chiasmal


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chi·as·ma

 (kī-ăz′mə) also chi·asm (kī′ăz′əm)
n. pl. chi·as·ma·ta (-mə-tə) or chi·as·mas also chi·asms
1. Anatomy A crossing or intersection of two tracts, as of nerves or ligaments.
2. Genetics The point of contact between paired chromatids during meiosis, resulting in a cross-shaped configuration and representing the cytological manifestation of crossing over.

[Greek khīasma, cross-piece, from khīazein, to mark with an X, from khei, khī, chi (from the letter's shape).]

chi·as′mal, chi·as′mic, chi′as·mat′ic (-măt′ĭk) adj.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Adj.1.chiasmal - of or relating to a chiasm
anatomy, general anatomy - the branch of morphology that deals with the structure of animals
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MRI confirmed tumor progression in sphenoid and ethmoid sinuses, both cavernous sinuses, with infiltration of the sellar wall, clivus, and chiasmal compression (Figure 1(b)).
Therefore, every case with a mild and transient VA improvement, or with a lack of response to systemic corticosteroid therapy, must be regarded as a warning sign of compressive lesion of optic nerve or chiasmal region, and it should warrant a proper and prompt neuroimaging diagnostics (MRI or CT head scans).
Pituitary tumors which were only more than 10mm in height could only cause chiasmal compression.
(5-8) Neurologic causes include injury to the optic nerve itself (normally monocular) or defects in the chiasmal or retrochiasmal regions (causing partial loss in both eyes).
The MRI demonstrated a homogeneously enhancing sellar/suprasellar lesion that extended to the planum sphenoidale causing optic chiasmal compression as well as compression of the right optic nerve.