L35 Patho of MS Flashcards
common sxs of MS (theres a ton)
visual problems
numbness
fatigue
motor weakness
gait problems
pain
spasticity
dizziness/vertigo
sexual dysfunction
main virus thought to be involved in developing MS
epstein barr virus
through what mechanism does the epstein barr virus cause MS?
molecular mimicry
True or False: Genetics play an important role in the development of MS
True
what are the 3 different types of MS
Relapsing-remitting MS (RRMS)
Secondary progressive MS (SPMS)
Primary Progressive MS (PPMS)
Relapse Remitting MS (RRMS)
- involves ….
- multifocal areas…
- initial sxs ….
- most cases….
- involves relapse of neurological dysfunction lasting weeks or months and affecting the brain, optic nerves and/or spinal cord
- multifocal areas of damage are revealed by MRI in the white matter
- initial sxs disappear, but less remission with each relapse
- most cases of RRMS eventually enter SPMS
Secondary Progressive MS (SPMS)
- characterized by ______
- involves ______
- less inflammation than RRMS
- involves slowly progressive neurological decline and CNS damage, with little remission
Primary Progressive MS (PPMS)
- resembles ___
- Mean age ____
- resembles SPMS at initial stage
- of onset is alter than RRMS bc inflammatory episodes of RRM S surpass the symptomatic threshold
know the figure on slide 8/20
okay i will be sure to go take a look at it
what is CIS?
Clinically isolated syndrome
- initial episode of neurologic sxs lasting >24 hours
- inflammation and demyelination in optic nerve, cerebrum, cerebellum, brainstem or spinal cord
- most cases progress to MS
What does the progressive phase of MS involve?
cytodegeneration (loss of myelin, axons, oligodendrocytes) and occurs with a similar rate in different forms of MS
what is the overall clinical presentation of MS determined by?
combo of underlying degeneration and the host’s immune reaction to it
first step autoimmune phase of MS
- antigens released from CNS or cross-reactive foreign antigens are presented to B and T cells in the lymph nodes
Degenerative phase of MS (2 things)
- CNS damage is triggered by activated B and T cells or by other insults such as stroke or infection
- antigens released from damaged sites in the CNS further prime immune cells in the periphery
T or F: the degenerative phase triggers MS
F, it is unclear which phase does it
second step autoimmune phase of MS
- B and T cells with high-affinity receptors for these antigens are expanded and migrate to CNS cites where they re-encounter and are activated by their target ligands
third step autoimmune phase MS
- activated B and T cells then carry out immune fxns at the CNS sites
autoimmune responses in MS:
what activates T cell responses in the peripheral lymphoid tissue?
dendritic cells
autoimmune responses in MS:
what allows for activated B and T cells to proliferate and infiltrate the CNS?
a4-integrin mediated binding and penetration of the BBB
autoimmune responses in MS:
what happens to B cells that re-encounter their specific antigen in the CNS?
they mature to plasma cells and release IgG antibodies that target the antigen on expressing cells
autoimmune responses in MS:
what do T cells do during this part lol
interact with their target ligands presented by oligodendrocytes, neurons, or microglia on MHC molecules
autoimmune responses in MS:
T cell activation results in _______ and ________, leading to damage in myelin sheath
cytokine release and macrophage stimulation
demyelinated regions can be. repaired via _____?
remyelination (no shit)
remyelination involves the recruitment of ____ to the lesion and the differentiation of these cells into myelin-producing ____________
OPCs and oligodendrocytes
why does remyelination typically fail in MS?
lack of OPCs or a failure of OPCs to differentiate
what is astrogliosis?
the invasion and propagation of astrocytes, resulting in irreversible formation of gliotic plaques or scars
demyelination is the loss of what two things?
myelin and oligodendrocytes
what does demyelination result in?
activation of microglia and astrocytes
what do activated microglia and astrocytes release?
pro-migratory factors and mitogens that recruit OPCs to the lesion and stimulate their proliferation
what eliminates myelin debris?
macrophages
what do recruited OPCs do?
differentiate into oligodendrocytes
what is the key step where remyelination fails in MS?
OPC differentiation
T or F: myelin sheath formed after remyelination is identical to its original form
F, they are thinner and shorter
3 treatment options for Guillain-Barre syndrome
ventilation
plasmapheresis
IV immunoglobulin administration
