ILA 1 - unilateral loss of vision Flashcards
Which cells does MS attack?
Myelin cells produced by oligodendrocytes
Do get sensory, motor or cognitive problems MS?
ALL of them
Which immune cells in MS attack neurones? What do they need to cross and how do they do it?
T-cells. Cross BBB by using the correct ligand.
Which type of hypersensitivity reaction is MS? What does this mean it releases?
Type IV [cell-mediated]; releases cytokines Il-1, Il-6, TNF-alpha, INF gamma
What do cytokines in MS also attract?
b cells and macrophages
Early on the disease stage of MS, what may occur to neurones?
Remyelination. However, over time irreversible damage occurs with loss of axons.
Exact cause of MS?
Unknown but linked to genetics [females and genes HLA-DR2] and environmental RFs [infx and vitamin D deficiency]
What are the type of MS?
4 types - RRMS - SPMS - PPMS - PRMS Related to time scales.
Most common type of MS?
RRMS, with boughts happening months or years apart so loss of vision then improves [residual disability], step wise
Type is SPMS?
Constant degradation over time
PPMS
constantly going down
PRMS
progressively worse in between
What causes the variety of Sx in MS?
Location of plaques
Common age to develop Ms?
20-40 years old
What is Charcot neurological triad?
dysarthria, difficulty unclear speech, plaques brainstem with conscious movement like earring/talking, unconscious like swallowing
What is nystagmus?
Involuntary eye movements with plaques nerve eyes
optic nerve = loss of vision and optic neuritis
Movements: pain and double vision
Causes intention tremor in MS?
Plaques along motor pathways, muscle weakness and spasms, tremors and ataxia, paralysis
Plaques in the sensory pathways form skin in MS?
Numbness, pins and needles, parenthesis
What is Lhermittes sign?
electric shock radiates to the limbs
Plaques autonomic NS
bowel and bladder and sexual dysfunction
Higher order MS Sx
Poor concentration, critical thinking, depression, anxiety
Suspected MS is when?
When Sx spread over space and time
What is Dx of MS supported by?
MRI showing multiple white matter plaques
Also, in the cerebrospinal fluid high antibodies
Visual evoked potentials [?]
Tx for MS
for RRMS: corticosteroids, cyclophosphamide, IV Ig, plasmapheresis [remove Ab], immunosuppressants [recombinant B-IFN], other immunosuppressants
T xor progressive MS: fewer options, manage Sx like bladder control, CBT, vitamin D, physical therapy
Two common causes of ON?
optic nerve inflamed from infection or nerve disease.
Inflammation usually causes temporary vision loss that typically happens in only one eye.
Sx of ON
vision gets dim and blurry, can’t see colours, eye hurts when move them, common people with MS
Causes of ON
bacterial infection like Lyme’s, viral infections like measles and mumps, IAD like sarcoidosis, lupus, medications like quinine
Half of people with MS have ON. Immune system attacks myelin on optic nerve.
Dx for ON
Eye examination colour vision, smallest letters can’t read, side or peripheral vision
Treatment for ON
usually recovers by self, can have steroids
Go through steps eye examination
- Visual acuity [Snellen chart, pinhole for refractive error]
- Near vision [fine print]
- Colour vision [Ishihara chart]
- Visual fields
- Blind spot
- Inspect the external eye
- inspect the pupil [size, shape, symmetry]
- Eyelids
- Pupillary reflexes
- Astrabismus
- Eye movmeents
- Fundoscopy
- Red eye reflex
Case - 23 y/o W - blurred and cloudy vision right eye - present one week - discomfort behind right eye - vision worse when hot bath - reduced light response R eye associated with reduced indirect response on the L Likely Dx?
MS!
name of Sx worse hot bath
Uhthoff’s phenomenon. Differentiating form other conditions, body gets overheated.
What is the Marcus Gun pupil?
Look up
How to test for Marcus Gun pupil?
Swinging light I think
Cause of RAPD
look up
How to test for reduced visual acuity?
Snellen chart; first number is viewing distance, second the distance away an average eye can read
5 components for the anatomy of vision
- aqueous humour
- vitreous humour
- retina
- vascular
- nerve
Which component of vision does cataracts affect?
retina
What does glaucoma effect?
Aqueous humour
What is acute glaucoma?
Drainage of aqueous humour, suddenly becomes occluded.
Results in rapid rise in IOP.
Pain, red eye, nausea and vomiting.
Sx and Sx of acute glaucoma
Very sick, nauseated, non-reactive pupils, painful red eye, look very unwell
What can glaucoma often be confused by?
Migraine [DDx]
What must you do with glaucoma like Sx?
Examine, as this cane easily missed.
What is a vitreous haemorrhage?
Haemorrhage into vitreous humour.
Prevents light travelling from lens to retina.
Signs of vitreous haemorrhage
Flashes/floaters, blurred vision.
Only becomes apparent flashes/floaters in fundoscopy.
What is a retinal detachment?
Retina puled away from underlying surface.
Flashes, floaters, ‘curtain’ over part of vision.
What conditions can flashes/floaters be seen in?
Vitreous haemorrhage and retinal detachment.
What conditions can curtain over part of vision be seen in?
Retinal detachment but also vascular issues.
What is the name for a swollen optic disc?
Anterior ischaemic optic neuropathy
What causes the swollen optic disc in AION?
Occlusion of the posterior ciliary artery that supplies the head of the optic nerve.
What should think of with AION?
GCA!
how to treat AION and why important to Tx?
Give high dose steroids, or can lose vision.
Sx and Sx of GCA
- jaw claudication
- scalp tenderness
- anorexia
- anorexia
- fatigue
- elevated ESR and CRP
- over 70 y/o [though actually can be over 50]
- no atherosclerotic RFs
how does a central retinal artery occlusion appear?
Pale disc.
Cherry spots at macula.
Cause of CRAO
occlusion of the central retinal artery [branch of the ophthalmic artery] which supplies the whole retina
Mx of CRAO
urgent intervention, stroke opinion as consider TIA [throug eye clinic]
Sx of central retinal vein occlusion
Dilatation of branch veins
Multiple retinal haemorrhages
Cotton wool patches around [hard exudate].
Distinct red picture on slides.
Term used to describe inflammation involving the nerve head~?
Papillitis
If papillitis is behind the nerve head, is that normal or abnormal?
Normal
What does optic atrophy look like and what does it indicate has happened?
Indicates clonicity [optic nerve damage has been there a while].
What does papilloedema look like?
Disc margins distorrted, haemorrhage in lower area.
Something pushing from the back centrally.
Swelling in this area of disc, means area is elevated.
Main Sx of optic neuritis
Reduced visual acuity over few days. pain on moving the eye. Exacerbated by heat or exercise. Afferent pupillary defect. Dyschromatopsia.
Aetiology of optic neuritis
Inflammation of optic nerve.
Often associated with MS. Can occur cliniically isolated syndrome.
Other causes include infection [Lyme, syphilis, HIV] B12 deficiency/arteritis]
Course of ON
Recovery of vision occurs [6w]
Tx of ON
Steroids help to reduce pain and hasten recovery
Is it essential or not to have pupillary defect for a Dx of ON?
yes, essential to have afferent pupillary defect [I think]
What can neuromyelitis optica lead to?
Long term damage [usually more severe version Sx, harder to Tx]
What is the 15 year risk of developing MS if have episode of ON?
40%
What indicator greatly increases the risk of developing MS after an ON episode?
If lesions on MRI:
- if MRI normal at 10 years risk of MS is 11%
- if MRI abnormal at 10 years risk of MS is 83%
What is a clinically isolated syndrome that could be a possible sign of MS?
First attack of demyelination [e.g. ON]
How is MS diagnosed? What criteria must be met?
Requires presence of multiple CNS lesions, which cause Sx that:
- last longer than 24 hours
- are disseminated in space [clinically, or on MRI]
- are disseminated in time [over 1 month apart]
List the typical features of MS
- Visual loss [optic neuritis], RAPD, INO, optic atrophy
- Pyramidal weakness, spastic paraparesis
- Sensory disturbance
- Cerebellar Sx [nystagmus, vertigo/tremor/ataxia/dysarthria/falls]
- Bladder involvement/sexual dysfunction
- Lhermitte’s and Uhthoff’s phenomenom
- Fatigue
- Cognitive impairment
Which CN are commonly affected in MS?
3rd and 6th
When does nystagmus typically present if it does in a pt with MS?
Later stages of the disease
Why are cerebellar Sx common in MS?
Posterior fossa common sight for inflammation [so cerebellar Sx]
What is Lhermitte’s phenomenon?
Shooting pain when bending neck
Ix for MS
MRI scan
- T2 lesions found in 4 regions: juxtacortical, periventricular, infratentorial, spinal cord
LP
- unmatched oligoclonal bands
When are oligoclonal bands typically useful?
patient two lesions [typical in MS], but can’t prove it’s a single episode over time, then LP unmatched oligoclonal bands can be helpful for Dx
Describe the PP of MS
Inflammatory
Focal loss of myelin, with relative preservation of axons
Neurodegenerative axonal loss may contribute to fixed and progressive deficits
What are the types of MS?
Describe course of each
Benign MS, RRMS, SCP, PP [10-20%].
Look at slides for course.
Tx for an acute episode of MS
Steroids
Benefits of taking steroids for MS
Doesn’t alter disease trajectory but hastens recovery [6-9 months disability the same]
What should r/o after an acute episode?
Infection cause of disability [pseudorelapse]; if something systemic happens NX will decompensate well with for example arm weakness being caused actually by a UTI
What should do before Rx steroids?
R/o infection of course. Do septic screen, examine them, check medication list.
If everything normal, then do MRI scan to see if any evidence of any new inflammation.
Se of having steroids
Avascular necrosis, bad blood sugars, secondary Cushings, osteoporosis, peptic ulcers [etc.]
Example pt which steroids may be useful for?
Young person who can’t skip 10d of work e.g.
For chronic Sx, list disease modifying medication that are based on NICE guidelines
- SC [traditional therapies]: inferferon beta, glatiramer acetate
- oral e.g. fingolimod
- IV e.g. natalizimab
- stem cell transplant
Which drug classes generally pretty effective for MS?
IV drugs like natalizimab. Though high SE profile.
Which Rx is stem cell transplant good for?
Stem cell transplant good inflamatory phase, neurodegenerative phase less important
How to examine RAPD/Marcus Gunn pupil?
Look up youtube
