Multiple Sclerosis Flashcards
What is MS
Multiple sclerosis (MS) is an acquired, chronic, immune-mediated, inflammatory condition of the central nervous system (CNS) that can affect the brain, brainstem, and spinal cord.
The inflammatory process causes areas of demyelination (damage to white matter), gliosis (scarring), and neuronal damage throughout the CNS.
What is myelin
Several layers of cytoplasmic membrane wrapped around axons.
Oligodendrocytes (central) or scwann cell (motor/peripheral)
What is demyelination
Loss of myelin disrupting neuronal function resulting in loss of function or hyper-excitable
describe pathology of MS
Results in plaques (areas of scarring).
Can occur in a number of different locations in the cns and different times.
common locations of plaques
- optic tract
- spinal cord
- brain stem
- basal ganglia
HOW
Supporting diagnosis and monitoring
MRI - to identify plaques
symptoms of MS
Methyl prednisolone works for noone
very common: pain, numbness, walking difficulty, muscle spasms, fatigue,
common: Depression, headache, dizziness, cognitive impairment
less common: visual problems, itching, tremor
rare: seizures, hearing problems, breathing difficulty
general
MS risk factors
Genetic + enviromental factors
Age: 25-40
obesity: alter inflamatory response
sex: higher risk in females (hormonal, not chromosome related)
enviromental
MS risk factors
Epstein-barr virus
smoking
latitude
vitamin D
Development of MS
Genetics/enviroment
>
Peripheral immune response with
activation and proliferation of self-reactive T-cells
>
Interaction with adhesion molecules on brain endothelial cells leads to crossing of the blood brain barrier (BBB)
>
Reactivation within the CNS leading to pro-inflammatory environment recruitment of more B cells, macrophages, microglia resulting in autoimmune demyelination
Relapsing/remitting MS (RRMS)
Periods of disability (relapse) with a stable periods of recovery (remission)
Secondary progressive MS (SPMS)
RMPS often (~50%) followed by slowly progressive clinical course known as Secondary Progressive (SP-MS)
* No longer have relapses
Benign form of MS
relapsing/remitting pattern but will make a full recovery from each episode
Primary progressive MS (PPMS)
Around 10% of patients will have steady progress over time Primary Progressive multiple sclerosis (PP-MS)
* Won’t have relapses early in disease course
Relapse periods
-symptoms arrise because myelin and oligodendrocytes are destroyed resluting in blocked/slowed nerve transmission
- The location of the plaques will determine the symptoms of MS