CN II/Visual Fields

Where do the superior arcuate fibers enter the optic nerve?

superior temporal

Where do the inferior arcuate fibers enter the optic nerve?

inferior temporal

What is the horizontal raphe significant in?

scotomas

When do the RGC fibers of the ONH move to internalize the maculopapillary bundle?

laminar region

Tumor of lateral rectus would compress what fibers? What field loss would the cause?

compress temporal (arcuate) fibers

nasal field loss

The arcuate fibers are where?

temporal

The radiating fibers are where?

nasal

What makes the anterior knees of wilbrand?

inferior nasal fibers

Path of the inferior nasal fibers in ON/chiasm/tract?

enters optic nerve medially

enters contralateral optic nerve

exits tract temporally

What makes the posterior knees of wilbrand?

superior nasal fibers

Path of superior nasal fibers in ON/chiasm/tract?

enters optic nerve medially the crosses temporally

enters contralateral optic tract

exits tract medially

What fibers are in medial optic tract?

superior temporal

superior nasal

What fibers are in lateral optic tract?

inferior temporal

inferior nasal

What affect would an aneurysm of the internal carotid on the optic nerve? What field loss would this cause?

compress the lateral optic nerve on one side, causing the nerve to be pushed over, pushing the lateral side of the other optic nerve

causes loss of binasal field (binasal hemianopsia)

What affect would a pituitary tumor have on the chiasm? What field loss would this cause? (in normal anatomy).

compress the center chiasm only, compressing only nasal fibers

results in bitemporal hemianopsia

What is a pre-fixed chiasm?

chiasm more anterior, the tract is over pituitary not chiasm

What is a post-fixed chiasm?

chiasm more posterior, the nerve is over the pituitary not the chiasm

What affect would a pituitary tumor have on someone with pre-fixed chaism?

compress optic tracts

What affect would a pituitary tumor have on someone with post-fixed chiasm?

compress optic nerves

What is Meyer's Loop?

optic radiations that dip down into temporal lobe

Where do the fibers in Meyers loop synapse?

lingual gyrus

What is Baum's loop?

optic radiations that enter parietal lobe

Where do the fibers in Baums loop synapse?

cuneus gyrus

What kind of fibers are optic radiations?

geniculocortical

What would damage to the loop of Meyer cause?

contralesional superior homonynmous quadrantanopsia

What can cause damage to the loop of Meyer?

temporal lobe lesion

What does damage to Baum's loop cause?

contralesional inferior homonymous quadrantanopsia

What can cause damage to Baums loop?

parietal lobe lesion

What does damage to the optic radiations in the occipital lobe cause?

contralesional homonymous hemianopsia with macular sparing

Any lesion post chiasm will give you what?

contralesional homonymous field loss

What is macular magnification?

macula (small region) getting so much of cortex

What part of the cortex is for the macula?

large area of posterior occipital lobe

What part of the cortex is for the peripheral fibers?

anterior occipital lobe

What could cause the entire occipital lobe to be wiped out?

lesion of entire posterior cerebral artery