Learning About MS
MS is a chronic disease that affects the central nervous system (CNS), which is made up of the brain, spinal cord, and nerve fibers to the eyes.
MS is widely thought to be an autoimmune disease, in which a mistaken immune response launches an attack on the body's own tissue. The destruction that results can disrupt the proper functioning of the CNS.
The CNS is made up mainly of nerve cells, which carry messages within the body. All the information sent to and from your brain and spinal cord is controlled by the CNS (Figure 1). MS puts these nerve cells and the messages they carry at risk. As a result, some people with MS may experience a decrease or loss of certain functions.
Nerves have a protective insulation around them, which is called myelin (Figure 2). Myelin helps ensure that messages are transmitted successfully.

- When myelin is damaged, it can cause scarring,
or lesions, in the brain and the spinal cord
(Figure 3). - This damage can slow or block the nerve messages from traveling throughout your body (Figure 4).
- Some people with MS affected by this communication breakdown may experience a decrease or loss of certain functions.
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MS symptoms show up differently depending on where nerve damage has occurred. For example, damage to one part of the brain may lead to difficulty thinking, whereas damage to another part of the brain may lead to a physical disability.
Silent damage can also occur. This is when damage is taking place, but no outward symptoms are present.



IS ALL MS THE SAME?
MS is a very individual disease. Patient journeys vary greatly. But, in general, a person diagnosed with MS can be classified into 1 of 4 main categories.
- Eighty-five of 100 newly diagnosed MS patients have relapsing-remitting MS (RRMS), which is characterized by a series of relapses followed by a complete or partial remission of symptoms
- Secondary progressive MS begins as relapsing-remitting but years later may become worse, with gradual progression occurring with or without remissions and relapses
- Ten of every 100 people in the MS population have primary-progressive MS. This type of MS is characterized by a gradual decline with no clear relapses or remissions, and no more than temporary or slight relief of symptoms
- Five of every 100 people in the MS population have progressive-relapsing MS. This type of MS is characterized by slow yet steady disease progression that occurs along with relapses

Moving Forward Toward a Greater Understanding of MS
No one knows for certain what causes multiple sclerosis. But there's more research happening today to advance our understanding of MS than ever before.
It is generally thought that an autoimmune response causes MS. However, what triggers the response, and what can be done to stop it, are ongoing areas of intense research.