Cranial Nerve Findings
Visual tract lesions. Adapted from public domain Gray's Anatomy (20th Edition).
: lesions of ipsilateral eye or
: lesion to optic chiasm, usually pituitary tumour.
: lesion to optic tract (blindness to contralateral side of visual fields to the
side of damaged optic tract).
: lesion to visual cortex, which sometimes spares the macular region (where the macular is represented).
This is not normally lost in higher cortical lesions.
: light shines in affected eye neither
and pupil constricts.
: affected eye does not constrict but contralateral does.
: Lesion to the sympathetic pathway causes unilateral meiosis (constriction).
: small constricted, accommodation
reflex preserved, light reflex absent
eye dilated (“hOlmes”)
: dilated pupil, slowly accomodating, light response absent
: III nerve palsy, Argyll Robertson, Horners (SNS lesion, so small,
look for ptosis & neck scars)
Eye points down and out. Ptosis (levetor palpebrae
superioris): due to unopposed action of VI & IV.
Diplopia on descending stairs as can not look inferiorly on adduction
Can not abduct eye. Diplopia on looking to affected side
Can not move muscles of facial expression on affected side of face.
Sparing of forehead w upper motor neuron lesion due to bilateral
Vertigo ± cochlear sx (hearing loss, tinnitus) = peripheral
lesions of labyrinth.
Vertigo + diplopia = brainstem lesion.