This may explain the findings of the present report, in which the meningioma located in the optic chiasm
(thalamic region) also caused multifocal neurological signs.
infindibulum, optic chiasm
, cavernous, and sphenoid sinus, elevated III ventricle.
(a) Coronal Tl-weighted image demonstrates a large sellar mass with suprasellar extension and slight mass effect on the optic chiasm
. This mass exhibits marked hyperintense signal on T1-weighted image (arrow), which indicates blood products and recent hemorrhage.
A repeat MRI demonstrated rapid enlargement of his pituitary mass, nearly doubled in size and described as a 2.2 cm by 1.2 cm mass impinging on the overlying optic chiasm
Fabian, "Ganglioglioma of the optic chiasm
: case report and review of the literature," American Journal of Neuroradiology, vol.
Larsson, "Binocular vision, the optic chiasm
, and their associations with vertebrate motor behavior," Frontiers in Ecology and Evolution, vol.
This is an artificial reference line rather than an anatomic line, but does parallel the normal ascending oblique orientation of the optic chiasm
, as shown in Figure 2.
Retinal axons exit the eye and extend ventrally to cross the midline at the optic chiasm
. They continue to extend dorsally and posteriorly to the tectum.
For intra-extracranial tumors in the anterior skull base, the anterior limit of ETA is the frontal sinus, and the posterior limit is the optic chiasm
and the anterior communication artery.
The decussation or separation of optic nerve fibres at the optic chiasm
means that the right hemifield is projected to the left striate cortex and the left hemifield is projected to the right striate cortex (see Figure 2).
After 30 months, radiographic imaging demonstrated a reduction and stabilization of the tumors in the optic chiasm
, hypothalamus, and left optic nerve.
Half-field pattern reversal that is used for localization of lesions behind the optic chiasm
has reduced clinical application in modern imaging procedures .
He demonstrated that contrast material tracked proximally along the nerve to the optic chiasm
, ultimately reaching the pons and midbrain.
(c) Coronal T2 weighted image demonstrates the mass abutting the lateral margin of the third ventricle and the superior margin of the optic chiasm
This suggests microglial activation in both eyes upon unilateral optic nerve damage, pointing towards cross-talk between both eyes, which may be orchestrated via the optic chiasm
or hematogenous transference [53, 55].