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8 Cards in this Set
- Front
- Back
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What are the tw oextraocular muscles that take their origin from the sheath of the optic nerve?
What condition causes pain during eye movements due to the above fact? |
The superior and medial recti muscles are closely attached to the dural sheath of the optic nerve. This fact may be responsible for the characteristic pain which accompanies extreme eye movements in retro-bulbar neuritis.
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he normal chiasm overlies the __________ and the pituitary, the prefixed chiasm overlies the __________, and the postfixed chiasm overlies the ___________.
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diaphragma sellae
tuberculum sellae dorsum sellae |
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Differentiate between optic neuritis and optic neuropathy
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-Optic neuritis usually presents with ACUTE or subacute visual loss in a patient younger than 50 years and is frequently associated with pain on eye movement. The vision usually improves substantially in optic neuritis with or without steroid treatment.
Compressive optic neuropathy presents as GRADUALLY progressive visual loss, which may not be painful. Vision may improve with steroid treatment only to deteriorate again when steroids are withdrawn. |
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Differentiate adenoma from craniopharyngioma
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pituitary adenomas and craniopharyngiomas differ from each other, as follows: 1) pituitary adenomas are the third most common type of intracranial tumor and represent a significant proportion of brain tumors affecting humans and approximately 80% of sellar lesions, whereas craniopharyngiomas represent only 1 to 3% of intracranial tumors; 2) whereas pituitary adenomas affect mainly adults, the incidence of craniopharyngiomas is bimodal, with peak incidences in children aged 5 to 14 years and again in older adults aged 65 to 74 years. In children, craniopharyngiomas represent 5 to 10% of all tumors and 56% of sellar and suprasellar tumors (7); and 3) pituitary adenomas are thought to originate from cells of the anterior lobe of the pituitary gland, whereas craniopharyngiomas have provoked a lot of discussion regarding their origin and treatment
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What is an apoplexy?
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apoplexy is defined as a sudden neurologic impairment, usually due to a vascular process
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discuss pre, post, and normal chiasm
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see picture
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If the optic chiasm is located more posteriorly over the sella turcica (post-fixed), it causes a pituitary tumour to compress the __________.
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optic nerve
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When a pituitary tumour enlarges upwards in pre- and post-fixed optic chiasms, aj_____________ tpye vision loss would be expected to form
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junctional scotoma
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