CPT1: Multiple Sclerosis Flashcards
What is MS?
A slow progressive immunological disease of the CNS.
It is characterised by inflammation and plaques of demyleination and axonal loss in the white matter of the brain and spinal cord
What is myelin and what is its function?
Several layers of cytoplasmic membrane wrapped around axons.
Purpose is to insulate and conduction (saltatory
What are the glial cells which produce myelin in the CNS and PNS called?
CNS - oligodendrocytes
PNS - Schwan cells
What does demyleination cause?
Distruption of neuronal function which leads to wither loss of cuntion or hyperfunction
What are sclerosis and why are they caused?
Where do they occur?
Plaques of scarring caused by demyleination associated with inflammation, axonal loss and odema
They can be multiple plaques in different locations of the CNS at different times
Where are common plaque locations?
- optical tract, soinal cord, brain stem, basal ganglia
What are symptoms of MS?
- Fatigue
- Anxiety, Depression
- numbness
- altered sensation - burning/ twitching
What are risk factors of the disease?
- Obestity - alters the inflammatory response
- Age - occurs late teens/ early adulthood
- Gender - Females more likely though not assoicated with x chromsome
- Genetics - HLA on chromosome 6
- Virus/ bacteria (epstein- barr virus)
- smoking
- lattitude
- vit D/ sunlight
- timing of exposure
describe the pathology/ development of MS
- At some stage you are exposed to a virus with the similar identiy/ antigens to mylein. There is activation of a peripheral immune response to get rid of the virus. There is T cell activation and poliferation.
- Activated immune cells adhere with the brain endothelial cells and penetrate the BBB
- There is reactivation of the immune response in the CNS. Pro inflamatory, B cells and macrophages intiate an inflamatory response and cause demyleination, axonal loss and neuronal degradation
what types of MS is there?
- Relapsing Remitting (MS) - perods of disability (relapse) and periods of recovery (remission)
- Secondary Progressive (MS) - Normalm RR initally then continous relapse with no periods of recovery
- Primary progressive (MS) - Continous increase in disability with no attacks
What causes the relapse periods?
- The effects of cytokines and signalling cascase on neuronal function. Mylein sheath and oligodendrocytes destroyed which blocks/ slows nerve transmission
the positions the placques occur detemrines symptoms
What causes remission period?
- Limited ability of CNS to repair/ replace damage byt more a reflection of the CNS redirecting signals through alternative routes
What is:
- Replapse
- Exacerbation
- fluccuations
- Disease progression
- New signs/ symptoms that orginate from new focial demyeilnation lesions in the CNS
- Worsening of existing symptoms
- New temporay changes in symptoms
- An accumulation of disability which can be continuously progressie or step wise
What does digagnosis of MS involve?
- No specific tests
- Neuroologist
- 2 or more relapses in previous 2 yeras
- 2 or more clinically defined lesions
What diagnosis tests is therE?
- MRI - to locate/ identify lesions
- Evoked potential - to stimulate neuronal pws to trst transmission strength and velolcity
- lumbar punctues - to measure oligo-clonal blands of IgG in cerebral spinal fluid - an inflam marker
- Differental diagnosis
