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23 Cards in this Set
- Front
- Back
How many axons in the ON
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1.2 million
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ON diameter in the fundus and after passing lamina cribrosa
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1mm in fundus, 3mm after passing lamina cribrosa due to myelin addition
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Oligodendroglia begin where
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Lamina cribrosa
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Nerve fiber layer is how thick?
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200 microns
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What is the cause of ON swelling?
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Not true edema b/c not extracellular
usually axoplasmic stasis = dilated axons |
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Ischemic optic neuropathy caused by lesion where?
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post ciliary arteries (off ophthalmic artery ->sup or inf)
have penetrating branches to ON head |
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ON hypoplasia sign
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double ring sign
sclera ring around optic nerve |
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What is the cause of ON hypoplasia
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abnormal pruning
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Inf vf defects in kids caused by what
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ON hypolasia in kids of diabetic mom
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Demorsiers syndrome
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micky-mouse sign - absense of septum pellucidum
must rule out pituitary abnormalities |
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What to rule out in ON hypoplasia
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tumors
Demorsiers syndrome diabetic mom |
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Tilted disc key feature
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associated with pseudobitermporal hemianopias - do not respect vertical
segmental nasal hypoplasia |
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Morning Glory disc anomaly association
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encephaloceles
moyamoya |
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Optic nerve colobomas found where?
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inferiorly
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ON Coloboma/hypoplasia -> rule out what
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basal encephalocele
brain tissue herniating into a sinus |
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Optic disc drusen are what and what does it mimic?
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hilum bodies on optic nerve
mimics papilledema |
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ON drusen association
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Retinitis pigmentosa
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Papilledema implies what
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elevated intracranial pressure, usually bilateral
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Pseudotumor cerebri most common presentation (4)
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headaches
also transient visual obscurations venous-soufle 6th nerve palsy |
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Dandy Criteria for dx of pseudotumor cerebri (3)
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Elevated Intracranial Pressure
Normal Imaging Normal neuro exam |
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Med causes of psuedotumor cerebri (4)
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Vit A
tetracyclines human growth hormone maladixic acid |
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How to monitor Pseudotumor cerebri
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VF testing
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Treatment for pseudotomor cerebri
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weight loss
diamox topamax |