Multiple Sclerosis For Dummies


By Rosalind Kalb Nancy Holland Barbara Giesser David L. Lander

John Wiley & Sons

Copyright © 2007 John Wiley & Sons, Ltd
All right reserved.

ISBN: 978-0-470-05592-2


Chapter One

Meeting MS Face to Face

In This Chapter

* Exploring how MS affects your body

* Determining what triggers MS

* Recognizing the uniqueness of your MS

* Taking a peek at the available MS treatments

* Understanding the impact of MS on your family and work life

* Gearing up to keep your life on track

Because you've picked up this book, we're assuming that your doctor has delivered the news that you have multiple sclerosis (MS). Or, perhaps he or she said that you may have this disease, or that you probably have this disease (which makes you wonder why you can't get a clear answer). Whether you got the news yesterday or several months ago, you're probably trying to figure out what it means for you, for your future, and for your family. In other words, you have about a zillion questions about what's in store.

Chances are, the answers you've received so far haven't been all that satisfying - mostly because MS still can't be cured, no one knows what causes it, and no doctor can predict with any certainty how your MS is going to behave in the future. However, the good news is that the treatment options are expanding, and people with MS are busy getting on with their lives - and you will too.

In this chapter, which is an introduction to MS and an overview of what we cover in the rest of the book, we fill you in on the available MS info - including what scientists have been able to discover about the workings of this disease and what questions remain to be answered. We explain why your MS is different from everyone else's, and we introduce you to the treatment strategies that can help you manage your MS. Finally, we glance at the ways that MS can affect life at home and at work, and we show you what you can do to ensure the best possible quality of life for you and the people you love.

Introducing the Roles Your Immune and Nervous Systems Play in MS

Surprise! Even though MS is described as the most common neurologic disorder diagnosed in young adults, the problem doesn't appear to originate with the nervous system. Instead, decades of research have pointed to the body's immune system as the culprit. Some kind of malfunction in the immune system interferes with the functioning of the body's nervous system, resulting in the symptoms commonly associated with MS. The current thinking is that the glitch is an autoimmune problem, which basically means that your body is mistakenly destroying some of its own healthy tissues and cells. But, this thinking has yet to be proven. We explain the autoimmune process in the section "What happens in MS" later in the chapter, but for now, it's important to understand how the immune system is supposed to work when it's healthy.

The immune system: Your body's frontline defender

The immune system - which is a complex network of glands, tissues, and circulating cells - is your body's frontline defense in the fight against infection by viruses, bacteria, and other bad guys. When confronted with an infection, the immune system gears up to neutralize the foreign invader and make you healthy again.

REMEMBER

In order for your immune system to do its job properly, it has to be able to distinguish between the good guys (the cells, tissues, and organs that make up your body) and the bad guys (any foreign invader, such as a virus or bacteria that doesn't share your genes). And get this: The immune system is so powerful that it would reject a pregnant woman's developing fetus (which shares only some of her genes) if the hormones of pregnancy didn't suppress her immune system. (Check out Chapter 16 to read more about how pregnancy hormones appear to affect MS.)

The nervous system: Your body's CEO

The nervous system, which controls all bodily functions, is made up of neurons, each of which consists of a cell body and its long extension - the axon. And each axon is covered by a protective or insulating coating called myelin. The neurons are gathered into small- and large-sized bundles called nerves.

The system is basically divided into two parts: The central nervous system (CNS), which consists of the brain, spinal cord, and optic nerves, is the target of the damage done in MS. The peripheral nervous system (PNS) includes the branching network of nerves and axons that connects the CNS to muscles, sensory organs, and glands in the rest of the body.

REMEMBER

The nervous system conducts three basic kinds of electrical signals throughout the body:

  •   Motor signals: These signals, which move from the CNS, through the PNS, and to muscles and other organs, control movement, strength, and other bodily functions.

  •   Sensory signals: These signals go back to the CNS from the eyes, ears, skin, and other sensory organs, and they provide information about the environment from those organs.

  •   Integrative signals: These signals travel from nerve cell to nerve cell within the nervous system and are thought to be responsible for many cognitive functions, such as thinking and memory (check out Chapter 9 for information about cognitive changes in MS).

    These electrical signals are like the current in an electrical wire: When everything is working fine, they travel long distances along the myelin-covered axons in the CNS, jumping from one axon to another as needed. The myelin (like the rubber or plastic insulation around an electrical wire), is what helps speed the electrical signals on their journey and smoothes out any bumps along the way.

    What happens in MS

    After you understand the role of the immune system and the nervous system, you can begin to understand how MS affects them. In autoimmune diseases like MS (and rheumatoid arthritis, myasthenia gravis, and Type I diabetes, among others), the immune system loses the ability to distinguish the good guys from the bad guys, and so it starts attacking the normal tissues in the body. In MS, this autoimmune response targets the myelin coating around the axons in the CNS as well as the axons themselves.

    REMEMBER

    The autoimmune attack happens because of a breakdown in the blood-brain barrier (BBB), which allows immune cells that have been living harmlessly in your blood to travel into your CNS to attack the myelin and axons, resulting in the symptoms associated with MS. The autoimmune process in MS follows these steps (see Figure 1-1):

    1. The inflammation that occurs during an MS relapse (also called an attack or exacerbation) damages the BBB, allowing the movement of immune cells into the CNS. (Skip to Chapter 6 for more info about MS relapses.)

    2. Toxic substances are released into the CNS, which can increase inflammation and result in the breakdown of myelin (in a process called demyelination) and the axons.

    3. Nervous system cells called astrocytes move into the locations where the damage has occurred and they form scar tissue (giving rise to the name multiple sclerosis, which means multiple scars).

    REMEMBER

    The results of the autoimmune process aren't all that pretty: The inflammation can cause swelling, which interferes with the conduction of signals in the nervous system. The demyelination results in a loss of insulation around the neurons' axons, which slows or interrupts nervous system conduction. And finally, the axons can be broken (a process referred to as axonal loss), which breaks the connections between the nervous system and parts of the body. (Figure 1-2 shows the steps involved in demyelination and axonal loss.) This whole process results in the symptoms that we describe in Chapters 7, 8, and 9. (Flip to Chapter 6 to read about the treatments that can reduce the inflammation and slow the destructive process.)

    Taking advantage of the body's natural healing process

    The body has a natural capacity to heal some of the damage caused by MS. For example, partial healing occurs following each MS relapse. Here's how it works: The inflammation that occurs during an MS relapse causes edema - the accumulation of fluids at the site of the damaged myelin (picture what happens when you sprain your ankle). Edema results in swelling that compresses the myelin-coated axons and interferes with the transmission of nerve signals. As the inflammation and swelling disappear, and the relapse comes to an end, some of the axons begin to decompress and are able to function normally again. The reduction of inflammation can happen through a natural healing process, or can sometimes be prodded along with steroid medications (which you can read about in Chapter 6).

    In addition, the myelin coating that has been damaged by the inflammation has some ability - but not a whole lot - to heal or regenerate. As long as the axon itself remains intact, the natural regeneration of myelin can smooth out the conduction of nerve impulses and result in some amount of improvement of symptoms over time. Check out the National MS Society Web site at www.nationalmssociety.org/myelin for more information on myelin and current research efforts to stimulate this natural healing process.

    REMEMBER

    After the nerve fiber itself has been damaged or severed, and scar tissue has formed, healing is much more difficult. Unfortunately, doctors haven't yet found a way to repair damaged axons or to remove the scars. Researchers are focusing a lot of attention on how to promote this kind of repair - and this is precisely where stem cell research may be most relevant in MS. To read about stems cells and their potential value in the treatment of MS, go to www.nationalmssociety.org/stemcell.

    Exploring Possible MS Triggers

    Assuming that MS is, in fact, an autoimmune disease, it's important to figure out what actually triggers the immune system's attack on the nervous system. Most scientists agree that no single virus or bacterium causes MS all by itself. They have also concluded that no single thing in the environment or in a person's diet is directly responsible for the disease.

    REMEMBER

    Currently, scientists believe that the disease is caused by a combination of several factors - including gender, racial or ethnic, geographic, genetic, and lifestyle factors that interact with an infectious trigger of some kind (for example, one or more viruses or bacteria) to stimulate the autoimmune process. This means that when a person with a genetic susceptibility to MS meets up with the environmental trigger or triggers, his or her immune system overreacts in a way that sets off the abnormal autoimmune process.

    This sounds simple enough, but the question of why some people get MS and others don't remains one of the great mysteries of this disease. Solving this mystery is important because identifying the factors that make some people susceptible to MS and others not would help scientists figure out the cause of MS. And, identifying the cause would make it a whole lot easier to find more effective treatment and, eventually, a cure.

    Gender clues

    The fact that MS doesn't occur equally in women and men has long piqued the curiosity of scientists and physicians. It turns out that some interesting differences exist between the sexes (in regard to MS, that is) that may provide important clues to the cause of MS:

  •   MS is two to three times more common in women than in men. However, prior to the onset of puberty, boys are as likely to get MS as girls (check out Chapter 15 for more info about MS in kids).

  •   Men tend to develop MS at a later age than women do, and they're more likely than women to be diagnosed with primary-progressive MS. (You can read more about the disease courses in the section "Distinguishing the four disease types" later in the chapter.)

    Ethnic or racial clues

    MS isn't unique to one racial or ethnic group, but certain groups are much more susceptible than others. Scientists are using the following clues to help themselves understand the genetic and environmental factors that may be causing these group differences:

  •   MS is most common among Caucasians of northern European ancestry.

  •   African-Americans and Hispanics develop MS half as often as Caucasians.

  •   Asians develop MS less frequently than Caucasians and generally have different types of symptoms.

  •   MS is rare (or unheard of) in pure Africans, Inuits, and some isolated populations around the world that have never mingled with other groups.

    Geographical clues

    The geographical distribution of MS has been known for a long time: In general, the further you live from the equator, the greater your chances are of developing MS. Like a lot of other aspects of MS, no one knows why this is true, but here are some possible explanations:

  •   Genetic/ethnic: Residents in the temperate areas of the world (except certain groups like the Inuits) tend to be of northern European descent.

  •   Climatatic/meteorologic: Residents of the tropics have greater exposure to the sun and vitamin D, which may offer some protection against MS.

  •   Infectious: Certain types of infectious agents may be more common in temperate areas of the world.

    Each of these possible explanations is the subject of intensive study in the MS research community.

    REMEMBER

    An interesting wrinkle in the geographical data - which no one can yet explain - suggests that timing may be the key. Data, particularly from Israel and South Africa, suggest that people who migrate from their birthplace before puberty take on the MS risk factor of their new home, whereas people who migrate after puberty maintain the risk level associated with their birthplace. Just remember that these are statistical statements that characterize large groups of people, not single people within that group. This means that these statements provide no kind of guarantee for you or your children. So, there's no need to pack your bags and relocate to the tropics.

    Genetic clues

    MS isn't an inherited disease. However, the evidence is quite strong that a genetic factor contributes to a person's risk of developing MS. The following facts point to a genetic component:

  •   Approximately 20 percent of people with MS have a close or distant relative with MS.

  •   The risk for someone who has one close relative with MS is 3 to 5 percent (compared to less than 1 percent in people without a relative with MS). For a person in a multiplex family - which has several members with MS - the risk of developing MS is even higher. Keep in mind, however, that even within the same family, close relatives can experience very different disease courses, symptoms, and levels of disability.

  •   If one identical twin develops MS, the risk for the other twin is about 30 percent - proving that the disease isn't directly inherited. Because identical twins share identical genetic traits, the risk would be would be 100 percent if genetics told the whole story.

    Lifestyle clues

    You've probably asked yourself (and your doctor) a hundred times what you did - or didn't do - to cause your MS. Just remember that it's clear from the study of geography, ethnicity, and genetics that the cause of MS - whatever it turns out to be - isn't anything simple or direct. You didn't do anything to cause MS to happen.

    However, here are some intriguing findings related to lifestyle:

  •   Even though exposure to sunlight and vitamin D is primarily determined by how close to the equator a person lives, it may also be related to time spent outdoors. One study also found that people who got extra vitamin D from a daily multivitamin were at a lower risk for MS.

  •   Some studies have suggested that dietary factors may play a role in determining a person's susceptibility to MS. For example, it has been suggested that Inuits don't get MS because of their fish-heavy diet.

    (Continues...)



    Excerpted from Multiple Sclerosis For Dummies by Rosalind Kalb Nancy Holland Barbara Giesser David L. Lander Copyright © 2007 by John Wiley & Sons, Ltd. Excerpted by permission.
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