Neuro-Opthalmology Flashcards
What are the features of central retinal artery occlusion on history and opthalmoscopy (3)?
(1) Patient typically a vasculopath
(2) Sudden, complete, painless unilateral vision loss.
(3) Cherry red spot on opthalmoscopy
What are the features of diabetic retinopathy on opthalmoscopy (5)?
(1) Cotton wool spots
(2) Microaneurysms
(3) Hard exudates
(4) Neovascularization
(5) Flame hemorrhages
What are the features of hypertensive retinopathy (6)?
(1) Cotton wool spots
(2) Hard Exudates
(3) Flame hemorrhages
(4) AV nicking
(5) Copper wiring
(6) Disc edema
Explain the innervation of the muscles that move the globe of the eye.
(1) CN VI - Lateral Rectus
(2) CN IV - Superior Oblique
(3) CN III - Medial, superior and inferior rectus, as well as inferior oblique.
What does CN III innervate with regards to the eye?
Medial rectus, inferior rectus, superior rectus and inferior oblique.
Levator palpebrae superioris (elevates eye lid)
Parasympathetics (contracts pupil)
What are the nerves that run through the cavernous sinus?
CNIII, IV, VI, V1, V2 & sympathetics.
Why is there ptosis in Horner’s syndrome?
The sympathetic fibres innervate a small smooth muscle called Muller’s muscle that is responsible for a minor portion of upper eyelid elevation and lower lid retraction. Loss of these fibres due to a lesion along the sympathetic chain results in ptosis.
What are the three characteristic features of Horner’s syndrome?
(1) Ptosis
(2) Miosis
(3) Anhidrosis (if 1st or 2nd order neuron affected).
What are the features of diplopia in a 6th cranial nerve palsy?
(1) Binocular Diplopia (Horizontal)
(2) Diplopia worse when looking to the side of the cranial nerve palsy (i.e., worse when looking left in left CN VI palsy)
(3) Diplopia worse when looking far away.
Where is the lesion in an intranuclear opthalmoplegia (INO)?
The lesion is in the ipsilateral medial longitudinal fasciculus (MLF) on the side ipsilateral to the eye that is unable to ADDUCT in lateral gaze.
