Multiple Sclerosis Flashcards
What areas are most likely to be affected in MS?
Optic nerve
Brainstem
Cerebellum
Spinal cord- corticospinal tracts
Spinal cord- dorsal columns
How is multiple sclerosis defined?
A chronic demyelinating disorder of the central nervous system characterised by multiple lesions separated in space and time
What eye signs would be especially suggestive of MS?
Internuclear ophthalmoplegia
Cerebellar eye signs
Optic atrophy (secondary to optic neuritis)
What is pseudoasthetosis and what is it a sign of?
Unconscious writhing movements of the fingers with the eyes closed
Indicates dorsal column involvement
Which gender is more commonly affected by MS?
F
What is the pathophysiology of MS?
Considered an autoimmune disease, though no one antibody identified
CD4-mediated destruction of oligodendrocytes –> demyelination –> loss of saltatory conduction and eventually neuronal death
Inflammatory demyelinating plaques are hallmark
Thought an initial viral inflammation may trigger disease.
What are the types of MS?
Relapsing-remitting: Most common
Secondary progressive: R-R form often reaches this stage
Primary progressive: 10-15% Progressive-relapsing
What symptoms might a patient with MS present with?
TEAM
Tingling
Eye signs: Optic neuritis –> reduced central vision and eye movement pain
Ataxia
Motor: Usually spastic paraparesis
What is Lhermitte’s sign?
Neck flexion –> rapid tingling/electric shocks down to arms and legs.
What does Lhermitte;s sign suggest?
Dorsal column damage
What are causes of Lhermitte’s sign?
MS
Cervical myelopathy
Cervical cord tumour
SACD of the cord
What is Uhtoff’s phenomenon?
Raised body temperature –> exacerbation of symptoms
What symptoms would a patient with optic neuritis complain of?
Pain on eye movement
Rapidly reduced central vision
What would you expect to find on examination of a patient with optic neuritis?
Reduced acuity
Reduced colour vision
White disc (optic atrophy)
Central scotoma
RAPD
What is the most useful investigation for confirming MS as a diagnosis?
MRI scan T2 weighted- hyperintense lesions of the periventricular white matter in brain and sc.
Gadolinium enhanced scan: shows active lesions
When is CSF analysis indicated in MS investigation?
If diagnosis uncertain and imaging and presentation raises suspicion of CNS infection
What is finding on CSF analysis would be indicative of MS?
IgG oligoclonal bands- not in all patients! Not present in serum
What are the differentials for IgG oligoclonal bands in the CSF?
MS
Neurosyphilis
SLE
GBS
What antibodies can be looked for in MS?
Anti-myelin basic protein
Neuromyelitis optica IgG- Devic’s syndrome (very specific)
What other investigation can be done to diagnose MS?
Evoked potentials- delayed auditory, visual and sensory
What is neuromyelitis optica (Devic’s disease)?
Inflammatory demyelinating condition of the CNS that mainly affects the optic nerves and spinal cord
Relapses more severe than MS, around sc
What antibody is highly suggestive of neuromyelitis optica (Devic’s disease)?
Neuromyelitis optica IgG (NMO IgG)
What does the NMO-IgG antibody target?
AQP4
What is the management of acute attacks of neuromyelitis optica (Devic’s disease)?
IV steroids
Plasmapharesis for steroid-unresponsive patients
What is the chronic management of neuromyelitis optica (Devic’s disease)?
Immunosuppressants- mainly azathioprine ± steroids.
What criteria are required to diagnose MS?
Lesions disseminated in time and space
May use McDonald criteria
What is the ddx for MS?
CNS sarcoid
SLE
Neuromyelitis optica (Devic’s disease)
What is the mx of MS?
Conservative: Physio, OTs, walking aids, visual aids Medical:
- Disease-modifying treatments include
- IFN-B: Requires specific criteria to be met (RR-MS, multiple relapses)
- Glatirimer acetate
- Natalizumab: Reduces relapses by 67%
- Symptomatic:
- Anti-spasticity meds e.g. baclofen
- Depression: SSRIs
- Pain
- Bladder dysfunction: Self intermittent catheterisation, anti-ACh
- Sexual dysfunction: counselling, sildafenil
What are the different disease modifying agents used in MS
Injectables - 30% effective at reducing relapses
- IFN-beta
- Glatiramer acetate
Oral tablets - 50% effective
- Dimethyl fumarate
- Fingolimod
Infusions - 70% effective
- Alemtuzumab
- Natalizumab
*The more effective drugs have a higher risk of PML
What is PML
Progressive multifocal leukoencephalopathy
Caused by JC virus
Requires frequent blood tests and MRIs
What gait would you expect in spastic paraparesis?
Scissoring gait
May be high steppage gait due to foot drop.
What is the differential for spastic paraparesis?
- MS
- Cord compression
- Transverse myelitis
- MND
- SACD of the cord
- Taboparesis
- Friedrich’s ataxia
- Hereditary spastic paraparesis
Differentiate based on presence of other signs- sensory/cerebellar/LMN signs.
What would raise the suspicion of cord compression as a cause of spastic paraparesis?
Identifying a sensory level- absence of symptoms above this level
What is the difference between spasticity and rigidity?
- Rigidity: Constant increase in tone throughout ROM. Independent of velocity
- Spasticity: Velocity-dependent increased tone showing clasp-knife phenomenon (increased at start of movement, decreasing suddenly as passive movement continues)
What is transverse myelitis?
A broad term describing acute inflammation of the cord. Tends to involve more than one level and all sc function –> bilateral sesnory, motor and sphincter deficit below the level of the lesion
What are the causes of transverse myelitis?
Bacterial infection: e.g. lyme disease, TB, syphilis
Viral infection: e.g. HSV, VZV, HIV
Demyelination
Radiation myelopathy
Vasculitis
What are the surgical options for treating spasticity?
Neurosurgery: Selective dorsal rhizotomy
Ortho: Contracture and tendon release, oseotomy
Other: Botulinum toxin injection
What are poor prognostic signs in MS?
Advanced age at dx
Motor signs at onset
Multiple early relapses
Multiple MRI lesions
Gender- M
