Multiple sclerosis
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Multiple sclerosis
Nervous system
Nervous system
Nervous system
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Multiple sclerosis
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Multiple sclerosis
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Baclofen
multiple sclerosis p. 541
β -interferon
multiple sclerosis p. 541
Cerebrospinal fluid (CSF)
multiple sclerosis p. 541
IgG antibodies p. 103
multiple sclerosis p. 541
Intention tremor p. 537
multiple sclerosis p. 541
Intention tremors
multiple sclerosis p. 719
Internuclear ophthalmoplegia p. 528, 563
multiple sclerosis p. 719
Marcus Gunn pupils p. 559
multiple sclerosis p. 541
Multiple sclerosis p. 541
Daclizumab p. NaN
heart murmur with p. 298
HLA-DR2 and p. 98
IFN- β for p. 201
internuclear ophthalmoplegia p. 563
natalizumab for p. 120
oligodendroglia in p. 509
presentation p. 719
recombinant cytokines for p. NaN
as type IV hypersensitivity p. 111
Muscarinic antagonists p. 242, 712
multiple sclerosis p. 541
Natalizumab p. 120
multiple sclerosis p. 541
Nystagmus
multiple sclerosis p. 541, 719
Steroids
multiple sclerosis p. 541
Urinary incontinence p. 624
multiple sclerosis p. 541
White matter
multiple sclerosis p. 541
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Multiple sclerosis is a demyelinating disease of the central nervous system, which includes the brain and the spinal cord.
Myelin is the protective sheath that surrounds the axons of neurons, allowing them to quickly send electrical impulses.
This myelin is produced by oligodendrocytes, which are a group of cells that support neurons.
In multiple sclerosis, demyelination happens when the immune system inappropriately attacks and destroys the myelin, which makes communication between neurons break down, ultimately leading to all sorts of sensory, motor, and cognitive problems.
Now, the brain, including the neurons in the brain, is protected by things in the blood by the blood brain barrier, which only lets certain molecules and cells through from the blood.
For immune cells like T and B cells that means having the right ligand or surface molecule to get through the blood brain barrier, this is kind of like having the a VIP pass to get into an exclusive club.
Once a T cell makes its way in it can get activated by something it encounters - in the case of multiple sclerosis, it’s activated by myelin.
Once the T-cell gets activated, it changes the blood brain barrier cells to express more receptors, and this allows immune cells to more easily bind and get in, it’s kind of like bribing the bouncer to let in a lot of people.
Now, multiple sclerosis is a type IV hypersensitivity reaction, or cell-mediated hypersensitivity. And this means that those myelin specific T-cells release cytokines like IL-1, IL-6, TNF-alpha, and interferon-gamma, and together dilate the blood vessels which allows more immune cells to get in, as well as directly cause damage to the oligodendrocytes.
Summary
Multiple sclerosis is a progressive, demyelinating disease on the central nervous system, characterized by the destruction of myelin, the protective sheath surrounding nerve cells, as well as inflammation and scarring of nerve fibers.
Damage to these nerves disrupts the ability of parts of the nervous system to transmit impulses, resulting in a wide range of signs and symptoms, including physical, mental, and sometimes psychiatric problems. Symptoms vary widely, but they may include muscle weakness, fatigue, vision problems, balance and coordination problems, and problems with memory and thinking.
Sources
- "Robbins Basic Pathology" Elsevier (2017)
- "Harrison's Principles of Internal Medicine" McGraw Hill Education/ Medical (2018)
- "Pathophysiology of Disease: An Introduction to Clinical Medicine 8E" McGraw-Hill Education / Medical (2018)
- "CURRENT Medical Diagnosis and Treatment 2020" McGraw Hill Professional (2019)
- "Multiple sclerosis" The Lancet (2008)
- "Defining the clinical course of multiple sclerosis: Results of an international survey" Neurology (1996)
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