Neuro-Opthalmology Flashcards
Describe the sympathetic neuronal pathway in the eye?
Hypothalamus → C8/T1 → Synpathetic chain (SCG) C2 → Superior division (Forehead sweat + Mullers muscle) & Inferior Division (dilator pupillae) of CN3
Travels as long ciliary nerve along with CN3 (so CN3 lesion may include this unless vascular)
Describe the parasympathetic neuronal pathway in the eye
EWN → along Inferior Division CN3 (but via ciliary ganglion as short ciliary nerve) → Sphincter + Ciliary
What is seen in a CN3 palsy? (3)
Eye down + out (LR+SO spared) Complete ptsosis (levator palpebrae) -ve light response
What is seen in CN4 palsy?
How may it present?
What may cause a bilateral CN4 palsy? (4)
Unable to look down/in Vertical diplopia on looking down+in /reading Head trauma (CN4 runs round back) + Congenital
What are the 4 aetiological categories of CN palsies
Inflamm/Infection
Trauma
Tumour
Vascular
How would a CN6 palsy present?
What is it caused by?
Unable to adduct eye (cross-eyed) (diplopia looking to affected side)
Caused by raised ICP
How would a CN7 palsy present in the eye? What complication(s) can arise in the eye as a result?
Unable to close + reduced tear coverage
Dry cornea + exposure keratitis
What is seen on fundoscopy in an optic disc swelling? (3)
Ill-defined disc margin
Remains pink + normal cup
Haemorrhages at edge of disc
What are the causes of optic disc swelling? (5)
Optic neuritis Papilloedema (bilateral) Malignant hypertension Arteritic AION (anterior ischaemic optic neuropathy) Non-arteritis AION
How does optic neuritis present
What is seen O/E (3)
What is the main cause
Young/middle aged pt
Blurred vision
Dull ache (esp on eye movement)
O/E:
Optic disc swelling (blurred margin / pink / normal cup)
Reduced central vision
Para-central blind spot
Main cause: MS (need MRI)
What is retrobulbar neuritis?
What would be seen O/E? (2)
Optic neuritis but further back (nerve swollen not disc)
RAPD (Dx)
Red desaturation
What is papilloedema due to?
What are the symptoms? (2)
Raised ICP (bilateral)
Transient loss of vision (but generally normal)
Headache
What are the retinal signs of papilloedema (5)
What signs in visual fields are a sign of early / late papilloedema?
Optic disc swelling Splinter haemorrhages Exudates CWSs Retinal folds
Early - bilaterally enlarged blind spots
Late - progressive field loss (atrophic/irreversible)
What are the causes of CN3 palsy (5)
Brain stem: Tumour, CVA, MS
Skull base: ICA/PCA aneurysm, Extradural haematoma
Cavernous sinus: Fistula, Tumour, Inflamm
Orbit: Trauma, Tumour, Inflamm
Vascular: Diabetes/BP (pupils spared as blood supply not within vasa nervorum)
Describe the physiology in a non-arteritic AION
Who is it seen in
What symptoms
How treated
Swollen aa from Artherosclerosis → Obliteration of posterior ciliary aa lumen → Optic nn infarction
50% Hypertensive/Diabetic
No systemic symps but visual impairment
Low dose aspirin
