Flashcards in MULTIPLE SCLEROSIS Deck (32)
What is multiple sclerosis?
An inflammatory disease in which the insulating covers of nerve cells in the brain and spinal cord are damaged.
Which age group are most affected by MS?
20-30 year olds
Where in the world is MS most prevalent?
The further from the equator you, the higher the prevalence of MS.
What are the theories regarding underlying cause of MS?
Immunological mechanisms - cytokines
Genetic factors - HLA-A3, B7, B18, DR2 and DW2
Infection - evidence of viral aetiology
What do we call the areas of demyelination in MS?
What structure do the lesions in MS lie in close relationship with?
Lesions lie in close relationship with the post-capillary venules (perivenular).
Which sites of the brain are most commonly affected by MS?
Periventricular region of cerebral hemisphere
Cerebellum and cerebellar peduncles
What is the underlying pathology in MS?
Myelin destruction with relative preservation of axons. An inflammatory infiltrate containing mono-nuclear cells and lymphocytes is found. Interstitial oedema occurs in acute lesions. It is postulated that chronic demyelination may account for loss of axons and subsequently the cell bodies.
What are the three main patterns of disease progression in MS?
Relapsing and remitting with lesions occuring at different times in different parts of the CNS - 90% of cases initially
Secondary progressive - Disease starts with relapsing and remitting picture but then progresses to a point where each recovery because less complete. 50% of cases with relapsing and remitting disease
Primary progressive - little or no recovery from relapses - 10% of cases.
What is acute demyelinating optic neuritis and how does it present?
Inflammation of the optic nerve as a result of MS.
Subacute visual loss
Pain on ocular movement
What will the ophthalmological findings be in someone with optic neuritis as a result of lesions in the optic nerve head (also called papilitis)?
Pink swollen disc
What will the ophthalmological findings be in someone with optic neuritis as a result of lesions in the optic nerve behind the eye (also called retrobulbar neuritis)?
Disc will look normal
At what point in MS does optic neuritis normally become an issue?
Early on in disease. In 70% of cases optic neuritis is a forerunner for further episodes of CNS demyelination.
What symptoms might be associated with MS affecting the brainstem or cerebellum?
Diplopia (commonly bilateral)
Pyramidal signs (with involvement of the corticospinal tracts)
Patchy sensory changes
What is the most common reason for presentation of MS?
Spinal cord lesion leading to a spastic paraparesis or tetraparesis. This leads to difficulty walking and sensory loss. Bladder symptoms are also very common.
What is Lhermitte's symptom, with regard to multiple sclerosis?
A brief, electric shock like sensation down the limbs on flexion of the neck.
Can seizures occur in MS?
Yes seizures are actually fairly common in MS.
What does the differential diagnosis of someone with signs and symptoms consistent with MS include?
Vitamin B12 deficiency
What is neuromyelitis optica?
A relapsing autoimmune condition in which patients present with a demyelinating optic neuritis and transverse myelitis.
How might you differentiate between neuromyelitis optica and MS?
NMO patients are typically positive for antibodies to aquaporin 4.
Do neuromyelitis optica patients have a worse or better prognosis than MS patients?
What investigations would you order for someone presenting with signs and symptoms consistent with MS?
MRI T2 weighted (CT is not accurate)
What might be seen on the MRI of someone with MS?
Lesions are typically found in the periventricular areas, the corpus callosum and juxtacortical white matter.
What might be found in the CSF of a patient with MS?
A mild lymphocyte pleocytosis. Slightly elevated protein.
Oligoclonal bands is highly suggestive of MS (IgG in CSF but not serum)
What is the criteria used in the diagnosis of MS?
The McDonald criteria - states that lesions should occur in different places at separate times.
What is the model answer to the question how do we treat MS?
What do we use to treat an acute relapse of MS? Give doses if possible.
Steroids - IV methylprednisolone 1gram a day for 3 days
500mg a day for 5 days PO
What are the main two disease modifying drugs used in the treatment of MS?
Beta-interferon 1a and 1b
When should disease modifying drugs be used in MS patients?
When they have had at least two relapse in the preceeding 24 months and in whom there is no progression between relapses.