Multiple sclerosis Flashcards
Define multiple sclerosis
Demyelination of the CNS. MS can’t be diagnosed by one episode-> episodes have to be ‘disseminated by time and space’
Which cells are affected in multiple sclerosis?
Oligodendrocytes (CNS myelinating cells)
What type of hypersensitivity reaction is MS?
Type 4
Describe pathophysiology for MS
- Molecular mimicry
- Initial infection-> the antigen is
recognised by T helper cells, after infection the myelin is recognised as an antigen leading to
cytokines being released and antibodies being formed
What are the risk factors/causes for MS?
- Female 20-40 (white)
- Autoimmune disease
- Family history
- EBV
- Genetic (HLA-DR2)
- Low vitamin D
- Smoking
- Obesity
What are the different types of MS?
- Relapsing-remitting
- Primary progressive
- Secondary progressive
Describe relapsing-remitting MS
Symptoms -> incomplete recovery -> symptoms
Describe primary progressive MS
Gradual degeneration without recovery
Describe secondary progressive MS
Relapsing remitting –> primary progressive
- 75% of R-R cases evolve into this
What is the 1st presenting sign of MS?
Optic neuritis
What are other symptoms of MS?
- Paraesthesia
- Blurred vision
- Uhthoff’s phenomenon
What is Uhthoff’s phenomenon?
Symptoms are exacerbated with heat eg. after a shower
What are the signs of MS?
- Optic neuritis (inflamed optic nerve, can’t see red properly)
- Internuclear ophthalmoplegia (lateral gaze impaired, damaged medial longitudinal fasciculus)
- Brainstem signs
- Sensory signs
- UMN signs (not LMN)
- Lhermitte phenomenon (electric shock sensation w/ neck flexion)
- Charcot neurological triad
What is Charcot’s neurological triad?
- Dysarthria (scanning or staccato speech)
- Nystagmus
- Intention tremor
How do you diagnose MS?
McDonald criteria
- 2 or more attacks disseminated in time (separate) + space (different part of CNS affected
What investigations do you do for MS?
MRI brain + cord
LP (lumbar puncture)
Delayed conduction speeds
What is seen on MRI for MS?
Dissemination in SPACE (where is white demyelination?) + TIME (give gadolinium contrast to show long they’ve been there for)
What is seen on LP for MS?
May see oligoclonal IgG bonds (non specific), increased lymphocytes
What is the treatment for MS?
- Acutely (in episodes) - IV or oral methylprednisolone for 3 days
- Prophylaxis - β interferon (DMARD, biologic) (also inflixamab)
