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Understanding MS book

The Multiple Sclerosis Association of America (MSAA) is a leading resource for the entire MS community, improving lives today through vital services and support. As part of its mission, MSAA provides useful, up-to-date information on multiple sclerosis (MS) to help people better manage MS and is pleased to share its information with visitors to the You Don't Know Jack About MS® website. For more information on the topics discussed on this page, please visit www.mymsaa.org/journey.

Understanding MS

  • MS can cause a variety of symptoms
  • For many, symptoms can flare-up and then subside over the course of days, months, or even years
  • MS is not contagious and its causes are not yet fully understood
  • MS is most frequently diagnosed in young adults

Multiple sclerosis (MS) is an unpredictable disorder that can cause a variety of symptoms which for many, can flare-up and then subside over the course of days, months, or even years. While MS is not contagious, its causes are not yet fully understood and researchers continue to search for answers.

MS is most frequently diagnosed in young adults, although individuals of any age may be diagnosed with this neurological condition. People who are not familiar with MS can easily be confused by its name and its unique symptoms. Particularly with today' s approved treatments and wellness strategies, most individuals with MS are able to live a full and productive life, with much hope for the future.

MS Process and Symptoms

  • MS is a disease of the central nervous system (CNS)
  • With MS, the protective covering (known as "myelin") that protects the nerves becomes damaged
  • Damaged myelin (and eventually nerves) disrupts the smooth flow of nerve impulses, causing the symptoms of MS
  • Common symptoms include fatigue, numbness, visual disturbances, bladder problems, mobility issues, and more
  • Areas of inflammation and damage in the brain or spinal cord are known as "lesions" or "plaques"

MS is a disease of the central nervous system (CNS). The CNS consists of the brain, optic nerves and spinal cord. With MS, areas of the CNS become inflamed, damaging the protective covering (known as "myelin") that surrounds and insulates the nerves (known as "axons"). In addition to the myelin, over time, the axons and nerve cells (neurons) within the CNS may also become damaged.

Drawing of a brain

The damage to the protective covering and also to the nerves disrupts the smooth flow of nerve impulses. As a result, messages from the brain and spinal cord going to other parts of the body may be delayed and have trouble reaching their destination - causing the symptoms of MS.

Symptoms of MS can vary from person to person, and the MSAA website discusses symptoms in further detail. Common symptoms may include:

  • bladder issues
  • dizziness/vertigo
  • fatigue
  • mobility and walking issues
  • numbness
  • spasticity (stiffness)
  • vision issues
  • weakness

Areas of inflammation and damage are known as "lesions." The changes in size, number, and location of these lesions may determine the type and severity of symptoms. While individuals with relapsing forms of MS are believed to experience more inflammation than those with progressive forms of MS, lesions still occur for individuals with all forms of MS. However, the lesions in progressive forms of MS may be less active and expand more slowly.

Drawing of a nerve

In addition to symptoms, disease activity may be evaluated from changes in the size or number of lesions. Frequently, MS may be "clinically silent," showing no increase in symptoms, yet continuing to show signs of disease activity within the CNS. For individuals with relapsing forms of MS, early and continued treatment with a disease-modifying therapy (DMT) can often slow the "clinically silent" disease activity in the brain, reducing the size and number of active lesions. This is why most neurologists, as well as the American Academy of Neurology, recommend that individuals with relapsing forms of MS begin treatment as soon as possible after the diagnosis is established.

Additionally, areas of thick scar tissue may eventually form along the areas of permanently damaged myelin. These areas of scar tissue are referred to as "plaques." The term "multiple sclerosis" originates from the discovery of these hardened plaques. Multiple refers to "many;" sclerosis refers to "scars."

Lesions and plaques are viewed on a magnetic resonance imaging (MRI) scanner. This technology is used to help diagnose MS and evaluate its progress at various intervals.

Who Gets MS?

  • Approximately 400,000 individuals have MS in the United States and 2.5 million worldwide
  • Most people with MS are diagnosed between the ages of 15 and 50
  • Women are more likely than men to develop relapsing-remitting MS
  • Geographically, people who live farther from the equator have a higher risk of MS
  • Caucasians have a higher incidence of MS than those of African heritage
  • African-Americans may experience more problems with vision and mobility
  • MS susceptibility is increased if a family member has MS
  • Smoking increases the risk of MS
  • A Vitamin D deficiency may increase the risk of MS

Types of MS

  • The most common types of MS are: relapsing-remitting MS (RRMS); secondary-progressive MS (SPMS); and primary-progressive MS (PPMS)
  • Uncommon types of MS include benign MS and fulminate MS
  • Prior to an MS diagnosis, individuals with "possible MS" may have clinically isolated syndrome (CIS) or radiologically isolated syndrome (RIS)

Multiple sclerosis (MS) affects each person differently. The most common types of MS are:

  • Relapsing-Remitting MS (RRMS)
  • Secondary-Progressive MS (SPMS)
  • Primary-Progressive MS (PPMS)

Initially, most people with MS experience symptom flare-ups, which are also known as relapses, exacerbations, or attacks. When someone experiences a relapse, he or she may be having new symptoms or an increase in existing symptoms. These usually persist for a short period of time (from a few days to a few months) and afterward may remain symptom-free for periods of months or years. This type of MS is referred to as relapsing-remitting MS (RRMS). Approximately 80 to 85 percent of MS patients are initially diagnosed with this form of the disease.

Drawing of a clock

Over time, RRMS may advance to secondary-progressive MS (SPMS). This form of MS does not have the dramatic variations in symptoms that RRMS does, but rather has a slow, steady progression - with or without relapses. If relapses do occur, they usually do not fully remit.

The MSAA and National Multiple Sclerosis Society (NMSS) recommend that patients get on treatment as soon as possible following diagnosis. Additional information on treatment can be found at the MSAA website.

10% of the MS population is diagnosed with primary-progressive MS (PPMS)

Individuals who are not initially diagnosed with RRMS may be experiencing a more steady progression of the disease from the onset. Approximately 10 percent of the MS population is diagnosed with primary-progressive MS (PPMS), where individuals experience a steady worsening of symptoms from the start, and do not have periodic relapses and remissions.

Other types of MS exist, but these are uncommon.

MS Relapse

  • Relapses are also referred to as exacerbations, attacks, or flare-ups
  • Relapses occur with relapsing-remitting, and sometimes secondary-progressive forms of MS
  • During a relapse, inflammation is occurring along the nerves and the myelin, causing a temporary worsening or recurrence of symptoms
  • A pseudoexacerbation is a temporary worsening of symptoms without actual myelin inflammation or damage
  • Treatments are available to reduce the severity and duration of a relapse
Drawing depicting a relapse in MS

Relapses, also referred to as exacerbations, attacks, flare-ups, episodes, or bouts, are initially experienced by most people diagnosed with MS. Relapses occur with relapsing-remitting, and sometimes secondary-progressive forms of MS. Relapses do not occur with primary-progressive MS, although patients may experience day-to-day fluctuations in how they feel.

During a relapse, inflammation is occurring along the nerves and the myelin, causing patients to have a temporary worsening or recurrence of existing symptoms and/or the appearance of new symptoms. This can range from a few days in duration to a few months, followed by a complete or partial recovery (remission). Acute physical symptoms and neurological signs must be present for at least 24 to 48 hours, without any signs of infection or fever, before the treating physician may consider this type of flare-up to be a true relapse.

Drawing of a thermometer

A pseudoexacerbation is a temporary worsening of symptoms without actual myelin inflammation or damage, brought on by other influences. Examples include other illnesses or infection, exercise, a warm environment, depression, exhaustion, and stress. When symptoms flare, checking for a fever is important, since even a minor infection and slight increase in temperature can cause symptoms to appear.

Urinary tract infection (UTI) is the most common type of infection to cause a pseudoexacerbation. Additionally, people with "heat-sensitive" MS will experience a temporary increase in symptoms when their body temperature rises, often after exercise. Many heat-sensitive individuals may opt to avoid hot tubs, saunas, or other situations that can raise the body's temperature.

The Immune System and MS

  • With MS, the body's own system of defense, known as the immune system, malfunctions
  • MS is believed to be an autoimmune disease
  • Immune-system cells that are misdirected to attack myelin, must cross the blood-brain barrier to enter the central nervous system (CNS)
  • Once in the CNS, immune-system cells cause inflammation and damage to the myelin (the protective covering to the nerves)
  • Early in the disease, myelin may be repaired (remyelination)
  • Later in the disease process, and with progressive forms of MS, remyelination does not occur as frequently

Diagnosing MS and Evaluating Disease Activity

  • Lesions may be viewed on an MRI scan of the brain and/or spine
  • By evaluating the size and location of lesions (areas of inflammation and myelin damage), disease activity within the CNS may be measured
  • A lumbar puncture is sometimes used to assist in the diagnosis of MS
  • Evoked potential (EP) tests measure the speed of the brain's response to visual, auditory (sound), or sensory (feeling) stimuli