Causes Of Multiple Sclerosis

Multiple sclerosis (MS), also referred to as disseminated sclerosis or encephalomyelitis disseminata is an autoimmune condition in which the immune system damages the central nervous system, resulting in demyelination. The disease targets usually young adults, and is found to be more common in women. Its prevalence rate ranges between 2 and 150 per 100,000. It was in 1868 that the disease was first described by Jean-Martin Charcot.

The exact cause of multiple sclerosis is yet to be ascertained. However, the most likely cause of the disease is considered to be a combination of hereditary factors, an environmental factor such as a virus and a deficiency in the immune system. Multiple sclerosis is an autoimmune disease, which implies that it is caused by an attack that is carried out by the body's own immune system.

For reasons yet to be clear, immune cells attack and destroy the myelin sheath that keeps neurons in the brain and spinal cord insulated. The function of this myelin sheath, formed with the help of other brain cells called glia, is to speed up transmission and prevent electrical activity in one cell from short-circuiting to another cell. As communication between the brain and other parts of the body is disrupted, the normal passage of sensations and control messages is adversely affected and it causes the appearance of symptoms of multiple sclerosis.

That the environmental factor is also a cause of multiple sclerosis can be concluded from the fact that certain regions of the world have an increased tendency of acquiring this disease. The regions that don't seem to get much sunlight have been found to have more incidences of multiple sclerosis. The role of environmental factor is indicated by researches on the effect of migration on the risk of developing the disease. Studies have revealed that an environmental factor, which may be protective or harmful, is acquired early in a person's life; the risk of multiple sclerosis at a later time in life is a manifestation of the early impact.

Some viruses such as measles, herpes, and flu viruses may also cause multiple sclerosis. Studies have suggested that a slow-acting virus, one that is acquired early on but exerts its harmful effects much later, may cause the disease. However, although a number of claims have been made emphasizing that some viruses, slow or otherwise, may cause the disease, no strong candidate has been identified so far.

The hereditary factor as a cause of multiple sclerosis has not also been ruled out. It has been found that the risk of developing the disease is higher if another family member is affected. This definitely indicates the presence of genetic factors. In this way, a brother, sister, parent, or child of a person with multiple sclerosis runs greater risk of acquiring the disease. Similarly, an identical twin runs a 30% chance of developing the disease whereas a non- identical twin has a much reduced risk of only 4%. if the other twin has the disease.

Furthermore, the higher incidence of multiple sclerosis among people of northern European background points to some sort of genetic susceptibility. The risk goes up in families where a first-degree relative is afflicted with the disease. These facts indicate that hereditary factors play a key role in multiple sclerosis.

• Matt Thompson
• 12/02/2009, 4:59 AM
• 0 Comments