Vision Affected

Question 1

Lesion at L optic radiation/lateral geniculate nucleus

Answer 1

Right homonymous hemianopia

Question 2

What will a lesion at the optic chiasm produce?

Answer 2

Bilateral hemianopia

Question 3

What will a lesion at the opric nerve produce?

Answer 3

Monocular blindness

Question 4

Lesion at R visual cortex: Remember to inverse them

Answer 4

Left homonymous hemianomia w/ macular sparing

Question 5

Whats Nystagmus?

Answer 5

Almost always implies ear or posterior fossa disease.

Nystagmus to 1 side: ⬆️ amplitude in ipsilateral eye eg nystagmus on looking righy, which is mostly marked on right eye:
1. Ipsilateral cerebellar/brainstem lesion
Vascular, neoplastic, demyelinating/ infective
2. Contralateral vestibular lesion- cochlear dysfx, CN8 D, viral neuritis, fatiguable seem on positioning testing, BPPV
3. Central: - not fatiguable, present at rest.
Vestubular nucleus damage, vascular, neoplastic, demyelinatinh, drugs (phenytoin, carbamezapine)

Vertical nystagmus-> central brainstem pathology
Upgaze: superior colliculus
Downgaze: foramen magnum level

Question 6

Whats BVVP?

Answer 6

Benign paroxysmal positional vertigo
Due to dislodged otoliths in seminular canals,
Presents w/ vertigo and nystagmus on movement.
Epleys manoeuvre

Question 7

Whats Strabismus?

Answer 7

Congenital squint (strabismus)
No dipolpia
Maybe decreased acuity in non fixating eye
Perform cover/uncover test

Ask pt to fix vision on ur finger held at arms leg
Cover the deviated eye and then other

The axis of deviated eye will move from its position when the good eye is covered, and return to postition when re-covered.