Multiple sclerosis Flashcards
What is multiple sclerosis?
A disease of the central nervous system in which the axons of nerves in the brain and spinal cord are demyelinated
It is a disease of white matter (as this is where myelinated axons are found)
What are the main risk factors for someone to develop MS?
People in their late 20s
Female
Genetics
Infection
Vitamin D deficiency
What are the main pathophysiological features of multiple sclerosis?
Destruction of myelin sheaths
Inflammation
Formation of plaques / lesions
What causes the destruction of myelin sheaths in MS?
Auto-immunity:
- T cells cross the Blood-brain barrier and start attacking myelin causing acute inflammation
- This demyelinates the axons obviously - and also leads to formation of scar tissue plaques
- This is type IV hypersensitivity (cell-mediated)
In the early stages of multiple sclerosis - how do the oligodendrocytes respond to the damage they receive from immune cells?
The oligodendrocytes are damaged - but are able to repair the myelin sheaths and thus restore function. This is remyelination.
Note that there are different types of MS - some will have varying stories of how they work
What are the 4 types of MS?
Relapsing-remitting (most common) - RRMS
Secondary progressive - SPMS
Primary progressive - PPMS
Progressive-relapsing - PRMS
What characterises Relapsing-remitting MS?
Bouts of auto-immune attacks with partial re-myelination afterwards
Recovery is partial so over time, disability increases
Most common type of MS
What characterises Secondary progressive MS?
Similar to RRMS for the first few years - ie there are bouts of attacks, with partial recovery and periods of rest
However, after some years, the auto-immune attack becomes constant - causing a steady progression of disability
What characterises primary progressive MS?
Constant immune attack meaning there are no periods of recovery
There is a steady progression of disability over the patient’s remaining life
What characterises Progressive-relapsing MS?
Constant auto-immune attack meaning there is always a progression in disability
However, there are also ‘relapses’ - ie bouts of (increased) attack - like with RRMS & SPMS
The symptoms seen with Multiple sclerosis vary and are generally related to where the plaques are located (basically where the damage is happening)…
What are the 3 main groups of symptoms and their plaque locations
Brainstem:
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