Multiple Sclerosis
Whom does this autoimmune disease affect?
MS usually presents between 20 and 40. 5% of the people with MS were diagnosed before age 21 (Early Onset MS) while 9.4% of those with MS were diagnosed after age 50; women are diagnosed with MS two to three times as often as men.
RACE: Caucasians of northern European descent are the largest ethnic group affected, but people of African, Asian, and Hispanic ethnic groups can also get it. Certain ethnic groups have absolutely no incidence of MS, such as Inuit, Yakutes, Hutterites, Hungarian Romani, Norwegian Lapps, Australian Aborigines, and New Zealand Maoris.
GEOGRAPHIC LOCATION: This was also touched on already, but MS seems to strike people in much greater frequency who live farther away from the equator (generally 40 degrees and higher). This tends to indicate that there is some sort of climactic input in determining who gets MS, but it is not the only factor. Also, migration to or from a particular geographic area tends to alter one's risk of getting MS. Also related is the age at which the migration takes place. Immigrants and their descendants tend to take on the risk level (higher or lower) of the area to which they move. If the move occurs before age 15, that person will see the new risk factor themselves. Moves after age 15 tend to show the risk factor in the next generation.
DISEASE: Scientists believe that there is some sort of exposure to a particular virus or bacteria that also triggers MS. Many viruses have been examined, such as rabies, herpes simplex virus, measles, corona virus, canine distemper virus, HTLV-1, Epstein-Barr virus, among others, but none has yet been confirmed as the trigger. The bacterial agent Chlamydia pneumoniae has also been suggested, but also has not been proven.
GENETICS: While there is no evidence that MS is directly inherited, there is some sort of genetic link as well. Genetic factors are thought to play a significant role in determining who develops MS. The average person in the United States has about one chance in 750 of developing MS.
RACE: Caucasians of northern European descent are the largest ethnic group affected, but people of African, Asian, and Hispanic ethnic groups can also get it. Certain ethnic groups have absolutely no incidence of MS, such as Inuit, Yakutes, Hutterites, Hungarian Romani, Norwegian Lapps, Australian Aborigines, and New Zealand Maoris.
GEOGRAPHIC LOCATION: This was also touched on already, but MS seems to strike people in much greater frequency who live farther away from the equator (generally 40 degrees and higher). This tends to indicate that there is some sort of climactic input in determining who gets MS, but it is not the only factor. Also, migration to or from a particular geographic area tends to alter one's risk of getting MS. Also related is the age at which the migration takes place. Immigrants and their descendants tend to take on the risk level (higher or lower) of the area to which they move. If the move occurs before age 15, that person will see the new risk factor themselves. Moves after age 15 tend to show the risk factor in the next generation.
DISEASE: Scientists believe that there is some sort of exposure to a particular virus or bacteria that also triggers MS. Many viruses have been examined, such as rabies, herpes simplex virus, measles, corona virus, canine distemper virus, HTLV-1, Epstein-Barr virus, among others, but none has yet been confirmed as the trigger. The bacterial agent Chlamydia pneumoniae has also been suggested, but also has not been proven.
GENETICS: While there is no evidence that MS is directly inherited, there is some sort of genetic link as well. Genetic factors are thought to play a significant role in determining who develops MS. The average person in the United States has about one chance in 750 of developing MS.
What are the causes of this disease? Is it inherited or contagious?
It is now generally accepted that MS involves an immune-mediated process—an abnormal response of the body’s immune system that is directed against the myelin (the fatty sheath that surrounds and insulates the nerve fibers) in the central nervous system (CNS—the brain, spinal cord and optic nerves). The exact antigen, or target that the immune cells are sensitized to attack, remains unknown -- which is why MS is considered by most experts to be immune-mediated rather than autoimmune. In recent years, however, researchers have been able to identify which immune cells are mounting the attack, some of the factors that cause them to attack, and some of the sites, or receptors, on the attacking cells that appear to be attracted to the myelin to begin the destructive process. Ongoing efforts to learn more about the immune-mediated process in MS—what sets it in motion, how it works, and how to slow or stop it—are bringing us closer to understanding the cause of MS.
Since initial exposure to numerous viruses, bacteria and other microbes occurs during childhood, and since viruses are well recognized as causes of demyelination and inflammation, it is possible that a virus or other infectious agent is the triggering factor in MS. More than a dozen viruses and bacteria, including measles, canine distemper, human herpes virus-6, Epstein-Barr, and Chlamydia pneumonia have been or are being investigated to determine if they are involved in the development of MS, but none have been definitively proven to trigger MS.
While MS is not hereditary in a strict sense, having a first-degree relative such as a parent or sibling with MS increases an individual's risk of developing the disease several-fold above the risk for the general population. Studies have shown that there is a higher prevalence of certain genes in populations with higher rates of MS. Common genetic factors have also been found in some families where there is more than one person with MS. Some researchers theorize that MS develops because a person is born with a genetic predisposition to react to some environmental agent that, upon exposure, triggers an autoimmune response. Sophisticated new techniques for identifying genes may help answer questions about the role of genes in the development of MS.
Since initial exposure to numerous viruses, bacteria and other microbes occurs during childhood, and since viruses are well recognized as causes of demyelination and inflammation, it is possible that a virus or other infectious agent is the triggering factor in MS. More than a dozen viruses and bacteria, including measles, canine distemper, human herpes virus-6, Epstein-Barr, and Chlamydia pneumonia have been or are being investigated to determine if they are involved in the development of MS, but none have been definitively proven to trigger MS.
While MS is not hereditary in a strict sense, having a first-degree relative such as a parent or sibling with MS increases an individual's risk of developing the disease several-fold above the risk for the general population. Studies have shown that there is a higher prevalence of certain genes in populations with higher rates of MS. Common genetic factors have also been found in some families where there is more than one person with MS. Some researchers theorize that MS develops because a person is born with a genetic predisposition to react to some environmental agent that, upon exposure, triggers an autoimmune response. Sophisticated new techniques for identifying genes may help answer questions about the role of genes in the development of MS.
What other factors may influence the development of this disease?
MS is known to occur more frequently in areas that are farther from the equator. Epidemiologists—scientists who study disease patterns—are looking at many factors, including variations in geography, demographics (age, gender, and ethnic background), genetics, infectious causes, and migration patterns, in an effort to understand why. Studies of migration patterns have shown that people born in an area of the world with a high risk of MS who then move to an area with a lower risk before the age of 15, acquire the risk of their new area. Such data suggest that exposure to some environmental agent that occurs before puberty may predispose a person to develop MS later on.
Some scientists think the reason may have something to do with vitamin D, which the human body produces naturally when the skin is exposed to sunlight. People who live closer to the equator are exposed to greater amounts of sunlight year-round. As a result, they tend to have higher levels of naturally-produced vitamin D, which is thought to have a beneficial impact on immune function and may help protect against autoimmune diseases like MS. The possible relationship between MS and sunlight exposure is currently being looked at in a Society-funded epidemiological study in Australia.
Other scientists study MS clusters—which are defined as higher-than-expected numbers of cases of MS that have occurred over a specific time period and/or in a certain area. These clusters are of interest because they may provide clues to environmental (such as environmental and industrial toxins, diet, or trace metal exposures) factors that might cause or trigger the disease. So far, cluster studies have not produced clear evidence for the existence of any triggering factor or factors in MS.
Some scientists think the reason may have something to do with vitamin D, which the human body produces naturally when the skin is exposed to sunlight. People who live closer to the equator are exposed to greater amounts of sunlight year-round. As a result, they tend to have higher levels of naturally-produced vitamin D, which is thought to have a beneficial impact on immune function and may help protect against autoimmune diseases like MS. The possible relationship between MS and sunlight exposure is currently being looked at in a Society-funded epidemiological study in Australia.
Other scientists study MS clusters—which are defined as higher-than-expected numbers of cases of MS that have occurred over a specific time period and/or in a certain area. These clusters are of interest because they may provide clues to environmental (such as environmental and industrial toxins, diet, or trace metal exposures) factors that might cause or trigger the disease. So far, cluster studies have not produced clear evidence for the existence of any triggering factor or factors in MS.
How is this disease diagnosed and treated?
The usual treatment for an initial MS attack is to inject high doses of a steroid drug, such as methylprednisolone, intravenously (into a vein) over the course of 3 to 5 days. It may sometimes be followed by a tapered dose of oral steroids. Intravenous steroids quickly and potently suppress the immune system, and reduce inflammation. Clinical trials have shown that these drugs hasten recovery.
The American Academy of Neurology recommends using plasma exchange as a secondary treatment for severe flare-ups in relapsing forms of MS when the patient does not have a good response to methylprednisolone. Plasma exchange, also known as plasmapheresis, involves taking blood out of the body and removing components in the blood’s plasma that are thought to be harmful. The rest of the blood, plus replacement plasma, is then transfused back into the body. This treatment has not been shown to be effective for secondary progressive or chronic progressive forms of MS.
The American Academy of Neurology recommends using plasma exchange as a secondary treatment for severe flare-ups in relapsing forms of MS when the patient does not have a good response to methylprednisolone. Plasma exchange, also known as plasmapheresis, involves taking blood out of the body and removing components in the blood’s plasma that are thought to be harmful. The rest of the blood, plus replacement plasma, is then transfused back into the body. This treatment has not been shown to be effective for secondary progressive or chronic progressive forms of MS.
How can it be prevented?
Currently, there is no available "cure" or prevention for this disease.
What research is under way on this disease?
Although researchers haven't been able to identify the cause of MS with any certainty, there has been excellent progress in other areas of MS research—especially in development of new treatments to prevent exacerbations of the disease. New discoveries are constantly changing treatment options for patients.
Some researchers are investigating promising avenues for therapeutics, such as drugs that would protect myelin cells from damage or that could help them recover after an attack. Interfering with the inflammatory cells and substances involved in the development of MS lesions or keeping immune system cells from crossing the blood-brain barrier could potentially thwart an attack.
Some researchers are investigating promising avenues for therapeutics, such as drugs that would protect myelin cells from damage or that could help them recover after an attack. Interfering with the inflammatory cells and substances involved in the development of MS lesions or keeping immune system cells from crossing the blood-brain barrier could potentially thwart an attack.