennet syndrome is what?
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released hallucinations
formed or unformed in pts with decrased vision like macular degeneration |
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Lesions where cause formed hallucinations?
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Temporal lobe
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