Multiple Sclerosis is an autoimmune disease affecting the central nervous system (CNS), which includes the brain, spinal cord, and optic nerves. When the immune system begins to attack the CNS, inflammation occurs, causing damage to the myelin sheath surrounding nerve fibers. While the myelin is being attacked, the nerve cell itself also becomes damaged. In addition to this, the cell and myelin develop scar tissue, also known as sclerosis, giving the disease its name. This damage leads to disruption in the signaling to and from the CNS. This disruption ranges from a slowing in the signal, to a complete halt in signaling, or cross-talk between signals.
Multiple sclerosis is more common among women and is generally diagnosed between the ages of twenty and thirty. The symptoms vary from patient to patient based on the severity and location of immune system attack. The symptoms of MS range everywhere from fatigue, numbness, pain and depression, to walking problems, balance and coordination problems, bowel and bladder dysfunction, impaired cognitive function, and spasticity. Other symptoms that are less common include things such as respiration problems, swallowing problems, speech disorders, tremors, and seizures.
There are four main categories, or courses, of MS: Relapsing-Remitting MS, Primary-Progressive MS, Secondary-Progressive MS, and Progressive-Relapsing MS. Relapsing-Remitting MS is the most common form and is “characterized by clearly defined acute attacks with full recovery or with residual deficit upon recovery”(NMSS). Typically in the periods between disease relapses, there is no disease progression. Primary-Progressive MS is a progression of the disease from its onset without acute attacks. Roughly 10% of people diagnosed with MS have the primary-progressive form. Secondary-Progressive MS can be thought of as a combination of relapsing-remitting and primary-progressive MS. In other words the patient starts with infrequent relapses and remissions and then moves towards a progressive worsening of the disease without remissions. According to several MS studies, “of the 85% who start with relapsing-remitting disease, more than 50% will develop SPMS within 10 years; 90% within 25 years” (NMSS). The last form, Progressive-Relapsing MS, is characterized by progressive worsening from the onset of the disease, but also acute relapses. This is the least common form and accounts for roughly 5% of patients with MS.
Quick Blurb about MS Review Article:
In the “Inflammation and MS Review” the authors contend that inflammation may not be completely detrimental to MS, as commonly thought, but may have beneficial roles as well. The review article continues on to describe the CNS and explain particularly beneficial roles of inflammation. In the CNS the brain is protected by the blood-brain barrier, which is composed of cerebral endothelial cells and tight junctions. In patients with MS the endothelial tight junctions of the blood-brain barrier are abnormal. As one might expect this allows for mononuclear cells and other detrimental factors to enter the brain. This breakdown in the blood-brain barrier is a main suspect as to how demyelination and axonal injury begins. The continuous influx of these cells and the inability to clear them leads to the activation of local immune cells and inflammatory mediators. The researchers of this article contend that while initial inflammation seems to play a large role in demyelination, it may be beneficial in the long run. When studying mice with the animal model of MS, they found that the morbidity rate increased 20% to 80% when treated with antibodies against proinflammatory cytokines. There research finds that inflammation may also be responsible for clearing toxins that are responsible for progressing the disease. There are clearly many details to the benefits and detriments of inflammation in MS so read the article and enjoy! Its very interesting!
(NMSS) "What Is Multiple Sclerosis? : National MS Society." Home : National MS Society. Web. 10 Apr. 2011.
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