Neuro 1.2 Flashcards

Question

AION - Symptoms and Signs

Answer 1

- Visual loss (both types) - Painless, monocular visual loss over hours to days - Altitudinal defects most common - Reduced central vision - RAPD - OD oedema present from onset

Answer 2

- 5-10% of AION cases - Occurs in older px's - Caused by GCA - Inflammatory and thrombotic occlusion of short PCA's causing ONH infarction - Variable, no systemic symptoms in 20%

Answer 3

- Variable, no systemic symptoms in 20% - Granulomatous necrotizing arteritis - Affects large and medium sized arteries, especially: - Superficial temporal artery - Ophthalmic artery - Posterior ciliary artery - Proximal vertebral artery - 5-10% of GCA have AAION

Answer 4

- Systemic - Usually 60-80 yrs old - Tender, hardened, non-pulsatile temporal artery - Scalp tenderness, especially on brushing hair - Jaw claudication (pain on speaking or chewing, almost pathognomonic - very indicative of condition) - Proximal muscle weakness (typically shoulders), may occur 1st - Reduced appetite - Unexplained weight loss - Unexplained lethargy, malaise, depression - Visual - Sudden, profound, visual loss - Usually unilateral (initially) - May be proceeded by transient visual obscuration's, flashing lights - Periocular pain

Answer 5

- Severe visual loss - Pale swollen OD (may appear pale initially due to blood supply being lost, complete optic atrophy not present until 4-6 weeks after - Cotton wool spots (retinal ischaemia) - Over 1-2 months, swelling resolves leaving optic atrophy

Answer 6

- Immediate, same day referral to ophth - Treatment aimed at preventing blindness of other eye - As px could get a blockage somewhere else and get a stroke Management by ophth - Immediate therapy essential - Confirmed with immediate blood results - Temporal artery biopsy confirms diagnosis - Usually overnight stay in hospital - High dose systemic steroids - Px's may remain on oral steroids for years (average 1-2yrs) to prevent future attack

Answer 7

- Visual loss usually permanent - Prompt administration of steroids may allow partial visual recovery - In 25% of cases 2nd eye affected despite treatment, could be within days

Answer 8

- 90% of AION cases - Occlusion of short PCA's causing infarction of ONH - Typically in 55-70 yrs, younger compared to AAION - Structural 'crowding' of the disc when cup is small/absent

Answer 9

- Diabetes - Hypertension - High cholesterol - Smoking

Answer 10

- Sudden, painless loss of vision - Unilateral (papilledema would be bilateral) - Visual impairment on wakening (nocturnal hypotension - BP reduces overnight, HR slows etc) - Lack of systemic symptoms

Answer 11

- VA - Moderate to severe reduction in VA in most px (6/24, 6/36) - 30% have normal or slightly reduced VA (6/12) - Visual fields - Commonly inferior altitudinal defect - Dyschromatopsia - reduced CV - Proportional to amount of VA loss - After initial visual loss, most px have no further visual loss (although in a small number, visual loss continues for about 6 weeks)

Answer 12

- Disc oedema diffuse or segmental - Disc hyperaemic with focal telangiectasia clustered on disc surface (general dilation of capillaries causing them to appear as small, red or clusters - often spidery which attempt to help with blood supply to that area which is lacking) - Often a few peripapillary splinter-shaped haemorrhages - Atrophy within 3-8 weeks of onset - Contralateral eye usually small with absent cup - 'disc at risk'

Answer 13

- Refer to ophth - In community, difficult to differentiate from other causes of swollen disc and AAION without appropriate blood tests - Treat underlying cause - Prophylaxis? Aspirin is frequently given but does not appear to reduce risk in fellow eye

Answer 14

- Most px have no further visual loss although in a small number, visual loss continues for about 6 weeks - Some recovery (e.g. 2 lines) in 31% at 2 years - Chance of other eye being affected is 15% over 5yrs (lower than arteritic) - Risk factors for other eye are: - poor VA in 1st eye - diabetes - Pseudo-Foster Kennedy Syndrome - unilateral disc swelling with contralateral optic atrophy in absence of mass compressing nerve

Answer 15

Arteritic...Non-arteritic Age Mean 70 years...Mean 60 years Sex F > M...F = M Associations Headache, tenderness, etc...Usually none Visual Acuity <6/60 in >60%...>6/60 in >60% Disc / fundus Pale disc oedema...Hyperaemic disc oedema ESR Mean 70...Mean 20-40 CRP Elevated...Normal Fluorescein Angiography Disc and choroid delay...Disc delay Natural History Rarely improves...31% improve Fellow eye >50%...Fellow eye 10 – 20% Treatment Systemic steroids...None

Answer 16

- Much rarer than AION - Obstruction of plial artery/capillary plexus leading to ischaemia to retrolaminar part of the ON - After surgical procedure, e.g. of spine - Arteritic (similar to AAION) - Non-arteritic (similar to NAION) - Diagnosis after ruling out other causes (compression, inflammation)

Answer 17

- Inflammation, infection or demyelinating process of the ON (Kanski) Retrobulbar neuritis - inflammation behind the ONH

Answer 18

- Infection of the ON - Caused by local infection e.g. sinus, syphilis, Lyme disease, HZO - Following a viral infection e.g. chicken pox, whooping cough, measles, mumps - Following an immunisation - Inflammation of the ON (non-infectious) - Sarcoid - Autoimmune - Demyelination of the ON (most common)

Answer 19

- Demyelination disrupts nerve conduction within brain, brainstem and spinal cord, spares peripheral nerves

Answer 20

- Multiple sclerosis (most common) - Only diagnosed as MS if 3 or more demyelination lesions - Isolated optic neuritis with no other demyelination, but that may subsequently develop - Devic disease or Schilder disease, both rare and produce bilateral optic neuritis - Brain stem demyelinating lesions may also cause: - CN palsies - Gaze palsies - Facial nerve palsies - Nystagmus

Answer 21

- MS is an inflammatory, demyelinating disease of the central nervous system (CNS) - Multiple exacerbations characterised by variable CNS involvement - Exacerbations are separated in time and anatomical location - Optic neuritis is the presenting feature in 15-20% of those with MS - 50% of those with MS will get optic neuritis at some point - If optic neuritis present, the overall 10 year risk of MS is 38%

Answer 22

- Monocular visual impairment - Subacute - develops over several days to 2 weeks - Discomfort, exacerbated by eye movements which comes before visual loss in most cases - Globe tenderness

Answer 23

- Reduced VA (6/18 - 6/60) - RAPD (affects amount of light being transmitted by one eye, that pupil will dilate when same light is shone in other eye) - Reduced CV - Reduced CS - VF defects - Generalised depression - Nerve fibre bundle defects - Central loss

Answer 24

- Normal in most cases - If px experiencing retrobulbar neuritis (inflammation behind ON) - Could get swollen disc

Answer 25

- A feature of optic neuritis - optic neuritis including macular and ONH involvement - macular star often forms

Answer 26

- Acute loss of vision (usually painless) - Disc oedema which is diffuse, spreads to involve around fovea at plexiform layer - Star pattern of exudates at macula

Answer 27

- Demyelination rare - 66% secondary to cat-scratch disease - Syphilis - Lyme disease - Viruses

Answer 28

- In community, difficult to differentiate from other causes of swollen disc - Most need no medical treatment - Intravenous steroids followed by oral course speed recovery by 1-2 weeks - Oral steroids alone associated with increased recurrence rate

Answer 29

- Recovery within 1 month, lasting up to 6 months - 75% recover to 6/9 or better - May be permanent loss of colour perception and contrast sensitivity - Will have optic atrophy after optic neuritis - Pseudo-Foster Kennedy syndrome may be present - If contralateral eye affected - Unilateral disc swelling with contralateral optic atrophy in absence of mass compressing nerve

Answer 30

- OD swelling in a diabetic patient - Difficult to diagnose (very rare) - Pathogenesis unclear - Caused by capillary damage? - Associations with small C:D ratio and rapid reduction in glycemia - Vascular leakage and oedema of the nerve fibres - Chronic ischaemia and secondary nerve swelling - Does not result in full blown ischaemic optic neuropathy - Usually diagnosed on examination rather than on symptoms

Answer 31

- Usually asymptomatic or with mild symptoms - Usually diagnosed on examination rather than on symptoms

Answer 32

- Unilateral - VA 6/12 or better - Mild or no RAPD - Visual field - Enlargement of blind spot - Constriction or altitudinal loss in severe cases - Frequently found on fundus examination

Answer 33

- Mild disc oedema with hyperaemia - Telangiectasia (dilated capillaries) which could be confused with neovascularisation (new BV's)

Answer 34

- In community, difficult to differentiate from other causes of swollen disc - Emergency referral to ophth - Little evidence that treatment is successful - Possibly corticosteroids/steroids

Answer 35

- Visual prognosis good: 6/12 or better - May take 6 months or longer for oedema to resolve - 5 to 15% progress to Non-Arteritic AION (diabetes is a risk factor)